Gap bootstrap methods for massive data sets with an application to transportation engineering

In this paper we describe two bootstrap methods for massive data sets. Naive applications of common resampling methodology are often impractical for massive data sets due to computational burden and due to complex patterns of inhomogeneity. In contrast, the proposed methods exploit certain structural properties of a large class of massive data sets to break up the original problem into a set of simpler subproblems, solve each subproblem separately where the data exhibit approximate uniformity and where computational complexity can be reduced to a manageable level, and then combine the results through certain analytical considerations. The validity of the proposed methods is proved and their finite sample properties are studied through a moderately large simulation study. The methodology is illustrated with a real data example from Transportation Engineering, which motivated the development of the proposed methods.Comment: Published in at http://dx.doi.org/10.1214/12-AOAS587 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Female Labor Force Participation and Economic Growth in Developing Countries

This paper examines the relationship between female labor force participation and its impact on economic growth The paper further explores whether the impact of the female labor force participation on economic growth is different for developing countries as a whole compared with countries in sub-Saharan Africa SSA I hypothesize that female labor force participation will have a positive effect on economic progress in developing countries including countries in SSA I use a panel data from the World Development Indicators WDI from 1975-2015 and employ a neoclassical growth model to examine how the female labor force participation affect economic growth Using the system GMM estimator my findings reveal that the female labor participation has a positive impact on economic growth in developing countries and that of SSA countries only This paper contributes to the literature analyzing the importance of female labor force participation on economic growth By examining the impact on 139 countries that make up the developing world analysis from this further strengthens the link between female labor force participation and economic growt

Betulinic Acid–Doxorubicin-Drug combination induced apoptotic death via ROS stimulation in a relapsed AML MOLM-13 cell model

In this study, cell death regulation and induction in AML cell line from a relapsed MLL-rearranged cell model (MOLM-13) was investigated with doxorubin (Dox) and betulinic acid (BetA), singly and in combination. CyQUANT Direct® and Annexin V/propidium iodide double staining were used to measure the cytotoxic and cell death induction effects of the compounds, respectively. Reactive oxygen species (ROS) generation was measured using 2′,7′-dichlorofluorescin diacetate staining. Expressions of proteins and genes were examined by Western blot and reverse transcription polymerase chain reaction analysis, respectively. BetA (20 μM) and Dox (1 μM) indicated a synergistic growth inhibitory effect on MOLM-13 cells. The combined drug caused more cells to reside in irreversible late apoptotic stage compared to the single treatments (p < 0.05). Elevation in ROS may be the synergistic mechanism involved in MOLM-13 cell death since ROS can directly disrupt mitochondrial activity. In contrast, in leukaemic U-937 cells, the combination treatments attenuated Dox-induced cell death. Dox and the drug combination selectively reduced (p < 0.05) a recently reported anti-apoptotic Bcl-2 protein isoform p15-20-Bcl-2 in MOLM-13 by our group, without affecting the usually reported p26-Bcl-2-α. Further studies using known inhibitors of apoptosis are required to confirm the potential of Dox-BetA combination to modulate these pathways

Potential groundwater pollution from improper oil and metal waste disposal in Suame, Ghana

Suame is an industrialized hub in Kumasi, Ghana, that is noted for vehicle repairs and servicing, sale of automobile spare parts, and metal fabrication. Some of these activities generate huge volumes of waste oil and metals that are often disposed off indiscriminately into the environment. These could pose a threat to the quality of groundwater in the area, especially if they continuously accumulate in the environment. This study, therefore, investigated the potential impact of the waste disposal on groundwater quality in the area. The methods employed involved mapping all the potential waste oil spillage sources and sampling the soils in such areas (at 0 – 30 and 30 – 60 cm depths) and groundwater supply points for laboratory analyses to determine the presence of the waste. In all, 36 samples (comprising 12 soil and 24 groundwater) were analysedfor the presence of heavy metals including Cd, Ni, Cu, Pb, Zn and Cr, which were used as traceelements for the presence of the waste in the samples. Computedgeo-accumulation indices from the results show the soils are moderately to heavily polluted with Cd and Pb whilst the groundwater, when compared to the WHO drinking water guidelines, is polluted with Pb and Ni. Althoughthe source of the high Pb content observed could be attributed to its transport directly from the activities in the area, the presence of high Ni makes it inconclusive since the Ni in the soil was within the concentration expected of the parent rock geochemistry. This notwithstanding, the study has indicated that groundwater in the area is not safe for human consumption unless the lead and nickel concentrations are reduced to acceptable standard for drinking.Keywords: Groundwater quality, pollution, waste disposal, Suame, Ghan

Length-Weight Relationships and Food Preference of Two Coastal Marine Fishes, Galeoides decadactylus (Polynemidae) and Sphyraena sphyraena (Sphyraenidae) off Cape Coast, Ghana

The food and feeding habits of most commercially important marine fish species in Ghana had not been studied. The aim of the paper was to study the diet spectrum of two coastal fishes of Ghana; Galeoides decadactylus (Polynemidae) Bloch, 1795 and Sphyraena sphyraena (Sphyraenidae) Linnaeus, 1758, both of tropical fish species. Fish samples were obtained in 2011 from sandy beaches near Cape Coast township in the Central Region of Ghana, noted for beach seining. Length-weight measurements were taken from well-preserved fish specimens from which stomachs were extracted for the analysis of the food contents, using frequency of occurrence, numerical and gravimetric methods, as well as index of relative importance. The length-frequency analysis showed a size distribution with a modal size of 11.0–13.9 cm for both species. The length-weight relationships for both fish species showed strong correlation between the weight and length with correlation coefficient (r2) and exponent b for Galeoides decadactylus as 0.9869 and 2.9893, and that for Sphyraena sphyraena as 0.9861 and 2.9094, respectively. Juvenile shrimp and fish fry formed the bulk of the food items in the stomachs of the two fish species. Juvenile shrimps occurred in 77.18% of the stomachs observed for G. decadactylus and accounted for 80.20% of the total number of the food items whilst comprising 63.14% of the weight of food consumed. That of S. sphyraena was, respectively, 66.7% by frequency, 87.0% by numbers and 96.3% by weight. Juvenile shrimp had the highest IRI in the diet of G. decadactylus whereas in S. sphyraena fish fry recorded the highest IRI. Literature evidence showed that the diet spectrum and aspects of growth of the two fish species reported elsewhere in the tropics were comparable to that off the coast of Cape Coast despite the differences in geographical location. The findings in this study will contribute to the knowledge gap on the diet of most commercially important fish species in Ghanaian waters

Livelihood and the risk of HIV/AIDS infection in Ghana: the case of female itinerant traders

Itinerant trading is the second major economic activity for women who constitute an important chain in the distribution of goods in West Africa. Historically they have played important roles in the political economy of Ghana. With the outbreak of AIDS these women, some of whom move far away from home sometimes for days or even weeks, stand the risk of being infected with HIV through their activities. Using a combination of methods including a survey, focus-group discussions and conversations with key informants, we examine how the trade is organized, the characteristics of the traders, and the risk factors that are likely to predispose them to contracting the AIDS virus. Itinerant women traders appear highly vulnerable, as women and as highly mobile people. This state of affairs, occasioned by the extremely difficult conditions in which the women work, is exploited for the sexual gratification of the men with whom they come into contact. The attempt to reduce the spread of AIDs through education has to target itinerant women traders at the points of transaction

Multivariate Analysis of the Effect of Climate Conditions on Gold Production in Ghana

The change in climatic conditions and its catastrophic effect on mining activities has become a source of worry for mining industries and therefore needs due attention. This study examined the effect some climate factors have on gold production in Ghana. First, a direct Multiple Linear Regression was applied on the climate factors with the aim of determining the relative effect of each factor on gold production which exhibited a time series structure. The consequence is that, the estimates of the coefficients and their standard errors will be wrongly estimated if the time series structure of the errors is ignored. In order to eliminate these deficiencies and better understand the effect of these climate factors on gold production, regression with ARIMA errors technique was employed after its appropriateness has been tested. The model was then compared in terms of prediction accuracy which resulted a MAPE of 9.78%. It was concluded that, gold production in Ghana is positively related to Temperature whilst negatively to Rainfall and Precipitate. It was recommended that mine operators in Ghana could base on this analysis to optimise their production planning and scheduling. Keywords: Gold Production, Climate, Multicollinearity, VIF, Regression Models with ARIMA Error

Doxorubicin selectively induces apoptosis through the inhibition of a novel isoform of Bcl‑2 in acute myeloid leukaemia MOLM‑13 cells with reduced Beclin 1 expression

The overexpression of anti-apoptotic Bcl-2 in acute myeloid leukaemia (AML) may contribute to difficulties in eradicating these cells during chemotherapy. In the present study, doxorubicin (Dox) was evaluated for its potential to induce selective apoptotic cell death in AML MOLM-13 cells and to modulate autophagy through Bcl-2 and Beclin 1 protein expression. Annexin V/propidium iodide and 5(6)-carboxyfluorescein diacetate succinimidyl ester (CFSE) flow cytometric analyses were conducted to determine the effects of Dox on cell death and cell proliferation, respectively, following 48 h of co-incubation with AML MOLM-13 or U-937 monocytic cells. The protein expression levels of Bcl-2 and Beclin 1 in untreated and treated cells were quantified by western blot analysis. Dox reduced the viability of MOLM-13 cells partly by inhibiting cell division and inducing cell apoptosis. Dox demonstrated a level of selectivity in its cytotoxicity against MOLM-13 compared to U-937 cells (P<0.05). Dox induced a significant decrease in Beclin 1 protein levels in MOLM-13 cells without significantly affecting the protein levels in U-937 monocytes. A novel Bcl-2 15-20 kDa (p15-20-Bcl-2) isoform was found to be selectively expressed in AML MOLM-13 cells (but absent in the leukaemic cell lines tested, OCI-AML2, CML K562 and U-937). Dox induced a highly significant inhibition of p15-20-Bcl-2 at concentrations of 0.5, 0.75 and 1 µM (P<0.01). However, the usual 26 kDa Bcl-2 (p26-Bcl-2-α) isoform protein expression was not affected by the drug in either the MOLM-13 or U-937 cells. It was thus postulated that Dox exhibited some selectivity by targeting the p15-20-Bcl-2 isoform in MOLM-13 cells and activating Beclin 1 to induce cell death