1,636 research outputs found

    Water Quality Status Within The Anchorage Space of Tema Harbour, Ghana

    Get PDF
    Marine pollution is attributable to anthropogenic introductions of contaminants above their natural background levels and being dispersed by ocean forcing. Assemblages of vessels within offshore platforms and seaport terminals could also be potential sources for marine water contamination. As such, nearshore perimeters of the Tema Port were assessed to review the vessel register and the seawater quality through Automatic Identification System (AIS), in-situ and laboratory analysis. The results of analysed satellite data suggested ~1,600 commercial vessels of over 50 flag states including Ghana were present in the West Africa territorial waters between 2016 and 2020. Bacterial load shows the following order: total heterotrophic bacterial [THB] (364-468 cfu/mL) > total coliform [TC] (26-73 cfu/100 mL) > faecal coliform [FC] (1-13 cfu/100 mL). Phytoplankton species abundances were in order Ceratium spp. (31.8%) >Protoperidinium spp. (30.1%) > Dinophysis spp. (9.3%) > Coscinodiscus sp. (7.3%) > Lingulodinium polyedra (6.9%) = Nitzschia sp. (6.9%). Water temperature ranged between 23.9 and 27.5 oC (surface to 25.4 m depth), salinity 36.03 ± 0.51‰, dissolved oxygen 6.54 ± 0.94 mg/L and pH 8.18 ± 0. 06. Phosphate, ammonia, Cd, As, and Pb levels were low (0.01 to 0.153 mg/L). Nitrate, silicate and Mg were relatively high (0.7 - 2.18 mg/L). Pearson correlation coefficient displayed 0.05 and 0.01 significant levels between total dissolved solids (TDS) and electrical conductivity and salinity, and dissolved oxygen and temperature and arsenic levels. Normalization physicochemical data suggested thermal stratification at 15 m depth. Nutrient and biological results indicated normal water quality conditions, however, relatively high levels of phytoplankton including harmful and toxic species suggested excess nutrient contamination in the study area. Further assessment is recommended to ascertain the link between phytoplankton and nutrient load at the anchorage space.&nbsp

    Coping with adversity: Resilience dynamics of livestock farmers in two agroecological zones of Ghana

    Get PDF
    Despite the increasing occurrence of adverse events including droughts and conflicts, livestock farmers in Ghana continue to raise animals to support their livelihoods and the national economy. We assessed the resilience of cattle farmers (CF) to adverse events they faced using a cross-sectional survey of 287 CF in two agroecological zones in Ghana. Resilience to adversities was assessed using the Resilience Scale (RS-14). Resilience scores and categories were computed and factors that explained variations in resilience categories assessed. The farmers kept, on average, 31 cattle per household, with a majority (91%) also growing crops. Key adverse events confronting them in both districts were animal disease outbreaks, pasture shortages, and theft, with 85% (240/287) losing, on average, seven cattle (15% of the herd size) over a one-year period. The mean resilience score was 71 (SD = 8) out of 98; 52% were highly resilient. Resilience was higher in the southern district (72 versus 70), albeit not statistically significant (p = 0.06). The resilience significantly improved with age, each unit increase in cattle in the herd, and having experience raising livestock (p < 0.001). The CF have relatively high resilience to adverse events affecting their productivity. The findings provide relevant information for implementing mitigation measures to improve production by reducing animal mortalities through high-quality veterinary services

    Spatial Data Analysis for Traffic Safety Network Screening

    Get PDF
    Problem - The roadway system represents a major investment, both public and private, and a valuable resource that enables mobility and accessibility to users. Due to degradation of aging infrastructure and increasing traffic, transportation agencies are seeking to effectively update or improve the system. With rising costs, tight budgets, and limited land resources, agencies are seeking effective techniques for identifying critical mobility and safety concerns. Historically, assignment of crashes to portions of the network, whether segments or intersections, has been the primary manner to link crash and road elements. Purpose – The primary goal is to explore a potentially more efficient and effective means of developing roadway connected crash cluster identification results as an input to network screening and diagnostics. Beyond this, using the data linkages, we intend to explore crash typology (e.g., severity, collision type) distributions and clusters with respect to network (traffic and roadway) characteristics. Nuance – The research uses GIS and spatiotemporal analysis techniques relying on crash locations as a basis rather than elements of the road network (e.g., intersections, non-intersections). The intent of the analysis is to develop crash clusters that can be flagged for further analysis and potential mitigation. Data – Crash, roadway geometrics, and traffic data of 5 years (2015-2019) were collected for Story County of Iowa. These readily available data are being analyzed using Geospatial Information System (GIS) and some statistical models such as the Markov Switching Models (MSM). Existing methodologies will also be used to develop results that will be compared with the new methodology. Prior Studies – There have been many network screening methods since the 1970s and the more widespread inception of computing resources. Though these methods have some advantages, they do have several shortcomings as well as detailed in the Highway Safety Manual (HSM). Due to these shortcomings, the HSM and other sources promote methods that address these shortcomings such as the Empirical Bayesian (EB) and Hierarchical Bayesian (HB) methods. Historically, assignment of crashes to segments or intersections, has been the primary manner to connect crashes and road elements. The use of GIS and spatial and temporal analysis, alternative methods for connecting crashes to the roadway network have been developed to replace the older methods like screening with additional differentiating criteria. Impact – The primary outcome of this research is the development of a new method of generating distributions and clusters of crashes along a roadway network for use in traffic safety screening. Practitioners should be able to utilize the process to develop network screening related to their jurisdictions, given sufficient and appropriate input data. Keywords –Transportation Engineering, Network screening, Crash rate, Spatial analysis, GIS, Iowa Data, Markov switching models

    Assessing Municipal Solid Waste Management Practices and Challenges in the Techiman Municipality, Ghana

    Get PDF
    Managing waste efficiently is essential for building sustainable, livable and healthy communities but this remains a challenge for many municipal governments due to limited municipal budget and other logistical challenges. Such challenges result in ineffective waste collection and disposal. However, identifying the challenges associated with municipal solid waste management often lead to developing solutions to mitigate the problem. This paper assesses the waste management practices and challenges within the Techiman municipality, the regional capital of the Bono East Region. By sampling residents’ perceptions and experiences it was observed that households and patrons were dissatisfied with Techiman’s Municipal Solid Waste Management (MSWM). Statistically the per capita per day rate of waste generation was 0.48kg/ per capita/per day, being higher than Ghana’s municipal waste generation of 0.40 kg/per capita/per day. Lack of collection of waste from the transfer stations to the landfill sites has resulted in about 67 heaps of uncollected waste in the municipality. The results show that lack of source separation and recycling, broken down trucks, low participation of private sector in waste collection, non-compliance of by-laws, poor road infrastructure leading to the landfill site, and inefficient landfill site have contributed to the waste problem in the municipality. Resorting to source separation, educating the public on waste management bye laws, increasing private sector participation and establishing engineered landfill sites can substantially contribute to sustainable Municipal Waste Management in the Techiman Municipality

    Spatial Data Analysis for the Development of Expected Adverse Weather Charts for Transportation Construction Projects

    Get PDF
    Problem - Seasonal and daily weather events impact construction projects across the various climate regions of South Dakota in differing fashions. Additionally, the impacts for similar weather events can impact grading, surfacing, and structural construction activities in various ways. Adverse weather conditions can cause major delays which may lead to time extensions and increase project cost. Purpose – To address these issues, South Dakota Department of Transportation (SDDOT) developed Working Day Weather Charts in 1998. However, advances in construction practices and weather prediction as well as climatic changes have occurred over the interim 25 years. This study is focused on developing updated zones, tables, charts, and recommendations for roads and bridges construction in South Dakota. Nuance – The tables and charts are planned to be developed on both weekly and monthly basis to determine the impact of adverse weather events on construction projects and for use in future contracts. Data - Weather, soil, and hydrographic data for South Dakota state are being considered for this study. The primary importance is on the weather data which is collected for 30 years (1991-2020) period from National Oceanic and Atmospheric Administration (NOAA). The important weather data parameters are temperature, snow, rainfall, and wind. The soil data have been collected from the broad-based inventory of soils and non-soil areas of the United States namely State Soil Geographic (STATSGO2). The key focus is to analyze the soil parameters in combination with adverse weather events that affect the construction of roads and bridges. The hydrographic data is focused on the peak flow at major water bodies in South Dakota that may cause flooding or ponding which affects road and bridge construction. Additionally, interviews with SDDOT personnel and construction contractors were conducted to determine factors important to the industry. Starting with data exploration of all the available data, key parameters will be analyzed to develop updated expected adverse weather day chart and updated zones. Prior Studies – A considerable amount of work has been done on effects of weather on construction type categories and various Department of Transportation agencies evaluate the use of adverse weather in contract time calculations. The Virginia Department of Transportation place contract determination guidelines online. The VDOT document provides steps in determining contract time but contained little information on the impact of adverse weather on contract time calculations. Another document from the National Research Council of Canada on construction work protocols during winter in 1971. Beyond that, a recent (2022) publication from the National Cooperative Highway Research Program (NCHRP) covers a systematic approach for determining construction contract time. However, in most papers, little information is documented on the impact of adverse weather and how to implement that in tables and charts for construction type activities across South Dakota. Impact – The results can directly help SDDOT engineers and contractors to estimate the appropriate contract time and warranted time extension due to unexpected adverse weather for variety of transportation construction projects across the diverse geographical terrains and climates of South Dakota. Keywords: Transportation, Adverse Weather, Construction, NOA

    Trends in extrapulmonary TB cases at three teaching hospitals in Ghana, 2008-2017

    Get PDF
    SETTING: Three teaching hospitals in Ghana. OBJECTIVE: To elucidate trends in demographics, clinical characteristics and treatment outcomes in extrapulmonary TB (EPTB) patients. DESIGN: This was a retrospective study involving the review and comparison of EPTB and pulmonary TB (PTB) data from 1 January 2008 to 31 December 2017 in TB registers and treatment cards. RESULTS: Of 15,392 TB cases, 4607 (30%) were EPTB, including 4477/4607 (97%) new cases. There were 2,679/4607 (58%) males and the age range was 0.3 to 96 years. Pleural TB (1021/4607, 22%) was the most common. Treatment success rates for EPTB and PTB were respectively 72% and 84%. HIV positivity was high among patients with disseminated/miliary TB (429/779, 55%) and TB meningitis (242/526, 46%). To note, disseminated/miliary TB (chi(2) = 33.53, P < 0.0001) increased, whereas TB meningitis (chi(2) = 19.43, P < 0.0001) decreased over the 10-year period. Mortality among EPTB patients was associated with increasing age (25 years), disseminated/miliary TB, TB meningitis and HIV positivity. CONCLUSIONS: There is male preponderance for both EPTB and PTB in Ghana. Increasing age, disseminated/ miliary TB, TB meningitis and HIV are risk factors for mortality among EPTB patients. This emphasises the need for public education on the risk factors for EPTB and preventive strategies

    Thermal tolerance, climatic variability and latitude

    Get PDF
    The greater latitudinal extents of occurrence of species towards higher latitudes has been attributed to the broadening of physiological tolerances with latitude as a result of increases in climatic variation. While there is some support for such patterns in climate, the physiological tolerances of species across large latitudinal gradients have seldom been assessed. Here we report findings for insects based on published upper and lower lethal temperature data. The upper thermal limits show little geographical variation. In contrast, the lower bounds of supercooling points and lower lethal temperatures do indeed decline with latitude. However, this is not the case for the upper bounds, leading to an increase in the variation in lower lethal limits with latitude. These results provide some support for the physiological tolerance assumption associated with Rapoport's rule, but highlight the need for coupled data on species tolerances and range size

    Prevalence of parasitic infections on cultured Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) In Bong County, Liberia

    Get PDF
    This study investigated the prevalence rate, relative abundance and mean intensity of par­asites infecting cultured Nile tilapia Oreochromis niloticus L. in three fish farms, Gbarnga, Warta and CARI in Bong County, Liberia. Organs from thirty fish samples were exam­ined from September 2016 to February 2017, along with water quality parameters. Results showed the occurrence of seven parasites including protozoans, monogeneans, digeneans, cestodes, hirudineans, nematodes and crustaceans which were organ specific in terms of infection. The prevalence of the parasites varied seasonally, with the highest numbers oc­curring in November-January. The low prevalence rate, relative abundance and mean in­tensity of the parasites showed no threat to fish farmers in Liberia. All the water quality parameters were at desirable levels for the culture of the fish except nitrite, which was beyond the threshold for sustainable fish culture. It is therefore concluded that although parasitic infections in the three farms in the Bong County were low, best farm management practices are essential

    Physicochemical influence on the spatial distribution of faecal bacteria and polychaetes in the Densu Estuary, Ghana

    Get PDF
    Coastal ecosystems are increasingly impacted by man-made disturbances including pollution from agriculture, aquaculture and municipal waste. This study employed multiple ecological indicators to assess environmental quality of the Densu Estuary and understanding of environmental controls on the spatial distribution of organisms. Physicochemical parameters were measured in situ. Water and sediment samples were collected from ten stations and analysed for nutrients, total suspended solids and organisms using standard methods. The water quality index for the Densu Estuary ranged from 359.5 to 484.4, suggesting an unhealthy ecosystem. The abundance of indicator species, e.g. faecal bacteria (Escherichia coli, Enterococcus species) and polychaetes (Capitella and Nereis species) varied significantly (p<0.05) among stations. Contaminated sites are located landwards with high human impacts. Faecal bacteria and polychaete abundance correlated significantly (p<0.05) with the respective physicochemical parameters. Canonical analysis (74.11%) showed the physicochemical influence on the spatial distribution of species. The pH significantly (p<0.05) controlled the spatial distribution of faecal bacteria and polychaetes in the Densu Estuary. The results suggest environmental pollution in the Densu Estuary, useful baseline information for effective legislation towards its sustainable management
    • …
    corecore