bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma membrane‐associated sialidase (NEU3) promotes formation of colonic aberrant crypt foci in azoxymethane‐treated transgenic mice
Authors: Shiozaki Kazuhiro , Yamaguchi Kazunori , Sato Ikuro , Miyagi Taeko 
Published: February 2009

Human plasma membrane‐associated sialidase (NEU3) specifically hydrolyzes gangliosides, and it is up‐regulated in colon cancer and plays an essential role in the expression of malignant phenotypes. To clarify the role of NEU3 in tumorigenesis in vivo, we examined the susceptibility of NEU3 transgenic mice to induction of colonic aberrant crypt foci (ACF) by azoxymethane. Mice were injected with azoxymethane (i.p., 15 mg/kg/week) for 6 weeks, and 4 weeks later ACF had formed in the NEU3 transgenic mice significantly more than in the control wild‐type mice. Enhanced phosphorylation of epidermal growth factor (EGF) receptor, Akt and ERK and up‐regulation of Bcl‐xL protein were observed in the transgenic colon mucosa, but no changes were found in cell proliferation, suggesting that the increased ACF formation is due to suppression of apoptosis. Immunohistological analysis with anti‐cleaved caspase 3 antibody showed an actual reduction in apoptotic cells in the transgenic mucosa at 6 h after the first azoxymethane injection, when apoptosis in the colonic crypt occurs. Consistent with our previous observations of human colon cancer, thin‐layer chromatography of the gangliosides from the transgenic colon mucosa revealed decreased GM3 and increased lactosylceramide as compared to those from the control mucosa, probably because of catalysis of gangliosides by NEU3. The results of this study provide the first evidence that NEU3 essentially increases azoxymethane‐induced ACF formation in colon mucosa by suppression of apoptosis, possibly via activation of the EGF signaling pathway, and thus indicate that up‐regulation of NEU3 is important to the promotion stage of colorectal carcinogenesis in vivo. (Cancer Sci 2009; 100: 588–594)
Clinically relevant radioresistant cells efficiently repair DNA double‐strand breaks induced by X‐rays
Authors: Kuwahara Yoshikazu , Li Li , Baba Taisuke , Nakagawa Hironobu , Shimura Tsutomu , Yamamoto Yoichiro , Ohkubo Yasuhito , Fukumoto Manabu 
Published: February 2009

Radiotherapy is one of the major therapeutic modalities for eradicating malignant tumors. However, the existence of radioresistant cells remains one of the most critical obstacles in radiotherapy and radiochemotherapy. Standard radiotherapy for tumor treatment consists of approximately 2 Gy once a day, 5 days a week, over a period of 5–8 weeks. To understand the characteristics of radioresistant cells and to develop more effective radiotherapy, we established a novel radioresistant cell line, HepG2‐8960‐R with clinical relevance from parental HepG2 cells by long‐term fractionated exposure to 2 Gy of X‐rays. HepG2‐8960‐R cells continued to proliferate with daily exposure to 2 Gy X‐rays for more than 30 days, while all parental HepG2 cells ceased. After exposure to fractionated 2 Gy X‐rays, induction frequencies of micronuclei and remaining foci of γ‐H2AX in HepG2‐8960‐R were less than those in HepG2. Flow cytometric analysis revealed that the proportion of cells in S‐ and G2/M‐phase of the cell cycle was higher in HepG2‐8960‐R than in HepG2. These suggest that the response of clinically relevant radioresistant (CRR) cells to fractionated radiation is not merely an accumulated response to each fractionated radiation. This is the first report on the establishment of a CRR cell line from an isogenic parental cell line. (Cancer Sci 2009; 100: 747–752)
Climate variability and change over southern Africa: impacts and challenges
Authors: Sithole Alec , Murewi Cyril T. F. 
Published: February 2009

AbstractIn this paper, the influence of climate variability and change on the environment was studied over southern Africa using ground‐based and remotely sensed data. A time series analysis of rainfall and temperature anomalies indicated that there was a high rainfall and temperature variability in the region. The influence of global teleconnections on rainfall patterns over southern Africa showed that in some areas there was a spatial variation in their strength, increasing from west to east. Maps of NDVI, from 1982 to 2004, showed that changes in vegetation cover were more apparent during the dry season than during the wet season. The study also revealed that climate variability and change are linked to decreasing rainfall and hence, decreasing regional water resources and biodiversity and increasing environmental degradation. With the regional population expected increase, this depletion of resources poses the greatest regional environmental challenge to humankind.
Land cover change and land degradation in parts of the southwest coast of Nigeria
Authors: Fasona Mayowa , Omojola Ademola 
Published: February 2009

AbstractFrequent alteration in land cover often leads to decreased stability of ecosystems which can also increase the vulnerability of rural communities to externalities of environmental change. This study carried out in parts of the coast of southwestern Nigeria utilized topographic base maps and two‐time Landsat TM imageries to assess the trend in land cover changes and ecosystems degradation for the three time periods 1965, 1986 and 2001. Remote sensing, geographic information systems and landscape pattern analysis were employed for data processing and analysis. The focus of the analysis was on land cover change, land degradation, and changes in landscape pattern resulting from interplay of natural and anthropogenic drivers.The results show increased trend in human‐induced land cover change with concomitant severe negative impacts on ecosystems and livelihoods. About 98,000ha (30% of the area) was seriously degraded as at 2001. About 33,000ha (10%) was under permanent saline water inundation with about 21 communities already dislocated. Loss of fragile ecosystems including marshland (from 7.7% in 1965 to 1% in 2001) and mangrove (from 14.6% in 1965 to 3.1% in 2001) was intense, while over 300 ponds/small lakes which are important for the local fishing economy have disappeared. About eighteen communities were also dislocated by erosion in a section around the southeastern parts of the coastline. Landscape metrics generated, suggested increased ecosystems perturbation and landscape fragmentation. The paper also discussed the implications of these rapid changes for ecosystems stability, food security and sustainable rural livelihoods in the area.
Impact of land use changes on water resources and biodiversity of Lake Nakuru catchment basin, Kenya
Authors: Raini Jackson Akama 
Published: February 2009

AbstractLake Nakuru, Kenya, is one of a series of saline–alkaline closed basin lakes in the eastern arm of the Rift Valley. The lake has been variously described as ‘the lake of a million flamingos’ and ‘the Worlds greatest ornithological spectacle’ and is bedrock to the areas’ tourism. The lake was designated a bird sanctuary in 1960, a National Park in 1968, first rhino sanctuary in 1987, first Kenyan Ramsar site in 1990, an Important Bird Area in 1999 and a world‐class national park in 2005. Over the last 40 years, its basin has been heavily settled, extensively cultivated, urbanized and industrialized. Environmental problems include poor agricultural practices, human encroachment, pollution, wildlife mortality/morbidity, human/wildlife conflicts, poverty, ethnic tensions and land clashes and lack of adequate legal and policy framework. Approaches to conservation have been initiated against identified existing problems and constraints. These approaches are (i) organizational and institutional development; (ii) hot spots and pollution loads management and (iii) catchment and park management. Constraints have been identified as unclear demarcation of responsibilities, lack of budget, skilled staff and know‐how and lack of environmental standards and regulations. The impacts of ecosystem changes on people’s lives and livelihoods are discussed.
Scattered trees as modifiers of agricultural landscapes: the role of waddeessa (Cordia africana Lam.) trees in Bako area, Oromia, Ethiopia
Authors: Yadessa Abebe , Itanna Fisseha , Olsson Mats 
Published: February 2009

AbstractScattered trees in general and scattered waddeessa (Cordia africana Lam.) trees in particular are very common across the agricultural landscapes in Oromia, Ethiopia. A study on this scattered waddeessa trees commonly growing on farmers’ agricultural fields was conducted at Bako in western Oromia, Ethiopia with the objective of assessing their role in modifying the soil properties in the agricultural landscape. Soil samples from surface layers (0–10 cm) were taken at three concentric transects (0.5, 2 and 4 m) around the tree and compared with soil samples from the adjacent open areas (15 m distance from the tree), and then analysed following the standard procedures. Results showed that scattered waddeessa trees significantly modified the overall properties of the soil in the agricultural landscape of Bako area. But soil texture was not affected, indicating that it is more related to parent material than the tree influence. Hence, the soil patches observed under these waddeessa trees can be important local nutrient reserves that may influence the rural agricultural landscape. They also play an important role in generating local household income from the sale of products and conserving biodiversity by providing habitats and resources that are otherwise absent or scarce in agricultural landscape.
Impact of eucalyptus and pine growing on rural livelihood: the lesson from Bukoba area, north western Tanzania
Authors: Mwanukuzi Phillip K. 
Published: February 2009

AbstractSustainable resource management intends to allocate resources in such a way that unnecessary deterioration of biophysical and socio‐economical systems is avoided. In Bukoba Area where rainfalls are plenty, evergreen grasslands were expansive and forests were limited, eucalypts (eucalyptus spp.) and pines (pinus spp.) were grown on grasslands for preventing land degradation through deforestation and for providing additional source of income for rural poor. This study shows that in addition to detrimental consequence of eucalyptus and pine forests on soil resources, conversion of Bukoban grasslands to forests has negatively impacted livelihood of the rural poor. Growing eucalypts and pines on grasslands prevented a farming system that enabled integration of grasslands, cattle keeping and crop production. Consequently, the grasslands role of nutrients cycling was disrupted, food crop production reduced, home‐gardens productivity declined, majority deprived important livelihood asset and foreign income flow into the area reduced.
The multidimensional nature of biodiversity and social dynamics and implications for contemporary rural livelihoods in remote Kalahari settlements, Botswana
Authors: Sallu S. M. , Twyman C. , Thomas D. S. G. 
Published: February 2009

AbstractDespite rapid socio‐economic development in Kalahari drylands, contemporary research suggests that biodiversity remains important as a component of the complex portfolio of livelihood strategies, as a real and perceived safety net in times of stress, and a key factor of cultural identity. The degree to which the spatially and temporally dynamic nature of biodiversity in drylands influences livelihoods is, however, little studied, particularly in socially complex contemporary rural settlements. Greater understanding in this area is required to allow better‐informed design and implementation of rural development, poverty alleviation and conservation initiatives. This is particularly true in the light of predicted increases in environmental dynamism with climate change. An interdisciplinary approach was used in two environmentally and socially distinct dryland settlements in Botswana, to investigate the extent to which the dynamic biodiverse setting influences contemporary rural livelihoods. Results illustrate that biodiversity, particularly its dynamics, is of critical contemporary importance to rural settlement livelihoods, particularly in times of inner settlement scarcity. Entitlements to biodiversity dynamics were, however, bound up by complex settlement‐specific social, economic and political factors. Unless such contextual within‐settlement dynamics are understood, the relative importance of biodiversity in rural development and poverty alleviation strategies in contemporary Kalahari drylands may be undermined.
Participatory land‐use planning and conservation in northern Tanzania rangelands
Authors: Kaswamila Abiud L. , Songorwa Alexander N. 
Published: February 2009

AbstractIn developing countries, participatory land‐use planning is seen as a panacea to mitigate land‐use conflicts and enhance land productivity. This assumption has not been thoroughly tested in wildlife corridors. Three villages were selected for this study. Several methods were used to provide indication of the performance of the plans against their stated objectives of mitigating conflicts and conserving wildlife corridors. Three hundred and fifty‐eight households and eight park and extension workers were interviewed. In addition, focus group discussion with the nomadic Barabeig, field assessment and review of land‐use plan/general management plan reports were carried out. Results reveal that land‐use plans failed to achieve their set objectives. For example, 75% of the households held this view. Major causes of failure were insufficient participation by stakeholders in the planning process, lack of robust, transparent and accountable implementation strategies, inadequacy of qualified staff and lack of ‘holistic approach’ to the planning process. Taking these findings into account, an improved buffer zone land‐use planning framework is suggested. For the framework to enhance both conservation and development and to enable policies and legislation, equitable benefit sharing and conservation education, initiation of compensation schemes for depredation caused by wild animals and intensification of patrols are required.
Land use/cover changes and their implications on rural livelihoods in the degraded environments of central Tanzania
Authors: Kangalawe Richard Y. M. 
Published: February 2009

AbstractThis paper examines the changes in land use/cover types in the degraded environment of central Tanzania over the last 45 years, and how such changes have influenced agricultural and livelihoods sustainability, especially in the Irangi Hills. Changes of land use/cover were measured through aerial photographs interpretations, while local perceptions and description of change were addressed through household interviews and field observations. The results of this study show that there have been variations over the years in terms of both the areas and spatial distribution of cultivated fields. The total land cultivated increased from 31% in the late 1970s to 35% in early 1990s, mainly because of agricultural expansion to sandy watercourses and former grazing areas. Water courses shrank by 55% between late 1970s and early 1990s providing new areas for cultivation. Over the last 45 years, the open and wooded grasslands, and tree‐cover types covered about 40% of the total land area, ranging from 29% in 1960 to 43–45% between late 1970s and early 1990s. Spatial and temporal distribution of the cultivated fields and other vegetation cover types were influenced by differences in the scale of land degradation, and the soil‐conservation initiatives that have been implemented. With increasing pressure on the land, however, sustaining livelihoods through agricultural production in the area remains a critical challenge.
Understanding future ecosystem changes in Lake Victoria basin using participatory local scenarios
Authors: Odada Eric O. , Ochola Washington O. , Olago Dan O. 
Published: February 2009

AbstractUnderstanding future ecosystem changes is central to sustainable natural resource management especially when coupled with in‐depth understanding of impacts of drivers, such as governance, demographic, economic and climate variations and land use policy. This offers comprehensive information for sustainable ecosystem services provision. A foresight process of systematic and presumptive assessment of future state and ecosystem integrity of Lake Victoria basin, as participatory scenario building technique, is presented. Four scenarios have been illustrated as possible future states of the basin over the next twenty years. Using a scenario building model developed in Ventana Simulation (VENSIM®) platform, the paper presents a scenario methodology for tracking changes in lake basin ecosystem status. Plausible trends in land use change, changes in lake levels and contribution of fisheries are presented. This is part of an initial attempt to setup long‐term environmental policy planning strategies for Lake Victoria basin. The assumptions, driving forces, impacts and opportunities under each scenario depict major departure and convergence points for an integrated transboundary diagnosis and analysis of regional issues in the basin as well as strategic action planning for long‐term interventions. The findings have been presented in terms of temporal, spatial, biophysical and human well‐being dimensions. The attempts in this study can be embedded in a policy framework for basin management priority setting and may guide partnerships for environmental management.
Land‐use and resource conflicts in the Okavango Delta, Botswana
Authors: Darkoh Michael B. K. , Mbaiwa Joseph E. 
Published: February 2009

AbstractThis study assesses land‐use conflicts in the Okavango wetland ecosystem. A survey of the livelihood activities of a sample of four villages has been carried out and a stakeholder approach used to identify and analyse the key actors involved in resource competition and conflicts in the area. Traditional and emerging stakeholders were identified and found to be in conflict not only with each other but within themselves. Institutional policies on land use in the area are not properly harmonized, and there has been a top‐down approach to development planning and implementation of development programmes. As a result, land‐use conflicts have escalated in the area. The Okavango Delta Management Plan adopted in 2007 should integrate and harmonize all the land‐use policies, and land management in the area.
Wetlands, livelihoods and sustainability in Tanzania
Authors: Mwakaje A. G. 
Published: February 2009

AbstractWetlands in Tanzania are among the world’s most biologically productive ecosystems and are rich in species diversity. Wetlands support family livelihoods through crop production, grazing pastures and direct resource extractions. Ecologically, wetlands are instrumental in water storage, filtration, flood control and toxic retention and are also important habitat for biodiversity both flora and fauna. The last 30 years have witnessed rapid degradation of wetlands which threatens livelihoods; disturbs ecological settings and leads into unsustainable development. In this study, an attempt has been made to describe the livelihoods and sustainability issues of the Bahi Wetlands in Central Tanzania. This is a semi‐arid area and therefore the wetland plays a key role socio‐economically and environmentally. Data were collected from 200 households in Ngaiti and Kitalalo villages using structured and semi‐structured questionnaires. There were also focused groups interviews, key informants and Participatory Rural Appraisal methods. Findings show Bahi Wetlands to play a significant role in livelihoods, cultural and ecological functions. However, the sustainability of the wetlands is threatened by over‐cultivation, overgrazing and over‐extraction of natural resources directly. Livelihood diversifications through credit provision, improved extension services and strengthened local institutions, are recommended. Wetlands policy and laws should be developed and enforced.
Using a historical map as a baseline in a land‐cover change study of northeast Tanzania
Authors: Börjeson Lowe 
Published: February 2009

AbstractVegetation data in an early 20th century map from northern Tanzania are presented and discussed for its potential of expanding the analytical time‐frame in studies of land‐use and land‐cover change. The starting point is that much research on land‐use and land‐cover change suffers from a time‐frame bias, caused by limitations in remote sensing data. At the same time, the use of historical maps as a complementary data‐set is rather insignificant. Can information in historical maps be used to extend the baseline in land‐use and land‐cover change studies? The historical context of the vegetation data is evaluated, and as an illustration of its potential for interdisciplinary research on land‐cover and ecosystems change, a section of the map is juxtaposed with a recent pollen record specifically addressing the impact of a ‘large infrequent disturbance’ (LID) event at the end of the 19th century. It is concluded that the vegetation data in the map are not likely to be reflecting an extreme situation due to the LID event. Finally, the historical vegetation data were visually compared with a national 1995 land‐cover data set, illustrating the possibility of using the map data as a baseline in land‐cover change studies.
Poly I:C-induced expression of intercellular adhesion molecule-1 in intestinal epithelial cells
Authors: Omagari D , Mikami Y , Suguro H , Sunagawa K , Asano M , Sanuki E , Moro I , Komiyama K 
Published: February 2009

SummaryIntercellular adhesion molecul-1 (ICAM-1) is a transmembrane glycoprotein belonging to the immunoglobulin superfamily of adhesion molecules and plays perdominant roles in recruitment and trafficking of leucocytes to sites of inflammation. ICAM-1 expression in intestinal epithelial cells (IECs) is enhanced by several stimuli, such as proinflammatory cytokines, bacterial infections or pathogen-associated molecular patterns. One of these stimuli, double-stranded RNA (dsRNA), is a by-product of viral replication and can be recognized by its cognate receptor Toll-like receptor 3 (TLR-3). In spite of expression of both TLR-3 and ICAM-1 in IECs, correlation between TLR-3-signalling and ICAM-1 expression has never been examined in IECs. In the present study, we investigated whether poly I:C, an analogue of dsRNA, can stimulate the expression of ICAM-1 in IEC line, HT-29. Poly I:C-stimulation up-regulated the expression of ICAM-1 mRNA by real-time polymerase chain reaction. Enhanced expression of ICAM-1 was confirmed in protein level by immunofluoresense cell staining and enzyme-linked immunosorbent assay by measuring the released soluble ICAM-1 in culture supernatant. As the stimulation effect was reduced by pre-treatment of the cells with anti-TLR-3 antibody, poly I:C-binding signal was thought to be sensed by TLR-3 on the surface of HT-29. The results of luciferase assay and nuclear factor kappa-b (NF-kB) inhibitor treatment experiments indicated that the downstream signal was mainly transduced by transcription factor, NF-kB. All these results demonstrated the connection between TLR-3 signalling and ICAM-1 expression in HT-29 cells and indicated the importance of coordinated function of both innate and adaptive immunity against viral infections.