Eight-year Interval Research Articles

Analysis of mangrove dynamics and its protection effect in the Guangdong-Hong Kong-Macao Coastal Area based on the Google Earth Engine platform

Mangroves are rapidly disappearing in several places of the world, and mangrove dynamics are becoming important evidence of ecological restoration and protection along the coast. Mangrove populations in the Guangdong-Hong Kong-Macao Coastal Area (GCA) have experienced a substantial impact of anthropogenic pressure in the 20th century. Monitoring its spatio-temporal variation and protection effect has been regarded as an important task in coastal management. In this study, we provided the comprehensive assessment of mangrove dynamics in the GCA and typical sites from 1988 to 2020 at eight-year intervals. At this time interval, mangrove ecosystems changed significantly as a result of global warming and human impacts. The geographical distribution of mangroves was obtained by applying the Random Forest (RF) classifier on Landsat images with a 30 m spatial resolution on the Google Earth Engine (GEE) platform, based on relevant indices such as Normalized Difference Mangrove Index (NDMI), Normalized Difference Vegetation Index (NDVI), Normalized Difference Suspended Sediment Index (NDSSI), Normalized Difference Built-up Index (NDBI) and Soil Adjusted Vegetation Index (SAVI). Quantitative evaluation indicated that overall accuracy of over 88% was achieved with RF classifier for mangrove extraction. In the GCA, mangrove area was 95.4 km2 in 1988, dropped to 71.4 km2 in 1996, then expanded to 127.5 km2 in 2020, with an overall dynamic rate of 1.02%. In typical sites, mangroves show a similar trend to the overall area. The subsequent mangrove growth is attributed to reserve establishment, accompanied by the expansion of replanted mangrove areas. In the GCA, provincial-level and county-level reserves show a high rate of mangrove dynamic, while national-level reserves display a low rate of mangrove dynamic. The dynamic rate in reserves of the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) is higher than other parts of the GCA, indicating that the effect of mangrove protection is better in the GBA. The results of this study will provide scientific foundations for the sustainable management and conservation of mangrove ecosystem, the quantification of ecosystem services (such as coastal protection and carbon storage), as well as the formulation of strategies for mitigating and adapting to climate change.

A longitudinal study of the association between attending cultural events and coronary heart disease

BackgroundThe experiences of art and music are an essential part of human life and this study aimed to examine the longitudinal association between cultural participation and coronary heart disease.MethodsThis was a longitudinal study on a randomly selected representative adult cohort (n = 3296) of the Swedish population. The study period was over 36 years (1982–2017) with three separate eight-year interval measurements of cultural exposure (for example, visiting theatres and museums) starting in 1982/83. The outcome was coronary heart disease during the study period. Marginal structural Cox models with inverse probability weighting were used to account for time-varying weights of the exposure and potential confounders during the follow-up. The associations were also examined through a time-varying Cox proportional hazard regression model.ResultsCultural participation shows a graded association, the higher the exposure the lower the risk of coronary heart disease; the hazard ratio was 0.66 (95% confidence interval, 0.50 to 0.86) for coronary heart disease in participants with the highest level of cultural exposure compared with the lowest level.ConclusionAlthough causality cannot be determined due to the remaining risk of residual confounding and bias, the use of marginal structural Cox models with inverse probability weighting strengthens the evidence for a potentially causal association with cardiovascular health, which warrants further studies.

Sacred kings of the Picts: the last cuckoos

ABSTRACT Sacred kings of Late Iron Age northern Britain are thought to have symbolised fertility and considered responsible for the wellbeing of the lands and people; components of a system of governance maintained by conservative religious beliefs and champions of a local goddess of sovereignty, also associated with the cuckoo and the planet Venus. Their regicide was undertaken by their successors with a sacred spear at cult-sites at eight-year intervals when Venus set at its evening extreme at Samhain. Titled after the cuckoo, the symbol of male fertility across Europe, they mimicked the cuckoo’s polygynous behaviour. Others have suggested their exploits were based on myths about the cuckoo. They are recalled in Irish legends, Arthurian tales and the writings of contemporary authors, depicted on stones and confirmed in recent place-name and archaeoastronomy studies, but not previously recognised. This paper explores the evidence for, and significance of, British, Irish and continental European warrior-champions named after the cuckoo. The study strongly suggests a continuity of cosmological beliefs, celestial associations, myths and legends, religious symbolism, sacred kingship and governance of tribal societies from the Indo-European immigrants to Britain until the adoption of Christianity and its associated form of kingship by the Picts.

Trend Changes in the individual contribution of risk factors for postpartum hemorrhage over more than two decades.

Postpartum hemorrhage is an obstetric emergency with a rising incidence. The aim of this study was to identify trends in the specific contribution of various risk factors for postpartum hemorrhage by observing their odds ratios throughout different time periods. In this population-based retrospective cohort study trends of change in odds ratios for known risk factors for postpartum hemorrhage occurring in three consecutive eight-year intervals between 1988 and 2014 were compared. Two multivariable logistic regression models were used in order to identify independent risk factors for postpartum hemorrhage in our population. Trends of various risk factors were compared along the time period of the study. The incidence of postpartum hemorrhage increased from 0.5% to 1988 to 0.6%. Using logistic regression models, preeclampsia, vacuum extraction delivery, retained placenta, perineal or vaginal tears and delivery of a large for gestational age neonate were recognized as independent risk factors for postpartum hemorrhage. While the odds ratios for perineal or vaginal tears significantly increased, odds ratios for delivery of a large for gestational age neonate significantly decreased. Odds ratios for the other risk factors did not change significantly. In our study, not only did the rates of statistically significant risk factors for postpartum hemorrhage change during the study period, the specific contribution of each risk factor changed as well. Having a better understanding of these trends might augment our ability to predict this grave obstetric complication and improve maternal outcomes in the future.

‘A dream come true’? Adolescents’ perspectives on urban relocation and life in condominiums in Addis Ababa, Ethiopia

ABSTRACT Relocation from inner cities and rehousing in suburbs is becoming an increasingly prevalent issue in developing countries. However, there is limited evidence about the perspectives of adolescents and most studies are from western contexts. In addressing this gap this study tracked adolescents before and after they were relocated over an eight-year interval from the centre of Addis Ababa to the outskirts, mainly to government-sponsored condominium housing. The paper also compares the views of those who were relocated with those who stayed behind. The paper argues that condominium housing enabled low-to-middle-income households to become house owners, while the poorest could not afford the costs, and the richest preferred building their own houses. From the perspective of adolescents who were relocated the move led to better housing and improved sanitation. However, students faced difficulties in the first year commuting, and schools and health centres were considered better quality in the previous locations; markets and shops were initially less well developed in the condominium areas, and there were fewer recreation options, though pollution and safety were greater concerns in the old neighbourhoods. A significant majority of the adolescents (79%) felt that the changes were positive or mainly positive and soon adapted to the new social environment, though social ties were less strong than in their previous neighbourhoods. Those who moved had better internet access and there were gender differences in decision-making, leisure activities and spending, with girls having less freedom, somewhat compensated for by mobile phones and social media.

Health system efficiency in OECD countries: dynamic network DEA approach

BackgroundIn recent years, measuring and evaluating the efficiency of health systems has been explored in the context of seeking resources to ensure the sustainability of ‘countries’ health and social systems and addressing various crises in the health sector. The study aims to quantify and compare the efficiency of OECD health systems in 2000, 2008, and 2016. The contribution to research in the field of efficiency in the healthcare system can be seen in the application of Dynamic Network Data Envelopment Analysis (DNDEA), which help us to analyse not only the overall efficiency of the healthcare system but analyse the overall efficiency as the result of the efficiencies of individual interconnected areas (public and medical care area). By applying the DNDEA model, we can realise the analysis not only within one year, but we can find out if the measures and improvements taken in the healthcare sector have a positive impact on its efficiency in a later period (eight-year interval).MethodsThe analysis focuses on assessing the efficiency of the health systems of OECD countries over three periods: 2000, 2008, and 2016. Data for this study were derived from the existing OECD database, which provides aggregated data on OECD countries on a comparable basis. In this way, it was possible to compare different countries whose national health statistics may have their characteristics. The input-oriented Dynamic Network Data Envelopment Analysis model was used for data processing. The efficiency of OECD health systems has been analysed and evaluated comprehensively and also separately in two divisions: public health sub-division and medical care sub-division. The analysis combines the application of conventional and unconventional methods of measuring efficiency in the health sector.ResultsThe results for the public health sub-division, medical care sub-division and overall health system for OECD countries under the assumption of constant returns to scale indicate that the average overall efficiency was 0.8801 in 2000, 0.8807 in 2008 and 0.8472 in 2016. The results of the input-oriented model with the assumption of constant returns to scale point to the overall average efficiency of health systems at the level of 0.8693 during the period. According to the Malmquist Index results, the OECD countries improved the efficiency over the years, with performance improvements of 19% in the public health division and 8% in the medical care division.ConclusionsThe results of the study are beneficial for health policymakers to assess and compare health systems in countries and to develop strategic national and regional health plans. Similarly, the result will support the development of international benchmarks in this area. The issue of health efficiency is an intriguing one that could be usefully explored in further research. A greater focus on combining non-parametric and parametric models could produce interesting findings for further research. The consistency in the publication and updating of the data on health statistics would help us establish a greater degree of accuracy.

An investigation of an Aberdeenshire ritual landscape: a site of human sacrifice associated with Venus

ABSTRACT A group of intervisible prehistoric monuments delineate a ritual landscape of 102 kilometres near Hatton of Fintray, Aberdeenshire. They act as back and foresights on solar and lunar horizon rising and setting extremes when viewed one from another. The identities of the local deities, syncretised as parish saints, an ethnographic analogy with pre-Christian Irish chieftains and an oral tradition that one of the monuments, the Gouk Stone (Old English for ‘cuckoo’), marks the location where a ‘general’ of that name was slain, support the hypothesis that local chieftains, titled after the bird and ‘married’ to the local goddess of sovereignty that personified Venus, were tied to the stone and ritually sacrificed. This occurred on the culturally significant day of Samhain at eight-year intervals from the Bronze Age until the late Iron Age. The interval coincided with the extreme evening setting of Venus at Samhain. In support of this hypothesis the stone acted as a horizon foresight for Venus setting extremes which occurred within a few days of Samhain and as a back sight with sunset behind a stone circle on Samhain. Place-names indicate the location remained an assembly/judicial site until the Medieval Period.

Building a Brain Tumor Practice: Objective Analysis of Referral Patterns and Implications for the Growth of a Subspecialty Surgical Program.

IntroductionGrowth of surgical caseload among specialties with a large contribution margin is an important financial objective for hospitals. In this study, we examined the diversity of referral patterns to a neurosurgeon over an eight-year interval and examined practice attributes related to surgical growth.MethodsThe electronic records of all patients undergoing an intracranial surgical procedure between August 2011 and August 2019 by an academic neurosurgeon were reviewed retrospectively. The Herfindahl-Hirschman index (HHI) was used to assess the distribution of referrals among community physicians who referred such patients; a value of HHI <0.15 indicates diversity. The yearly HHI trend was evaluated using meta-regression.ResultsThe neurosurgeon’s brain surgery caseload progressively increased on an annual basis from 1.4 to 12.5 cases per week between 2012 and 2018. Among the 1540 cases referred by 1775 different physicians, 78% were from three counties in southeast Florida and 8.1% from two counties in southwest Florida. The HHI declined between 2013 and 2018 by 0.023 per year (0.0046 standard error [SE], p = 0.0073) with the estimated value 0.0063 (0.0014 SE) < 0.15 in 2018 (p < 0.0001). The findings indicate that the base of referring physicians was highly diverse and that growth in caseload was accompanied by significantly less concentration of referrals.ConclusionSurgical growth in the neurosurgeon’s practice resulted from a small number of referrals from many physicians, not from many referrals from a small number of physicians. Few physicians referred a sufficient number of patients to warrant attribution of the referral itself to personal knowledge of their patients' eventual outcomes. Rather, factors promoting timely access to patient care appear to have been the driving force for growth.

Trends of changes in the specific contribution of selected risk factors for shoulder dystocia over a period of more than two decades.

Objectives Shoulder dystocia (SD) is an obstetrical emergency with well-recognized risk factors. We aimed to identify trends of changes in the specific contribution of risk factors for SD over time. Methods A nested case control study comparing all singleton deliveries with and without SD was undertaken. A multivariable logistic regression model was used in order to identify independent risk factors for SD and a comparison of the prevalence and the specific contribution (odds ratio (OR)) of the chosen risk factors in three consecutive eight-year intervals from 1988 to 2014 was performed. Results During the study period, there were 295,946 deliveries.Of them 514 (0.174%) were complicated with SD.Between 1988 and 2014 the incidence of SD has decreased from 0.3% in 1988 to 0.1% in 2014. Using a logisticregression model grandmultiparity, diabetes mellitus (DM), fetal weight, and large for gestational age (LGA) were found to be independent risk factors for SD (OR 1.25 95% CI 1.04-1.51, p=0.02; OR 1.53 95% CI 1.19-1.97, p=0.001; OR 1.002 95% CI 1.001-1.002, p<0.001; OR 3.88 95% CI 3.09-4.87, p<0.001; respectively). While the OR for grandmultiparity, fetal weight, and LGA has significantly changed during the study period with a mixed trend, the OR of DM has demonstrated a significant linear increase over time. Conclusions The individual contribution of selected risk factors for the occurrence of SD has significantly changed throughout the years. The contribution of DM has demonstrated a linear increase over time, emphasizing the great impact of DM on SD.

Competition, Climate, and Size Effects on Radial Growth in an Old-Growth Hemlock Forest

Research Highlights: We applied neighborhood and dendro-ecological methods in a stand with a 33-year record of forest dynamics, finding that growth will decrease for several species under predicted climate trends. Background and Objectives: Conventional tree-ring analysis removes the influence of competition and size on growth, precluding assessment of the relative influence of these factors. An old-growth eastern hemlock forest in east–central New York was mapped in 1978 and was measured at eight-year intervals since then. Our objective was to use these data to examine the influence of climate, neighborhood, and tree size on radial growth. Materials and Methods: We evaluated an array of climatic indices to find which ones had the strongest influence on radial growth from increment cores of eastern hemlock (Tsuga canadensis L.), yellow birch (Betula alleghaniensis Britton), and sugar maple (Acer saccharum Marsh.). We used the strongest climatic indices in combination with neighborhood and target-tree size information to create growth models for the three tree species. Results: Size accounted for 2% to 21% of observed growth; the shade-tolerant sugar maple and eastern hemlock grew fastest when large, but the mid-tolerant yellow birch grew fastest when small. Competition accounted for 9% to 21% of growth; conifers had a weaker competitive effect than deciduous trees, and eastern hemlock was less sensitive to competition than sugar maple and yellow birch. Climate accounted for only 2% of growth variation; eastern hemlock showed a positive response to warming climate trends, but yellow birch and sugar maple showed negative responses. Conclusions: Predicted climate trends are likely to result in decreased growth of sugar maple and yellow birch, and the sensitivity of these species to competition suggests the effect will be exacerbated when they grow in crowded conditions.

710: Trends of change over time in the specific contribution of different risk factors for PPH

Post- partum hemorrhage (PPH) is an obstetrical emergency with rising incidence. The prevalence of some of the risk factors for PPH has changed over the years, however, less is known about the specific contribution of each risk factor throughout the years. The aim of the current study was to identify trends in the specific contribution of different risk factors for PPH, by observing their odds ratios (OR) throughout different time periods. In this population-based retrospective cohort study trends of changes in odds ratios (ORs) of different known risk factors for PPH occurring in three consecutive eight-year intervals from 1988 to 2014 (T1 – 1988-1996; T2 – 1997-2005; T3 – 2006-2014) were compared. Data was retrieved from the medical center's computerized perinatal database. Several multivariable logistic regression models were used in order to identify independent risk factors for PPH in our population. Chi square test for trends was used to compare the trends of the different ORs along the time periods. During the study period 285,992 pregnancies met the inclusion criteria of them 1684 (0.58%) were complicated with PPH. Between 1988 to 2014 the incidence of PPH has gradually increased from 0.5% in 1988 to 0.6% in 2014. Using a logistic regression model for the prediction of PPH, pre-eclampsia, vacuum extraction delivery, manualysis, perineal tear and large for gestational age (LGA) neonate were recognized as independent risk factors for PPH (Table 1). While the ORs of pre-eclampsia and vacuum extraction delivery, as risk factors, have not changed significantly throughout the follow up period, ORs of manualysis, perineal tear and LGA neonate have significantly increased (Table 2). In our study, not only did the rates of different statistically significant risk factors for PPH change during the study period, the specific contribution of each risk factor for the occurrence of PPH has changed as well. Having a better understanding of these trends might be beneficial to our ability to predict this grave obstetrical complication and to improve maternal outcome.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Prospects for a revival in U. S. productivity growth

Abstract The growth rate of total-economy U.S. labor productivity during the eight-year period between 2010:Q3 and 2018:Q3 was only 0.53 percent, lower by a large margin than any other eight-year interval in U.S. postwar quarterly data. This paper divides the question of a possible revival in productivity growth into two questions. The first is the possibility of a procyclical response in the gap between actual and trend productivity growth, and the second is a revival in the productivity growth trend itself. An econometric study of the procyclical gap elasticity takes account of a smaller response in the data since the mid-1980s. Because there is no post-1985 procyclicality in the productivity gap, in simulations of our equation estimated through 2015 we find that projections of the coefficients accurately track the failure of productivity growth to exhibit any revival during the three quarters of 2018 during which output growth has accelerated. Lacking a procyclical revival of the productivity gap, the chance of a revival rests with the productivity growth trend itself. An equation that estimates the responsiveness of that trend to labor market tightness and to capital deepening yields our second conclusion that, based on forecasts of the future trajectory of the unemployment rate and the capital-labor ratio, a revival in trend productivity growth of 0.2 percentage points may occur during 2019-21.

Forty-year review of developments in underwater acoustic modeling

This is the sixth paper in a series of reviews presented at eight-year intervals starting in 1979 [J. Acoust. Soc. Am. 65, S42 (1979); 82, S102 (1987); 97, 3312 (1995); 114, 2430 (2003); 129, 2631 (2011)]. All surveys covered basic acoustic models and sonar performance models. Basic acoustic models included 143 propagation, 29 noise, and 32 reverberation models. Propagation models were categorized according to ray theory, multipath expansion, normal mode, fast field, and parabolic approximation formulations; further distinctions were made between range-independent and range-dependent solutions. Noise models included ambient noise and beam-noise statistics models. Reverberation models included cell and point-scattering formulations. The 44 sonar performance models included active sonar models, model operating systems, and tactical decision aids. Active sonar models integrated basic acoustic models, signal-processing models, and supporting databases into cohesive operating systems organized to solve the sonar equations. Model operating systems provided a framework for the direct linkage of data-management software with computer-implemented codes of acoustic models. Tactical decision aids represented a form of engagement-level simulation that blended environmental and sonar performance information with tactical rules. The overall inventory increased by 5 models per year; historical references are maintained in the fifth edition of Underwater Acoustic Modeling and Simulation.

Is utilitarian sacrifice becoming more morally permissible?

A central tenet of contemporary moral psychology is that people typically reject active forms of utilitarian sacrifice. Yet, evidence for secularization and declining empathic concern in recent decades suggests the possibility of systematic change in this attitude. In the present study, we employ hypothetical dilemmas to investigate whether judgments of utilitarian sacrifice are becoming more permissive over time. In a cross-sectional design, age negatively predicted utilitarian moral judgment (Study 1). To examine whether this pattern reflected processes of maturation, we asked a panel to re-evaluate several moral dilemmas after an eight-year interval but observed no overall change (Study 2). In contrast, a more recent age-matched sample revealed greater endorsement of utilitarian sacrifice in a time-lag design (Study 3). Taken together, these results suggest that today’s younger cohorts increasingly endorse a utilitarian resolution of sacrificial moral dilemmas.

Seasonal variations of mesopause temperature and the amplitude of the VLF signals of the Novosibirsk radio station during 2009-2016

Dynamics of seasonal variations of the amplitude of the VLF radio signal received in Yakutsk from the navigation station near Novosibirsk and the P-branches of the OH band (6-2) radiation intensity in the wavelength range 835 - 853 nm are considered. The radiation variations give information about mesopause region measured at the Maimaga station (130 km from Yakutsk). The observation from 2009 to 2016 covers period with minimum and maximum solar activity. The mesopause temperature and the VLF signal increase with increasing solar flux F10.7 in winter. The mesopause temperature seasonal variations and the VLF signal strength for the Novosibirsk-Yakutsk path are regularly inverted from year to year. By decade data averaging the VLF radio signal strength dependence on the temperature of the atmosphere at the OH excitation height can be expressed by a linear function. The coefficient of determination: R 2 = 0.59, the anticorrelation coefficient: r 10 = - 0.77. The variations of the VLF radio noise and the radio station signal for the eight-year interval are similar to solar activity (F10.7 index). The signal level of the radio station and radio noise registered in the winter is more sensitive to variations of F10.7 index in 24th solar cycle activity.

Comments on Manning, Zhang, and Yi’s "Volume and Direction of the Atlantic Slave Trade, 1650-1870”

Patrick Manning, Yun Zhang and Bowen Yi’s essay is, to our knowledge, the first since Slavevoyages went live in late 2008 to address the question of the size and direction of the largest coerced migration in global history. Given that the Markov Chain Monte Carlo (MCMC) methodology that they employ has moved to center stage of statistical inquiry in this eight-year interval, their work is indeed timely. Our commentary has three parts. First we point out several problems in their use of data from the Trans-Atlantic Slave Trade Database (hereafter TASTDB) on which their estimates are based; second we call attention to our own estimates of the volume of the slave trade which are higher than those mentioned in the essay; and third we argue that, as currently constituted, their work is broadly supportive of the statistical picture that we drew in 2008 ­ albeit without the benefit of MCMC.

Linking Environmental Assessment and Management of Highway Construction in Southeastern Brazil

Effective delivery of mitigation remains a challenge in environmental impact assessment (EIA) practice. Actual environmental protection outcomes depend as much on an appropriate ex-ante assessment as on the capacity of project proponents of implementing preventative, corrective and compensatory programs, using environmental management tools to ensure demonstrable performance. The context question explored here is: How can the EIA follow-up phase take advantage of the features and resources of environmental management systems (EMS)? Evidence was obtained by studying two cases of highway construction affecting valued environments. The projects, intentionally selected, were built in the same area with an eight-year interval between them. Follow-up resulted in the identification of significant unforeseen geo-environmental impacts leading to the adoption of corrective action not required in the terms and conditions of approval. It was found that lessons learned by different actors involved in the first project led to stronger environmental management procedures incorporated in the latter.

Increased dental visits in patients prior to diagnosis of primary Sjögren’s syndrome: a population-based study in Taiwan

The objective of this study was to investigate the utilization of ambulatory dental services in patients with primary Sjögren's syndrome (pSS) prior to their diagnosis using a population-based health claim database in Taiwan. From the Registry of Catastrophic Illness database in the National Health Insurance Research Database in Taiwan, we identified 389 patients who were diagnosed with pSS from 2005 to 2010. We also obtained 1,945 control subjects frequency-matched on sex, 10-year age interval, and enrollment date from the Longitudinal Health Insurance Database. Both groups were retrospectively traced to 1997 to obtain any records of utilization of dental care services that occurred preceding the index date. Patients with pSS had significantly higher utilization of annual ambulatory dental services over an eight-year interval preceding diagnosis. A significantly higher proportion of patients with pSS (95.1 %) had utilized ambulatory dental services over the whole eight-year interval preceding diagnosis compared with the controls (88.8 %) (p < 0.001). Utilization of ambulatory dental services for dental caries, pulpitis, gingivitis, stomatitis, and periodontitis were significantly greater in patients with pSS over a three-year period prior to diagnosis compared with the controls. In conclusion, the utilization of ambulatory dental services was significantly increased in patients with pSS preceding its diagnosis. Health professionals can play an important role in the early recognition of pSS by including it in the differential diagnosis for xerostomia-related complaints.

Rangelands in Zimbabwe’s initial resettlement schemes: Spatial and temporal change analyses

Change in size and extent of cultivation and vegetation cover was analysed in three villages of an initial resettlement scheme in Zimbabwe using change detection depicted on serial aerial photographs taken at eight-year intervals from inception in 1981 to 1997. A geographic information system was used as an analytical tool. Interpretations were done using aerial photographs and 1995 Spot Images. The spot images were geo-referenced to Universal Transverse Mercator (UTM) coordinate system to ensure continuity of features. All images were enhanced using TNTmips to come up with clearer images. Aerial photographs for the three selected villages were scanned and geo-referenced and then exported to ARC VIEW 3.2 for on-screen digitising of land parcels as cultivated and vegetation theme layers. Overlay and spatial analysis were also done in ARC VIEW 3.2 for change detection. Results showed an average increase in size of cultivated areas by 281% between 1981 and 1997 and a increase of 52% between 1989 and 1997 in the three villages. Rangelands declined by a mean 42% during 1981 and 1997. There was a shift in land-use in 1987/8, which exaggerated cultivated areas due to fuzzy classification of land reverting to grazing areas by 1989. This shift in cultivation sites was adequately captured on overlaid aerial photographs for each of the three villages. It was concluded that spatial and temporal changes occurred in resettlement schemes rangelands and were due to the actions of resettled farmers. Keywords: Resettlement schemes, change detection, spatial analysis.

Pleural dissemination of esophageal gastrointestinal stromal tumors after an eight-year interval following the primary surgery

A 71-year-old man who had undergone surgical resection of esophageal gastrointestinal stromal tumors (GISTs) through a right posterolateral thoracotomy 8 years earlier was referred for treatment of an anterior mediastinal mass discovered on a follow-up chest radiograph in October 2007. Computed tomography findings revealed a tumor, 82 x 49 mm, with calcification, in the anterior mediastinum. When we radically resected the tumor via a median sternectomy, we found that it was actually located in the pleural cavity, and there was a small nodule near the main tumor on other pleura. Microscopically, the tumor was comprised of uniform spindle cells with fibrillary eosinophilic cytoplasm. In addition, immunostaining showed that the tumor was positive for CD117 (c-kit). The diagnosis was pleural dissemination of esophageal GISTs 8 years after primary surgery, making this the first report of pleural dissemination of esophageal GISTs after such a prolonged postsurgical interval.