Boundary Characterization Experiment Series Overview

Ocean acoustic propagation and reverberation in continental shelf regions is often controlled by the seabed and sea surface boundaries. A series of three multi-national and multi-disciplinary experiments was conducted between 2000-2002 to identify and measure key ocean boundary characteristics. The frequency range of interest was nominally 500-5000 Hz with the main focus on the seabed, which is generally considered as the boundary of greatest importance and least understood. Two of the experiments were conducted in the Mediterranean in the Strait of Sicily and one experiment in the North Atlantic with sites on the outer New Jersey Shelf (STRATAFORM area) and on the Scotian Shelf. Measurements included seabed reflection, seabed, surface, and biologic scattering, propagation, reverberation, and ambient noise along with supporting oceanographic, geologic, and geophysical data. This paper is primarily intended to provide an overview of the experiments and the strategies that linked the various measurements together, with detailed experiment results contained in various papers in this volume and other sources

不同治理度下小流域正态整体模型试验——林草措施对小流域径流泥沙的影响

首次运用正态整体模型模拟试验方法研究不同林草植被覆盖度下小流域径流泥沙变化规律,结果表明 :小流域林草植被具有良好的减水减沙效益 ,初步得出小流域治理水土保持林草措施最低下限值为60 % ,取得最佳水保效益的林草覆盖度值为78% ,流域径渗比临界值为林草覆盖度65%。

黄土丘陵区小流域系统生态经济要素分析——以宁夏隆德县李太平小流域为例

以隆德县李太平小流域为例,对比分析了退化小流域系统恢复重建过程中系统的生态经济要素变化,揭示系统演变趋势。应用能值方法分析了投入产出的动态变化,评价治理的生态经济效果。结果显示:农、林、牧业用地比例由1990年的6·2∶2·0∶1·0变为2003年的1·9∶1·4∶1·0,土地利用及种植结构趋于合理,农业产值所占比重由79·6%下降为54·8%,林业、牧业、副业产值比例分别由9·6%、9·6%、1·1%上升为22·7%、15·1%、7·4%,收入多样性指数也呈增加趋势,显示了流域收入构成的多元化,有利于生态经济系统的稳定。同时,恩格尔系数减小,表明人民生活水平日益提高。基于能值的流域生态经济系统投入产出效率动态研究结果表明在调整后的土地利用格局及种植结构下,净能值产出率由1990年的2·5增长到2003年的3·41,资源利用效率逐年提高,环境负荷率在1990、1995和2003年分别为2·55、2·44和2·11,呈减小趋势,能值持续性指数从1990年的0·98增加到2003年的1·62,经济与生态环境的协调性不断提高。研究结果表明该治理模式是成功的。

Impacts of land use change and climate variations on annual inflow into Miyun Reservoir,Beijing, China

The Miyun Reservoir, the only surface water source for Beijing city, has experienced water supply decline in recent decades. Previous studies suggest that both land use change and climate contribute to the changes of water supply in this critical watershed. However, the specific causes of the decline in the Miyun Reservoir are debatable under a non-stationary climate in the past 4 decades. The central objective of this study was to quantify the separate and collective contributions of land use change and climate variability to the decreasing inflow into the Miyun Reservoir during 1961–2008. Different from previous studies on this watershed, we used a comprehensive approach to quantify the timing of changes in hydrology and associated environmental variables using the long-term historical hydrometeorology and remote-sensing-based land use records. To effectively quantify the different impacts of the climate variation and land use change on streamflow during different sub-periods, an annual water balance model (AWB), the climate elasticity model (CEM), and a rainfall–runoff model (RRM) were employed to conduct attribution analysis synthetically. We found a significant (p  <  0.01) decrease in annual streamflow, a significant positive trend in annual potential evapotranspiration (p  <  0.01), and an insignificant (p  >  0.1) negative trend in annual precipitation during 1961–2008. We identified two streamflow breakpoints, 1983 and 1999, by the sequential Mann–Kendall test and double-mass curve. Climate variability alone did not explain the decrease in inflow to the Miyun Reservoir. Reduction of water yield was closely related to increase in actual evapotranspiration due to the expansion of forestland and reduction in cropland and grassland, and was likely exacerbated by increased water consumption for domestic and industrial uses in the basin. The contribution to the observed streamflow decline from land use change fell from 64–92 % during 1984–1999 to 36–58 % during 2000–2008, whereas the contribution from climate variation climbed from 8–36 % during the 1984–1999 to 42–64 % during 2000–2008. Model uncertainty analysis further demonstrated that climate warming played a dominant role in streamflow reduction in the most recent decade (i.e., 2000s). We conclude that future climate change and variability will further challenge the water supply capacity of the Miyun Reservoir to meet water demand. A comprehensive watershed management strategy needs to consider the climate variations besides vegetation management in the study basin.

Selection of Postacute Stroke Rehabilitation Facilities: A Survey of Discharge Planners From the Northeast Cerebrovascular Consortium (NECC) Region.

The process of determining the level of care and specific postacute care facility for stroke patients has not been adequately studied. The objective of this study was to better understand the factors that influence postacute care decisions by surveying stroke discharge planners. Requests were sent to discharge planners at 471 hospitals in the Northeast United States to complete an online survey regarding the factors impacting the selection of postacute care. Seventy-seven (16%) discharge planners completed the online survey. Respondents were mainly nurses and social workers and 73% reported ≥20 years healthcare experience. Patients and families were found to be significantly more influential than physicians (P < 0.001) and other clinicians (P = 0.04) in influencing postdischarge care. Other clinicians were significantly more influential than physicians (P < 0.001). Insurance and quality of postacute care were the factors likely to most affect the selection of postacute care facility. Insurance was also identified as the greatest barrier in the selection of level of postacute care (70%; P < 0.001) and specific postacute care facility (46%; P = 0.02). More than half reported that pressure to discharge patients quickly impacts a patients' final destination. Nonclinical factors are perceived by discharge planners to have a major influence on postacute stroke care decision making.

Xanthoria parietina as a biomonitor of airborne heavy metal pollution in forest sites in the North East of Morocco

Xanthoria parietina, common foliose lichen, growing in its natural habitat, was analysed for the concentration of five heavy metals (Fe, Cr, Zn, Pb and Cu) from different forest sites of North East of Morocco (Kenitra, Sidi Boughaba, Mkhinza, Ceinture Verte near Temara city, Skhirate, Bouznika and Mohammedia). The quantification was carried out by inductively coupled plasma - atomic emission spectrometry (ICP-AES). Results were highly significant p<0,001. The concentration of metals is correlated with the vehicular activity and urbanization. The total metal concentration is highest at the Kenitra area, followed by Ceinture Verte site near Temara city, which experience heavy traffic throughout the year. Scanning electron microscopy (SEM) of particulate matter on lichen of Xanthoria parietina was assessed as a complementary technique to wet chemical analysis for source apportionment of airborne contaminant. Analysis revealed high level of Cu, Cr, Zn and Pb in samples near roads.  

Welfare Effort and Poverty from the Monetary and Capabilities Approach: A Cross-Country Analysis in Latin American and the Caribbean (1990-2010)

There is abundant empirical evidence on the negative relationship between welfare effort and poverty. However, poverty indicators traditionally used have been representative of the monetary approach, excluding its multidimensional reality from the analysis. Using three regression techniques for the period 1990-2010 and controlling for demographic and cyclical factors, this paper examines the relationship between social spending per capita —as the indicator of welfare effort— and poverty in up to 21 countries of the region. The proportion of the population with an income below its national basic basket of goods and services (PM1) and the proportion of population with an income below 50% of the median income per capita (PM2) were the two poverty indicators considered from the monetarist approach to measure poverty. From the capability approach the proportion of the population with food inadequacy (PC1) and the proportion of the population without access to improved water sources or sanitation facilities (PC2) were used. The fi ndings confi rm that social spending is actually useful to explain changes in poverty (PM1, PC1 and PC2), as there is a high negative and signifi cant correlation between the variables before and after controlling for demographic and cyclical factors. In two regression techniques, social spending per capita did not show a negative relationship with the PM2. Countries with greater welfare effort for the period 1990-2010 were not necessarily those with the lowest level of poverty. Ultimately social spending per capita was more useful to explain changes in poverty from the capability approach.

Impact of the intrinsic motivation on the academic performance through voluntary assignments: An empirical analysis

The students academic performance is a key aspect for all agents involved in a higher education quality program. However, there is no unanimity on how to measure it. Some professionals choose assessing only cognitive aspects while others lean towards assessing the acquisition of certain skills. The need to train increasingly adapted professionals in order to respond to the companies’ demands and being able to compete internationally in a global labour market requires a kind of training that goes beyond memorizing. Critical and logical thinking are amongst written language skills demanded in the field of Social Sciences. The objective of this study is to empirically demonstrate the impact of voluntary assignments on the academic performance of students. Our hypothesis is that students who complete high quality voluntary assignments are those more motivated and, therefore, those with higher grades. An experiment with students from the "Financial Accounting II" during the academic year of 2012/13 at the Business and Economics School of the UCM was carried out. A series of voluntary assessments involving the preparation of accounting essays were proposed in order to develop skills and competencies as a complement to the lessons included in the curriculum of the subject. At the end of the course, the carrying-out or not of the essay together with its critical, reflective quality and style, were compared. Our findings show a relationship between the voluntarily presented papers of quality and the final grade obtained throughout the course. These results show that the students intrinsic motivation is a key element in their academic performance. On the other hand, the teachers role focuses on being a motivating element through the learning process.

Adaptation of a questionnaire to assess the epistemological beliefs of mathematics in secondary school teachers

The objective of the study is to determine the psychometric properties of the Epistemological Beliefs Questionnaire on Mathematics. 171 Secondary School Mathematics Teachers of the Central Region of Cuba participated. The results show acceptable internal consistency. The factorial structure of the scale revealed three major factors, consistent with the Model of the Three Constructs: beliefs about knowledge, about learning and teaching. Irregular levels in the development of the epistemological belief system about mathematics of these teachers were shown, with a tendency among naivety and sophistication poles. In conclusion, the questionnaire is useful for evaluating teacher’s beliefs about mathematics.

Analysis of the reading and comprehension control in scientific texts in high school students

Students' learning process can be negatively affected when their reading and comprehension control is not appropriated. This research focuses on the analysis of how a group of students from high school evaluate their reading comprehension in manipulated scientific texts. An analysis tool was designed to determine the students' degree of comprehension control when reading a scientific short text with an added contradiction. The results have revealed that the students from 1st and 3rd ESO do not properly self-evaluated their reading comprehension. A different behavior has been observed in 1st Bachillerato, where appropriate evaluation and regulation seem to be more frequent. Moreover, no significant differences have been found regarding the type of text, year or gender. Finally, as identified by previous research, the correlations between the students' comprehension control and their school marks have shown to have a weak relationship and inversely proportional to the students' age.

Quaternary pollen analysis: recent progress in palaeoecology and palaeoclimatology

During the last decade Quaternary pollen analysis has developed towards improved pollen-taxonomical precision, automated pollen identification and more rigorous definition of pollen assemblage zones. There have been significant efforts to model the spatial representation of pollen records in lake sediments which is important for more precise interpretation of the pollen records in terms of past vegetation patterns. We review the difficulties in matching modelled post-glacial plant migration patterns with pollen-based palaeorecords and discuss the potential of DNA analysis of pollen to investigate the ancestry and past migration pathways of the plants. In population ecology there has been an acceleration of the widely advocated conceptual advance of pollen-analytical research from vaguely defined ‘environmental reconstructions’ towards investigating more precisely defined ecological problems aligned with the current ecological theories. Examples of such research have included an increasing number of investigations about the ecological impacts of past disturbances, often integrating pollen records with other palaeoecological data. Such an approach has also been applied to incorporate a time perspective to the questions of ecosystem restoration, nature conservation and forest management. New lines of research are the use of pollen analysis to study long-term patterns of vegetation diversity, such as the role of glacial-age vegetation fragmentation as a cause of Amazonian rain forest diversity, and to investigate links between pollen richness and past plant diversity. Palaeoclimatological use of pollen records has become more quantitative and has included more precise and rigorous testing of pollen-climate calibration models with modern climate data. These tests show the approximate nature of the models and warn against a too straightforward climatic interpretation of the small-scale variation in reconstructions. Pollenbased climate reconstructions over the Late Glacial–early Holocene boundary have indicated that pollen-stratigraphical changes have been rapid with no evidence for response lags. This does not rule out the possibility of migrational disequilibrium, however, as the rapid changes may be mostly due to nonmigrational responses of existing vegetation. It is therefore difficult to assess whether the amplitude of reconstructed climate change reflects real climate change. Other outstanding problems remain the obscure relationship of pollen production and climate, the role of human impact and other nonclimatic factors, and nonanalogue situations.

Inscribir el declive en el tiempo. Detroit: Auge y crisis de la ciudad industrial

A comienzos del siglo XX, Detroit era una ciudad dinámica en pleno desarrollo. Pronto se convirtió en la cuarta ciudad de Estados Unidos, la capital de la naciente industria automovilística. El crecimiento se prolongó hasta finales de los años 50, cuando, a pesar del auge económico de Estados Unidos y de su área metropolitana, Detroit comenzó a mostrar los primeros signos de estancamiento. La crisis se ha prolongado hasta hoy, cuando Detroit constituye el paradigma de la ciudad industrial en declive. Estas dos imágenes contrapuestas, el auge y la crisis, no parecen explicar por sí mismas las causas de la intensidad y persistencia del declive de Detroit. Analizar las interacciones entre crecimiento económico, políticas públicas locales y desarrollo urbano a lo largo del tiempo permitirá subrayar las continuidades y comprender en qué medida el declive de Detroit ancla sus raíces en el modelo planteado durante la etapa de auge.

Biological influence on the morphology and micromorphology of selected Podzols (Spodosols) and Cambisols (Inceptisols) from the Eastern United States and Northeast Scotland

Biological activities greatly influence the formation of many soils, especially forest soils under cool humid climates. The objective of this study was to investigate the effects of vegetation and soil biota on the formation of selected soils. Field morphology, micromorphology, and carbon and organic matter analysis were determined on six Podzols (Spodosols) and two Cambisols (Inceptisols) from the eastern United States and north-east Scotland. Humification of plant material by soil fauna and fungi occurs in all organic horizons. Thick organic coatings are observed on soil peds and rock fragments from the E1 to the Bs horizon in a Haplic Podzol from Clingmans Dome Mt., TN. Thin sections reveal large accumulations of root material in different stages of decomposition in the spodic horizons of a Haplic Podzol from Whiteface Mt., NY. Organic carbon ranges from 5.4 to 8.5% in the spodic B horizons of the Whiteface Mt. Podzol. Earthworms and enchytraeids have a great effect on the structure of the surface and subsurface horizons in the Dystric Cambisols from Huntly and Clashindarroch Forests, Scotland and a Cambic Podzol from the Corrie Burn Basin, Scotland. Podzols from Speymouth Forest, Scotland (Gleyic Podzol), Cling-mans Dome Mt., and Whiteface Mt. have thick organic horizons. The Podzols from the Flatwoods in Georgia, the Pine Barrens in New Jersey, the Corrie Burn Basin, and the Cambisol from Huntly Forest have only A horizons at the surface. The Clashindarroch Forest soil has a very thin organic horizon. Warm and humid climates and sandy parent material are responsible for thick E horizons and lack of thick organic horizons in the Flatwoods (Carbic Podzol) and Pine Barrens (Ferric Podzol) soils. Earthworms and enchytraeids thrive in the Corrie Burn Basin and Huntly Forest soils due to the vegetation and the highly weathered basic parent material. The site at Clashindarroch once carried oak, and then birch forest, both of which produce a mild litter and also encourage earthworm and enchytraeids. This fauna is responsible for much mixing of the topsoil. The present conifer vegetation will eventually produce a deep litter and cause podzolization.

El significado de la prosopopeya de las Leyes en el "Critón" de Platon

El objeto de este trabajo es realizar un estudio iusfilosófico sobre la aparición de las Leyes (nómoi) personificadas de Atenas en el Critón de Platón. La prosopopeya de las Leyes resulta ser un aspecto central para poder comprender la obra, ya que éstas entablan un diálogo imaginario con Sócrates en el cual instalan diversos argumentos filosóficos para fundamentar la autoridad de la pólis. A los fines de identificar el valor argumentativo de este recurso en la obra, analizaré el significado del nómos en la Atenas del siglo V a. C. y la naturaleza de las Leyes en el contexto general del diálogo. Se busca demostrar la importancia que tienen aquéllas para explicar la decisión de Sócrates de beber la cicuta.

Sufrimiento y pesimismo en Schopenhauer

El presente artículo investiga de qué forma la centralidad del sufrimiento en la filosofía de Schopenhauer sirve para fundamentar su pesimismo. Tres son los argumentos analizados: el lugar del sufrimiento en el mundo, su lugar en la conciencia humana y su lugar frente a la felicidad. A la luz de estos tres argumentos, se destaca que el vínculo indisoluble entre el sufrimiento y la esencia del mundo, la determinación del sufrimiento en la conciencia, tanto en su génesis como en su intensidad, y su anterioridad ontológica frente a la felicidad hacen del pesimismo una categoría necesaria. Finalmente, se señala una posible contribución del pesimismo schopenhaueriano a la crítica social contemporánea, considerando la idea de mundo que el capitalismo tardío promueve.