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Last Century (last + century)
Selected AbstractsTHE FLUCTUATIONS OF ITALIAN GLACIERS DURING THE LAST CENTURY: A CONTRIBUTION TO KNOWLEDGE ABOUT ALPINE GLACIER CHANGESGEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 3 2007MICHELE CITTERIO ABSTRACT. This paper describes the recent evolution of Italian glaciers through an analysis of all available terminus fluctuation data that the authors have entered in a glaciers database (named GLAD) containing 883 records collected on glaciers from 1908 to 2002. Furthermore, a representative subset of data (249 glaciers located in Lombardy) was analysed regarding surface area changes. For the analysis of terminus fluctuations, the glaciers were sorted by size classes according to length. The data showed that during the 20th century Italian Alpine glaciers underwent a generalized retreat, with one distinct and well documented readvance episode that occurred between the 1970s and mid-1980s, and a poorly documented one around the early 1920s. The rates of terminus advance and retreat have changed without significant delays for the larger glaciers with respect to the smaller ones. However, the smaller the glacier, the more limited the advance (if any) during the 1970s and early 1980s. The behaviour of glaciers shorter than 1 km appears to have changed in the last decade, and between 1993 and 2002 they retreated at a very high rate. The analysis of the subset of data led to a quanti-fication of surface reduction of c. 10% from 1992 to 1999 for glaciers in Lombardy. Small glaciers proved to contribute strongly to total area loss: in 1999, 232 glaciers (c. 90% of the total) were smaller than 1 km2, covering 27.2 km2 (less than 30% of the total area), but accounted for 58% of the total loss in area (they had lost 7.4 km2). [source] How Views about Flow Adaptations of Benthic Stream Invertebrates Changed over the Last CenturyINTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 4-5 2008Bernhard StatznerArticle first published online: 15 OCT 200 Abstract Throughout the last century, stream ecologists tried to answer the question: how do benthic invertebrates cope with the flows prevailing in streams? Whereas the pioneers frequently sought answers using imagination and speculation in a hefty debate, subsequent research on flow adaptations of stream invertebrates relied increasingly on the transfer of concepts (from fluid mechanics to stream ecology) and technological innovations. Correspondingly, views about flow adaptations of stream invertebrates changed considerably over the last century. However, stream ecologists are still far from understanding how stream invertebrates are adapted to the many different flow conditions they face during their life, because the near-bottom flows they experience are extremely complex and create so diverse constraints that adaptation to all of them is physically impossible. This instance shows how ignorant we are of the physical factors in the environment which ultimately shape the organisms, and how difficult it is to understand the utility of a structure without knowing the requirements for which it is produced Sunder Lal Hora, 1930 (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Downstream from calcium signalling: mitochondria, vacuoles and pancreatic acinar cell damageACTA PHYSIOLOGICA, Issue 1 2009S. Voronina Abstract Ca2+ is one of the most ancient and ubiquitous second messengers. Highly polarized pancreatic acinar cells serve as an important cellular model for studies of Ca2+ signalling and homeostasis. Downstream effects of Ca2+ signalling have been and continue to be an important research avenue. The primary functions regulated by Ca2+ in pancreatic acinar cells , exocytotic secretion and fluid secretion , have been defined and extensively characterized in the second part of the last century. The role of cytosolic Ca2+ in cellular pathology and the related question of the interplay between Ca2+ signalling and bioenergetics are important current research lines in our and other laboratories. Recent findings in these interwoven research areas are discussed in the current review. [source] A History of Dermatologic Surgery in the United StatesDERMATOLOGIC SURGERY, Issue 1 2000William P. Coleman III MD Background. Dermatologic surgery has a long and distinguished history in the United States. Objective. To examine the specific contributions of American dermatologic surgeons. Method. The medical literature on cutaneous reconstructive and cosmetic surgery for the last century and a half was researched. Results. Numerous American dermatologic surgeons have had a major impact on scientific and technological discoveries in cutaneous surgery. Dermatologic surgeons have been significantly involved in cutaneous surgery since the second half of the 19th century. Dermatologic surgeons have contributed many important advances to the fields of chemical peeling, cryosurgery, dermabrasion, electrosurgery, hair transplantation, soft tissue augmentation, tumescent liposuction, laser surgery, phlebology, Mohs chemosurgery, cutaneous reconstruction, wound healing, botulium toxin, blepharoplasty, and rhytidectomy. Conclusion. Dermatologic surgeons in the United States have contributed significantly to the history of reconstructive and cosmetic surgery. Dermatologic surgeons have been leaders in advancing this field and are poised to continue in the future. [source] The dynamics of development and evolution: Insights from behavioral embryologyDEVELOPMENTAL PSYCHOBIOLOGY, Issue 8 2007Robert Lickliter Abstract The perspective that features of species-typical behavior could be traced to experience that occurred prenatally was raised by Zing-Yang Kuo [1921 Journal of Philosophy 18: 645,664] early in the last century and Gilbert Gottlieb subsequently elaborated on and provided empirical support for this idea over the course of more than four decades of innovative psychobiological research. Although we are still a long way from fully understanding the specific pathways and processes by which prenatal experience can influence postnatal development, Gottlieb's research with precocial birds provided significant insights into the conditions and experiences of prenatal development involved in the achievement of species-typical perception and behavior. In particular, his elegant series of studies on the development of species identification in ducklings documented how the features and patterns of recurring prenatal sensory experience (including self-stimulation) guide and constrain the young individual's selective attention, perception, learning, and memory during both prenatal and postnatal periods. I review how this body of research supports the view that the structure and functions of the developing organism and its developmental ecology together form a relationship of mutual influence on the emergence, maintenance, and transformation of species-typical behavior. I also explore how Gottlieb's empirical demonstrations of the prenatal roots of so-called "instinctive" behavior provided a foundation for his conceptual efforts to define the links between developmental and evolutionary change. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 749,757, 2007. [source] Cardiovascular metabolic syndrome , an interplay of, obesity, inflammation, diabetes and coronary heart diseaseDIABETES OBESITY & METABOLISM, Issue 3 2007J. S. Rana Cardiovascular disease is currently one of the biggest causes of morbidity and mortality facing humanity. Such a paradigm shift of disease pattern over the last century has only worsened due to the alarming global prevalence of obesity and type 2 diabetes. In recent years there is increasing focus on inflammation as one of the key players in the patho-physiology of these disorders. In addition to these overt risk factors new research is unraveling the significance of a constellation of early metabolic abnormalities that include weight gain, insulin resistance, prehypertension and a specific pattern of dyslipidaemia. There exists a complex interrelationship of these various metabolic disorders and their effect on cardiovascular system. Simplified explanation can be that inflammation increases insulin resistance, which in turn leads to obesity while perpetuating diabetes, high blood pressure, prothrombotic state and dyslipidaemia. While inflammation and insulin resistance have direct adverse effects on cardiac muscle, these metabolic abnormalities as a whole cause causes cardiovascular complications; warranting a multi pronged therapeutic and preventive approach for the ,Cardiovascular Metabolic Syndrome' as an entity. [source] New Humanitarianism: Does It Provide a Moral Banner for the 21st Century?DISASTERS, Issue 4 2001Fiona Fox There is a ,new humanitarianism' for the new millennium. It is ,principled', ,human-rights based' and politically sensitive. Above all it is new. It marks a break from the past and a rejection of the traditional principles that guided humanitarianism through the last century. New humanitarians reject the political naivety of the past, assess the long-term political impact of relief and are prepared to see humanitarian aid used as a tool to achieve human rights and political goals. New Humanitarianism is compelling, in tune with our times and offers a new moral banner for humanitarians to cling to as we enter the new millennium. Or does it? After outlining the key elements of new humanitarianism, including the human rights approach and developmental relief, the paper spells out some of the dangers. The author claims that new humanitarianism results in an overt politicisation of aid in which agencies themselves use relief as a tool to achieve wider political goals. The paper shows how this approach has spawned a new conditionality which allows for aid to be withheld and has produced a moral hierarchy of victims in which some are more deserving than others. The paper concludes with a plea for a revival of the principle of universalism as the first step to a new set of principles. [source] Burying beetle Nicrophorus investigator reproduction on Pacific salmon carcassesECOLOGICAL ENTOMOLOGY, Issue 1 2006M. D. Hocking Abstract., 1.,In many undisturbed watersheds along the Pacific Rim, anadromous salmon (Oncorhynchus spp.) provide a predictable source of carrion to the riparian zone, largely due to horizontal transfer of salmon carcasses by bears (Ursus spp.) and other vertebrates. 2.,Burying beetles are important members of the north-temperate carrion fauna, and may utilise salmon carcasses and remnants for breeding. In this study, isotopic and observational data are reported that demonstrate previously unrecognised Nicrophorus investigator (Zetterstedt) reproduction on large salmon carcasses from five watersheds in coastal British Columbia. 3.,Stable isotope signatures (,15N and ,13C) of adult beetles collected in autumn indicate a diet of salmon origin in all but one individual from all watersheds, suggesting that this beetle,salmon association is widespread. Comparison of autumn isotope signatures to individuals collected randomly in summer suggests that isotope signatures represent the larval carrion source from the previous autumn rather than immediate adult diet. 4.,In a survey of N. investigator use of salmon carcasses from two watersheds, 35 broods were observed on chum and pink salmon carcasses, including 16 natural brood complexes containing over 100 larvae, and five ranging from 250 to 750 larvae. 5.,Overall, north-coastal populations of N. investigator breed on the rich and reliable salmon resource and may exhibit a system of communal breeding on these carcasses. This is most relevant when the dramatic reduction in salmon spawning biomass over the last century is considered. [source] China and the world financial markets 1870,1939: Modern lessons from historical globalization1ECONOMIC HISTORY REVIEW, Issue 2 2007WILLIAM N. GOETZMANN In this article we review the development of Chinese capital markets over a crucial period in the history of markets worldwide, and place that development in context. Despite fundamental differences between China today and China 100 years ago, it is still important to consider the effects of an imbalance between domestic and international investor markets, and the mismatch between domestic and foreign expectations about investor protection. The lessons of the last century suggest that China today should consider opening Chinese investor access to foreign capital markets in order to equilibrate the level of diversification between foreign and domestic investors. In addition, our analysis suggests that protecting of domestic corporate investor rights is at least as important as protecting foreign investor rights. [source] Problems of resistance development in arthropod pests of agricultural crops in RussiaEPPO BULLETIN, Issue 1 2008G. I. Sukhoruchenko This paper presents the results of long-term monitoring of insecticide resistance in populations of agricultural pests in Russia. Over the last 45 years, resistance developments were recorded for 36 arthropod pest species in 11 agricultural crops and pastures in relation to nearly all commonly used plant protection products. Development of group, cross and multiple resistance has been revealed in populations of many economically important pests. Toxicological and phenotypical (for Colorado potato beetle) methods have been devised to monitor the development of pesticide resistance. Based on experience over the last century, systems aimed at preventing the development of pest resistance to insecticides and acaricides are elaborated. These systems are based on resistance monitoring and using plant protection measures which minimize the toxic pressure on agroecosystems. [source] Teaching forensic odontology: an opinion on its content and format,EUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 3 2006A. B. Acharya Abstract, Forensic odontology involves dentists' participation in assisting legal and criminal issues. Formal teaching in forensic odontology has existed for over a 100 years. Over the last century, forensic odontology has evolved and, today, it is an integral part of undergraduate dental training in many countries. Dentists have been trained in the specialty, and dedicated departments established in institutes and universities around the world. A survey undertaken at five universities revealed that these centres have developed detailed curricula in forensic odontology, and a general standard exists in teaching forensic odontology, however, coverage of recent advances in forensic science may be lacking. While recognising that these programmes are not representative of teaching in forensic odontology worldwide, suggestions are made for an alternative approach to teaching the subject. Moreover, it is stressed that teaching be undertaken by qualified forensic odontologists. [source] The necessity of observing real life situations: Palestinian-Israeli violence as a laboratory for learning about social behaviourEUROPEAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 6 2004Dr Daniel Bar-Tal Social psychology emerged in the early part of the last century as a distinct discipline that focused on the study of social behaviour of individuals and collectives. Over time, however, social psychology has relatively ignored the ,social' part of the equation and has become mainly concerned with individual behaviour. The major part of social psychological research was carried out in the artificial context of the experimental laboratory. Studying social behaviour in real life contexts is essential, not only to return social psychology to its roots, but also to ensure that our contributions are both theoretically rich and socially valuable. Observation of real life situations is essential if we want to advance our understanding of how individuals and collectives behave. To illustrate the importance of a contextually rich social psychology and the usefulness of natural observations, the recent violent confrontation between the Israelis and the Palestinians is described and analysed, focusing on social behaviours of Israeli Jews. In conclusion, it is argued that social psychology should strive towards equilibrium between natural and experimental approaches, between personal and contextual emphases and between micro and macro perspectives. Copyright © 2004 John Wiley & Sons, Ltd. [source] Roots, rhizosphere and soil: the route to a better understanding of soil science?EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 1 2006P.J. Gregory Summary The centenary of Hiltner's recognition of a rhizosphere effect is a convenient point to assess the impact of such thinking on the direction of soil science. A review of the major soil journals suggests that for much of the last century, Hiltner's insight had little effect on mainstream thinking outside of soil microbiology, but this situation is changing rapidly as the consequences of spatial and temporal heterogeneity on soil functioning assumes greater importance. Studies of root growth, root distributions and of rhizosphere processes over the last 25 years demonstrate both the size and distribution of root systems and the associated inputs from roots to soils. These inputs result in a plethora of dynamic reactions at the root,soil interface whose consequences are felt at a range of temporal and spatial scales. Root growth and respiration, rhizodeposition, and uptake of water and nutrients result in biological, chemical and physical changes in soils over variable distances from the root surface so that the rhizosphere has different dimensions depending on the process considered. At the root length densities common for many crop species, much of the upper 0.1 m of soil might be influenced by root activity for mobile nutrients, water and root-emitted volatile compounds for a substantial proportion of the growing season. This brief review concludes that roots are an essential component of soil biology and of soil science. [source] Characterizing regime shifts in the marine environmentFISH AND FISHERIES, Issue 2 2006Kathryn Lees Abstract Recent years have seen a plethora of studies reporting that ,regime shifts' have occurred in the North Atlantic and Pacific Oceans during the last century. In many cases, the criteria used to distinguish a regime shift have not been explicitly stated. In other cases, a formal definition has been proposed and the data set assessed against it. Developing a universal quantitative definition for identifying and distinguishing between purported climatic and ecological regime shifts has proved problematic as many authors have developed criteria that seem unique to the system under study. Consequently, they throw little light on the drivers of ecological regime shifts. Criteria used to define regime shifts are reviewed and on the basis of evidence from purported regime shifts, common characteristics in the speed and amplitude of the changes and the duration of quasi-stable states are used to propose a more clearly defined set of criteria for defining climatic and ecological regime shifts. Causal drivers of regime shifts are explored using correlation analysis. Limitations of these methods are discussed. [source] Variation in abundance of Norwegian spring-spawning herring (Clupea harengus, Clupeidae) throughout the 20th century and the influence of climatic fluctuationsFISH AND FISHERIES, Issue 3 2000R. Toresen A long-term (1907,98) virtual population analysis (VPA) was made for Norwegian spring-spawning herring (NSSH), which is a huge pelagic fish stock in the north-east Atlantic. It shows that this herring stock has had large fluctuations during the last century; these fluctuations have mainly been determined by variations in the temperature of the inflowing water masses to the region. The spawning stock biomass (SSB) increased from a rather low level in the early years of this century and reached a high level of around 14 million tons by 1930. The spawning stock biomass then decreased to a level of around 10 million tons by 1940, but increased again to a record high level of 16 million tons by 1945. The stock then started to decrease and during the next 20-year period fell to a level of less than 50 000 tons by the late 1960s. Through the 1970s and 1980s, the stock slowly recovered and after the recruitment of strong year classes in 1983 and 1990,1992 the stock recovered to a spawning stock biomass of about 10 million tons. The long-term fluctuation in spawning stock biomass is caused by variations in the survival of recruits. It is found that the long-term changes in spawning stock abundance are highly correlated with the long-term variations in the mean annual temperature of the inflowing Atlantic water masses (through the Kola section) into the north-east Atlantic region. The recruitment is positively correlated with the average temperature in the Kola section in the winter months, January,April, which indicates that environmental factors govern the large-scale fluctuations in production for this herring stock. [source] Discourses and Ethics: The Social Construction of British Foreign PolicyFOREIGN POLICY ANALYSIS, Issue 4 2006JAMIE GASKARTH The last decade has given rise to a wealth of literature on the ethics of British foreign policy. However, much of this has focused on a few narrow issues based around specific policy actions. As such, it has largely been reactive and mirrored governmental attitudes to the possibilities in foreign policy and the constraints under which decisions are made. Important issues, such as how the concepts of foreign policy and ethics have been described and enacted historically in Britain, the political effects of these past readings, and how the idea of discussing ethics should be so controversial, are underexplored. To investigate these naturalized understandings, this article conducts a discourse analysis of the articulation of foreign policy in Hansard over the last century. In doing so, it seeks to explore how past expressions of foreign policy and ethics privilege certain ways of thinking about policy and exclude others through their modes of description. The effect of these structures, it is argued, is to suppress democratic dissent and individual accountability and marginalize discussion on the (contestable) ethical basis of policy making and policy behavior. [source] On the climate and weather of mountain and sub-arctic lakes in Europe and their susceptibility to future climate changeFRESHWATER BIOLOGY, Issue 12 2009R. THOMPSON Summary 1.,The complex terrain and heterogeneous nature of the mountain environment coupled with remoteness from major centres of human activity makes mountains challenging locations for meteorological investigations. Mountainous areas tend to have more varied and more extreme weather than lowlands. 2.,The EMERGE program has the primary aim of assessing the status of remote mountain and sub-arctic lakes throughout Europe for the first time. In this study, we describe the main features of the climate, ice-cover durations and recent temperature trends of these areas. The main weather characteristics of European mountain and sub-arctic lakes are their cold temperatures and year-round precipitation. Mean annual temperatures are generally close to 0 °C, and maximum summer temperatures reasonably close to 10 °C. 3.,Maritime versus continental settings determine the main differences in annual-temperature range among lake districts (10.5 °C in Scotland to 26.7 °C in Northern Finland), and a similar factor for ice-cover duration. Radiation ranges from low (120 W m,2) in the high latitude sub-arctic and high (237 W m,2) in the southern ranges of the Pyrenees and Rila. Similarly, precipitation is high in the main Alpine chain (250 cm year,1 in the Central Southern Alps) and low in the continental sub-arctic (65 cm year,1 in Northern Finland). 4.,The main temporal patterns in air temperature follow those of the adjacent lowlands. All the lake districts warmed during the last century. Spring temperature trends were highest in Finland; summer trends were weak everywhere; autumn trends were strongest in the west, in the Pyrenees and western Alps; while winter trends varied markedly, being high in the Pyrenees and Alps, low in Scotland and Norway and negative in Finland. 5.,Two new, limnological case studies on Lake Redon, in the Pyrenees, highlight the sensitivity of remote lakes to projected changes in the global climate. These two case studies involve close linkages between extreme chemical-precipitation events and synoptic wind-patterns, and between thermocline behaviour and features of the large-scale circulation. 6.,Individual lakes can be ultra-responsive to climate change. Even modest changes in future air temperatures will lead to major changes in lake temperatures and ice-cover duration and hence probably affect their ecological status. [source] Deconstructing language by comparative gene expression: from neurobiology to microarrayGENES, BRAIN AND BEHAVIOR, Issue S1 2006M. C. Oldham Language is a defining characteristic of our species that has emerged quite recently on an evolutionary timescale. Understanding the neurobiological substrates and genetic underpinnings of language constitutes a basic challenge for both neuroscience and genetics. The functional localization of language in the brain has been progressively refined over the last century through studies of aphasics and more recently through neuroimaging. Concurrently, structural specializations in these brain regions have been identified by virtue of their lateralization in humans and also through comparisons with homologous brain regions in non-human primate species. Comparative genomics has revealed the genome of our closest living relative, the chimpanzee, to be astonishingly similar to our own. To explore the role that changes in the regulation of gene expression have had in recent human evolution, several groups have used microarrays to compare expression levels for thousands of genes in the brain between humans and chimpanzees. By applying this approach to the increasingly refined peri-sylvian network of brain regions involved in language, it may be possible to discern functionally significant changes in gene expression that are universal among humans but unique to our species, thus casting light on the molecular basis of language in the brain. [source] ON THE GEOCHRONOLOGICAL METHOD VERSUS FLOW SIMULATION SOFTWARE APPLICATION FOR LAHAR RISK MAPPING: A CASE STUDY OF POPOCATÉPETL VOLCANO, MEXICOGEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 3 2010ESPERANZA MUÑOZ-SALINAS ABSTRACT. Lahars are hazardous events that can cause serious damage to people who live close to volcanic areas; several were registered at different times in the last century, such as at Mt St Helens (USA) in 1980, Nevado del Ruiz (Colombia) in 1985 and Mt Pinatubo (Philippines) in 1990. Risk maps are currently used by decision-makers to help them plan to mitigate the hazard-risk of lahars. Risk maps are acquired based on a series of tenets that take into account the distribution and chronology of past lahar deposits, and basically two approaches have been used: (1) The use of Flow Simulation Software (FSS), which simulates flows along channels in a Digital Elevation Model and (2) The Geochronological Method (GM), in which the mapping is based on the evaluation of lahar magnitude and frequency. This study addresses the production of a lahar risk map using the two approaches (FSS and GM) for a study area located at Popocatépetl volcano , Central Mexico. Santiago Xalitzintla, a town located on the northern flank of Popocatépetl volcano, where volcanic activity in recent centuries has triggered numerous lahars that have endangered local inhabitants, has been used for the case study. Results from FSS did not provide satisfactory findings because they were not consistent with lahar sediment observations made during fieldwork. By contrast, the GM produced results consistent with these observations, and therefore we use them to assess the hazard and produce the risk map for the study area. [source] Talus Instability in a Recent Deglaciation Area and Its Relationship to Buried Ice and Snow Cover Evolution (Picacho Del Veleta, Sierra Nevada, Spain)GEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 2 2003Antonio Gómez The southernmost glacier in Europe formed during the Little Ice Age at the foot of the north wall of Picacho del Veleta (3 398 m) in Sierra Nevada, in the southeast region of the Iberian Peninsula (lat. 37,03,N, long. 3,22,W). The glacier gradually retreated during the last century, leaving a large talus slope at the base of the wall. The unconsolidated material covering the ice masses acted as a thermal insulator. Recent bottom temperature of snow (BTS) analyses and drillings indicate that the ice still exists within the talus. Evidence from field observations made during the period 1995,2001, revealed that large mass movements occurred during the driest summers (1998 and especially, 1999 and 2000) when the talus was snow free. These conditions suggest a direct relationship between talus stability and thermal insulation from the snow cover in areas where buried ice or decaying marginal permafrost exists. [source] Surface deformation induced by present-day ice melting in SvalbardGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 1 2009H. P. Kierulf SUMMARY The vertical movement of the Earth's surface is the result of a number of internal processes in the solid Earth, tidal forces and mass redistribution in the atmosphere, oceans, terrestrial hydrosphere and cryosphere. Close to ice sheets and glaciers, the changes in the ice loads can induce large vertical motions at intraseasonal to secular timescales. The Global Positioning System (GPS) and Very Long Baseline Interferometry (VLBI) antennas in Ny-Ålesund, Svalbard that started observations in 1991 and 1995, respectively, observe vertical uplift rates on the order of 8 ± 2 mm yr,1, which are considerably larger than those predicted by postglacial rebound (PGR) models (order 2 mm yr,1). The observations also indicate increased uplift rates starting some time in 2000. A local GPS campaign network that has been reoccupied annually since 1998, reveals a tilting away from the neighbouring glaciers. The Svalbard glaciers have been undergoing melting and retreat during the last century, with increased melting since about 2000. We compared the observed vertical motion to the motion predicted by loading models using a detailed ice model with annual time resolution as forcing. The model predictions correlate well with the observations both with respect to the interannual variations and the spatial pattern of long-term trends. The regression coefficients for predicted and observed interannual variations in height is 1.08 ± 0.38, whereas the regression coefficient for the predicted and observed spatial pattern turns out to be 1.26 ± 0.42. Estimates of the predicted secular trend in height due to PGR and present-day melting are on the order of 4.8 ± 0.3 mm yr,1 and thus smaller than the observed secular trend in height. This discrepancy between predictions and observations is likely caused by the sum of errors in the secular rates determined from observations (due to technique-dependent large-scale offsets) and incomplete or erroneous models (unaccounted tectonic vertical motion, errors in the ice load history, scale errors in the viscoelastic PGR models and the elastic models for present-day melting). [source] Regeneration patterns and persistence of the fog-dependent Fray Jorge forest in semiarid Chile during the past two centuriesGLOBAL CHANGE BIOLOGY, Issue 1 2008ALVARO G. GUTIÉRREZ Abstract The persistence of rainforest patches at Fray Jorge National Park (FJNP) in semiarid Chile (30°40,S), a region receiving approximately 147 mm of annual rainfall, has been a source of concern among forest managers. These forests are likely dependent on water inputs from oceanic fog and their persistence seems uncertain in the face of climate change. Here, we assessed tree radial growth and establishment during the last two centuries and their relation to trends in climate and canopy disturbance. Such evaluation is critical to understanding the dynamics of these semiarid ecosystems in response to climate change. We analyzed forest structure of six forest patches (0.2,22 ha) in FJNP based on sampling within 0.1 ha permanent plots. For the main canopy species, the endemic Aextoxicon punctatum (Aextoxicaceae), we used tree-ring analysis to assess establishment periods, tree ages, growing trends and their relation to El Niño Southern Oscillation (ENSO), rainfall, and disturbance. The population dynamics of A. punctatum can be described by a continuous regeneration mode. Regeneration of A. punctatum was sensitive to different canopy structures. Growth release patterns suggest the absence of large scale human impact. Radial growth and establishment of A. punctatum were weakly correlated with rainfall and ENSO. If water limits forests patch persistence, patches are likely dependent on the combination of fog and rain water inputs. Forest patches have regenerated continuously for at least 250 years, despite large fluctuations in rainfall driven by ENSO and a regional decline in rainfall during the last century. Because of the positive influence on fog interception, forest structure should be preserved under any future climate scenario. Future research in FJNP should prioritize quantifying the long-term trends of fog water deposition on forests patches. Fog modeling is crucial for understanding the interplay among physical drivers of water inputs under climate change. [source] Development of a stable isotope index to assess decadal-scale vegetation change and application to woodlands of the Burdekin catchment, AustraliaGLOBAL CHANGE BIOLOGY, Issue 7 2007EVELYN KRULL Abstract Forty-four study sites were established in remnant woodland in the Burdekin River catchment in tropical north-east Queensland, Australia, to assess recent (decadal) vegetation change. The aim of this study was further to evaluate whether wide-scale vegetation ,thickening' (proliferation of woody plants in formerly more open woodlands) had occurred during the last century, coinciding with significant changes in land management. Soil samples from several depth intervals were size separated into different soil organic carbon (SOC) fractions, which differed from one another by chemical composition and turnover times. Tropical (C4) grasses dominate in the Burdekin catchment, and thus ,13C analyses of SOC fractions with different turnover times can be used to assess whether the relative proportion of trees (C3) and grasses (C4) had changed over time. However, a method was required to permit standardized assessment of the ,13C data for the individual sites within the 13 Mha catchment, which varied in soil and vegetation characteristics. Thus, an index was developed using data from three detailed study sites and global literature to standardize individual isotopic data from different soil depths and SOC fractions to reflect only the changed proportion of trees (C3) to grasses (C4) over decadal timescales. When applied to the 44 individual sites distributed throughout the Burdekin catchment, 64% of the sites were shown to have experienced decadal vegetation thickening, while 29% had remained stable and the remaining 7% had thinned. Thus, the development of this index enabled regional scale assessment and comparison of decadal vegetation patterns without having to rely on prior knowledge of vegetation changes or aerial photography. [source] Climate change-driven forest fires marginalize the impact of ice cap wasting on KilimanjaroGLOBAL CHANGE BIOLOGY, Issue 7 2005Andreas Hemp Abstract The disappearing glaciers of Kilimanjaro are attracting broad interest. Less conspicuous but ecologically far more significant is the associated increase of frequency and intensity of fires on the slopes of Kilimanjaro, which leads to a downward shift of the upper forest line by several hundred meters as a result of a drier (warmer) climate since the last century. In contrast to common belief, global warming does not necessarily cause upward migration of plants and animals. Here, it is shown that on Kilimanjaro the opposite trend is under way, with consequences more harmful than those due to the loss of the showy ice cap of Africa's highest mountain. [source] Allelic heterogeneity of molecular events in human coagulation factor IX in Asian Indians,,HUMAN MUTATION, Issue 5 2007Anubha Mahajan Abstract Mutations in Factor IX gene (F9) cause X-linked recessive bleeding disorder hemophilia B. Here, we characterized molecular events in nine North Indian hemophiliac families identifying four missense mutations (three novel), two nonsense mutations, and a deletion. We have also captured the mutational spectrum of this disease in India based on available reports and established their genotype/phenotype relationships. Indian F9 mutations data indicate the absence of an important germline mutagen in the Indian subcontinent over the last century, and are consistent with previously made conclusions that universal, presumably endogenous factors are predominant in the causation of the spontaneous mutations in F9. We also analyzed the distribution of Ala194Thr polymorphism in 1231 Asian Indians and have established that Ala variant is far more frequent and can certainly be exploited for carrier detection, contrary to earlier reports. © 2007 Wiley-Liss, Inc [source] Global potential soil erosion with reference to land use and climate changesHYDROLOGICAL PROCESSES, Issue 14 2003Dawen Yang Abstract A GIS-based RUSLE model is employed to study the global soil erosion potential for viewing the present situation, analysing changes over the past century, and projecting future trends with reference to global changes in land use and climate. Scenarios considered in the study include historical, present and future conditions of cropland and climate. This research gives the first overview of the global situation of soil erosion potential considering the previous century as well as the present and future. Present soil erosion potential is estimated to be about 0·38 mm year,1 for the globe, with Southeast Asia found to be the most seriously affected region in the world. It is estimated that nearly 60% of present soil erosions are induced by human activity. With development of cropland in the last century, soil erosion potential is estimated to have increased by about 17%. Global warming might significantly increase the potential for soil erosion, and the regions with the same increasing trend of precipitation and population might face much more serious problems related to soil erosion in the future. Copyright © 2003 John Wiley & Sons, Ltd. [source] Molecular strategies of plant defense and insect counter-defenseINSECT SCIENCE, Issue 1 2005KEYAN ZHU-SALZMAN Abstract The prediction of human population growth worldwide indicates there will be a need to substantially increase food production in order to meet the demand on food supply. This can be achieved in part by the effective management of insect pests. Since plants have co-evolved with herbivorous insects for millions of years, they have developed an array of defense genes to protect themselves against a wide variety of chewing and sucking insects. Using these naturally-occurring genes via genetic engineering represents an environmentally friendly insect pest-control measure. Insects, however, have been actively evolving adaptive mechanisms to evade natural plant defenses. Such evolved adaptability undoubtedly has helped insects during the last century to rapidly overcome a great many human-imposed management practices and agents, including chemical insecticides and genetically engineered plants. Thus, better understanding of the molecular and genetic basis of plant defense and insect counter-defense mechanisms is imperative, not only from a basic science perspective, but also for biotechnology-based pest control practice. In this review, we emphasize the recent advance and understanding of molecular strategies of attack-counterattack and defense-counter-defense between plants and their herbivores. [source] Detection of a possible change point in atmospheric variability in the North Atlantic and its effect on Scandinavian glacier mass balanceINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 14 2005Rowan Fealy Abstract Climate change, resulting from an increase in global temperatures, is likely to have a large impact on glaciers and glacier meltwater during the course of the present century resulting in significant contributions to sea level rise. Globally, glaciers are in retreat, partly as a response to the return to warmer conditions after the last neoglacial period during the Little Ice Age but also because of the almost continuous increases evident in global temperature since then. In contrast, Scandinavian glaciers, particularly maritime glaciers, were maintaining equilibrium or advancing over the closing decades of the last century possibly resulting from an increased moisture flux over the North Atlantic. While the more continental glaciers were still declining, the rate of decline diminished during the late 1980s. This coincides with an accelerated rate of increase evident on the maritime glaciers in southwestern Norway. A change point in atmospheric variability in the North Atlantic is identified as having occurred during this period. This change point is associated with an intensification of westerlies over Europe, particularly since the late 1980s, which significantly contributes to increases in temperature and precipitation over northern Europe while suppressing the penetration of warm, moist air into more southern European locations. Regional variations in temperature and precipitation from selected Scandinavian stations are also found to be consistent with the changes in the large-scale modes of atmospheric variability in the North Atlantic. Copyright © 2005 Royal Meteorological Society [source] Trends in indices for extremes in daily temperature and precipitation in central and western Europe, 1901,99INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 9 2005Anders Moberg Abstract We analyse 20th century trends in six indices for precipitation extremes and four indices for temperature extremes, calculated from daily observational data for European stations. The indices chosen reflect rather moderate extremes. Most of the ,80 stations used are situated in central and western Europe; therefore, results mainly refer to this region. Trends are calculated over 1901,99, 1921,99, 1901,50 and 1946,99. Two different trend estimators are used, and significance is assessed with a bootstrap technique. We find that: Significant increasing precipitation trends over the 20th century dominate in winter for both average precipitation intensity and moderately strong events. Simultaneously, the length of dry spells generally increased insignificantly. There are few significant trends of any sign for precipitation indices in summer, but there are insignificant drying trends over Scandinavia and wetting trends over central and western Europe for 1921,99. The length of dry spells in summer generally increased insignificantly. Both the warm and cold tails of the temperature distribution in winter warmed over the entire 20th century. Notably low values in the cold tail for daily Tmax and Tmin occurred in the early 1940s, leading to strong but insignificant negative trends for 1901,50, whereas little change occurred before 1940. Warming of winters during 1946,99 occurred in both the warm and cold tails for both Tmax and Tmin, with the largest warming in the cold tail for Tmin. The warm tail of daily Tmin (and to a smaller extent Tmax) in summer warmed significantly during the past century. There is more evidence for summer warming in the first half of the century compared with the second half. During 1946,99, the warm tail of daily Tmax in summer was generally warming while the cold tail was cooling (both insignificantly). More digitized daily observational data from various European sub-regions are needed to permit a spatially more extensive analysis of changes in climate extremes over the last century. Copyright © 2005 Royal Meteorological Society [source] ENSO variability, teleconnections and climate change,INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 15 2001Henry F. Diaz Abstract An overview is presented of the principal features of the El Niño,Southern Oscillation (ENSO) teleconnections in terms of regional patterns of surface temperature, precipitation and mid-tropospheric atmospheric circulation. The discussion is cast in the context of variations in the associations over time, with decadal scale changes emphasized. In the five decades or so for which we have adequate records to reliably analyse the global aspects of ENSO effects on regional climates around the world, we have witnessed one major decadal scale change in the overall pattern of sea-surface temperatures (SST) in the global ocean, and concomitant changes in the atmospheric response to those changes. The analysis underscores the connection between low frequency changes in tropical SST, ENSO and decadal scale changes in the general atmospheric circulation, pointing to the complex interplay between the canonical ENSO system, slow changes in SST in the Indo-Pacific over the last century, and long-term changes in the atmospheric circulation itself. Published in 2001 by John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||