bluuebunny/crossref_metadata_2025 huggingface dataset:
β4 Integrin Is a Transforming Molecule that Unleashes Met Tyrosine Kinase Tumorigenesis
Authors: Bertotti Andrea , Comoglio Paolo M. , Trusolino Livio
Published: December 2005

Cell multiplication in the absence of integrin-derived adhesive signals (anchorage-independent growth) is the phenotypic hallmark of neoplastic transformation. Therefore, the frequently observed up-regulation of some integrins in tumors has been interpreted as an epiphenomenon and not as a causative factor of oncogenic conversion. β4 integrin stimulates proliferation and survival of epithelial cells and is overexpressed in human carcinomas, often in concomitance with up-regulation of the Met tyrosine kinase receptor for hepatocyte growth factor. Met is not endowed with transforming ability but can exploit the β4 cytoplasmic tail as a substrate/adaptor for amplification of mitogenic and antiapoptotic responses, independently of cell adhesion. Here, we show that overexpression of β4 is sufficient to transform rodent fibroblasts, enhances anchorage-independent growth of breast carcinoma cells, and induces tumorigenesis in nude mice; conversely, RNA interference–mediated depletion abrogates the transformed phenotype of neoplastic cells. These autonomous oncogenic properties are dramatically exacerbated upon Met coexpression, suggesting that the integrin can instigate the latent tumorigenic potential of the kinase. A β4 nonadhesive variant still cooperates with Met for cellular transformation, confirming the adhesion-independent function of β4 in magnification of Met biological effects. Conversely, a β4 signaling-incompetent mutant that cannot be efficiently tyrosine phosphorylated by Met and displays reduced ability to activate phosphatidylinositol 3-kinase–dependent and Ras-dependent pathways aborts transformation. Our findings define β4 as a signaling accomplice (a “servo-oncogene”) of tyrosine kinase proto-oncogenes in primary carcinogenesis, evoke an unorthodox function for a prototypic adhesion molecule in the positive regulation of anchorage-independent growth, and suggest the use of β4 as a target for anticancer therapy.
Dirty work designations: How police officers account for their use of coercive force
Authors: Dick Penny
Published: December 2005

The concept of ‘dirty work’ has much potential to offer insights into processes related to the construction of organizational identities and work-group cultures. In this article, I use a social constructionist framework, to argue that ‘dirty workers’ perform their identities in two conceptually distinct contexts: ‘front regions’ and ‘back regions’ (Goffman, 1959), each producing its own subjective challenges. I use a critical discourse analysis to explore how, within the research interview setting, police officers deal with the moral dilemma of their use of coercive authority. I argue that what is designated as ‘dirty’ within any specific role differs according to the perspective of the observer, revealing the boundaries and landscape of different moral and social orders and how these overlap and compete. It is further argued that, within specific interactional contexts, occupational identity comprises a site of contestation for these different moral and social orders. The utility of the dirty work concept is explored in relation to its ability to illuminate the dynamics of ideological reproduction and transformation.
Different responses to job insecurity of Chinese workers in joint ventures and state-owned enterprises
Authors: Wong Yui-Tim , Wong Chi-Sum , Ngo Hang-Yue , Lui Hon-Kwong
Published: December 2005

Job insecurity has become an important issue for western organizations in the last decade due to uncertain economic conditions, global competition, and the advancement of information technology. In this study, we integrate social exchange theory and rational choice theory to explain employees’ responses to job insecurity in the Chinese context. We distinguish short-term transactional exchange from long-term relational exchange, and argue that joint ventures (JVs) and state-owned enterprises (SOEs) are characterized by different kinds of employee-organization exchange. An integrated theoretical framework is developed to explain why workers in these organizations respond differently to job insecurity. A total of 548 supervisor-subordinate dyads in a JV and a SOE in China are used to test the hypotheses derived from our framework. The results of hierarchical regression analysis indicate that the effects of job insecurity on organizational citizenship behavior (OCB) and job performance depend on both organizational types and employees’ trust in their organization.
Problems, problems, problems: The social construction of ‘leadership’
Authors: Grint Keith
Published: December 2005

The invasion of Iraq was premised upon accounts of the situation that have proved unsustainable, but that has not generated a change in the strategy of the coalition forces. Conventional contingency accounts of leadership suggest that accurate accounts of the context are a critical element of the decision-making apparatus but such accounts appear incapable of explaining the decisions of those engaged. An alternative model is developed that adapts the Tame and Wicked problem analysis of Rittell and Webber, in association with Etzioni’s typology of compliance, to propose an alternative analysis that is rooted in social constructivist approaches. This is then applied to three asymmetric case studies which suggest that decision-makers are much more active in the constitution of the context than conventional contingency theories allow, and that a persuasive rendition of the context then legitimizes a particular form of action that often relates to the decision-maker’s preferred mode of engagement, rather than what ‘the situation’ apparently demands. In effect, the context is reconstructed as a political arena not a scientific laboratory.
Foreign Investment and Disparities in Economic Development and Poverty Reduction
Authors: Kerbo Harold
Published: December 2005

To remain economically competitive in the 21st century a nation must be able to secure resources beyond its borders and protect itself from other nations trying to do the same. While the situation has been shown to be more complex, the original assumption among world system researchers remains that multinational corporate penetration in the periphery can have negative effects on their prospects for economic development. But we now know that these negative effects upon long-term economic development can be prevented. The existence of a strong development state can be critical for this protection. In addition to supplying ‘good governance’ (as the World Bank now calls it), a strong development state can provide protection in the global economy so that multinational corporate penetration is beneficial rather than harmful to less developed nations. But given the importance of a strong development state it is surprising that little research has been directed to the question of how a nation acquires a development state and ‘good governance.’ To begin answering this question, this article focuses on the countries of Southeast Asia. After examination of the wide contrast among Southeast Asian nations with respect to economic development and poverty reduction, a comparative-historical analysis is employed to develop a model which helps us explain these contrasts. Previous research on economic development in East and Southeast Asia only recognized the impact of ‘Asian values’ on unity, respect for authority, and a work ethic among the masses. Beginning with the impact of ancient civilizations and the potential for nation-building, this research also suggests the importance of a sense of national identity and responsibility among elites. The model then turns to how this potential for a strong development state can be affected by different aspects of colonialism. Finally, the article considers the model’s potential application to Africa and Latin America in helping us understand differing rates of economic success for other periphery and semiperiphery nations in the modern world system.
Exactly How Has Income Inequality Changed?
Authors: Alderson Arthur S. , Beckfield Jason , Nielsen François
Published: December 2005

The recent resurgence of income inequality in some of the core societies has spawned a wide-ranging debate as to the culprits. Progress in this debate has been complicated by the fact that many of the theories that have been developed to account for the inequality upswing imply radically different patterns of distributional change, while predicting the same outcome in terms of the behavior of standard summary measures (e.g. a rise in the Gini coefficient or in Theil’s inequality). Handcock and Morris (1999) have developed methods that allow the analyst to precisely identify patterns of distributional change and a set of summary measures to characterize such changes. These are based on the relative distribution, defined for our purposes as the ratio of the fraction of households in the baseline year to the fraction of households in the comparison year in each decile of the distribution of income. We use the available high-quality data from the Luxemburg Income Study to explore the evolution of household income inequality in 16 core societies. We describe exactly how inequality grew in some core societies since the late 1960s and discuss the extent to which patterns of distributional change were homogeneous or heterogeneous across the core. We find that: 1) rising inequality is generally associated with polarization, rather than upgrading or downgrading alone; 2) among those societies experiencing the largest increases in inequality, upgrading typically takes precedence over downgrading in the course of such polarization; and 3) declining inequality, where it occurs, has been the result of convergence, with the magnitude of the shift from the lower tail to the middle exceeding that of the shift from upper tail to the middle.
Psychosocial Dynamics of the US Catholic Church Sexual Abuse Crisis
Authors: Barber William H.
Published: December 2005

Background: This paper presents open systems analysis of the organizational dynamics of the US Catholic Church sexual abuse crisis. Most of the current literature on the crisis assigns culpability to various parties involved – in most cases to bishops and Church officials in Rome. This analysis offers a way of understanding events that goes beyond assigning culpability on the part of Church leaders.

Material and Discussion: As an open system, a church is a system of interdependent, purposive activities, one that survives and develops through interchanges with its environment including the society of which it is a part. Key elements in this discussion include the dynamics that result from the idiosyncratic church structures and processes, and the apparent preoccupation with sexual matters, all of which are imbedded in a religious belief system and a high dependency culture.

Conclusions: The picture is of a church experiencing the catastrophe of thousands of cases accusing priests of sexual abuse of young people, of an institution that has lost its capacity for openness as it is overwhelmed by the heapedon needs of members from a flood of constituencies. Key elements in this discussion include the description of the Church as an open system, the notions of primary task, sentient group life, a high dependency culture and the unconscious motivation operating in individuals, groups and the total Church enterprise.
Compensatory patterns of sibling support in emerging adulthood: Variations in loneliness, self-esteem, depression and life satisfaction
Authors: Milevsky Avidan
Published: December 2005

This study examines how the compensatory effects of social support received from siblings relate to psychological adjustment in emerging adulthood. Participants completed measures of social support from a variety of sources and several indicators of well-being. Sibling support was associated with lower loneliness and depression and with higher self-esteem and life satisfaction. Also, sibling support compensated for low parental and peer support. Sibling support compensated for low support from mothers for depression and self-esteem. Sibling support compensated for low support from fathers for loneliness, self-esteem, and life satisfaction. Finally, sibling support partially compensated for low support from friends for all of the well-being measures and completely compensated for self-esteem, depression, and life satisfaction. The potential benefits of sibling support warrant a closer examination of the wide-ranging issues involved in sibling relations.
Judgments about the hypothetical behaviors of friends and romantic partners
Authors: Flannagan Dorothy , Marsh Dianna L. , Fuhrman Robert
Published: December 2005

Two studies investigated college students' ratings about hypothetical behaviors performed by a self-reported friend or romantic partner. In Study 1 participants read scenarios involving themselves and a friend, romantic partner or unfamiliar peer whose behavior resulted in either a positive or negative outcome for the participant. Ratings of the partner's behavior were equally positive for friends and romantic partners and were both significantly higher than behavioral ratings for unfamiliar peers. Ratings of friends' and romantic partners' behavior were also related to participants' ratings of the quality of those relationships. In Study 2 participants read scenarios describing situations in which behavioral expectations might differ for friends and romantic partners, resulting in participants generally providing higher ratings for friends' behaviors. Results are discussed in terms of partner enhancement and relationship expectations.
The role and value of public libraries in the age of digital technologies
Authors: Aabø Svanhild
Published: December 2005

Discusses public libraries’ role and value in the age of digital technologies. Reassessments of their role due to technological development and widespread public use of the Internet are analysed. Central challenges of the digital society, including an increased digital divide and a weakening of local community identity, have resulted in lower social participation and involvement in community issues. Previous research has demonstrated that public libraries have a wide social impact on both individuals and local communities. This article focuses on the special characteristics of public libraries to assess their potentially enhanced role and value, as a public room and social and physical meeting place in the digitised age. The article identifies a need to strengthen the public libraries’ democratic role in the information society by furthering social inclusiveness and citizenship.
Unorthodox Sisters
Authors: Gallo Ester
Published: December 2005

This article explores the relation between women's active engagement with trans-national migration and transformations in the meanings and practices of marriage through the lens of gender relations and generational change. After reconstructing the history of Malayali migration in Italy, I will show how ideologies and practices surrounding marriage and dowry, far from being confined to one country, are subjects of negotiation between different contexts and heterogeneous household expectations. My conclusions are two-fold. I will argue that the relation between women's transnational migration and changes in household relations and practices should be understood as a dialectical process. Second, I will argue that the analysis of transnational marriages through the perspective of life-cycle transformations and generational change is a basic condition for understanding how multiple meanings of modernity inform processes of change in contemporary Malayali marriage.
Cost-Effectiveness in Individual Development Accounts
Authors: Schreiner Mark , Ng Guat Tin , Sherraden Michael
Published: December 2005

Because resources are limited, the benefits and costs of social-work interventions—like all interventions—must be compared with the benefits and costs of alternatives. Evidence-based practice should ask, What works? How well does it work? And what does it cost? This article analyzes the provision of Individual Development Accounts (IDAs) with a new cost-effectiveness framework meant to help make assumptions and judgments explicit. In the specific IDA program examined, 1 month of services for 1 participant costs about $64. The mere existence of a cost figure— regardless of whether it is seen as high or low—has sparked many questions in the IDA community: How can costs be reduced without sacrificing quality? Which features of IDAs are essential? Are IDAs worth it? This sort of healthy questioning is precisely the purpose of cost-effectiveness analysis in social-work practice.
Studies of the Cost-Effectiveness of Social Work Services in Aging: A Review of the Literature
Authors: Rizzo Victoria M. , Rowe Jeannine M.
Published: December 2005

The American population aged 65 years and older is growing rapidly, creating an increased demand for social workers. Reimbursement structures of Medicare and Medicaid present significant barriers for aging individuals seeking social work services as well as social workers wanting to provide services to the elderly. To build a case for the modification of these reimbursement structures, a review of studies of social work services in aging was conducted to (a) make explicit the current knowledge of the efficacy and cost-effectiveness of these services, (b) identify current gaps in knowledge, (c) promote a research agenda to address the gaps, and (e) assure that the knowledge identified addresses payers'needs to understand the value of social work services in aging. The results indicate that social work interventions can have a positive impact on the health care costs, the use of health care services, and the quality of life of older Americans.
Lifetime cumulative adversity, mental health and the risk of becoming a smoker
Authors: Lloyd Donald A. , Taylor John
Published: December 2005

We analyze the effect of stress exposure on the transition to heavy smoking, in a community sample of 1747 young adults in Miami, Florida. The effects of distal life stress are assessed in the context of recent stress exposure. Distal stress exposure predicts smoking independently of recent stress. Intervening stressful events do not appreciably mediate the influence of distal stress. We investigate the extent to which stress effects may be mediated by psychiatric and substance dependence disorders. We conclude that the effect of social stress on the risk for smoking is additive over time. The significant independent effect of early stress exposure implies that youths who are at greater risk for eventual heavy smoking may be identified at ages considerably younger than peak initiation age.
Outcome following emergency surgery for refractory severe ulcerative colitis in a tertiary care centre in India
Authors: Pal Sujoy , Sahni Peush , Pande Girish K , Acharya Subrat K , Chattopadhyay Tushar K
Published: December 2005

Background

Steroid-based intensive medical therapy for severe ulcerative colitis is successful in 60–70% of such patients. Patients with complications or those refractory to medical therapy require emergency colectomy for salvage. Little is known about the impact of timing of surgical intervention and surgical outcomes of such patients undergoing emergency surgery in India where the diagnosis is often delayed or missed in patients who are poor, malnourished and non-compliant to medical treatment.

Methods

The clinical records of all patients undergoing emergency surgery for severe ulcerative colitis or its complication in the Department of GI surgery AIIMS, New Delhi, India, between January 1985 and December 2003 were retrieved and data pertaining to demographic features, duration of intensive medical therapy, presence of complications, time from admission to emergency surgery, surgical procedure, in-hospital morbidity and mortality and follow up status extracted.

Results

A total of 72 patients underwent emergency surgery (Subtotal colectomy: 60; ileostomy alone under local anaesthesia: 12). Poor nutritional status was seen in 61% of the patients.

Twenty-one patients (29%) underwent emergency surgery for complications of severe ulcerative colitis such as colonic perforation (spontaneous 6, iatrogenic 4), massive lower gastrointestinal haemorrhage (5), toxic megacolon (4) and large bowel obstruction (2). The remaining patients (n = 51) underwent emergency surgery following failed intensive therapy; 17 underwent surgery ≤5 days (Group I) and 34 were operated >5 days (Group II) after initiation of intensive therapy. In this group all the post-operative deaths (n = 8) occurred in those who were operated after 5 days. The difference in mortality in these two groups (i.e. surgical intervention ≤ or >5 days) was statistically significant {0/17 (Group I) vs 8/34 (Group II); p = 0.03}.

Overall, 12 patients died (in-hospital mortality: 16.7%). The mortality was higher (10/43; 23.3%) in our early experience (i.e. 1985–1995) when compared to our subsequent experience (2/29; 6.9%) (1996–2003).

A total of 48 patients (including 3 awaiting a restorative procedure) are alive on follow up (66.7%; 3 patients lost to follow up). A restorative procedure could be successfully completed in 81% of the survivors of the emergency procedure.

Conclusion

To optimize the outcome, a combined team of physicians and surgeons should be involved in the management of patients with severe ulcerative colitis with focus on nutritional support, correction of metabolic derangements, close clinical monitoring and timely assessment for the need for emergency surgery. This retrospective analysis shows that improved results can be achieved with experience and by following a policy of early surgical intervention within 5 days, especially in patients who have failed intensive medical therapy.
On the genetic involvement of apoptosis-related genes in Crohn's disease as revealed by an extended association screen using 245 markers: no evidence for new predisposing factors
Authors: Wagenleiter Sonja EN , Jagiello Peter , Akkad Denis A , Arning Larissa , Griga Thomas , Klein Wolfram , Epplen Jörg T
Published: December 2005

Crohn's disease (CD) presents as an inflammatory barrier disease with characteristic destructive processes in the intestinal wall. Although the pathomechanisms of CD are still not exactly understood, there is evidence that, in addition toe.g. bacterial colonisation, genetic predisposition contributes to the development of CD. In order to search for predisposing genetic factors we scrutinised 245 microsatellite markers in a population-based linkage mapping study. These microsatellites cover gene loci the encoded protein of which take part in the regulation of apoptosis and (innate) immune processes. Respective loci contribute to the activation/suppression of apoptosis, are involved in signal transduction and cell cycle regulators or they belong to the tumor necrosis factor superfamily, caspase related genes or the BCL2 family. Furthermore, several cytokines as well as chemokines were included. The approach is based on three steps: analyzing pooled DNAs of patients and controls, verification of significantly differing microsatellite markers by genotyping individual DNA samples and, finally, additional reinvestigation of the respective gene in the region covered by the associated microsatellite by analysing single-nucleotide polymorphisms (SNPs). Using this step-wise process we were unable to demonstrate evidence for genetic predisposition of the chosen apoptosis- and immunity-related genes with respect to susceptibility for CD.
Hypoxia silences the neural activities in the early phase of the phrenic neurogram of eupnea in the piglet
Authors: Akay Metin
Published: December 2005

Objective

We investigated phrenic neurogram patterns during eupnea (normal breathing) and severe hypoxia (gasping) during early maturation in the piglet.

Methods

We used continuous wavelet transform and short time Fourier transform methods to examine the similarity of breathing patterns in both time and frequency domains during early maturation. The phrenic neurogram was recorded during eupnea, severe hypoxia, and recovery from severe hypoxia in piglets in three different age groups: 3–6 days, 10–15 days and 29–35 days.

Results

During the first week of postnatal age, respiratory patterns of phrenic activity were marked by frequency components between 30 and 300 Hz during both the early (first half) and late (second half) phases of the neurogram signals during eupnea. The results suggest that there is little difference between the respiratory patterns in both time and frequency domains during eupnea compared to gasping for the first week of postnatal age in piglets. After the first week of postnatal age, the duration of the phrenic neurogram burst significantly increases and the patterns during the early phase of the phrenic neurogram are different from those observed for gasping. However, the patterns that mark the late phase of the phrenic neurograms are still the same as those of gasping.

Conclusion

Our most significant finding is that hypoxia silences the neural activity in the early phase of phrenic neurogram regardless of maturation.
Adolescent idiopathic scoliosis screening for school, community, and clinical health promotion practice utilizing the PRECEDE-PROCEED model
Authors: Mirtz Timothy A , Thompson Mark A , Greene Leon , Wyatt Lawrence A , Akagi Cynthia G
Published: December 2005

Background

Screening for adolescent idiopathic scoliosis (AIS) is a commonly performed procedure for school children during the high risk years. The PRECEDE-PROCEDE (PP) model is a health promotion planning model that has not been utilized for the clinical diagnosis of AIS. The purpose of this research is to study AIS in the school age population using the PP model and its relevance for community, school, and clinical health promotion.

Methods

MEDLINE was utilized to locate AIS data. Studies were screened for relevance and applicability under the auspices of the PP model. Where data was unavailable, expert opinion was utilized based on consensus.

Results

The social assessment of quality of life is limited with few studies approaching the long-term effects of AIS. Epidemiologically, AIS is the most common form of scoliosis and leading orthopedic problem in children. Behavioral/environmental studies focus on discovering etiologic relationships yet this data is confounded because AIS is not a behavioral. Illness and parenting health behaviors can be appreciated. The educational diagnosis is confounded because AIS is an orthopedic disorder and not behavioral. The administration/policy diagnosis is hindered in that scoliosis screening programs are not considered cost-effective. Policies are determined in some schools because 26 states mandate school scoliosis screening. There exists potential error with the Adam's test. The most widely used measure in the PP model, the Health Belief Model, has not been utilized in any AIS research.

Conclusion

The PP model is a useful tool for a comprehensive study of a particular health concern. This research showed where gaps in AIS research exist suggesting that there may be problems to the implementation of school screening. Until research disparities are filled, implementation of AIS screening by school, community, and clinical health promotion will be compromised. Lack of data and perceived importance by school/community health planners may influence clinical health promotion practices.
Mid-to late-Holocene land-use change and lake development at Dallund S0, Denmark: study aims, natural and cultural setting, chronology and soil erosion history
Authors: Rasmussen Peter , Bradshaw Emily G.
Published: November 2005

Dallund S0, a lake on the island of Funen, Denmark, is positioned in a landscape that has been heavily impacted by human activities and land-use change over thousands of years. In 1998 a project was initiated to utilize a variety of palaeoecological analyses to investigate lake response to changing land use through the period of agricultural impact on the Danish landscape, i.e., the last 6000 years. This paper describes the overall aims of the study, the natural and cultural setting, sediment core collection, sampling and physical properties, the chronology and erosion history. The long-term changes in the terrestrial and aquatic ecosystem are assessed in the following papers in this Research set using (i) pollen, (ii) diatoms, macrofossils and Pediastrum and (iii) zooplankton. These papers are followed by a synthesis paper focusing on the linkage between land-use change and lake development.
Mid-to late-Holocene land-use change and lake development at Dallund S0, Denmark: vegetation and land-use history inferred from pollen data
Authors: Rasmussen Peter
Published: November 2005

Pollen and plant macrofossil analysis of an 11-m sediment core from Dallund So, a lake situated in the plains of north Funen, Denmark, provide a record of the last 7000 years of vegetation history in response to changing land-use practices. Around 3900 BC, a distinct Ulmus decline is registered. The first agricultural activity is evidenced c. 400 years after the elm decline by the occurrence of cereal pollen (AvenalTriticum-type). Shortly after this, the Neolithic ‘landnam’ sensu Iversen was detected. Around the transition Late Bronze Age/Pre-Roman Iron Age (500 BC), extensive forest clearances followed by a major expansion of grazing areas, cultivated fields and meadows was inferred. The immigration time of Fagus is hard to identify but a threshold percentage > 2 was reached c. 700 BC, suggesting a local presence of Fagus woodland by then. In the Late Iron Age (AD 400-AD 1050), rising abundances of cereal and Cannabis-type pollen indicate increased arable farming. A contemporary Fagus/Quercus woodland expansion may be due to a change in the agricultural system. Linum-retting in the lake in this period is suggested by the macrofossil record. At the beginning of the Mediaeval period, new major deforestation was inferred, accompanied by a massive expansion of arable farming (cereals, Fagopyrum, Linum, Cannabis). Extensive Linum-retting in the Mediaeval period is documented by the macrofossil record and high values of Cannabis-type pollen in the sediments also suggest intensive retting of hemp plants. In the seventeenth and eighteenth centuries the catchment probably witnessed the strongest agricultural impact of the last 7000 years.
Mid- to late-Holocene land-use change and lake development at Dallund Sø, Denmark: trends in lake primary production as reflected by algal and macrophyte remains
Authors: Bradshaw Emily G. , Rasmussen Peter , Nielsen Helle , Anderson N. John
Published: November 2005

Diatom, macrofossil, pollen, Pediastrum and biogenic silica analyses were carried out on an 11-m sediment sequence from the Danish lake Dallund Sø, demonstrating major changes in the aquatic ecosystem over the last 7000 years. A diatom-phosphorus calibration model was applied to the fossil diatom record to reconstruct in-lake total phosphorus (TP) concentrations over this period. Prior to the introduction of agriculture to the region, c. 6000 years ago, the lake was relatively deep and had low diatom-inferred TP concentrations ( c. 20 υg TP/L), with limited macrophyte growth. Moderate nutrient enrichment of the lake was inferred during the Bronze Age (1700-500 Bc) and Iron Age (500 BC-AD 1050) periods and evidence for water-level lowering was observed. Marked eutrophication of the lake (reconstructed TP levels consistently > 100 υg/L) was associated with major changes in agriculture during the Mediaeval period (AD 1050-1536) and continued to the present day. These data document the long-term anthropogenic impact on Dallund Sø, a lake in an area with a long history of human activity.
Mid- to late-Holocene land-use change and lake development at Dallund Sø, Denmark: trophic structure inferred from cladoceran subfossils
Authors: Johansson Liselotte Sander , Amsinck Susanne Lildal , Bjerring Rikke , Jeppesenl Erik
Published: November 2005

Analyses of cladoceran remains were conducted on an 11-m sediment core from Dallund Sø Denmark, covering approximately the last 7000 years. The densities of planktivorous fish and macrophyte coverage were inferred from previously established transfer functions for Danish lakes using pelagic and plant-associated cladocerans, respectively, as palaeoenvironmental indicators. This is the first reconstruction of the abundance of fish and macrophytes covering millennial timescales. The cladoceran assemblages indicated an early period (4830 BC to c. 750 BC) with low species diversity, being dominated mainly by small-sized pelagic taxa. An intervening period (750 BC-AD 1100) followed, dominated by macrophyte-associated taxa and large-sized pelagic species. A marked increase in the abundance of remains occurred at C. AD 1200 coincident with the introduction of the mouldboard plough to Denmark and major forest clearance in the lake catchment. Further upcore (AD 1300-1700) mud-dwelling taxa increased in importance. Finally (AD 1700-1998), a shift occurred towards taxa characterizing eutrophic conditions. Redundancy analyses and cladoceran-inferred submerged macrophyte coverage and planktivorous fish density indicated overall low levels of nutrients and chlorophyll a, moderate macrophyte coverage (10-24%) and moderate to high fish predation prior to the Roman Iron Age (AD 0-400) followed by higher levels of nutrients and chlorophyll a and lower macrophyte coverage (< 10%) and moderate fish predation in recent times. The results suggest that the lake became increasingly eutrophic through time, not least after forest clearance and intensification of agriculture in Mediaeval times.
Mid-to late-Holocene land-use change and lake development at Dallund S0, Denmark: synthesis of multiproxy data, linking land and lake
Authors: Bradshaw Emily G. , Rasmussen Peter , Odgaard Bent Vad
Published: November 2005

Multiproxy palaeoecological data for lake Dallund S0, Denmark, were synthesized to explore the link between changes in the terrestrial environment (from pollen, and sediment physical properties) with those in the aquatic environment (from diatom, macrofossil, zooplankton and Pediastrum data) since the introduction of agriculture c. 6000 years ago. The lake was relatively insensitive to catchment disturbance during the Neolithic (3870-1700 BC) and Early Bronze Age (1700-1000 BC) periods but was dramatically impacted by environmental changes associated with a major deforestation phase at the transition from the Late Bronze Age (1000-500 BC) to the Pre-Roman Iron Age (500 BC-AD 0). A major eutrophication of the lake took place as a result of a changing agricultural system and also the retting of flax and hemp during the Mediaeval period (AD 1050-1536). Analyses of the data sets representing the terrestrial and aquatic environments demonstrate that human activities over thousands of years have not only impacted and shaped the Danish landscape but have also played a major role in lake development.
Environmental reconstruction from a varve network in the southern Coast Mountains, British Columbia, Canada
Authors: Menounos Brian , Clague John J. , Gilbert Robert , Slaymaker Olav
Published: November 2005

Cores of annually laminated sediments (varves) from five lakes in the southern Coast Mountains of British Columbia, Canada, document clastic sediment response to climate and geomorphic change over the past 120 years. Interannual varve thickness correlates with annual flood magnitude. Interdecadal trends in varve thickness are influenced by other environmental factors such as glacier recession. Despite major differences in the lakes and their contributing watersheds, substantial concordance is observed among the records. A pronounced change in the nature of lake sedimentation, accompanied by higher interannual variability, occurred in 1980. The change coincides with an increase in the magnitude of autumn flooding and major re-organization of the North Pacific climate system. These results highlight new directions for palaeoenvironmental research using varved sediment records, specifically to study the magnitude and spatial extent of past hydro-climatic events.
Palaeohydrology of the Southwest Yukon Territory, Canada, based on multiproxy analyses of lake sediment cores from a depth transect
Authors: Anderson Lesleigh , Abbott Mark B. , Finney Bruce P. , Edwards Mary E.
Published: November 2005

Lake-level variations at Marcella Lake, a small, hydrologically closed lake in the southwestern Yukon Territory, document changes in effective moisture since the early Holocene. Former water levels, driven by regional palaeohydrology, were reconstructed by multiproxy analyses of sediment cores from four sites spanning shallow to deep water. Marcella Lake today is thermally stratified, being protected from wind by its position in a depression. It is alkaline and undergoes bio-induced calcification. Relative accumulations of calcium carbonate and organic matter at the sediment-water interface depend on the location of the depositional site relative to the thermocline. We relate lake-level fluctuations to down-core stratigraphic variations in composition, geochemistry, sedimentary structures and to the occurrence of unconformities in four cores based on observations of modern limnology and sedimentation processes. Twenty-four AMS radiocarbon dates on macrofossils and pollen provide the lake-level chronology. Prior to 10 000 cal. BP water levels were low, but then they rose to 3 to 4 m below modern levels. Between 7500 and 5000 cal. BP water levels were 5 to 6 m below modern but rose by 4000 cal. BP. Between 4000 and 2000 cal. BP they were higher than modern. During the last 2000 years, water levels were either near or 1 to 2 m below modern levels. Marcella Lake water-level fluctuations correspond with previously documented palaeoenvironmental and palaeoclimatic changes and provide new, independent effective moisture information. The improved geochronology and quantitative water-level estimates are a framework for more detailed studies in the southwest Yukon.
Integrated diatom-pollen based Holocene environmental reconstruction of lake Las Margaritas, eastern savannas of Colombia
Authors: Velez M. I. , Wille M. , Hooghiemstral H. , Metcalfe S.
Published: November 2005

A multiproxy analysis that includes diatoms, pollen, element geochemistry, carbon content analysis, and radiocarbon dates was carried out on a core from Las Margaritas (3023‘N, 73026’W) in order to reconstruct environmental and climatic change. This lake is hydrologically closed and is located in the transitional area between the Amazonian rainforest and the savannas of the eastern part of Colombia. It therefore offers an excellent opportunity to study climatic change as expressed by competition between the biomes and changes in lake level caused by changes in water balance. Dry conditions, with a landscape covered by savanna and an incipient lake still influenced by the river system, characterized the period between 11 150 and 9100 cal. yr BP (11 190-8130 4C yr BP). More humid conditions prevailed between 9100 and 7330 cal. yr BP (8130-6470 14C yr BP), during which the forest advanced over the savanna and a swampy, isolated lake was formed. From 7330 to 1870 cal. yr BP, generally humid conditions prevailed, except for two dry periods between 5700-5200 cal. yr BP (4990-4620 14C yr BP) and 2750-1870 cal. yr BP (2640-1920 14C yr BP) that caused a marked decrease in lake level. A period of frequent shifts between drier and wetter periods occurred between 4180 and 2750 cal. yr BP (3810-2640 14C yr BP) and caused dynamic competition between the savanna and the forest and frequent oscillations in lake level. During dry periods lake level dropped and the water had higher conductivity and was richer in nutrients. Swamps with palms (Arecaceae) were formed. During humid periods, the lake had high water levels, the water was acidic, of low conductivity and poor in nutrients; Mauritia swamps surrounded the lake. Modern climates and limnological conditions have been established since 1870 cal. yr BP. The change to more consistently humid conditions observed after 9100 cal. yr BP and comparison with other environmental and climatic reconstructions from northern Colombia, the Llanos Orientales, and the Amazon allow us to conclude that humidity in this zone has been driven by millennial shifts in the Inter Tropical Convergence Zone and is mainly dependent on moisture coming from the Amazon region.
Holocene sea levels and palaeoenvironments, Malay-Thai Peninsula, southeast Asia
Authors: Horton B. P. , Gibbard P. L. , Mine G. M. , Morley R. J. , Purintavaragul C. , Stargardt J. M.
Published: November 2005

Sedimentological and palynological investigations of Great Songkhla Lakes, east coast of the Malay-Thai Peninsula, Southeast Asia, reveal sedimentary sequences rich in palynomorph assemblages dominated by pollen of mangroves and freshwater swamps. Compared with other regions in Southeast Asia the assemblages are of relatively low diversity. Geochronological data indicate that the Great Songkhla Lakes record one of the earliest mangrove environments in Southeast Asia (8420-8190 cal. yr BP), which are subsequently replaced by a freshwater swamp at 7880-7680 cal. yr BP owing to the decline of marine influence. Sea-level observations from Great Songkhla Lakes and other areas of the Malay-Thai Peninsula reveal an upward trend of Holocene relative sea level from a minimum of -22 m at 9700-9250 cal. yr BP to a mid-Holocene high stand of 4850-4450 cal. yr BP, which equates to a rise of c. 5.5 mm/yr. The sea-level fall from the high stand is steady at c. - 1.1 mm/yr. Geophysical modelling shows that hydroisostasy contributes a significant spatial variation to the sea-level signal between some site locations (3-4 m during the mid-Holocene), indicating that it is not correct to construct a single relative sea-level history for the Malay-Thai Peninsula.
Fire ecology north and south of the Alps since the last ice age
Authors: Tinner Willy , Conedera Marco , Ammann Brigitta , Lotter Andre F.
Published: November 2005

Wildfires are very rare in central Europe, which is probably why fire effects on vegetation have been neglected by most central European ecologists and palaeoecologists. Presently, reconstructions of fire history and fire ecology are almost absent. We analysed sediment cores from lakes on the Swiss Plateau (Lobsigensee and Soppensee) for pollen and charcoal to investigate the relationship between vegetation and fire. Microscopic charcoal evidence suggests increasing regional fire frequencies during the Neolithic (7350-4150 cal. BP, 5400-2200 BC) and the subsequent prehistoric epochs at Lobsigensee, whereas at Soppensee burnings remained rather rare until modern times. Neolithic peaks of charcoal at 6200 and 5500 cal. BP (4250 and 3550 BC) coincided with declines of pollen of fire-sensitive taxa at both sites (e.g., Ulmus, Tilia, Hedera, Fagus), suggesting synchronous vegetational responses to fire at regional scales. However, correlation analysis between charcoal and pollen for the period 6600-4400 cal. BP (4650-2650 BC) revealed no significant link between fire and vegetation at Soppensee, whereas at Lobsigensee increases of Corylus and decreases of Fagus were related to fire events. Fire impact on vegetation increased during the subsequent epochs at both sites. Correlation analyses of charcoal and pollen data for the period 4250-1150 cal. BP (2300 BC -AD 800) suggest that fires were intentionally set to disrupt forests and to provide open areas for arable and pastoral farming (e.g., significant positive correlations between charcoal and Cerealia, Plantago lanceolata, Asteroideae). These results are compared with southern European records (Lago di Origlio, Lago di Muzzano), which are situated in particularly fire-prone environments. After the Mesolithic period (I1 200-7350 cal. BP, 9250-5400 BC), charcoal influx was higher by an order of magnitude in the south, suggesting more frequent fires. Neolithic fires caused similar though more pronounced responses of vegetation in the south (e.g., expansions of Corylus). Post-Neolithic land-use practices involving (controlled) burning culminated in both regions at about 2550 cal. BP (c. 600 BC). However, fire-caused disappearances of entire forest communities were confined to the southern sites. Such differences in fire effects among the sites are explained by the dissimilar importance of fire as a result of different climatic conditions and cultural activities. Our results imply that the remaining (fire-sensitive) fragments of central European vegetation north of the Alps are especially endangered by increasing fire frequencies resulting from predicted climatic change.
The Holocene 15,8 (2005) pp. 1227-1235 A geoarchaeological chronology of Holocene dune building on San Miguel Island, California
Authors: Erlandson Jon M. , Rick Torben C. , Peterson Curt
Published: November 2005

A data base of 114 14C dates from 40 archaeological sites in San Miguel Island sand dunes provides a general chronology for Holocene dune building. Although rising seas have probably submerged earlier evidence, postglacial dune building on San Miguel began as early as 10000 years ago. More intensive dune building dates to the middle and late Holocene, including large parabolic dunes that traverse the island and climb some of the highest landforms. Native American peoples lived on and altered island sand dunes for nearly 10 000 years, and native burning and other landscape alterations may have contributed to periodic destabilization of island dunefields. Accumulation of cultural debris also facilitated anthropogenic soil formation in many coastal localities, however, and over the millennia midden debris protected large expanses of the island's coastal perimeter from wind erosion. With the introduction of sheep c. AD 1850, destabilization and erosion of dune soils caused by overgrazing and other human impacts reached unprecedented levels, devastating the island's natural ecology. In recent decades, with the removal of sheep and other exotic animals from the island, the dunes have begun to restabilize.
A Holocene record from a former coastal lagoon in Bahia Kino, Gulf of California, Mexico
Authors: Caballero M. , Peinalba M. C. , Martinez M. , Ortega-Guerrerol B. , Vazquez L.
Published: November 2005

A 10-m-long core was recovered from the coastal flood plain on the eastern margin of the Gulf of California (Bahia Kino, Sonora). Sediments were analysed for loss-on-ignition, magnetic susceptibility, pollen, diatoms, ostracodes and foraminifera. Three levels were dated by 14C. The combined data suggest that the site was flooded during the middle Holocene as sea level increased. At about 6600 yr BP the area was a freshwater to brackish marsh dominated by Typha domingensis and Cyperaceae. Freshwater to brackish conditions suggest the presence of a local source of freshwater during this time and therefore a climate wetter than present. Continued rise in sea level was associated with an increase in depth and salinity. By c. 6350-6250 yr BP, the coring site was an inner lagoon, by c. 6125 yr BP a central lagoon and by c. 5900 yr BP the site was close to the mouth of the lagoon (lower lagoon). Lower lagoon conditions persistel until the top of the record, showing sea-level stabilization; which was followed by the formation of the dune ridge that presently separates the coring site from the sea.