Composition and characteristics of the ferromanganese crusts from the western Arctic Ocean

Layered ferromanganese crusts collected by dredge from a water depth range of 2770 to 2200 m on Mendeleev Ridge, Arctic Ocean,were analyzed formineralogical and chemical compositions and dated using the excess 230Th technique. Comparison with crusts from other oceans reveals that Fe-Mn deposits of Mendeleev Ridge have the highest Fe/Mn ratios, are depleted inMn, Co, and Ni, and enriched in Si and Al aswell as some minor elements, Li, Th, Sc, As and V. However, the upper layer of the crusts shows Mn, Co, and Ni contents comparable to crusts from the Atlantic and Indian Oceans. Growth rates vary from3.03 to 3.97mm/Myr measured on the uppermost 2mm. Mn and Fe oxyhydroxides (vernadite, ferroxyhyte, birnessite, todorokite and goethite) and nonmetalliferous detrital minerals characterize the Arctic crusts. Temporal changes in crust composition reflect changes in the depositional environment. Crust formation was dominated by three main processes: precipitation of Fe-Mn oxyhydroxides from ambient ocean water, sorption of metals by those Fe and Mn phases, and fluctuating but large inputs of terrigenous debris.

Ecological responses of Western Palearctic avian species to late Quaternary climate oscillations

This PhD thesis explores the ecological responses of bird species to glacial-interglacial transitions during the late Quaternary in the Western Palearctic, using multiple approaches and at different scales, enhancing the importance of the bird fossil record and quantitative methods to elucidate biotic trends in relation to long-term climate changes. The taxonomic and taphonomic analyses of the avian fossil assemblages from four Italian Middle and Upper Pleistocene sedimentary successions (Grotta del Cavallo, Grotta di Fumane, Grotta di Castelcivita, and Grotta di Uluzzo C) allowed us to reconstruct local-scale patterns in birds’ response to climate changes. These bird assemblages are characterized by the presence of temperate species and by the occasional presence of cold-dwelling species during glacials, related to range shifts. These local patterns are supported by those identified at the continental scale. In this respect, I mapped the present-day and LGM climatic envelopes of species with different climatic requirements. The results show a substantial stability in the range of temperate species and pronounced changes in the range of cold-dwelling species, supported by their fossil records. Therefore, the responses to climate oscillations are highly related to the thermal niches of investigated species. I also clarified the dynamics of the presence of boreal and arctic bird species in Mediterranean Europe, due to southern range shifts, during the glacial phases. After a reassessment of the reliability of the existing fossil evidence, I show that this phenomenon is not as common as previously thought, with important implications for the paleoclimatic and paleoenvironmental significance of the targeted species. I have also been able to explore the potential of multivariate and rarefaction methods in the analyses of avian fossils from Grotta del Cavallo. These approaches helped to delineate the main drivers of taphonomic damages and the dynamics of species diversity in relation to climate-driven paleoenvironmental changes.

Evidence of long-term changes in the distribution of key intertidal species

World Congress of Malacology, Ponta Delgada, July 22-28, 2013.

Changes in prolactin secretion in the short- and long-term after adrenalectomy

OBJECTIVE: To evaluate the modulation of the hypothalamus-pituitary-adrenal axis (HPA) on prolactin secretion in rats after adrenalectomy (ADX). MATERIALS AND METHODS: Plasma corticosterone, ACTH, and prolactin concentrations were measured by radioimmunoassay in rats after bilateral ADX in the short- (3 hours and 1day) and long-term (3, 7, and 14 days). RESULTS: Animals that underwent ADX showed undetectable corticosterone levels and a triphasic ACTH response with a transient increase (3h), a decrease (1d), and further increase in the long-term after ADX. Sham animals showed a marked increase in corticosterone and ACTH levels three hours after surgery, with a decrease to basal levels thereafter. Plasma prolactin levels were not changed after ADX. CONCLUSION: There are different points of equilibrium in the HPA axis after the glucocorticoid negative feedback is removed. Prolactin plasma secretion is not altered in the short or long- term after ADX, suggesting that the peptidergic neurons essential for prolactin release are not activated after ADX.

Determining the long-term changes in biodiversity and provisioning services along a transect from Central Europe to the Mediterranean

Climate, land use and fire are strong determinants of plant diversity, potentially resulting in local extinctions, including rare endemic and economically valuable species. While climate and land use are decisive for vegetation composition and thus the species pool, fire disturbance can lead to landscape fragmentation, affecting the provisioning of important ecosystem services such as timber and raw natural resources. We use multi-proxy palaeoecological data with high taxonomic and temporal resolution across an environmental gradient to assess the long-term impact of major climate shifts, land use and fire disturbance on past vegetation openness and plant diversity (evenness and richness). Evenness of taxa is inferred by calculating the probability of interspecific encounter (PIE) of pollen and spores and species richness by palynological richness (PRI). To account for evenness distortions of PRI, we developed a new palaeodiversity measure, which is evenness-detrended palynological richness (DE-PRI). Reconstructed species richness increases from north to south regardless of time, mirroring the biodiversity increase across the gradient from temperate deciduous to subtropical evergreen vegetation. Climatic changes after the end of the last ice age contributed to biodiversity dynamics, usually by promoting species richness and evenness in response to warming. The data reveal that the promotion of diverse open-land ecosystems increased when human disturbance became determinant, while forests became less diverse. Our results imply that the today’s biodiversity has been shaped by anthropogenic forcing over the millennia. Future management strategies aiming at a successful conservation of biodiversity should therefore consider the millennia-lasting role of anthropogenic fire and human activities.

The long-term development of avalanche risk in settlements considering the temporal variability of damage potential

Recent studies on the avalanche risk in alpine settlements suggested a strong dependency of the development of risk on variations in damage potential. Based on these findings, analyses on probable maximum losses in avalanche-prone areas of the municipality of Davos (CH) were used as an indicator for the long-term development of values at risk. Even if the results were subject to significant uncertainties, they underlined the dependency of today's risk on the historical development of land-use: Small changes in the lateral extent of endangered areas had a considerable impact on the exposure of values. In a second step, temporal variations in damage potential between 1950 and 2000 were compared in two different study areas representing typical alpine socio-economic development patterns: Davos (CH) and Galtür (A). The resulting trends were found to be similar; the damage potential increased significantly in number and value. Thus, the development of natural risk in settlements can for a major part be attributed to long-term shifts in damage potential.

Long-term Responses of Mountain Ecosystems to Environmental Changes: Resilience, Adjustment, and Vulnerability

The steep environmental gradients of mountain ecosystems over short distances reflect large gradients of several climatic parameters and hence provide excellent possibilities for ecological research on the effects of environmental change. To gain a better understanding of the dynamics of abiotic and biotic parameters of mountain ecosystems, long-term records are required since permanent plots in mountain regions cover in the best case about 50 - 70 years. In order to extend investigations of ecological dynamics beyond these temporal limitations of permanent plots, paleoecological approaches can be used if the sampling resolution can be adapted to ecological research questions, e.g. a sample every 10 years. Paleoecological studies in mountain ecosystems can provide new ecological insights through the combination of different spatial and temporal scales. [f we thus improve our understanding of processes across both steep environmental gradients and different time scales, we may be able to better estimate ecosystem responses to current and future environmental change (Ammann et al. 1993; Lotter et al. 1997). The complexity of ecological interactions in mountain regions forces us to concentrate on a number of sub-systems - without losing sight of the wider context. Here, we summarize a few case studies on the effects of Holocene climate change and disturbance on the vegetation of the Western Alps. To categorize the main response modes of vegetation to climatic change and disturbance in the Alps we use three classes of ecological behaviour: "resilience", "adjustment", and "vulnerability", We assume a resilient (or elastic) behaviour if vegetation is able to recover to its former state, regaining important ecosystem characteristics, such as floristic composition, biodiversity, species abundances, and biomass (e.g. Küttel 1990; Aber and Melillo 199 1). Conversely, vegetation displacements may occur in response to climatic change and/or disturbance. In some cases, this may culminate in irreversible large-scale processes such as species and/or community extinctions. Such drastic developments indicate high ecosystem vulnerability (or inelasticity or instability, for detailed definitions see Küttel 1990; Aber and Melillo 199 1) to climatic change and/or disturbance. In this sense, the "vulnerability" (or instability) of an ecosystem is expressed by the degree of failure to recover to the original state before disturbance and/or climatic change. Between these two extremes (resilience vs. vulnerability), ecosystem adjustments to climatic change and/or disturbance may occur, including the appearance of new and/or the disappearance of old species. The term "adjustment" is hence used to indicate the response of vegetational communities, which adapted to new environmental conditions without losing their main character. For forest ecosystems, we assume vegetational adjustments (rather than vulnerability) if the dominant (or co-dominant) tree species are not outnumbered or replaced by formerly unimportant plant species or new invaders. Adaptation as a genetic process is not discussed here and will require additional pbylogeographical studies (that incorporate the analysis of ancient DNA) in order to fully understand the distributions of ecotypes.

Changes in biodiversity and trade-offs among ecosystem services, stakeholders, and components of well-being: the contribution of the International Long-Term Ecological Research network (ILTER) to Programme on Ecosystem Change and Society (PECS)

The International Long-Term Ecological Research (ILTER) network comprises > 600 scientific groups conducting site-based research within 40 countries. Its mission includes improving the understanding of global ecosystems and informs solutions to current and future environmental problems at the global scales. The ILTER network covers a wide range of social-ecological conditions and is aligned with the Programme on Ecosystem Change and Society (PECS) goals and approach. Our aim is to examine and develop the conceptual basis for proposed collaboration between ILTER and PECS. We describe how a coordinated effort of several contrasting LTER site-based research groups contributes to the understanding of how policies and technologies drive either toward or away from the sustainable delivery of ecosystem services. This effort is based on three tenets: transdisciplinary research; cross-scale interactions and subsequent dynamics; and an ecological stewardship orientation. The overarching goal is to design management practices taking into account trade-offs between using and conserving ecosystems toward more sustainable solutions. To that end, we propose a conceptual approach linking ecosystem integrity, ecosystem services, and stakeholder well-being, and as a way to analyze trade-offs among ecosystem services inherent in diverse management options. We also outline our methodological approach that includes: (i) monitoring and synthesis activities following spatial and temporal trends and changes on each site and by documenting cross-scale interactions; (ii) developing analytical tools for integration; (iii) promoting trans-site comparison; and (iv) developing conceptual tools to design adequate policies and management interventions to deal with trade-offs. Finally, we highlight the heterogeneity in the social-ecological setting encountered in a subset of 15 ILTER sites. These study cases are diverse enough to provide a broad cross-section of contrasting ecosystems with different policy and management drivers of ecosystem conversion; distinct trends of biodiversity change; different stakeholders’ preferences for ecosystem services; and diverse components of well-being issues.

Short-term and long-term changes in corneal power are not correlated with axial elongation of the eye induced by orthokeratology in children

PURPOSE: To assess the relationship between short-term and long-term changes in power at different corneal locations relative to the change in central corneal power and the 2-year change in axial elongation relative to baseline in children fitted with orthokeratology contact lenses (OK). METHODS: Thirty-one white European subjects 6 to 12 years of age and with myopia −0.75 to −4.00 DS and astigmatism ≤1.00 DC were fitted with OK. Differences in refractive power 3 and 24 months post-OK in comparison with baseline and relative to the change in central corneal power were determined from corneal topography data in eight different corneal regions (i.e., N[nasal]1, N2, T[temporal]1, T2, I[inferior]1, I2, S[superior]1, S2), and correlated with OK-induced axial length changes at two years relative to baseline. RESULTS: After 2 years of OK lens wear, axial length increased by 0.48±0.18 mm (P0.05). CONCLUSION: The reduction in central corneal power and relative increase in paracentral and pericentral power induced by OK over 2 years were not significantly correlated with concurrent changes in axial length of white European children.

Long-term changes in fish communities of the Ria Formosa coastal lagoon (southern Portugal) based on two studies made 20 years apart

Fish communities of the Ria Formosa coastal lagoon (south Portugal) were sampled on a monthly basis with a beach seine at 4 sites, during two different time periods: 1980-1986 and 2001-2002. Community indices, species ranking and multivariate analysis were used in order to identify changes in the fish community between the two time periods. A total of 153,511 fish representing 57 taxa were recorded. Although species composition was very similar for both sampling periods, multivariate analysis performed on annual species abundance in number and weight revealed differences in fish community structure between the two periods. Structural changes in fish community were related mostly to a sharp decrease in the abundance of Mugilidae from 1980-1986 to 2001-2002. These changes were probably associated to a decrease in organic matter contents and nutrients concentrations due to improvements in sewage treatment and better water circulation inside the lagoon. The changes in fish community structure are more evident in the inner areas of the lagoon than near the inlet. The association between changes in sewage patterns and changes in the ichthyofaunal community structure reinforces the importance of fish communities as a biological indicator of human induced changes in marine systems. (c) 2007 Elsevier Ltd. All rights reserved.

Long-term Postoperative Atrophy Of Contralateral Hippocampus And Cognitive Function In Unilateral Refractory Mtle With Unilateral Hippocampal Sclerosis.

This study aimed to evaluate long-term atrophy in contralateral hippocampal volume after surgery for unilateral MTLE, as well as the cognitive outcome for patients submitted to either selective transsylvian amygdalohippocampectomy (SelAH) or anterior temporal lobe resection (ATL). We performed a longitudinal study of 47 patients with MRI signs of unilateral hippocampal sclerosis (23 patients with right-sided hippocampal sclerosis) who underwent surgical treatment for MTLE. They underwent preoperative/postoperative high-resolution MRI as well as neuropsychological assessment for memory and estimated IQ. To investigate possible changes in the contralateral hippocampus of patients, we included 28 controls who underwent two MRIs at long-term intervals. The volumetry using preoperative MRI showed significant hippocampal atrophy ipsilateral to the side of surgery when compared with controls (p<0.0001) but no differences in contralateral hippocampal volumes. The mean postoperative follow-up was 8.7 years (± 2.5 SD; median=8.0). Our patients were classified as Engel I (80%), Engel II (18.2%), and Engel III (1.8%). We observed a small but significant reduction in the contralateral hippocampus of patients but no volume changes in controls. Most of the patients presented small declines in both estimated IQ and memory, which were more pronounced in patients with left TLE and in those with persistent seizures. Different surgical approaches did not impose differences in seizure control or in cognitive outcome. We observed small declines in cognitive scores with most of these patients, which were worse in patients with left-sided resection and in those who continued to suffer from postoperative seizures. We also demonstrated that manual volumetry can reveal a reduction in volume in the contralateral hippocampus, although this change was mild and could not be detected by visual analysis. These new findings suggest that dynamic processes continue to act after the removal of the hippocampus, and further studies with larger groups may help in understanding the underlying mechanisms.

High-energy events and short-term changes in superficial beach sediments

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Clinical changes of cervical dystonia pattern in long-term botulinum toxin treated patients

Cervical dystonia (CD) is a complex disorder but the response to long-term botulinum toxin (BTX) therapy is satisfactory in most cases. Bad results are attributed by some authors to changes in muscle activation. Our purpose is to verify if the change in head deviation affects negatively the response to BTX therapy it) a long-term follow-up, and if there are any differences in clinical parameters of these patients in comparison to those with stable pattern. From a total of 88 patients evaluated at the Movement Disorders Clinics of Hospital das Clinicas - University of Sao Paulo School of Medicine between January 1993 and December 2005, 67 were included. In 24 (35.8%) change in pattern of CID was observed, in a medium follow-up period of 80 months. The time between onset of dystonia and the diagnosis of pattern change was 9.7 years. Comparing with patients with no changes in CD pattern, there were no significant statistical differences. Improvement of symptoms around 60% was reported in both groups. In conclusion, the change in head deviation observed in CD was not responsible for bad response to therapy with BTX and there were no significant differences between both groups. (C) 2009 Elsevier Ltd. All rights reserved.

Can ECG changes predict the long-term outcome in patients admitted to hospital for suspected acute myocardial infarction?

7,028 patients with suspected acute myocardial infarction and discharged alive from hospital were followed in a 10-year community-based study. The long-term prognosis was relatively good if the electrocardiograms (ECGs) were normal (5-year all-cause death rate 5%), poor with uncodable ECGs showing rhythm or conduction disturbances (37%), and intermediate with new Q wave, new ST elevation, new T wave inversion or ischemic ECG (17-21%), and with new ST depression (27%). Similar patterns were found for ischemic cardiac death and reinfarction. The long-term prognosis of patients with suspected acute myocardial infarction is relatively good if the ECGs are normal and poor if ECGs are uncodable. ST depression may be a marker for a worse long-term outcome.

Long-term maintenance of the analgesic effects of transcranial magnetic stimulation in fibromyalgia

We assessed for the first time the long-term maintenance of repetitive transcranial magnetic stimulation (rTMS)-induced analgesia in patients with chronic widespread pain due to fibromyalgia. Forty consecutive patients were randomly assigned, in a double-blind fashion, to 2 groups: one receiving active rTMS (n = 20) and the other, sham stimulation (n = 20), applied to the left primary motor cortex. The stimulation protocol consisted of 14 sessions: an ""induction phase"" of 5 daily sessions followed by a ""maintenance phase"" of 3 sessions a week apart, 3 sessions a fortnight apart, and 3 sessions a month apart. The primary outcome was average pain intensity over the last 24 hours, measured before each stimulation from day 1 to week 21 and at week 25 (1 month after the last stimulation). Other outcomes measured included quality of life, mood and anxiety, and several parameters of motor cortical excitability. Thirty patients completed the study (14 in the sham stimulation group and 16 in the active stimulation group). Active rTMS significantly reduced pain intensity from day 5 to week 25. These analgesic effects were associated with a long-term improvement in items related to quality of life (including fatigue, morning tiredness, general activity, walking, and sleep) and were directly correlated with changes in intracortical inhibition. In conclusion, these results suggest that TMS may be a valuable and safe new therapeutic option in patients with fibromyalgia. (C) 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.