Heavy metals in coastal sediments of South Caspian Sea: natural or anthropogenic source?

This paper focuses on heavy metal distribution patterns in sediments of central Guilan (CG) and east Mazandaran (EM) in the south Caspian Sea coasts, north of Iran. Sediment sub-samples were retrieved from core and surficial samples in different environments of marine and coastal lagoons as well as coastal outcrops. Inductively Coupled Plasma Mass Spectrometry and Atomic Emission Spectrometry (ICP-MS and ICP-AES) analysis were used to determine the metal chemistry. Concentration of the selected heavy metals exhibited variations through sediment samples which are partially related to grain size and organic matter content. Geoaccumulation index and statistical procedures have been implemented for analyzing the absolute metal values. Result of the geoaccumulation index demonstrated that the metal distribution reflects the influence of geological background of the watershed area. Some elements including Pb, Ni, Cu, Sr and Ba showed elevated concentration in the CG that could be attributed to development of industrial activities. A comparison of the metal concentration in the marine sediments and the Late Holocene outcrops revealed that the level of the metals concentration at the sea generally corresponds to natural background. The northern part of Iranian multi-lithological catchments basin is the main source for the sediments that drained by the rivers to the South Caspian Sea basin

Human responses to environmental change on the southern coastal plain of the Caspian Sea during the Mesolithic and Neolithic periods

This paper presents results of a multidisciplinary research initiative examining human responses to environmental change at the intersection of the southern coastal plain of the Caspian Sea and the foothills of the Alborz Mountains during the terminal Pleistocene and early Holocene. Our palaeo-environmental analysis of two sedimentary cores obtained from a lagoon in close proximity to four caves, occupied by human groups during the transition from hunting and gathering to food-producing ways of life in this region, confirms Charles McBurney's 1968 hypothesis that when Caspian Sea levels were high, Mesolithic hunters were reliant on seal and deer, but as water levels receded and a wide coastal plain emerged, hunters consumed a different range of herbivorous mammalian species. Palynological evidence obtained from these two cores also demonstrates that the cool and dry climatic conditions often associated with the Younger Dryas stadial do not appear to have been extreme in this region. Thus, increasingly sedentary hunting and gathering groups could have drawn on plant and animal resources from multiple ecological niches without suffering significant resource stress or reduced population levels that may have been encountered in neighbouring regions. Our analyses of botanical, faunal and archaeological remains from a recently-discovered open-air Mesolithic and aceramic Neolithic site also shows an early process of Neolithization in the southern Caspian basin, which was a very gradual, low-cost adaptation to new ways of life, with neither the abandonment of hunting and gathering, nor a climatic trigger event for the emergence of a low-level, food-producing society.This paper presents results of a multidisciplinary research initiative examining human responses to environmental change at the intersection of the southern coastal plain of the Caspian Sea and the foothills of the Alborz Mountains during the terminal Pleistocene and early Holocene. Our palaeo-environmental analysis of two sedimentary cores obtained from a lagoon in close proximity to four caves, occupied by human groups during the transition from hunting and gathering to food-producing ways of life in this region, confirms Charles McBurney's 1968 hypothesis that when Caspian Sea levels were high, Mesolithic hunters were reliant on seal and deer, but as water levels receded and a wide coastal plain emerged, hunters consumed a different range of herbivorous mammalian species. Palynological evidence obtained from these two cores also demonstrates that the cool and dry climatic conditions often associated with the Younger Dryas stadial do not appear to have been extreme in this region. Thus, increasingly sedentary hunting and gathering groups could have drawn on plant and animal resources from multiple ecological niches without suffering significant resource stress or reduced population levels that may have been encountered in neighbouring regions. Our analyses of botanical, faunal and archaeological remains from a recently-discovered open-air Mesolithic and aceramic Neolithic site also shows an early process of Neolithization in the southern Caspian basin, which was a very gradual, low-cost adaptation to new ways of life, with neither the abandonment of hunting and gathering, nor a climatic trigger event for the emergence of a low-level, food-producing society.status: publishe

Late Little Ice Age palaeoenvironmental records from the Anzali and Amirkola Lagoons (south Caspian Sea): Vegetation and sea level changes

This is a postprint version of the article. The official published article can be found from the link below - Copyright @ 2011 Elsevier Ltd.Two internationally important Ramsar lagoons on the south coast of the Caspian Sea (CS) have been studied by palynology on short sediment cores for palaeoenvironmental and palaeoclimatic investigations. The sites lie within a small area of very high precipitation in a region that is otherwise dry. Vegetation surveys and geomorphological investigations have been used to provide a background to a multidisciplinary interpretation of the two sequences covering the last four centuries. In the small lagoon of Amirkola, the dense alder forested wetland has been briefly disturbed by fire, followed by the expansion of rice paddies from AD1720 to 1800. On the contrary, the terrestrial vegetation reflecting the diversity of the Hyrcanian vegetation around the lagoon of Anzali remained fairly complacent over time. The dinocyst and non-pollen palynomorph assemblages, revealing changes that have occurred in water salinity and water levels, indicate a high stand during the late Little Ice Age (LIA), from AD < 1620 to 1800–1830. In Amirkola, the lagoon spit remained intact over time, whereas in Anzali it broke into barrier islands during the late LIA, which merged into a spit during the subsequent sea level drop. A high population density and infrastructure prevented renewed breaking up of the spit when sea level reached its maximum (AD1995). Similar to other sites in the region around the southern CS, these two lagoonal investigations indicate that the LIA had a higher sea level as a result of more rainfall in the drainage basin of the CS.The coring and the sedimentological analyses were funded by the Iranian National Institute for Oceanography in the framework of a research project entitled “Investigation of the Holocene sediment along the Iranian coast of Caspian Sea: central Guilan”. The radiocarbon date of core HCGL02 was funded by V. Andrieu (Europôle Méditerranéen de l'Arbois, France) and that of core HCGA04 by Brunel University

Phacoemulcification with Intravitreal Bevacizumab Injection in Patients with Cataract and Coexisting Diabetic Retinopathy: Prospective Randomized Study

Objective: To evaluate efficacy of intravitreal injection of bevacizumab at the time of cataract surgery on the postoperative progression of diabetic retinopathy (DR) and diabetic maculopathy. Methods: Patients were randomized to a standardized procedure of phacoemulsification with intraocular lens implantation alone (control group; 30 eyes) or to receive 1.25 mg intravitreal bevacizumab (0.05 mL of solution prepared from avastin, 100 mg/4 mL vial) at the end of surgery (IVB group; 27 eyes). Efficacy measures included best-corrected visual acuity (BCVA) testing, optical coherence tomography (OCT), and ophthalmoscopic examination at each postoperative visit during a 6-month follow-up. Results: There were no significant differences in central macular thickness (CMT), BCVA, or systemic condition between the control and IVB groups at baseline. Progression of diabetic maculopathy occurred in 15 eyes (50%) in the control group and 2 eyes (7.4%) in the intervention group (P = 0.0008). There was no statistically significant difference in postoperative visual acuity between the 2 groups after 6 months (P = 0.5). Five eyes in the control group and 1 eye in the intervention group progressed to neovascular glaucoma. Difference in mean postoperative CMT was not statistically significant between both groups (P = 0.54). Conclusions: Intravitreal administration of 1.25 mg bevacizumab at the time of cataract surgery was safe and effective in preventing the progression of DR and diabetic maculopathy in patients with cataract and DR

The Persian Gulf&apos;s Holocene data: XRF, organic geochemistry, palynology and sediment

The dataset contains the results of different analyses on three short sediment cores from deepest areas of the Persian Gulf. It includes organic geochemistry, palynology, sedimentology, C and N analysis and XRF data that are organized in different tabs.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Trace of

In present work, we investigated K^{-}+\, ^{3}\mathrm {He} reaction at low energies. The coupled-channel Faddeev AGS equations were solved for $${\bar{K}}Nd-\pi \varSigma {d}$$ three-body system in momentum representation to extract the scattering amplitudes. To trace the signature of the $$\varLambda$$(1405) resonance in the $$\pi \varSigma$$ invariant mass, the deuteron energy spectrum for K^{-}+\,^{3}\mathrm {He}\rightarrow \pi \varSigma {d} reaction was obtained. Different types of $${\bar{K}}N-\pi \varSigma$$ potentials based on phenomenological and chiral SU(3) approaches were used. As a remarkable result of this investigation, it was found that the deuteron energy spectrum, reflecting the $$\varLambda$$(1405) mass distribution and width, depends quite sensitively on the $${\bar{K}}N-\pi \varSigma$$ model of interaction. Hence accurate measurements of the $$\pi \varSigma$$ mass distribution have the potential to discriminate between possible mechanisms at work in the formation of the $$\varLambda$$(1405)

QuickLakeH: Rapidly changing large lakes and human response

WOS: 000377882700001

Assessing the centennial-scale hydrological variability of Lake Maharlou (SW Iran) over the last 3500 years using sedimentological and geochemical analysis

https://hal.archives-ouvertes.fr/hal-02567362International audienc