单种属泥炭纤维素碳稳定同位素组成与全新世青藏高原东部西南季风变化

泥炭的形成和积累主要受控于气候，其次是地质、地貌和水文等因素。作为一种重要和理想的气候信息载体，泥炭己经与冰芯、海洋及湖泊沉积、黄土堆积、洞穴碳酸盐沉积、树轮和珊瑚礁等其它类型的自然地质档案一样，逐渐为国内外致力于古气候变化研究的学者所接受，并将其重点应用于全新世以来气候变化信息的提取。本研究在已有的泥炭混合植物残体纤维素碳稳定同位素记录青藏高原东部地区气候信息的基础上，首次提取泥炭中单一种属植物残体一木里苔草（Calexmulieensis）纤维素，测定其碳稳定同位素，并以其时间序列作为一种新的西南季风代用指标，揭示该区域全新世以来气候变化。研究表明：1．木里苔草的碳稳定同位素时间序列是西南季风强度变化的敏感代用指标。约11800～11加0 cal aBP期间，木里苔草纤维素的613C记录处于最大值，表明该时段西南季风活动鼻弱，气候干冷，对应于普遍发生并存在的新仙女木事件；它清晰地指示了该区全新世的下限年龄为约11200 cal aBP（14c年龄约9900aB玲从约11200 oal aBP起该区迅速进入湿暖的全新世阶段，季风活动迅速增强；在约10800～5500 cal aBP期间，季风总体保持在强盛状态，但其间有4次突然减弱，气候变干冷；约从5500 cala即起季风活动在波动中逐渐减弱，其中有4次减弱最为明显。2．木里苔草纤维素碳同位素所记录的犯000年以来的所有9次西南季风活动的突然减弱与同时期北大西洋发生的冰力｝漂移碎屑沉积物事件（IRD事件）一一对应。这种密切的相关关系表明，西南季风强度的波动可能是对全球气候变化特别是对海洋热盐环流引起的地球南北方气撇动变化的响应。3．木里苔草纤维素碳稳定同位素所指示的西南季风有952，乓57，475，312，211和77年等一系列周期。其中557年和77年两个周期分别与北大西洋深层海水环流的550年的周期和76年的气候周期非常吻合。这表明西南季风与北大西洋气候间有很好的相关关系。由于557年和77年的季风周期又都分别类似于53。年和80年的太阳活动周期，这表明太阳活动可能对西南季风和北大西洋气候间的联系有着影响。4．红原泥炭木里苔草纤维素和泥炭混合纤维素别3c时间序列在千年至万年时间尺度上的变化趋势很相近。两种代用记录都一致反映了冰后期的气候变化，即均指示西南季风强度变化可分为三个明显的大阶段。这说明它们对过去12000年的西南季风变化具有相同的响应。对于目前经过较详细研究的那些全球大范围发生的突然气候变化事件，木里苔草纤维素δ~(13)C代用记录与泥炭混合纤维素δ~(13)C代用记录一样，都有相同的响应，但是，相对于泥炭中单一的木里苔草敏感地记录到历次北大西洋I劝事件而言，泥炭混合纤维素δ~(13)C记录对其中的几次突然气候变化事件似乎没有表现出明显的响应。这个结果表明对数百年尺度的突然气候变化，木里苔草纤维素比混合纤维素的酬3c指标似乎要更敏感一点。因此，在能获得足够数量的单种植物·残体的情况下，单种植物残体纤维素的δ~(13)C指标有很好的使用价值。

The Iranian Foreign Policy in the Persian Gulf Region under the Rule of President Hassan Rouhani: Continuity of Change

Although Iran borders with many states and has direct access to the Caspian Sea as well as the Indian Ocean, the Persian Gulf region seems to be the most vital area to its security and prosperity. Yet since the 70’s Iran’s relations with the Arab states in the region have been rather strained and complex. The main reason for that had been the success of the Islamic revolution in 1979 which later resulted in a new dimension of Sunni-Shia rivalry. Moreover, post-revolutionary Iranian authorities also intended to maintain the regional hegemony from the Imperial State of Iran period. As a result, successive Iranian governments competed for hegemony in the Persian Gulf with the littoral Arab states which consolidated their regional positions due to close links and intensive cooperation with the West especially with the United States. Despite some political and economic initiatives which were undertaken by President Mahmoud Ahmadinejad, this rivalry was also evident between 2005–2013. The main aim of this article is to find out whether Iranian foreign policy towards the Arab states in the Persian Gulf region has undergone any significant changes since Hassan Rouhani became the President of the Islamic Republic of Iran in August 2013. According to Mohammad Reza Deshiri, the Iranian foreign policy after 1979 can be divided into so-called waves of idealism and realism. During dominance of idealism values and spirituality are more important than pragmatism while during the realistic waves political as well as economic interests prevail over spirituality. Iranian idealism is connected with export of revolutionary ideas, Shia dominance as well as the restoration of unity among all muslims (ummah). On this basis both presidential terms of Mahmoud Ahmadinejad can be classified as ‘waves of idealism’, albeit some of his ideas were very pragmatic. The question is if Hassan Rouhani’s foreign policy represents a continuity or a change. Is the current Iran’s foreign policy towards the Persian Gulf region idealistic or rather realistic? The main assumption is that there will be no Arab-Iranian rapprochement in the Persian Gulf without a prior normalization of political relations between Iran and the West especially the United States.

Are the native giant tortoises from the Seychelles really extinct? A genetic perspective based on mtDNA and microsatellite data.

The extinction of the giant tortoises of the Seychelles Archipelago has long been suspected but is not beyond doubt. A recent morphological study of the giant tortoises of the western Indian Ocean concluded that specimens of two native Seychelles species survive in captivity today alongside giant tortoises of Aldabra, which are numerous in zoos as well as in the wild. This claim has been controversial because some of the morphological characters used to identify these species, several measures of carapace morphology, are reputed to be quite sensitive to captive conditions. Nonetheless, the potential survival of giant tortoise species previously thought extinct presents an exciting scenario for conservation. We used mitochondrial DNA sequences and nuclear microsatellites to examine the validity of the rediscovered species of Seychelles giant tortoises. Our results indicate that the morphotypes suspected to represent Seychelles species do not show levels of variation and genetic structuring consistent with long periods of reproductive isolation. We found no variation in the mitochondrial control region among 55 individuals examined and no genetic structuring in eight microsatellite loci, pointing to the survival of just a single lineage of Indian Ocean tortoises.

A new species of Tortanus (Atortus) (Copepoda: Calanoida) from the Seychelles, Mauritius and Madagascar

A new species of the planktonic copepod Tortanus (Atortus) (Calanoida: Tortanidae), T. (A.) magnonyx is described from Seychelles, Mauritius and Madagascar. This is the sixth species of the Indian Ocean recticauda species group, of the Indo-West Pacific recticauda species complex, that has been described from the western Indian Ocean. The inshore areas where these copepods are found have been poorly surveyed, so the number of species found implies a high diversity.