The present study was conducted to examine the distributional characteristics of floral communities along the altitudinal gradients in Hoang Lien National Park (HLNP), located in Lao Cai province, Vietnam. We recorded...The present study was conducted to examine the distributional characteristics of floral communities along the altitudinal gradients in Hoang Lien National Park (HLNP), located in Lao Cai province, Vietnam. We recorded the relatively abundant flora system with 3252 species (including 361 endemic species and 237 endangered species), belonging to 1126 genera, 230 families and 6 different phyla. Methodology of sampling, specimen collection and identification, statistical analysis are simultaneously used for investigating the complex changes of composition and richness of plant assemblages. The study results indicated the divisions in quantity and composition, especially differentiation of endemic and rare species in accordance with altitudinal gradients.展开更多
Human exposure to arsenic (As) is primarily through drinking water and food ingestion. Arsenic is naturally present in the environment and has been known as “the king of poisons” since the Middle Ages. It is mutagen...Human exposure to arsenic (As) is primarily through drinking water and food ingestion. Arsenic is naturally present in the environment and has been known as “the king of poisons” since the Middle Ages. It is mutagenic, teratogenic, and carcinogenic and approximately 70% comes from ingested food and 29% from water. Once ingested, arsenic can bio-accumulate in the human body or be excreted. Arsenic in groundwater is a main source of As in humans and the two arsenicals most abundant in water are arsenite (+3 oxidation state) and arsenate (+5 oxidation state). In order of toxicity from the most toxic to least toxic are arsines, arsenites, arsenoxides, arsenates, pentavalent arsenicals, Arsenic compounds, and metallic arsenic. Arsenic accumulates in the body when ingested in small doses. It often takes decades before physical symptoms of As poisoning show. While As is element normally found in the human body, it is highly toxic in excess amounts. The lethal dose for rates is 48 μg/L which translates to 125 mg for a middle-aged male. The maximum safe limit for As ingestion for an average Vietnamese middle-aged male is 220 μg per day. This lethal dosage puts As in a highly toxic category in food and toxicology. Most of the As in the Mekong Delta groundwater is from natural alluvial sediment sources. Other anthropic sources include the burial of millions of Vietnamese with elevated As levels since 1962, industrial sources, smelting by-products, water treatment plants, sewage and wastewater treatment discharges into waterways have added to the Mekong Delta As levels in the soil and groundwater. However, Agent Blue, the As-based herbicide, used during the Vietnam War, did contribute a significant amount (over 1,132,400 kg of manufactured (anthropic) As) to Southern Vietnam landscape. The As spikes and levels in the Mekong Delta soils and groundwater need restoration. The uptake of trace amounts of As in rice is indeed a critical food security and human health issue and requires mitigation.展开更多
本文介绍了升龙皇城遗址(Hoàng thành Th?ng Long)出土的17-18世纪越南黎朝中兴时期海阳瓷器(甲、乙、丙、丁组),产地集中于平江制瓷中心的柿窑(C?y)、劳窑(Láo)和合礼窑(H?p L?)等。作者通过分析其特征、类型后,推断该...本文介绍了升龙皇城遗址(Hoàng thành Th?ng Long)出土的17-18世纪越南黎朝中兴时期海阳瓷器(甲、乙、丙、丁组),产地集中于平江制瓷中心的柿窑(C?y)、劳窑(Láo)和合礼窑(H?p L?)等。作者通过分析其特征、类型后,推断该时期升龙城本地的窑口可能已经衰落,而民窑瓷器开始涌入宫廷,同时按照功能对这批瓷器进行类型归纳。通过对海阳瓷器的研究,可以看到当时升龙皇宫内贵族们嗜好饮酒、抽水烟、嚼槟榔等多样的生活面貌。展开更多
文摘The present study was conducted to examine the distributional characteristics of floral communities along the altitudinal gradients in Hoang Lien National Park (HLNP), located in Lao Cai province, Vietnam. We recorded the relatively abundant flora system with 3252 species (including 361 endemic species and 237 endangered species), belonging to 1126 genera, 230 families and 6 different phyla. Methodology of sampling, specimen collection and identification, statistical analysis are simultaneously used for investigating the complex changes of composition and richness of plant assemblages. The study results indicated the divisions in quantity and composition, especially differentiation of endemic and rare species in accordance with altitudinal gradients.
文摘Human exposure to arsenic (As) is primarily through drinking water and food ingestion. Arsenic is naturally present in the environment and has been known as “the king of poisons” since the Middle Ages. It is mutagenic, teratogenic, and carcinogenic and approximately 70% comes from ingested food and 29% from water. Once ingested, arsenic can bio-accumulate in the human body or be excreted. Arsenic in groundwater is a main source of As in humans and the two arsenicals most abundant in water are arsenite (+3 oxidation state) and arsenate (+5 oxidation state). In order of toxicity from the most toxic to least toxic are arsines, arsenites, arsenoxides, arsenates, pentavalent arsenicals, Arsenic compounds, and metallic arsenic. Arsenic accumulates in the body when ingested in small doses. It often takes decades before physical symptoms of As poisoning show. While As is element normally found in the human body, it is highly toxic in excess amounts. The lethal dose for rates is 48 μg/L which translates to 125 mg for a middle-aged male. The maximum safe limit for As ingestion for an average Vietnamese middle-aged male is 220 μg per day. This lethal dosage puts As in a highly toxic category in food and toxicology. Most of the As in the Mekong Delta groundwater is from natural alluvial sediment sources. Other anthropic sources include the burial of millions of Vietnamese with elevated As levels since 1962, industrial sources, smelting by-products, water treatment plants, sewage and wastewater treatment discharges into waterways have added to the Mekong Delta As levels in the soil and groundwater. However, Agent Blue, the As-based herbicide, used during the Vietnam War, did contribute a significant amount (over 1,132,400 kg of manufactured (anthropic) As) to Southern Vietnam landscape. The As spikes and levels in the Mekong Delta soils and groundwater need restoration. The uptake of trace amounts of As in rice is indeed a critical food security and human health issue and requires mitigation.
文摘本文介绍了升龙皇城遗址(Hoàng thành Th?ng Long)出土的17-18世纪越南黎朝中兴时期海阳瓷器(甲、乙、丙、丁组),产地集中于平江制瓷中心的柿窑(C?y)、劳窑(Láo)和合礼窑(H?p L?)等。作者通过分析其特征、类型后,推断该时期升龙城本地的窑口可能已经衰落,而民窑瓷器开始涌入宫廷,同时按照功能对这批瓷器进行类型归纳。通过对海阳瓷器的研究,可以看到当时升龙皇宫内贵族们嗜好饮酒、抽水烟、嚼槟榔等多样的生活面貌。
