State of rare earth elements in the sediment and their bioaccumulation by mangroves: a case study in pristine islands of Indian Sundarban.

The mangrove ecosystems are known to efficiently sequester trace metals both in sediments and plant biomass. However, less is known about the chemistry of rare earth elements (REE) in the coastal environments, especially in the world's largest mangrove province, the Sundarban. Here, the concentration of REE in the sediment and plant organs of eight dominant mangrove species (mainly Avicennia sp.) in the Indian Sundarban was measured to assess REE sources, distribution, and bioaccumulation state. Results revealed that light REE (LREE) were more concentrated than the heavy REE (HREE) (128-144 mg kg-1 and 12-15 mg kg-1, respectively) in the mangrove sediments, with a relatively weak positive europium anomaly (Eu/Eu* = 1.03-1.14) with respect to North American shale composite. The primary source of REE was most likely linked to aluminosilicate weathering of crustal materials, and the resultant increase in LREE in the detritus. Vertical distribution of REE in one of the long cores from Lothian Island was altered by mangrove root activity and dependent on various physicochemical properties in the sediment (e.g., Eh, pH, organic carbon, and phosphate). REE uptake by plants was higher in the below-ground parts than in the above-ground plant tissues (root = 3.3 mg kg-1, leaf + wood = 1.7 mg kg-1); however, their total concentration was much lower than in the sediment (149.5 mg kg-1). Species-specific variability in bioaccumulation factor and translocation factor was observed indicating different REE partitioning and varying degree of mangrove uptake efficiency. Total REE stock in plant (above + live below ground) was estimated to be 168 g ha-1 with LREE contributing ~ 90% of the stock. This study highlighted the efficiency of using REE as a biological proxy in determining the degree of bioaccumulation within the mangrove environment.

Epidemiology of cervical spinal cord injury in eastern India: an autopsy-based study.

AIMS: Cervical spinal cord injury is a major cause of fatality among trauma victims. Unlike developed countries, national spinal cord injury database is not maintained in India. Paucity of data hampers the understanding of epidemiology of the event in India. So, this study was conducted to ascertain the epidemiological pattern of death due to cervical spinal cord injury and to identify the risk factors; also to find the association of vertebral injuries with various epidemiological parameters. METHODS: Among autopsies conducted in Burdwan Medical College and Hospital from 2000 to 2010, cases with autopsy report mentioning "death due to cervical spinal cord injury" either primary or secondary were included in the study. It was a retrospective observational study based on autopsy report. RESULTS: 536 cases met the inclusion criteria. Among them 89.4% were male and 10.6% were female; 63.8% victims were young adults (20-39 years). Mean (plus or minus S.D.) age was 33.5 years (plus or minus 12.8). All, apart from 5.4%, suffered from single segment injury with commonest site being C3-C4 (37.3%). Highest number of trauma occurred between 6 am to 9 am, 56.6% of the victims died before hospitalisation. Commonest mode of injury was road traffic accident (52.2%) followed by fall from height (25.0%); 53.7% cases had vertebral fracture with dislocation, 34.3% had only vertebral fracture. Only dislocation was significantly high up to 19 years age (p<0.001) and among females (p=0.029). All elderly suffered from fracture. CONCLUSIONS: This study revealed an unusually high male:female ratio with much representation of the younger age groups in the injuries in comparison to other parts of world. In absence of national database, this result can be used as a surrogate data.