Role of hydrocarbon pollutants, salinity, tidal height, bioenergetics and competition in colonization of oyster reefs by commensal assemblages

Effects of hydrocarbons, salinity, tidal height, bioenergetics and competition on the oyster reef fauna were studied. Dried oyster shell was exposed to crude oil in the laboratory and plastic trays filled with control and oil-exposed shell were then deployed at two locations, in two seasons and at two tidal levels, with immersion periods of two and five weeks. Salinity exhibited a significant effect with sub tidal site having higher diversity. Hydrocarbon effects were less prominent. To determine effects of cleaners, Corexit 9580 was applied both alone and in combination with oil on cultch. At high concentrations, the cleaner ameliorated hydrocarbon effects. Hydrocarbon effects seemed to be less prominent than salinity and aerial exposure. In the next chapter, effects of salinity on the survival and bioenergetics of mud crabs Panopeus simpsoni and Eurypanopeus depressus were examined. Crabs were exposed to a range of salinities to determine the effects of salinity on tolerance. P. simpsoni exhibited a 28d LC50 of 6.97 PSU while E. depressus had a 28d LC50 of 0.19 PSU. Crabs were exposed to four salinities for bioenergetic measurements. Energy expenditure was highest at the lowest salinity and decreased as salinity increased. Scope for growth declined below 17.5 PSU. E. depressus was capable of surviving lower salinities than P. simpsoni. However, the physiological responses do not significantly differ between the two species. In the next chapter laboratory experiments were conducted to see if these two crab species differ in resource holding potential. Crabs were placed in aquaria at two salinities and refugia were checked daily for shelter occupancy. To determine if resource holding potential for refugia influenced predation risk, a second laboratory experiment was performed with a blue crab predator in each tank. The numbers of mud crabs of each species surviving were recorded. E. depressus was dominant over P. simpsoni in occupying the shelters at both salinity levels. E. depressus exhibited a higher survival in the presence of the predator. E. depressus’s ability to tolerate lower salinities, and its dominance in resource holding potential, may lessen predation risk and allow colonization of more estuarine sites

High tension electrocution- Long term complications and other medico-legal issues

Case history: A 33 year old plumber sustained high-tension electrocution from overhead cables as an occupational hazard while climbing up to the third floor of a building under construction. He was thrown on to the concrete slab of the second floor with multiple extensive burns. Though hurriedly taken to hospital, he remained unconscious for nearly two hours almost unattended. CT scan done at a later date showed cerebral infarctions. He was treated for neurological and other complications in the ward for two months. Other complications such as blindness were discovered subsequent to his discharge from the ward. He was re-admitted to the same ward only to die few hours after admission. The post-mortem examination revealed yet undiscovered complications and the cause of death was attributed to the complications of electrocution.Discussion: Though short-term complications of electrocution are quite heard of, long-term sequele are under-reported in the medical literature. Neurological, psychological, ocular and pain-related complications are not uncommon. The term diffuse electrical injury is used to designate combinations of such complications not directly related to the theoretical pathway of the current inside the body. Doctors working in emergency care and surgical units should be made aware of such complications and the importance of proper initial care in preventing or minimizing the above should be emphasized which might otherwise amount to medical negligence

A Study on Injury Patterns of Motorcyclists Met with Traffic Accidents

Injuries following road traffic accidents (RTA) are recognized as a man-madehealth hazard across the globe. This is also the common knowledge of any surgeonworking in any busy hospital.The general objective of this study was to identify the injury patterns anddemographic characteristics such as age, gender, ethnicity and educational level ofmotor-bike victims of RTAs. As specific objectives, the injury types, subtypes,commonly affected body parts, the outcome of injuries, the level of medicalinterventions needed, the category of hurt, the causative, contributing and predisposingfactors for accidents have been studied in depth. The study was carried out at theAccident Service Unit of the Colombo South Teaching Hospital-Kalubowila for aperiod of six months using 100 motorcyclists. The ethical clearance was granted by theEthical Review Committee of the Medical Faculty. A researcher administered structuredinterview was held with each participant. Medical data were obtained from the BedHead Ticket (BHT) of the patients.Some major findings of the study: Mostly affected age group was 21-40yrs (86%).Males were mostly affected (94%). Most accidents occurred on week days and duringday time. Most common side of collision was frontal (head-on). Fractures were thecommonest type of injuries (79%) followed by abrasions (76%), contusions (56%) andlacerations (10%). Head injuries were encountered by 35% of victims. It was claimedthat helmets were worn by 95%. The lower limbs were the most commonly affectedbody part (41%). Most victims needed fracture management (79%), wound toileting(76%) and suturing (10%). Only 04% needed critical surgical interventions. Overspeeding(33%), overtaking from wrong side (18%), careless disobedience to road ruleswere the commonly accepted triggers. Consumption of alcohol was a contributory factorin a minority.Key words: Traffic injuries, Motorcyclists, Accidents, Casualties, Head injurie

Relative importance of hydrocarbon pollutants, salinity and tidal height in colonization of oyster reefs

The relative effects of hydrocarbon pollutants, salinity and tidal height on the invertebrates and fish that inhabit oyster reefs were studied along the Louisiana Gulf of Mexico coastline. Dried oyster shell (cultch) was first exposed to crude oil in the laboratory. In a series of experiments, plastic trays filled with control and oil-exposed cultch were then deployed at two locations differing in salinity, in two seasons and at two tidal levels. In experiments on hydrocarbon, salinity, and seasonal effects, trays were colonized for one month. To examine the effects of colonization time, half of the trays were retrieved after two and the rest after five weeks. Salinity dramatically affected oyster reef assemblages, with species richness and total abundance halved at the estuarine site. Hydrocarbon effects were less prominent, whether cultch was dosed with light or heavy crude oil. The sub-tidal site had higher colonization rates, but colonization interval did not affect colonization, and seasonal differences occurred only at the higher-diversity, sub-tidal site. To determine effects of cleaners, Corexit 9580 was applied alone and with oil on cultch, and trays were colonized for one month. At high concentrations, the cleaner ameliorated hydrocarbon effects. In general, hydrocarbon effects were less prominent than salinity and aerial exposure in explaining colonization of oyster reef assemblages. Gas chromatography/mass spectrometry analysis of oyster shells after one month immersion revealed considerable losses of oil, especially with higher flow at the inter-tidal site. Sediment on shell also diluted oil. We argue that oyster reef assemblages should recover from small-scale spills, unless they occur during periods of reproduction and dispersal. © 2006 Elsevier Ltd. All rights reserved

Early stages of Alzheimer's disease are alarming signs in injury deaths caused by traffic accidents in elderly people (≥60 years of age): A neuropathological study

© 2018 Indian Journal of Psychiatry. Background: There is little information available in the literature concerning the contribution of dementia in injury deaths in elderly people (≥60 years). Aim: This study was intended to investigate the extent of dementia-related pathologies in the brains of elderly people who died in traffic accidents or by suicide and to compare our findings with age-And sex-matched natural deaths in an elderly population. Materials and Methods: Autopsy-derived human brain samples from nine injury death victims (5 suicide and 4 traffic accidents) and nine age-And sex-matched natural death victims were screened for neurodegenerative and cerebrovascular pathologies using histopathological and immunohistochemical techniques. For the analysis, Statistical Package for the Social Sciences (SPSS) version 16.0 was used. Results: There was a greater likelihood for Alzheimer's disease (AD)-related changes in the elders who succumbed to traffic accidents (1 out of 4) compared to age-And sex-matched suicides (0 out of 5) or natural deaths (0 out of 9) as assessed by the National Institute on Aging - Alzheimer's Association guidelines. Actual burden of both neurofibrillary tangles (NFTs) and (SPs) was comparatively higher in the brains of traffic accidents, and the mean NFT counts were significantly higher in the region of entorhinal cortex (P < 0.05). However, associations obtained for other dementia-related pathologies were not statistically important

Differences in refuge use are related to predation risk in estuarine crabs

We determined the dominance hierarchy in competition for refuges by the xanthid crabs Panopeus simpsoni, Eurypanopeus depressus, Rhithropanopeus harrisii, and juvenile Callinectes sapidus, and used it to predict predation risk from adult blue crabs in laboratory experiments at two salinities. Experiments were first run with pairwise combinations of species with limited refuges. To determine any effects of diffuse competition on dominance and predation risk, all four species were then held together with limited refuges. The same process was then repeated in experiments with a blue crab predator, again with limited refuges. Juvenile C. sapidus and E. depressus were dominant over P. simpsoni and R. harrisii in occupying shelters at both salinities, in both paired-and multiple-species combinations. Dominance in refuge use increased with salinity in C. sapidus, E. depressus, and P. simpsoni, but not in R. harrisii. Because they were more dominant, C. sapidus and E. depressus sustained lower mortality to predation than P. simpsoni, and R. harrisii. Furthermore, field sampling indicated the least dominant species, R. harrisii, was common only in low-salinity areas with few predators. The greater dominance of C. sapidus and E. depressus may thus decrease their predation risk in estuarine waters and explain their broader distribution across salinities

Cytoskeletal pathologies of age-related diseases between elderly Sri Lankan (Colombo) and Indian (Bangalore) brain samples

© 2016 Bentham Science Publishers. Within South Asia, Sri Lanka represents fastest aging with 13% of the population was aged over 60’s in 2011, whereas in India it was 8%. Majority of the Sri Lankan population based genetic studies have confirmed their origin on Indian mainland. As there were inadequate data on aging cytoskeletal pathologies of these two nations with their close genetic affiliations, we performed a comparison on their elderly. Autopsy brain samples of 50 individuals from Colombo, Sri Lanka (mean age 72.1yrs ± 7.8, mean ± S.D.) and 42 individuals from Bangalore, India (mean age 65.9yrs ± 9.3) were screened for neurodegenerative pathologies using immunohistochemical techniques. A total of 79 cases with incomplete clinical history (Colombo- 47 and Bangalore- 32) were subjected to statistical analysis and 13 cases, clinically diagnosed with dementia and/or Parkinsonism disorders were excluded. As per National Institute on Aging Alzheimer’s Association guidelines, between Colombo and Bangalore samples, Alzheimer’s disease neuropathologic change for intermediate/ high level was 4.25% vs. 3.12% and low level was 19.15% vs. 15.62% respectively. Pathologies associated with Parkinsonism including brainstem predominant Lewy bodies-6.4% and probable progressive supra nuclear palsy2.13% were found solely in Colombo samples. Alzheimer related pathologies were not different among elders, however, in Colombo males, neurofibrillary tangle grade was significantly higher in the region of hippocampus (odds ratio = 1.46, 95% confidence interval = 0.07-0.7) and at risk in midbrain substantia nigra (p = 0.075). Other age-related pathologies including spongiform changes (p < 0.05) and hippocampus cell loss in dentate gyrus region (p < 0.05) were also identified prominently in Colombo samples. Taken together, aging cytoskeletal pathologies are comparatively higher in elderly Sri Lankans and this might be due to their genetic, dietary and/ or environmental variations

Vascular Contributions in Alzheimer's Disease-Related Neuropathological Changes: First Autopsy Evidence from a South Asian Aging Population

© 2016 - IOS Press and the authors. All rights reserved. Background: Evidence from various consortia on vascular contributions has been inconsistent in determining the etiology of sporadic Alzheimer's disease (AD). Objective: To investigate vascular risk factors and cerebrovascular pathologies associated in manifestation of AD-related neuropathological changes of an elderly population. Methods: Postmortem brain samples from 76 elderly subjects (≥50 years) were used to study genetic polymorphisms, intracranial atherosclerosis of the circle of Willis (IASCW), and microscopic infarcts in deep white matters. From this cohort, 50 brains (≥60 years) were subjected to neuropathological diagnosis using immunohistopathological techniques. Results: Besides the association with age, the apolipoprotein E ϵ4 allele was significantly and strongly associated with Thal amyloid-β phases ≥1 [odds ratio (OR)=6.76, 95 confidence interval (CI) 1.37-33.45] and inversely with Braak neurofibrillary tangle (NFT) stages ≥III (0.02, 0.0-0.47). Illiterates showed a significant positive association for Braak NFT stages ≥IV (14.62, 1.21-176.73) and a significant negative association for microscopic infarcts (0.15, 0.03-0.71) in deep white matters. With respect to cerebrovascular pathologies, cerebral small vessel lesions (white matter hyperintensities and cerebral amyloid angiopathy) showed a higher degree of associations among them and with AD-related neuropathological changes (p<0.05) compared to large vessel pathology (IASCW), which showed a significant association only with Braak NFT stages ≥I (p=0.050). Conclusion: These findings suggest that besides age, education, and genetic factors, other vascular risk factors were not associated with AD-related neuropathological changes and urge prompt actions be taken against cerebral small vessel diseases since evidence for effective prevention is still lacking