The medial temporal lobe supports conceptual implicit memory

The medial temporal lobe (MTL) is generally thought to be critical for explicit, but not implicit, memory. Here, we demonstrate that the perirhinal cortex (PRc), within the MTL, plays a role in conceptually-driven implicit memory. Amnesic patients with MTL lesions that converged on the left PRc exhibited deficits on two conceptual implicit tasks (i.e., exemplar generation and semantic decision). A separate functional magnetic resonance imaging (fMRI) study in healthy subjects indicated that PRc activation during encoding of words was predictive of subsequent exemplar generation. Moreover, across subjects, the magnitude of the fMRI and behavioral conceptual priming effects were directly related. Additionally, the PRc region implicated in the fMRI study was the same region of maximal lesion overlap in the patients with impaired conceptual priming. These patient and imaging results converge to suggest that the PRc plays a critical role in conceptual implicit memory, and possibly conceptual processing in general.     

Influence of suspended particulate matter on nutrient biogeochemistry of a tropical shallow lagoon,Chilika, India

The behaviour of suspended particulate matter (SPM), salinity profile, dissolved nutrients, total (T.Chl-a) and size fractionated chlorophyll-a (F.Chl-a) were studied seasonally at Chilika Lagoon, east coast of India, during 2008–2009. The study showed large spatio-temporal variations among these parameters. The concentration of dissolved inorganic nitrogen and inorganic phosphate were found to be maximum during the monsoon, followed by post- and pre-monsoon, although the mean N:P ratios, which indicate the relative availability of N with respect to P, were 9.13 ± 3.09, 16.57 ± 11.53 and 5.47 ± 3.13, respectively. It was evident from the results that during pre-monsoon and postmonsoon, the lagoon exhibits nitrogen limitation. Mean T.Chl-a biomass in the lagoon showed distinct seasonality with maximum values during the pre-monsoon (23.12 ± 9.75 mg m^?3) followed by monsoon and post-monsoon. Irrespective of seasons, maximum T.Chl-a was found in the northern part of the lagoon. SPM concentrations during the monsoon were relatively higher in the freshwater dominated zones compared to seawater dominated areas, indicating its riverine sources. The correlation between SPM and various dissolved nutrients (p < 0.05) suggests its influence on the physico-chemical conditions at varying levels. It is summarized that seasonal variation of SPM and nutrients contributed by rivers, wind induced re-suspension events and in situ  regeneration processes play a crucial role in the lagoon biogeochemical cycle.     

Stochastic risk assessment of water quality using advection dispersion equation and Bayesian approximation: A case study

The influence of various heterogeneous parameters, stochastic uncertain factors, and pollutant particles from the industrial effluents in the water system is investigated using advection dispersion equation (ADE) and the Bayesian approximation. Here, the decay coefficient is decomposed into the exact part and the deviation part. The coefficient is used to find out the errors and deviation in decay during the flow of pollutants. Two Bayesian models are developed to analyze the posterior distributions and to find out the Bayes factor for the stochastic covariance estimation. The Bayesian calibration focused the characteristics of both on mechanistic and statistical approximation. The efficiency and accuracy of the developed models are checked from the results obtained on the basis of the confidence interval. Markov chain Monte Carlo simulation is used to acquire the convergence point of parameters for the posterior estimation. The stochastic covariance or white noise represents the effect of random factors on the river system. The analysis revealed that the rate of decay is dependent upon the duration and distance traveled by the pollutants. The collaboration of ADE and Bayesian approximation encourage the water-quality management and environmental modeling.     

Systemic arterial blood supply to the trachea and lung in sheep

We studied the systemic arterial blood supply to the trachea and lung in adult sheep. After anesthesia, sheep were exsanguinated and then studied by intra-arterial injection of one of the following materials: saline containing dyes of various colors (n = 24), Microfil (n = 8), or Batson's solution (n = 6). The systemic blood supply to the cervical trachea originated from the two common carotid arteries via three to four small branches (rami tracheales cervicales) on each side. A segment of the thoracic trachea between the thoracic inlet and the origin of the tracheal bronchus (bronchus trachealis) and the bronchial tree of the right cranial lobe (lobus cranialis dexter) were supplied by the tracheal bronchial branch (ramus bronchalis trachealis), which originated from the brachiocephalic trunk (truncus brachiocephalicus). A portion of thoracic trachea between the origin of the tracheal bronchus and the tracheal carina was supplied by the thoracic tracheal branch (ramus trachealis thoracica), arising from the bronchoesophageal artery (arteria bronchoesophagea) or directly from the thoracic aorta. The bronchial branch (ramus bronchalis) originated from the bronchoesophageal artery, and its branches supplied the remainder of the bronchial tree. At 120 cmH2O pressure (n = 8), the bronchial branch contributed approximately 50% and the other two approximately 25% each of the total tracheobronchial blood flow. These three branches also supplied the visceral pleura. Additionally, several small vessels (rami pleurales pulmonales) originated from the esophageal branch (ramus esophagea) of the bronchoesophageal artery, traversed the pulmonary ligaments, and supplied the visceral pleura.