Morphology, biology, and distribution of Ichthyophis kodaguensis (Amphibia:Gymnophiona), a rare caecilian from the Western Ghats, India

Of the amphibian orders, the Gymnophiona (caecilians) have the lowest number of species and are the least known. We report new information on the morphology, biology, range, and distribution of Ichthyophis kodaguensis, a striped ichthyophiid caecilian from the Western Ghats, India that shows the first evidence of possible sexual-dimorphism in this species. Based on the clutch size, limited range, relatively low fecundity, and agricultural practices in their habitats, we consider that I. kodaguensis is highly threatened when compared to other striped ichthyophiids from the Western Ghats, a biodiversity hotspot.

A comparison of morphometric traits of sheep breeds of Karnataka in the farmers' flocks

The study revealed that the 4 sheep breeds of Karnataka differed significantly with respect to body weight and other physical traits. Kenguri and Bellary breeds of sheep were larger and heavier than Hassan and Mandya sheep breeds. Amongst them Kenguri rams were heaviest followed by Bellary, Mandya and Hassan but in ewes the above order was reversed in breeds of southern Karnataka. The overall difference in body weights of Kenguri and Bellary rams was 9.66 kg whereas in Hassan and Mandya rams it was 4.37 kg. The corresponding values in ewes were 4.06 kg and 1.5 kg. In ewes, the increase in magnitude of a morphometric trait from a lower age group to next higher age group was marginal. All the sheep breeds of Karnataka attained maximum weight at 8-tooth age

Phospholipase C-β4 Is Essential for the Progression of the Normal Sleep Sequence and Ultradian Body Temperature Rhythms in Mice

BACKGROUND: THE SLEEP SEQUENCE: i) non-REM sleep, ii) REM sleep, and iii) wakefulness, is stable and widely preserved in mammals, but the underlying mechanisms are unknown. It has been shown that this sequence is disrupted by sudden REM sleep onset during active wakefulness (i.e., narcolepsy) in orexin-deficient mutant animals. Phospholipase C (PLC) mediates the signaling of numerous metabotropic receptors, including orexin receptors. Among the several PLC subtypes, the beta4 subtype is uniquely localized in the geniculate nucleus of thalamus which is hypothesized to have a critical role in the transition and maintenance of sleep stages. In fact, we have reported irregular theta wave frequency during REM sleep in PLC-beta4-deficient mutant (PLC-beta4-/-) mice. Daily behavioral phenotypes and metabotropic receptors involved have not been analyzed in detail in PLC-beta4-/- mice, however. METHODOLOGY/PRINCIPAL FINDINGS: Therefore, we analyzed 24-h sleep electroencephalogram in PLC-beta4-/- mice. PLC-beta4-/- mice exhibited normal non-REM sleep both during the day and nighttime. PLC-beta4-/- mice, however, exhibited increased REM sleep during the night, their active period. Also, their sleep was fragmented with unusual wake-to-REM sleep transitions, both during the day and nighttime. In addition, PLC-beta4-/- mice reduced ultradian body temperature rhythms and elevated body temperatures during the daytime, but had normal homeothermal response to acute shifts in ambient temperatures (22 degrees C-4 degrees C). Within the most likely brain areas to produce these behavioral phenotypes, we found that, not orexin, but group-1 metabotropic glutamate receptor (mGluR)-mediated Ca(2+) mobilization was significantly reduced in the dorsal lateral geniculate nucleus (LGNd) of PLC-beta4-/- mice. Voltage clamp recordings revealed that group-1 mGluR-mediated currents in LGNd relay neurons (inward in wild-type mice) were outward in PLC-beta4-/- mice. CONCLUSIONS/SIGNIFICANCE: These lines of evidence indicate that impaired LGNd relay, possibly mediated via group-1 mGluR, may underlie irregular sleep sequences and ultradian body temperature rhythms in PLC-beta4-/- mice

Thalamic neuromodulation and its implications for executive networks

The thalamus is a key structure that controls the routing of information in the brain. Understanding modulation at the thalamic level is critical to understanding the flow of information to brain regions involved in cognitive functions, such as the neocortex, the hippocampus, and the basal ganglia. Modulators contribute the majority of synapses that thalamic cells receive, and the highest fraction of modulator synapses is found in thalamic nuclei interconnected with higher order cortical regions. In addition, disruption of modulators often translates into disabling disorders of executive behavior. However, modulation in thalamic nuclei such as the midline and intralaminar groups, which are interconnected with forebrain executive regions, has received little attention compared to sensory nuclei. Thalamic modulators are heterogeneous in regards to their origin, the neurotransmitter they use, and the effect on thalamic cells. Modulators also share some features, such as having small terminal boutons and activating metabotropic receptors on the cells they contact. I will review anatomical and physiological data on thalamic modulators with these goals: first, determine to what extent the evidence supports similar modulator functions across thalamic nuclei; and second, discuss the current evidence on modulation in the midline and intralaminar nuclei in relation to their role in executive function

Prioritization of sub-watersheds for sustainable development and management of natural resources: An integrated approach using remote sensing, GIS and socio-economic data

The study area is one of the watersheds of North Pennar basin, covering an area of 570 km 2 and lies between latitude 13°55′–14°17′N and longitude 77°05′–77°25′E in Pavagada area, Tumkur District, Karnataka and a small portion in Ananthpur District, Andhra Pradesh, India, forming a part of the hardrock terrain. The drainage network shows dendritic to sub-dendritic pattern and is non-perennial in nature. Poor soil cover, sparse vegetation, erratic rainfall and lack of soil moisture characterize the area for most part of the year. Recurring drought coupled with increase in ground-water exploitation results in decline the groundwater level. The entire study area has been further divided into nine sub-watersheds, namely Byadanur, Devada-betta, Talamaradahalli, Gowdatimmanahalli, Naliga-nahalli, Nagalamadike, Maddalenahalli, Paluvalli tank and Dalavayihalli, ranging in geographical area from 49 to 75 km 2 . It has been taken up for prioritization based on available natural resources derived from sat-ellite images and socio-economic conditions, including drainage density, slope, water yield capacity, ground-water prospects, soil, wasteland, irrigated area, forest cover and data on agricultural labourers, SC/ST population and rainfall. On the basis of priority and weightage assigned to each thematic map, the sub-watersheds have been grouped into three categories: high, medium and low priority. The prioritization re-sults reveal that Nagalamadike, Maddalenahalli and Dalavayihalli sub-watersheds rank highest on the basis of weightage and are considered as high priority. These sub-watersheds may be taken up with development and management plans to conserve natural resources on sustainable basis with immediate effect, which will ultimately lead to soil and water conservation

Ore petrology of the V-Ti magnetite (lodestone) layers of the Kurihundi area of Sargur schist belt, Dharwar craton

The V-Ti magnetite layers (lodestone) occur within the layered gabbro-anorthosites-ultramafic rocks emplaced into the migmatitic gneisses close to the high grade Archeaen Sargur supracrustal rocks in the Kurihundi area. The ore petrographic studies of the lodestone reveal the presence of primary Ti-magnetite, ilmenite, ulvospinel, pleonaste, hematite and pyrite, chalcopyrite, pyrrhotite and secondary Ti-maghemite, martite and goethite as well as secondary covellite. These layers contain Ti-magnetite (60%) and ilmenite (30%) with silicates (< 5%) exhibiting granular mosaic texture with well-defined triple junctions and are classified as adcumulus rocks. The grain-boundary relationships in the ores indicate considerable postcumulus growth and readjustment due to combined effects of sintering and adcumulus growth. Intergrowth textures (ulvospinel, ilmenite and pleonaste in Ti-magnetite and hematite in ilmenite) reflects exsolution features crystallized from solid-solutions compositions under different conditions of oxygen fugacities. Larger bodies of pleonaste and ilmenite in Ti-magnetite become lensoid or rounded in outline and these morphological modifications took place during the regional upper amphibolite to lower granulite facies metamorphism at 2.6 Ga ago. The lodestone contains high TiO(2) (20 to 22.59 wt%), with V(2)O(5) (0.85 to 1.15%) and Fe(2)O(3) (t) (72.03 to 74.25%). Ti-magnetite shows alteration to Ti-maghemite, martite and goethite due to low temperature oxidation and hydration during weathering

Morphometry using remote sensing and GIS techniques in the sub-basins of Kagna river basin, Gulburga district, Karnataka, India

The study area is a part of Kagna river basin in the Gulburga district of Karnataka, India. It covers an area of 1320 km2 and it has been subdivided into 4 sub-basins namely Wadi, Chitapur, Sedam and Kurkunta, which range in area from 184 to 537 km2. The drainage pattern of these sub-basins are delineated using Geo-coded FCC bands 2,3,4 of IRS 1C and 1D(LISS III+PAN merged) on 1:50,000 scale and Survey of India toposheets as reference. The morphometric parameters are computed using ArcInfo and ArcView GIS softwares. The drainage pattern of the study area is dendritic to sub-dendritic with stream orders ranging from IV to VII orders. Drainage density ranges from 1.40 to 1.86 km/km2 suggesting coarse to moderate drainage texture. The change in values of stream length ratio indicate their late youth stage of geomorphic development. The values of bifurcation ratio ranging from 2.00 to 4.71 indicate that all the sub-basins fall under normal basin category. The values of form factor and circulatory ratio, suggest that the Kurkunta sub-basin is elongated and the remaining sub-basins are more or less circular in shape. Elongation ratio indicates that the Wadi sub-basin is a region of very low relief whereas the other sub-basins are associated with moderate to high relief and steep ground slopes. It is concluded that remote sensing and GIS have been proved to be efficient tools in drainage delineation and updation. In the present study these updated drainages have been used for the morphometric analysis