Spatial distribution of groundwater-surface water connectivity in the Kosimegafan, north India

<p>We conducted a systematically integrated surface water and groundwater interaction study in the Kosimegafan in north India using the stable isotopes (δ<sup>18</sup>O and δ<sup>2</sup>H) of water and depth to water level data. In a field campaign in December 2019, we have collected a water sample from 65 different locations for isotopic analysis. This includes 21 samples from the groundwater and 44 from different surface water bodies (Kosi River-02, streams-09, waterlogged patches-29, and canal-04).</p><p>The δ<sup>18</sup>O and D-excess values of groundwater and waterlogged samples show marked spatial variation across the study area. Using a two-component mixing model, we estimate the fraction contribution of streams and rainwater in the groundwater and waterlogged patches. This shows a marked spatial and depth-related variability in stream water contribution to the groundwater recharge and varies from about 83% (maximum) at 6 m below ground level (bgl) to 45% (minimum) at 9 m bgl. We also analysed the spatial and temporal variation in groundwater levels from 1996 to 2017. During this period, the water level shows a significant variation from 1.1 to 7.8 m bgl. Further, using the water table fluctuation approach, we estimate the recharge rate. We found a higher recharge rate (22 mm/year) in the central part of the western lobe and northern part of the central lobe, and minimum (1 mm/year)in both the northern part of the western and southern part of the central lobe of the Kosi fan. This study provides new insight into the recharge processes in the study area.</p>

A new species of Lophiaris (Orchidaceae, Oncidiinae) from Quiché, Guatemala, in the L. straminea complex

A new species of Lophiaris (Orchidaceae, Onciidinae), Lophiaris quichensis Coxic, Cetzal, Mó & Carnevali, from the department of Quiché, Guatemala, is herein described, illustrated, and characterized based on morphological features. It is here referred to the L. straminea complex (along with L. aurisasinorum, L. sierracaracolensis, and L. straminea) from which it is easily distinguished by the color of the flowers: sepals and petals yellow, and the whole surface covered with pale reddish-brown spots, the claws with a pale reddish-brown stain, the labellum yellow with a reddish-brown blotch covering the central portion of the central lobe, the disc and partially the teeth of the callus, the lateral lobes with a brown spot at the base of the same. The etymology, distribution, ecology, and comparative differences of the new species with respect to other species of L. straminea complex are discussed. We also provide a comprehensive key to identify the species of L. straminea complex. The conservation status of L. quichensis is assessed as CR by the IUCN criteria.

A new species of Pleurothallis (Orchidaceae, Pleurothallidinae) from northwestern Ecuador with affinities to both subgenera Ancipitia and Scopula

A new species, Pleurothallis ecomingae, from near Chical, Carchi Province, Ecuador, is described and illustrated. This species is unique in that it has characteristics typical of both subgenera Scopula and Ancipitia. The plant has narrowly lanceolate leaves with a near-apical fascicle of single-flowered peduncles, previously only seen in Scopula. And, it has flowers with a minute, pubescent, tri-lobed lip in which the basal lobes are modified into ‘horns’, and an apical orifice in the central lobe, a feature previously only seen in Ancipitia. This intermediate morphology supports the previous suggestion that, at least based on morphology, the two subgenera should be combined.

Microsurgical management of a high-grade brain arteriovenous malformation in the central lobe after unsuccessful radiosurgery

The recommendation for the great majority of high-grade brain arteriovenous malformations (bAVMs) is observation, except for those patients with recurrent hemorrhages, progressive neurological deficits, steal-related symptoms, or AVM-related aneurysms, for whom intervention should be considered. These are general recommendations, and the decision should be made on an individual basis. Surgical resection of an AVM in the central lobe may cause postoperative sensorimotor deficits since this anatomical region includes the pre- and postcentral gyri on the lateral surface and the paracentral lobule on the medial surface.The authors present a patient with a ruptured high-grade bAVM in the central lobe who underwent previous surgery for hematoma evacuation and previous radiosurgery, and whose indication for reoperation was proposed based on progressive hemiparesis. Microsurgical resection was possible after a wide frontoparietal craniotomy, which made all the nidus borders accessible. This case illustrates the anatomy and surgical technique for large nidus AVMs in eloquent areas, showing that complete microsurgical resection is possible with good clinical outcome.The video can be found here: https://youtu.be/Cpd1PK6BLIM.