Tapado Glacier (30.15°S, 69.93°W) is a 1.6 km2 ice mass located at high-altitude in Chile’s Desert Andes. This region reaches up to 6000 m a.s.l. and is characterised by high solar radiation and scarce and episodic precipitation. Despite its relatively small size, the glacier extends from 4500 to 5500 m a.s.l and contains several types of surfaces and features, such as a debris-covered section populated by ice cliffs and supraglacial ponds, a field of large snow and ice penitentes, a steep section with crevasses and seracs, and wind-exposed upper areas with minimal snow accumulation. As the ablation and evolution of these elements depend on several physical processes occurring at different rates, monitoring and modelling changes on Tapado Glacier is challenging. Our study describes and quantifies the main glacier changes over the last five years amidst rising summer temperatures and below-average precipitation from a process perspective. Monitoring techniques include direct mass balance and surface geometry measurements, flights of uncrewed aerial vehicles (UAVs), geophysical methods, satellite products, terrestrial LiDAR and automatic cameras.Enhanced melt at ice cliffs and supraglacial ponds primarily drives ablation in the debris-covered section. Ice cliffs and ponds have persisted on the glacier surface since at least 1955. Satellite products and photogrammetrically derived Digital Elevation Models (DEMs) from UAV flights in the period 2020-2023 show that the ablation over a selected cliff and pond was about 10 times higher than over the rest of the debris-covered section. Analysis of historical satellite imagery tracks the evolution of the selected cliff from its formation between 1978 and 2000 to its recent disappearance in 2023, which was corroborated by an automatic camera. Geophysical measurements suggest the presence of ancient supraglacial lakes within the debris cover. The debris-free section shows consistent patterns of thinning and increasing surface roughness. Terrestrial LiDAR indicates an annual surface lowering of about −0.4 m, while UAV flights and direct observations show that the end-of-summer height of penitentes has increased from 1-2 m to more than 2 m, reaching up to almost 6 m in spots. In the upper parts of the glacier, we have observed increasing instability from a serac that produces frequent ice and rock falls into the penitentes-covered area. Summer ablation at the top of the glacier, mainly by sublimation, varied from 0.15 to 1.15 m during 2021-2023. Using recent data from ablation stakes and UAVs, we estimate a summer glacier mass balance of about −0.8 m w.e., which is equivalent to 1.3 million m3 of water.Tapado Glacier exemplifies how different physical processes can drive glacier mass loss and runoff contribution. Recent changes in the glacier have made the field monitoring difficult and pose interesting challenges for glacier modelling.
GIFT GUIDE Holiday gift ideas ShareShare onFacebookTwitterWechatLinked InRedditEmail Bethany HalfordC&EN BostonC&EN, 2018, 96 (47), p 40November 26, 2018Cite this:C&EN 96, 47, 40Gel electrophoresis scarf Electrify your wardrobe with this biochemistry-inspired scarf for $65 at Artologica on Etsy. (Credit: Artologica)Figure1of8Gay pride enamel pin Any chemist can proudly wear this 2-cm pin for about $7.50 from Yas Petit Poulet. (Credit: Yas Petit Poulet)Figure1of8"The Story of Snow" Snuggle up with the kids and read this Chronicle Books classic available on Amazon for $16.99. (Credit: Chronicle Books)Figure2of8Ice bucket Chill out with a stainless-steel container that features ice's crystal structure from ThinkGeek for $39.99. (Credit: ThinkGeek)Figure3of8Chemistry lab planner Organizing the week is easy with this personalized notepad for $19.95 from LaPetiteNote on Etsy. (Credit: LaPetiteNote)Figure4of8Glass tea infuser Learn science while you steep with this glass-and-steel flask from Cognitive Surplus for $34.95. (Credit: Cognitive Surplus)Figure5of8Glowing soap These element-inspired soaps from United Nuclear can make you glow even with the lights out at $25 for all four. (Credit: United Nuclear)Figure6of8Science socks Stay a step ahead with this brainy footwear for $11.50 from Sock It to Me, also available in women's and kids' sizes. (Credit: Sock It to Me)Figure7of8What to get the chemistry lovers in your life Please send comments and suggestions to [email protected]..Download PDF
Coronavirus is a pandemic that has kept us in great grief for the past few months. These days have created a devastating effect all through the world. As coronavirus has lot of similarities with other lung diseases, it becomes a challenging task for medical practitioners to identify the virus. A fast and robust system to identify the disease has been the need of the hour. In this chapter, we have used convolutional CapsNet for detecting COVID-19 disease using chest X-ray images. This design aims at obtaining fast and accurate diagnostic results. The proposed technique with less trainable parameters, COVID-CAPS, produced an accuracy of 87.5%, a sensitivity of 90%, a specificity of 95.8%, and an area under the curve (AUC) of 0.97. The main advantage of using CapsNet is that it can capture affine transformation in data that is a common scenario while dealing with real-world X-ray images. The CapsNet model is trained with normal data and tested with affine transformed data. The accuracy level obtained in the proposed method is comparatively much better along with having less learnable parameters and computational speed as compared to standard architectures such as ResNet, MobileNet, etc.
Purpose: Olpasiran, an N-acetyl galactosamine- conjugated, hepatocyte-targeted, small interfering RNA, is being developed to reduce plasma lipoprotein (Lp)-(a) concentration by directly targeting the LPA gene. This study evaluated the pharmacokinetics, pharmacodynamics, and tolerability of a single SC injection of olpasiran in healthy, Japanese and non -Japanese participants. Methods: In this Phase I, open-label, parallel-design study, Japanese participants were randomized in a 1:1:1:1 ratio to receive a single 3, 9, 75, or 225 mg dose of olpasiran. Non-Japanese participants received a single 75 mg dose of olpasiran. The primary end points were pharmacokinetic parameters, including Cmax, AUC inf, tmax, and t 1/2 . Tolerability and change in Lp(a) concentration were also assessed.Findings: A total of 27 enrolled participants had a mean (SD) age of 48.0 (12.5) years. Olpasiran Cmax and AUCinf were increased in an approximately dose -proportional manner in the Japanese groups. Mean (SD) Cmax values were 242 (121.0) and 144 (71.3) ng/mL, and mean (SD) AUCinf values were 3550 (592.0) and 2620 (917.0) h middotng/mL, in the Japanese and non-Japanese groups, respectively, given 75 mg of olpasiran. Median tmax ranged from 3.0 to 9.0 hours and mean (SD) t 1/2 ranged from 4.0 (0.3) to 6.9 (1.6) hours across all groups. The maximal Lp(a) reduction occurred at day 57, with mean (SD) Lp(a) percentage reductions from baseline ranging from 56.0% (21.0%) to 99.0% (0.2%). A reductions in Lp(a) was observed as early as day 4. All adverse events were mild in severity, with no serious or fatal adverse events. No clinically important changes in tolerability-related laboratory analytes or vital signs were observed. Implications: In this population of healthy Japanese participants, dose-proportional increases in exposure and reduced Lp(a) in a dose-dependent manner were found with single 3, 9, 75, and 225 mg doses of olpasiran. The magnitude and durability of Lp(a) reductions were similar between the Japanese and non -Japanese groups. Olpasiran was well tolerated, with no clinically important adverse events or laboratory or vital sign abnormalities. (Clin Ther. 2022;44:1237- 1247.) (c) 2022 Amgen Inc. Published by Elsevier Inc. This is an open access article under the CC BY-NC -ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )
Darevskia is a particularly species-rich radiation of Palearctic rock lizards from the Caucasus region. Thanks to intense systematic and taxonomic research, the knowledge of species-level diversity within this genus has increased over the last quarter century. Here, we described a new species, Darevskia salihae sp. nov. from northeastern Turkey. The new taxon is differentiated from other nearby taxon by the low number of dorsal scales in the middle of the body, the shorter body length, and the absence of blue dots both on the lateral region above the forelimbs and on the margin of the ventral plates. In addition to their morphological differences, the new taxon is phylogenetically different from close groups. It is located in a separate subclade from the rudis-valentini-portschinskii subclade. This distinction is supported by both a high bootstrap value (100) and a high posterior probability value (1.00). These two subclades are separated from each other by a genetic distance of almost 4%. This separation is supported not only genetically and morphologically, but also geographically. Since the habitat of the new taxon is limited to a high mountain and a narrow valley, it does not provide an opportunity for a different Darevskia species to shelter because it creates geographical isolation. However, Darevskia parvula that live closest to the habitat of the new taxon live only at the habitat boundaries and do not enter areas where the new taxon is found. Therefore, it might be possible that while it was separated from the rudis-valentini-portschinskii group during the evolutionary transformation, it remained as a refuge and relict in a narrow area as a result of the collapse of the valleys and the partial uplift of the Kaçkar Mountains.
