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Point-of-care ultrasound (POCUS)-performed by a clinician during a patient encounter and used in patient assessment and care planning-has many potential applications in nephrology. Yet, US nephrologists have been slow to adopt POCUS, which may affect the training of nephrology fellows. This study sought to identify the current state of POCUS training and implementation in nephrology fellowships.Concise survey instruments measuring attitudes toward POCUS, its current use, fellow competence, and POCUS curricula were disseminated to (Fellow and training program directors/associate program directors response rates were 69% and 37%, respectively. Only 38% of fellows (240 respondents) reported receiving POCUS education during their fellowship, and just 33% of those who did receive POCUS training reported feeling competent to use POCUS independently. Similarly, just 23% of training program directors/associate program directors indicated that they had a POCUS curriculum in place, although 74% of training program directors and associate program directors indicated that a program was in development or that there was interest in creating a POCUS curriculum. Most fellow and faculty respondents rated commonly covered POCUS topics-including dialysis access imaging and kidney biopsy-as "important" or "very important," with the greatest interest in diagnostic kidney ultrasound. Guided scanning with an instructor was the highest-rated teaching strategy. The most frequently reported barrier to POCUS program development was the lack of available instructors.Despite high trainee and faculty interest in POCUS, the majority of current nephrology fellows are not receiving POCUS training. Hands-on training guided by an instructor is highly valued, yet availability of adequately trained instructors remains a barrier to program development.This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2022_09_21_CJN01850222.mp3.

We present a 1D numerical model which calculates the age of ice around Dome C. It accounts either for melting or for a layer of stagnant ice above the bedrock, depending on the value of an inverted mechanical ice thickness. It is constrained by horizons picked from radar observations and dated using the EPICA Dome C (EDC) ice core age profile. We used 3 different radar datasets with the widest reaching airbourne radar system covering an area of 10,000 km2 and zooming in to 5 km transects over Little Dome C (LDC) with a ground based system. We find that stagnant ice exists in many places including above the LDC relief where the new Beyond EPICA drill site (BELDC) is located. The modelled thickness of this layer of stagnant ice roughly corresponds to the thickness of the basal unit observed in one of the radar surveys and observations made with Autonomous phase-sensitive Radio-Echo Sounder (ApRES). At BELDC, the modelled stagnant ice thickness is 182 ± 63 m and the modelled maximum age (that we define as the age at a maximum age density of 20 kyr m−1) is 1.49 ± 0.18 Ma at a depth of 2505 ± 34 m. This is very similar to all sites situated on the LDC relief such as that of the Million Year Ice Core project being conducted by the Australian Antarctic Division (AAD). The model was also applied to radar data in the area 10–20 km north of EDC (North Patch, NP), where we find either a thin layer of stagnant ice (generally < 60 m) or a very low melt rate (< 0.1 mm yr−1). The modelled maximum age at NP is over 2 Ma in most places, with ice at 1.5 Ma having a resolution of 9–12 kyr m−1 , making it an exciting prospect for a future oldest ice drill site.

Euglenoids (Euglenida) are unicellular flagellates possessing exceptionally wide geographical and ecological distribution. Euglenoids combine a biotechnological potential with a unique position in the eukaryotic tree of life. In large part these microbes owe this success to diverse genetics including secondary endosymbiosis and likely additional sources of genes. Multiple euglenoid species have translational applications and show great promise in production of biofuels, nutraceuticals, bioremediation, cancer treatments and more exotically as robotics design simulators. An absence of reference genomes currently limits these applications, including development of efficient tools for identification of critical factors in regulation, growth or optimization of metabolic pathways. The Euglena International Network (EIN) seeks to provide a forum to overcome these challenges. EIN has agreed specific goals, mobilized scientists, established a clear roadmap (Grand Challenges), connected academic and industry stakeholders and is currently formulating policy and partnership principles to propel these efforts in a coordinated and efficient manner.

The dynamic mass loss of ice sheets due to ice flow constitutes one of the biggest uncertainties in projections of ice-sheet evolution and sea-level rise. One central, understudied aspect of ice flow is how the bulk orientation of the ice-crystal lattice (fabric) translates to the mechanical anisotropy of ice. Here, we present a comprehensive analysis of the depth-averaged fabric distribution and corresponding directional flow enhancement factors covering a large area of the Northeast Greenland Ice Stream onset region. Our results are based on a combination of methods applied to extensive airborne and ground-based radar surveys, ice-core observations, and numerical ice-flow modelling. They show a strong spatial variability of the horizontal fabric anisotropy and a rapid crystal reorganization on the order of hundreds of years coinciding with the ice-stream geometry. The ice in parts of the ice stream is found to be up to one order of magnitude harder for pure-shear deformation in flow direction compared to isotropic ice, while the shear margins are potentially softened for horizontal simple shear by a factor of two. The high spatial resolution and large-scale coverage of our results is unprecedented and significantly contributes towards more accurate ice-flow models and a better understanding of ice-stream dynamics. Moreover, our estimated time scale of crystal reorganization and methodological approaches can potentially also be transferred to the investigation of ice on extraterrestrial bodies and other geologic materials.

This letter presents a simple, lightweight, and ultrawideband, the very high frequency/ultrahigh frequency (VHF/UHF) open-sleeve dipole antenna array for airborne ice measuring radar. The proposed antenna array achieves a wide bandwidth of 300 MHz via mutual coupling from neighboring excited elements. A hollow aluminum tube is used for both dipole and parasitic elements to minimize the antenna's weight. The simulation results show that to achieve a bandwidth of 300 MHz with a peak realized gain up to 12 dBi in the frequency range from 170 to 470 MHz, the length of the dipole ( L dip) and parasitic elements ( L para) of elements 1 and 4 of the four-element antenna array need to be 670 mm and 200 mm, respectively. At the same time, elements 2 and 3 require an L dip of 640 mm and L para of 180 mm. Based on these dimensions, a four-element antenna array is fabricated and tested. The measured antenna performance results show a good agreement with the simulated results.

Introduction Medial arterial calcification is a common and progressive lesion in end-stage renal disease that is associated with poor cardiovascular outcomes. Whether this lesion can be arrested or reversed is unknown, and was examined retrospectively by measuring progression of breast arterial calcification before and after kidney transplantation. Methods Arterial calcification was measured on serial mammograms from patients with previous kidney transplantation and compared to measurements performed before transplantation or in patients on the active waitlist. Serum creatinine >2.0 mg/dl after transplantation or warfarin use were exclusions. Results Median (interquartile range) progression of arterial calcification was 12.9 mm/breast per year (5.9 to 32.6) in 34 patients before or awaiting transplantation compared to just 1.2 mm/breast per year (−0.54 to 5.1) in 34 patients after transplantation (P < 0.001). Slowing of progression was also seen in longitudinal analyses of patients with mammograms performed both before and after transplantation. Duration of end-stage renal disease before transplantation but not age, diabetes, baseline calcification, or serum chemistries correlated with progression after transplantation. Significant regression was not observed in any patient. Conclusion In this first quantitative study of the effect of kidney transplantation, medial arterial calcification appeared to slow to rates seen in patients with normal renal function, indicating that the effect of renal failure may be completely abrogated. Overall, however, there was no significant regression, suggesting that calcification is irreversible and emphasizing the importance of prevention. Duration of pretransplant end-stage renal disease but not baseline calcification was a determinant of progression, consistent with cumulative, permanent changes to arteries that promote calcification., Graphical abstract

An electrically large ultrawideband ultrahigh frequency (UHF) monopole antenna array has been designed to sound up to 3 km of ice and meet the logistical requirements of transportation to arctic regions. The monopole array is comprised of 16 planar subarray modules, which in combination form a 16 m by 17 m Mills cross array configuration to maximize sensitivity and spatial selectivity in both cross-track and along-track directions. Each planar subarray module is 1 m by 2 m in size with a 6.35 cm thick rigid insulation foam panel separating the individual monopole elements from metal foil ground plane on the top such that the maximum radiation is directed to nadir. Each subarray panel consists of 4 by 8 circular monopole antenna elements with a spacing of 0.25 m. Each monopole element is printed on a 130 mm by 80 mm 62 mil FR4 board. The total weight of each subarray panel is 9 kg, making for very lightweight and low-profile antenna construction. The antenna array together with the radar system was deployed to the East Greenland Ice-coring Project site in August 2018 for demonstrating surface-based ice sounding at the UHF band.

Hemodialysis solutions typically contain a high alkali concentration designed to counter interdialytic acidosis, but this could result in persistent alkalosis in some patients. The prevalence and significance of persistent alkalosis were therefore examined at four outpatient centers over a 10-year period.Alkalosis was defined as a pre-dialysis serum [HCO444 of 1271 patients had alkalosis that persisted in 73. Compared to control patients, persistently alkalotic patients were older, but gender, race, starting weight, comorbidities, and mortality did not differ. Dialysis dose was 7% greater, protein catabolic rate was 11% lower, and interdialytic weight gain was 29% lower, all p 0.001. Persistently alkalotic patients had double the incidence of cardiac arrhythmias (p = 0.07) and a 20% greater intradialytic blood pressure decrease (p 0.001).Alkalosis is common in hemodialysis patients and can be persistent, likely due to decreased protein catabolic rate and increased dialysis dose, and may have detrimental cardiovascular effects.

teaserEuglenoids show great promise to benefit our world; as biofuels, environmental remediators, anti-cancer agents, robotics design simulators and food nutritional agents, but the absence of reference genomes currently limit realizing these benefits. The Euglena International Network (EIN) (https://euglenanetwork.org/) aims to address these challenges, and is currently seeking formative phase support and funding.Body startOf the nearly 1000 known species of euglenoids (Triemer and Zakryś, 2015), including Euglena gracilis and Rhabdomonas costata, fewer than 2 % have been explored for any level of translational potential in the past 20 years. The absence of reference genomes currently limits biotechnology applications, including the development of efficient tools for genetic manipulation in euglenoids.EIN aims to advance euglenoid science through a creative amalgam of academic institutions, national research institutes and biotechnology industry, to translate and exploit euglenoids through genome sequencing. EIN has defined goals, mobilized scientists, established a clear roadmap (Grand Challenges), connected academic and industry professionals and is currently formulating policy and partnership principles, driven by EIN Executive and Science committees. However, for EIN’s activities to be maintained and durable, long-term support is vital. We call on national and continental funding agencies and research councils, protists and algae communities, and biotechnology and pharmaceutical industries, to embrace, support and fund translational exploitation of these highly valuable organisms.

The area near Dome C, East Antarctica, is thought to be one of the most promising targets for recovering a continuous ice-core record spanning more than a million years. The European Beyond EPICA consortium has selected Little Dome C (LDC), an area ∼ 35 km southeast of Concordia Station, to attempt to recover such a record. Here, we present the results of the final ice-penetrating radar survey used to refine the exact drill site. These data were acquired during the 2019–2020 austral summer using a new, multi-channel high-resolution very high frequency (VHF) radar operating in the frequency range of 170–230 MHz. This new instrument is able to detect reflectors in the near-basal region, where previous surveys were largely unable to detect horizons. The radar stratigraphy is used to transfer the timescale of the EPICA Dome C ice core (EDC) to the area of Little Dome C, using radar isochrones dating back past 600 ka. We use these data to derive the expected depth–age relationship through the ice column at the now-chosen drill site, termed BELDC (Beyond EPICA LDC). These new data indicate that the ice at BELDC is considerably older than that at EDC at the same depth and that there is about 375 m of ice older than 600 kyr at BELDC. Stratigraphy is well preserved to 2565 m, ∼ 93 % of the ice thickness, below which there is a basal unit with unknown properties. An ice-flow model tuned to the isochrones suggests ages likely reach 1.5 Myr near 2500 m, ∼ 65 m above the basal unit and ∼ 265 m above the bed, with sufficient resolution (19 ± 2 kyr m−1) to resolve 41 kyr glacial cycles.

The area near Dome C, East Antarctica, is thought to be one of the most promising targets for recovering a continuous ice-core record spanning more than a million years. The European Beyond EPICA consortium has selected Little Dome C, an area ~35 km south-east of Concordia Station, to attempt to recover such a record. Here, we present the results of the final ice-penetrating radar survey used to refine the exact drill site. These data were acquired during the 2019–2020 Austral summer using a new, multi-channel high-resolution VHF radar operating in the frequency range of 170–230 MHz. This new instrument is able to detect reflections in the near-basal region, where previous surveys were unable to trace continuous horizons. The radar stratigraphy is used to transfer the timescale of the EPICA Dome C ice core (EDC) to the area of Little Dome C, using radar isochrones dating back past 600 ka. We use these data to derive the expected depth–age relationship through the ice column at the now-chosen drill site, termed BELDC. These new data indicate that the ice at BELDC is considerably older than that at EDC at the same depth, and that there is about 375 m of ice older than 600 ka at BELDC. Stratigraphy is well preserved to 2565 m, below which there is a basal unit with unknown properties. A simple ice flow model tuned to the isochrones suggests ages likely reach 1.5 Ma near 2525 m, ~40 m above the basal unit and ~240 m above the bed, with sufficient resolution (14±1 ka m−1) to resolve 41 ka glacial cycles.

Patients with chronic kidney disease (CKD) and end-stage kidney disease (ESKD) experience an increased risk of cerebrovascular disease and cognitive dysfunction. Hemodialysis (HD), a major modality of renal replacement therapy in ESKD, can cause rapid changes in blood pressure, osmolality, and acid-base balance that collectively present a unique stress to the cerebral vasculature. This review presents an update regarding cerebral blood flow (CBF) regulation in CKD and ESKD and how the maintenance of cerebral oxygenation may be compromised during HD. Patients with ESKD exhibit decreased cerebral oxygen delivery due to anemia, despite cerebral hyperperfusion at rest. Cerebral oxygenation further declines during HD due to reductions in CBF, and this may induce cerebral ischemia or “stunning.” Intradialytic reductions in CBF are driven by decreases in cerebral perfusion pressure that may be partially opposed by bicarbonate shifts during dialysis. Intradialytic reductions in CBF have been related to several variables that are routinely measured in clinical practice including ultrafiltration rate and blood pressure. However, the role of compensatory cerebrovascular regulatory mechanisms during HD remains relatively unexplored. In particular, cerebral autoregulation can oppose reductions in CBF driven by reductions in systemic blood pressure, while cerebrovascular reactivity to CO2may attenuate intradialytic reductions in CBF through promoting cerebral vasodilation. However, whether these mechanisms are effective in ESKD and during HD remain relatively unexplored. Important areas for future work include investigating potential alterations in cerebrovascular regulation in CKD and ESKD and how key regulatory mechanisms are engaged and integrated during HD to modulate intradialytic declines in CBF.

Ice sounding and mapping internal layers with radars over large areas is an effective way to obtain data to understand and model ice dynamics. To map the bottom most layers and determine the ice-bed topography of more than 3-km Greenland ice with fine resolution, we developed a 180 - 340 MHz ultrawide band (UWB) dual-polarized ice sounding radar. The radar was deployed as a part of the East Greenland Ice-core Project (EGRIP) in summer 2019. It is configured as a 12-channel multiple-input-multiple-output (MIMO) system. We designed and built a dual-polarized tightly coupled antenna-array. This paper presents the radar design, antenna performance and sample results from the data collected in the field.

An ultrawide-band radar system was developed to measure snow thickness from an airborne platform. It is a second-generation device, improving upon a system that was deployed to Antarctica in 2018–2019. The radar operates from 2.7 -10.7 GHz and from 10–18 GHz for a theoretical resolution of less than 2 cm, It was deployed to the Grand Mesa National Forest in Colorado on a Twin Otter DHC-6 aircraft in March of 2019. The system successfully mapped the air-snow and snow-ground interfaces as well as some internal layering over both vegetative and non-vegetative areas. In this paper, we discuss the design, development and deployment of this radar and show some preliminary results.

Polar regions are among the least known and most challenging areas of Earth in terms of their topography, water mass and transport, and accessibility. This paper shows a solution for advanced SAR capabilities on a unique light sport aircraft (LSA) platform suitable for widespread radar measurements of Polar regions. The LSA is integrated with an 8 channel 170–470 MHz ultra-wideband (UWB) radar capable of sounding Polar ice sheets and ice layers down to the bed. We designed, constructed, and tested the sub-systems, including a test of the RF electronics with a surface vehicle on the Greenland ice sheet.

A simple, ultrawideband, and high gain VHF/UHF open-sleeve dipole antenna and array for airborne ice measuring radar are presented. To satisfy the desired bandwidth of 300 MHz and realized gain of 10 dBi or higher in the frequency range of 170 and 470 MHz, the geometry and dimensions of the antenna are optimized under the real aircraft wing structure. The simulation results show that the 4-element antenna array having a dipole length of 720 mm, a parasitic element length of 280 mm, a separation between dipole and a parasitic element of 64 mm, and separation between antenna elements of 640 mm satisfies the desired bandwidth and gain requirements.

An ultra-lightweight L-band patch antenna array is designed for the high sensitivity ground-based ice-sounding radar system. The antenna array achieves a realized gain of 29 dBi, which is benefit from the $2.88\ \mathrm{m}\times 1.44\ \mathrm{m}$ large aperture size. Despite its large size, the overall weight of the array including power dividers, cables and mechanical structures is only 36 kg and the thickness is less than 2 cm. The modulated design enables easy transportation to polar regions. For low-profile and wideband performance, U-slot air-substrate patch is used as single antenna element. The $16\times 8$ large array operates from 1.17 to 1.48 GHz with a bandwidth of 310 MHz. Also, the antenna array is combined to 8 channels for the radar system, each channel can handle 2 kW peak power with customized power divider design. The antenna array was deployed in Antarctica in 2019 field season.

Contains fulltext : 200345.pdf (Publisher’s version ) (Open Access) Introduction: Medial arterial calcification is common in chronic kidney disease (CKD) and portends poor clinical outcomes, but its progression relative to the severity of CKD and the role of other risk factors is unknown because of the lack of reliable quantification. Methods: Calcification of breast arteries detected by mammography, which is exclusively medial and correlates with medial calcification in peripheral arteries and with cardiovascular outcomes, was used to measure the progression of medial arterial calcification in women with CKD and end-stage renal disease (ESRD). Measurements showed intra- and interobserver correlations of 0.98, an interstudy variability of 8% to 11%, and a correlation with computed tomographic measurements of 0.92. Results: Progression of calcification was measured in 60 control subjects (estimated glomerular filtration rate (eGFR) >/= 90 ml/min per 1.73 m(2)) and 137 subjects with CKD (eGFR < 90 ml/min per 1.73 m(2)). Progression in control subjects was linear over time and independent of age. The rate of progression was increased in CKD but only at eGFR < 40 ml/min per 1.73 m(2) (median, 8.1 vs. 3.9 mm/breast/yr in controls; P = 0.006). Progression accelerated markedly in subjects with ESRD (median, 20 mm/breast/yr; n = 36), but did not differ from controls after kidney transplantation (n = 25). Diabetes significantly augmented progression in subjects with CKD and ESRD but not in controls. Conclusion: Mammography is a convenient and reliable method to measure the progression of medial arterial calcification. Progression does not increase until advanced stages of CKD, accelerates markedly in ESRD, and returns to control rates after kidney transplantation. Diabetes significantly increases progression in CKD and ESRD.