Advanced Projects Research Incorporated (United States)

Abstract. The orientation of ice crystals plays a significant role in determining their radiative and precipitating effects; horizontally oriented ice crystals (HOICs) reflect up to ∼40 % more shortwave radiation back to space than randomly oriented ice crystals (ROICs). This study introduces an automatic range-resolved algorithm for HOIC identification using a combination of ground-based zenith-pointing and 15° off-zenith-pointing polarization lidars. The lidar observations provided high-resolution cloud-phase information. The data were collected in Beijing over 354 d in 2022. A case study from 13 October 2022 is presented to demonstrate the effectiveness and the feasibility of the detection method. The synergy of lidars and collocated Ka-band cloud radar, radiosonde, and ERA5 data provides phenomenological insights into HOIC events. While cloud radar Doppler velocity data allowed the estimation of ice crystal size, Reynolds numbers, and turbulent eddy dissipation rates, corresponding environmental and radar-detected variables are also provided. HOICs were present, accompanied by weak horizontal wind of 0–20 m s−1 and relatively high temperature between −8 and −22 °C. Compared to the ROICs, HOICs exhibited larger reflectivity, larger spectral width, a larger turbulent eddy dissipation rate, and a median Doppler velocity of about 0.8 m s−1. Ice crystal diameters (1029 to 1756 µm for 5th and 95th percentiles) and Reynolds numbers (28 to 88 for 5th and 95th percentiles) are also estimated with the help of cloud radar Doppler velocity using an aerodynamic model. One interesting finding is that the previously found switch-off region of the specular reflection in the region of cloud base shows a higher turbulence eddy dissipation rate, probably caused by the latent heat released due to the sublimation of ice crystals in the cloud-base region. The newly derived properties of HOICs have the potential to aid the derivation of the likelihood of their occurrence in output from general circulation models (GCMs) of the atmosphere.

Bone defect repair is an interdisciplinary research field encompassing surgical orthopedics, regenerative medici- ne, tissue engineering, immunology (addressing biocompatibility challenges), materials science and technology (including additive manufacturing, porosity, and mechanical strength), and nanotechnology for developing bio- compatible matrices that enhance bone regeneration. This literature review highlights recent advancements in bone tissue engineering, focusing on the application of autologous biomaterials in combination with biocompatible matrices to improve bone regeneration outcomes.

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Deep learning’s immense capabilities are often constrained by the complexity of its models, leading to an increasing demand for effective sparsification techniques. Bayesian sparsification for deep learning emerges as a crucial approach, facilitating the design of models that are both computationally efficient and competitive in terms of performance across various deep learning applications. The state-of-the-art – in Bayesian sparsification of deep neural networks – combines structural shrinkage priors on model weights with an approximate inference scheme based on stochastic variational inference. However, model inversion of the full generative model is exceptionally computationally demanding, especially when compared to standard deep learning of point estimates. In this context, we advocate for the use of Bayesian model reduction (BMR) as a more efficient alternative for pruning of model weights. As a generalization of the Savage-Dickey ratio, BMR allows a post-hoc elimination of redundant model weights based on the posterior estimates under a straightforward (non-hierarchical) generative model. Our comparative study highlights the advantages of the BMR method relative to established approaches, which are based on hierarchical horseshoe priors over model weights. We illustrate the potential of BMR across various deep learning architectures, from classical networks like LeNet to modern frameworks such as Vision Transformers and MLP-Mixers.

During the last decade, the management of blunt hepatic injury has considerably changed. Three options are available as follows: nonoperative management (NOM), transarterial embolization (TAE), and surgery. We aimed to evaluate in a systematic review the current practice and outcomes in the management of Grade III to V blunt hepatic injury. The MEDLINE database was searched using PubMed to identify English-language citations published after 2000 using the key words blunt, hepatic injury, severe, and grade III to V in different combinations. Liver injury was graded according to the American Association for the Surgery of Trauma classification on computed tomography (CT). Primary outcome analyzed was success rate in intention to treat. Critical appraisal of the literature was performed using the validated National Institute for Health and Care Excellence "Quality Assessment for Case Series" system. Twelve articles were selected for critical appraisal (n = 4,946 patients). The median quality score of articles was 4 of 8 (range, 2-6). Overall, the median Injury Severity Score (ISS) at admission was 26 (range, 0.6-75). A median of 66% (range, 0-100%) of patients was managed with NOM, with a success rate of 94% (range, 86-100%). TAE was used in only 3% of cases (range, 0-72%) owing to contrast extravasation on CT with a success rate of 93% (range, 81-100%); however, 9% to 30% of patients required a laparotomy. Thirty-one percent (range, 17-100%) of patients were managed with surgery owing to hemodynamic instability in most cases, with 12% to 28% requiring secondary TAE to control recurrent hepatic bleeding. Mortality was 5% (range, 0-8%) after NOM and 51% (range, 30-68%) after surgery. NOM of Grade III to V blunt hepatic injury is the first treatment option to manage hemodynamically stable patients. TAE and surgery are considered in a highly selective group of patients with contrast extravasation on CT or shock at admission, respectively. Additional standardization of the reports is necessary to allow accurate comparisons of the various management strategies. Systematic review, level IV.

A kidney allocation system based on full human leukocyte antigen (HLA)-DR compatibility was described in this journal to be simple and more equitable (1). The authors concluded their article with the suggestion that with this allocation system, kidneys could be regionally allocated. We simulated the use of such a kidney allocation system in our region, The Netherlands. The algorithm was made in Microsoft Visual Basic 6.0 and contains a set of tiers with allocation rules arranged according to their priority. First, kidneys have to be ABO blood group compatible with the recipients. Second, HLA-DR antigens of kidney and recipient have to match at the split level (HLA-DR1-DR18). HLA-DR homozygous patients are given priority if a kidney is HLA-DR homozygous. Kidneys should not have HLA split antigens against which the recipient is known to produce antibodies (unacceptable HLA mismatches). Finally, the patients with the same matching degree are prioritized by their time on the waiting list from the start of dialysis. In this simulation, 1416 kidneys from 708 Dutch postmortem donors from 2004 to 2006 were offered to a nonexhaustive waiting list starting with the 1014 Dutch patients on January 1, 2004 waiting list. Each time a patient leaves this list, it is replenished with data from a new patient that was put on the Dutch waiting list between 2004 and 2006. If HLA antigens were only known on the broad level, than HLA split types were assigned according to the antigen frequency distribution in the Dutch population (2). In this simulation, 26% of the patients have rare HLA-DR antigens (2), and 21% of the patients have antibodies against specific HLA-A, -B, and -DR antigens. The results of the simulation are shown in Table 1. Patients with rare HLA-DR antigens did not have significantly longer waiting times until transplantation than other patients. Of the patients remaining on the waiting list after the simulation, 34% have rare DR antigens compared with 20% of the transplanted patients. On average, transplanted patients with antibodies against specific HLA antigens waited 6 months longer than other patients. Transplanted patients and patients still on the waiting list have similar proportions of patients with antibodies against specific HLA antigens.TABLE 1: Results of the allocation systems based on DR identityHowever, the simulated system failed to allocate 13% of the kidneys, which should be allocated to either HLA-DR–mismatched recipients in The Netherlands or HLA-DR–matched recipients in other countries. At present, The Netherlands and other Eurotransplant member states use the Eurotransplant kidney allocation system. This pointscoring system takes into account: HLA-A, B, and DR mismatch, mismatch probability, time on dialysis, distance between donor and transplantation center, import or export balance, high urgency patients, and pediatric patients (3, 4). Analysis on the kidney exchange rate within Eurotransplant between 2001 and 2004 had shown that from 1409 Dutch donor kidneys, only 58 (4%) were nonmandatory exchanged. By using the simulated system, this percentage would increase to 13%. In conclusion, a kidney allocation system based on full HLA-DR compatibility cannot be implemented in a region or a small country without disturbing the import or export balance or allocating kidneys over an HLA-DR mismatch. Martin B. A. Heemskerk Bernadette J. J. M. Haase-Kromwijk Dutch Transplant Foundation Leiden, The Netherlands Frans H. J. Claas Ilias I. N. Doxiadis Geert W. Haasnoot Department of Immunohematology and Blood transfusion Leiden University Medical Centre Leiden, The Netherlands Jaap J. Homan van der Heide Department of Nephrology University Medical Centre Groningen Groningen, The Netherlands Willem W. Weimar Department of Internal Medicine Erasmus Medical Centre Rotterdam Rotterdam, The Netherlands Andries J. Hoitsma Dutch Transplant Foundation Leiden, The Netherlands Department of Nephrology Radboud University Medical Centre Nijmegen Nijmegen, The Netherlands

In this work, we develop a method for dynamic output feedback covariance control of the state covariance of linear dissipative stochastic partial differential equations (PDEs) using spatially distributed control actuation and sensing with noise. Such stochastic PDEs arise naturally in the modeling of surface height profile evolution in thin film growth and sputtering processes. We begin with the formulation of the stochastic PDE into a system of infinite stochastic ordinary differential equations (ODEs) by using modal decomposition. A finite-dimensional approximation is then obtained to capture the dominant mode contribution to the surface roughness profile (i.e., the covariance of the surface height profile). Subsequently, a state feedback controller and a Kalman-Bucy filter are designed on the basis of the finite-dimensional approximation. The dynamic output feedback covariance controller is subsequently obtained by combining the state feedback controller and the state estimator. The steady-state expected surface covariance under the dynamic output feedback controller is then estimated on the basis of the closed-loop finite-dimensional system. An analysis is performed to obtain a theoretical estimate of the expected surface covariance of the closed-loop infinite-dimensional system. Applications of the linear dynamic output feedback controller to the linearized stochastic Kuramoto-Sivashinsky equation are presented.

Hepatitis B virus (HBV) patients with cirrhosis are at risk for developing costly, morbid, or mortal events, and therefore need highly effective therapies. Lamivudine is effective but is limited by viral resistance. In contrast, adefovir and entecavir have lower viral resistance, but are more expensive. The most cost-effective approach is uncertain. We evaluated the cost-effectiveness of six strategies in HBV cirrhosis: (1) No HBV treatment ("do nothing"), (2) lamivudine monotherapy, (3) adefovir monotherapy, (4) lamivudine with crossover to adefovir on resistance ("adefovir salvage"), (5) entecavir monotherapy, or (6) lamivudine with crossover to entecavir on resistance ("entecavir salvage"). The primary outcome was the incremental cost per quality-adjusted life-year (QALY) gained. The "do nothing" strategy was least effective yet least expensive. Compared with "do nothing," using adefovir cost an incremental US dollars 19,731. Entecavir was more effective yet more expensive than adefovir, and cost an incremental US dollars 25,626 per QALY gained versus adefovir. Selecting between entecavir versus adefovir was highly dependent on the third-party payer's "willingess-to-pay" (e.g., 45% and 60% of patients fall within budget if willing-to-pay US dollars 10K and US dollars 50K per QALY gained for entecavir, respectively). Both lamivudine monotherapy and the "salvage" strategies were not cost-effective. However, between the two salvage strategies, "adefovir salvage" was more effective and less expensive than "entecavir salvage." Both entecavir and adefovir are cost-effective in patients with HBV cirrhosis. Choosing between adefovir and entecavir is highly dependent on available budgets. In patients with HBV cirrhosis with previous lamivudine resistance, "adefovir salvage" appears more effective and less expensive than "entecavir salvage."

This overview of the diabetic/neuropathic pathways has been utilized as a basic teaching document in the health care field. The information provided applies to the education of patients as well as professionals with a basic understanding of the progression of complications and prevention of catastrophic events. Detailed descriptions include evaluation techniques that can be used for early neuropathy detection, footwear and modification requirements, and follow-up protocol. Chronic complications are detailed to allow health care professionals to detect and refer for proper treatment. Off-loading techniques provide optimal wound healing for wound clinical settings. (Adapted with permission from Wound Care, A Collaborative Practice Manual for Physical Therapists and Nurses, Sussman C, Barbara M. Bates-Jensen, eds. Gaithersburg, MD: Aspen Publishers; 2000).