Non-relativistic limit of Randall-Sundrum model: solutions, applications and constraints

In the Randall-Sundrum model with one brane, we found the approximate and exact solutions for gravitational potentials and accelerations of test bodies in these potentials for different geometrical configurations. We applied these formulas for calculation of the gravitational interaction between two spheres and found the approximate and exact expressions for the relative force corrections to the Newton's gravitational force. We demonstrated that the difference between relative force corrections for the approximate and exact cases increases with the parameter $l$ (for the fixed distance $r$ between centers of the spheres). On the other hand, this difference increases with decreasing of the distance between the centers of the spheres (for the fixed curvature scale parameter $l$). We got the upper limit for the curvature scale parameter $l\lesssim 10\, \mu$m. For these values of $l$, the difference between the approximate and exact solutions is negligible.Comment: LaTex 11 pages, 3 figure

Developing European conservation and mitigation tools for pollination services: approaches of the STEP (Status and Trends of European Pollinators) project

Pollinating insects form a key component of European biodiversity, and provide a vital ecosystem service to crops and wild plants. There is growing evidence of declines in both wild and domesticated pollinators, and parallel declines in plants relying upon them. The STEP project (Status and Trends of European Pollinators, 2010-2015, www.stepproject.net) is documenting critical elements in the nature and extent of these declines, examining key functional traits associated with pollination deficits, and developing a Red List for some European pollinator groups. Together these activities are laying the groundwork for future pollinator monitoring programmes. STEP is also assessing the relative importance of potential drivers of pollinator declines, including climate change, habitat loss and fragmentation, agrochemicals, pathogens, alien species, light pollution, and their interactions. We are measuring the ecological and economic impacts of declining pollinator services and floral resources, including effects on wild plant populations, crop production and human nutrition. STEP is reviewing existing and potential mitigation options, and providing novel tests of their effectiveness across Europe. Our work is building upon existing and newly developed datasets and models, complemented by spatially-replicated campaigns of field research to fill gaps in current knowledge. Findings are being integrated into a policy-relevant framework to create evidence-based decision support tools. STEP is establishing communication links to a wide range of stakeholders across Europe and beyond, including policy makers, beekeepers, farmers, academics and the general public. Taken together, the STEP research programme aims to improve our understanding of the nature, causes, consequences and potential mitigation of declines in pollination services at local, national, continental and global scales

Midgut epithelial endocrine cells are a rich source of the neuropeptides APSGFLGMRamide (Cancer borealis tachykinin-related peptide Ia) and GYRKPPFNGSIFamide (Gly\u3csup\u3e1\u3c/sup\u3e-SIFamide) in the crabs Cancer borealis, Cancer magister and Cancer productus

Over a quarter of a century ago, Mykles described the presence of putative endocrine cells in the midgut epithelium of the crab Cancer magister (Mykles, 1979). In the years that have followed, these cells have been largely ignored and nothing is known about their hormone content or the functions they play in this species. Here, we used a combination of immunohistochemistry and mass spectrometric techniques to investigate these questions. Using immunohistochemistry, we identified both SIFamide-and tachykinin-related peptide (TRP)-like immunopositive cells in the midgut epithelium of C. magister, as well as in that of Cancer borealis and Cancer productus. In each species, the SIFamide-like labeling was restricted to the anterior portion of the midgut, including the paired anterior midgut caeca, whereas the TRP-like immunoreactivity predominated in the posterior midgut and the posterior midgut caecum. Regardless of location, label or species, the morphology of the immunopositive cells matched that of the putative endocrine cells characterized ultrastructurally by Mykles (Mykles, 1979). Matrix-assisted laser desorption/ ionization-Fourier transform mass spectrometry identified the peptides responsible for the immunoreactivities as GYRKPPFNGSIFamide (Gly 1-SIFamide) and APSGFLGMRamide [Cancer boreatis tachykinin-related peptide Ia (CabTRP Ia)], respectively, both of which are known neuropeptides of Cancer species. Although the function of these midgut-derived peptides remains unknown, we found that both Gly1-SIFamide and CabTRP Ia were released when the midgut was exposed to high-potassium saline. In addition, CabTRP Ia was detectable in the hemolymph of crabs that had been held without food for several days, but not in that of fed animals, paralleling results that were attributed to TRP release from midgut endocrine cells in insects. Thus, one function that midgut-derived CabTRP Ia may play in Cancer species is paracrine/hormonal control of feeding-related behavior, as has been postulated for TRPs released from homologous cells in insects

APIR4EMC: Autocalibrated parallel imaging reconstruction for extended multi-contrast imaging

Purpose: To improve image quality of multi-contrast imaging with the proposed Autocalibrated Parallel Imaging Reconstruction for Extended Multi-Contrast Imaging (APIR4EMC). Methods: APIR4EMC reconstructs multi-contrast images in an autocalibrated parallel imaging reconstruction framework by adding contrasts as virtual coils. Compensation of signal evolution along the echo train of different contrasts is performed to improve signal prediction for missing samples. As a proof of concept, we performed prospectively accelerated phantom and in-vivo brain acquisitions with T1, T1-fat saturated (Fatsat), T2, PD, and FLAIR contrasts. The k-space sampling patterns of these acquisitions were jointly optimized. Images were jointly reconstructed with the proposed APIR4EMC method as well as individually with GRAPPA. Root mean square error (RMSE) to fully sampled reference images and g-factor maps were computed for both methods in the phantom experiment. Visual evaluation was performed in the in-vivo experiment. Results: Compared to GRAPPA, APIR4EMC reduced artifacts and improved SNR of the reconstructed images in the phantom acquisitions. Quantitatively, APIR4EMC substantially reduced noise amplification (g-factor) as well as RMSE compared to GRAPPA. Signal evolution compensation reduced artifacts. In the in-vivo experiments, 1 mm3 isotropic 3D images with contrasts of T1, T1-Fatsat, T2, PD, and FLAIR were acquired in as little as 7.5 min with the acceleration factor of 9. Reconstruction quality was consistent with the phantom results. Conclusion: Compared to single contrast reconstruction with GRAPPA, APIR4EMC reduces artifacts and noise amplification in accelerated multi-contrast imaging

Autocalibrated parallel imaging reconstruction with sampling pattern optimization for GRASE: APIR4GRASE

Purpose: To reduce artifacts and scan time of GRASE imaging by selecting an optimal sampling pattern and jointly reconstructing gradient echo and spin echo images. Methods: We jointly reconstruct images for the different echo types by considering these as additional virtual coil channels in the novel Autocalibrated Parallel Imaging Reconstruction with Sampling Pattern Optimization for GRASE (APIR4GRASE) method. Besides image reconstruction, we identify optimal sampling patterns for the acquisition. The selected optimal patterns were validated on phantom and in-vivo acquisitions. Comparison to the conventional GRASE without acceleration, and to the GRAPPA reconstruction with a single echo type was also performed. Results: Using identified optimal sampling patterns, APIR4GRASE eliminated modulation artifacts in both phantom and in-vivo experiments; mean square error (MSE) was reduced by 78% and 94%, respectively, compared to the conventional GRASE with similar scan time. Both artifacts and g-factor were reduced compared to the GRAPPA reconstruction with a single echo type. Conclusion: APIR4GRASE substantially improves the speed and quality of GRASE imaging over the state-of-the-art, and is able to reconstruct both spin echo and gradient echo images

The democratic interface: technology, political organization, and diverging patterns of electoral representation

Democracies are experiencing historic disruptions affecting how people engage with core institutions such as the press, civil society organizations, parties, and elections. These processes of citizen interaction with institutions operate as a democratic interface shaping self-government and the quality of public life. The electoral dimension of the interface is important, as its operation can affect all others. This analysis explores a growing left-right imbalance in the electoral connection between citizens, parties, elections, and government. This imbalance is due, in part, to divergent left-right preferences for political engagement, organization, and communication. Support on the right for clearer social rules and simpler moral, racial and nationalist agendas are compatible with hierarchical, leader-centered party organizations that compete more effectively in elections. Parties on the left currently face greater challenges engaging citizens due to the popular meta-ideology of diversity and inclusiveness and demands for direct or deliberative democracy. What we term connective parties are developing technologies to perform core organizational functions, and some have achieved electoral success. However, when connective parties on the left try to develop shared authority processes, online and offline, they face significant challenges competing with more conventionally organized parties on the right

Histomorphometry of the Sural Nerve for Use as a CFNG in Facial Reanimation Procedures

Facial palsy (FP) is a debilitating nerve pathology. Cross Face Nerve Grafting (CFNG) describes a surgical technique that uses nerve grafts to reanimate the paralyzed face. The sural nerve has been shown to be a reliable nerve graft with little donor side morbidity. Therefore, we aimed to investigate the microanatomy of the sural nerve. Biopsies were obtained from 15 FP patients who underwent CFNG using sural nerve grafts. Histological cross-sections were fixated, stained with PPD, and digitized. Histomorphometry and a validated software-based axon quantification were conducted. The median age of the operated patients was 37 years (5–62 years). There was a significant difference in axonal capacity decrease towards the periphery when comparing proximal vs. distal biopsies (p = 0.047), while the side of nerve harvest showed no significant differences in nerve caliber (proximal p = 0.253, distal p = 0.506) and axonal capacity for proximal and distal biopsies (proximal p = 0.414, distal p = 0.922). Age did not correlate with axonal capacity (proximal: R = −0.201, p = 0.603; distal: R = 0.317, p = 0.292). These novel insights into the microanatomy of the sural nerve may help refine CFNG techniques and individualize FP patient treatment plans, ultimately improving overall patient outcomes

Unilateral optic neuropathy following subdural hematoma: a case report

<p>Abstract</p> <p>Introduction</p> <p>Unilateral optic neuropathy is commonly due to a prechiasmatic affliction of the anterior visual pathway, while losses in visual hemifields result from the damage to brain hemispheres. Here we report the unusual case of a patient who suffered from acute optic neuropathy following hemispherical subdural hematoma. Although confirmed up to now only through necropsy studies, our case strongly suggests a local, microcirculatory deficit identified through magnetic resonance imaging <it>in vivo</it>.</p> <p>Case presentation</p> <p>A 70-year-old Caucasian German who developed a massive left hemispheric subdural hematoma under oral anticoagulation presented with acute, severe visual impairment on his left eye, which was noticed after surgical decompression. Neurologic and ophthalmologic examinations indicated sinistral optic neuropathy with visual acuity reduced nearly to amaurosis. Ocular pathology such as vitreous body hemorrhage, papilledema, and central retinal artery occlusion were excluded. An orbital lesion was ruled out by means of orbital magnetic resonance imaging. However, cerebral diffusion-weighted imaging and T2 maps of magnetic resonance imaging revealed a circumscribed ischemic lesion within the edematous, slightly herniated temporomesial lobe within the immediate vicinity of the affected optic nerve. Thus, the clinical course and morphologic magnetic resonance imaging findings suggest the occurrence of pressure-induced posterior ischemic optic neuropathy due to microcirculatory compromise.</p> <p>Conclusion</p> <p>Although lesions of the second cranial nerve following subdural hematoma have been reported individually, their pathogenesis was preferentially proposed from autopsy studies. Here we discuss a dual, pressure-induced and secondarily ischemic pathomechanism on the base of <it>in vivo </it>magnetic resonance imaging diagnostics which may remain unconsidered by computed tomography.</p

Tribute to Professor David Bruck

A tribute to Professor David I. Bruck, who served on the faculty of the Washington and Lee University School of Law from 2004 to 2020. Bruck directed W&L\u27s death penalty defense clinic, the Virginia Capital Case Clearinghouse, also known as VC3 . He became Professor of Law, Emeritus in 2020