Miracle-dz/UniFAR-FTUs huggingface dataset:
Angular domain pilot design and channel estimation for FDD massive MIMO networks

The huge training overhead for obtaining channel state information (CSI) at the BS has been recognized as a major challenge in frequency division duplex (FDD) massive multiple-input multiple-output (MIMO) cellular networks. To solve this problem, we propose an angular domain pilot design and channel estimation scheme to reduce the required overhead by exploiting the angle domain channel sparsity. Specifically, we firstly propose the downlink dominant angular set estimation by utilizing the directional reciprocity of FDD channels, where an index calibration algorithm is introduced to handle the effect of different wavelengths in FDD systems. Then, two kinds of angular domain pilots design schemes, named complete orthogonal pilot design and partial orthogonal pilot design, together with their corresponding feedback frameworks are proposed for channel estimation. Simulation results demonstrate that our proposed angular domain pilot design and channel estimation scheme could provide good mean square error (MSE) performance with much reduced pilot overhead, and consequently achieve much larger downlink throughput in comparison to the conventional scheme adopted in LTE.
Comparison of Driving Errors Between On-the-Road and Simulated Driving Assessment: A Validation Study

Objective: Driving simulation provides a convenient and safe method for assessing driving behaviors. Many authors, however, agree that validation is a key component of any study that utilizes simulators to assess driving performance. The purpose of this study was to test driver response validity by discerning whether behavioral responses of drivers, as expressed by type and number of errors, are similar on the road and in the simulator. Methods: We replicated real-world intersections in our driving simulator (STISIM M500W; Systems Technology Inc.) and assessed the number and type of driving errors committed by the same 39 participants while negotiating a right and a left turn both on the road and in the simulator. Results: We found no significant interactions between the type of vehicle (road vs. simulator) and the type of turn (right versus left) for any of the driving errors, indicating that the same trends exist between driving errors made on the road and in the simulator and thus suggesting relative validity of the simulator. We also found no significant differences between the road and the simulator for lane maintenance, adjustment to stimuli, and visual scanning errors, indicating absolute validity for these types of errors. Conclusions: The findings suggest early support for external validity for our driving simulator, indicating that the results of assessing driving errors when negotiating turns in the simulator can be generalized or transferred to the road under the same testing conditions. A follow-up study with larger sample size is needed to establish whether driving performance in the simulator is predictive of driving performance on the road.
Three‐dimensional segmentation of nuclei and mitotic chromosomes for the study of cell divisions in live Drosophila embryos

Drosophila embryogenesis is an established model to investigate mechanisms and genes related to cell divisions in an intact multicellular organism. Progression through the cell cycle phases can be monitored in vivo using fluorescently labeled fusion proteins andtime‐lapse microscopy. To measure cellular properties in microscopic images, accurate and fast image segmentation methods are a critical prerequisite. To quantify static and dynamic features of interphase nuclei and mitotic chromosomes, we developed a three‐dimensional (3D) segmentation method based on multiple level sets. We tested our method on 3D time‐series images of live embryos expressing histone‐2Av‐green fluorescence protein. Our method is robust to low signal‐to‐noise ratios inherent to high‐speed imaging, fluorescent signals in the cytoplasm, and dynamic changes of shape and texture. Comparisons with manual ground‐truth segmentations showed that our method achieves more than 90% accuracy on the object as well as voxel levels and performs consistently throughout all cell cycle phases and developmental stages from syncytial blastoderm to postblastoderm mitotic domains. © 2011 International Society for Advancement of Cytometry
Multiple endocrine neoplasia type 1 (MEN1): clinical heterogeneity in a large family with a nonsense mutation in the MEN1 gene (Trp471Stop)

Familial multiple endocrine neoplasia type 1 (MEN1) is an hereditary dominant trait characterized by tumours of the parathyroids, anterior pituitary and endocrine pancreatic glands, among others. The MEN1 gene has recently been cloned, and MEN1‐mutations have been identified in several families as well as in a number of sporadic cases. The aim of this study was to search for mutations in a large MEN1‐family in order to define the clinical heterogeneity among mutation‐carriers. We also analysed DNA from several tumour tissues in order to test the ‘two hit’ model for inactivation of the MEN1 gene.
Disrupted nighttime sleep in narcolepsy.

STUDY OBJECTIVES Characterize disrupted nighttime sleep (DNS) in narcolepsy, an important symptom of narcolepsy. METHODS A panel of international narcolepsy experts was convened in 2011 to build a consensus characterization of DNS in patients with narcolepsy. A literature search of the Medline (1965 to date), Medline In-Process (latest weeks), Embase (1974 to date), Embase Alert (latest 8 weeks), and Biosis (1965 to date) databases was conducted using the following search terms: narcolepsy and disrupted nighttime sleep, disturbed nighttime sleep, fragmented sleep, consolidated sleep, sleep disruption, and narcolepsy questionnaire. The purpose of the literature search was to identify publications characterizing the nighttime sleep of patients with narcolepsy. The panel reviewed the literature. Nocturnal sleep can also be disturbed by REM sleep abnormalities such as vivid dreaming and REM sleep behavior disorder; however, these were not reviewed in the current paper, as we were evaluating for idiopathic sleep disturbances. RESULTS The literature reviewed provide a consistent characterization of nighttime sleep in patients with narcolepsy as fragmented, with reports of frequent, brief nightly awakenings with difficulties returning to sleep and associated reports of poor sleep quality. Polysomnographic studies consistently report frequent awakenings/arousals after sleep onset, more stage 1 (S1) sleep, and more frequent shifts to S1 sleep or wake from deeper stages of sleep. The consensus of the International Experts' Panel on Narcolepsy was that DNS can be distressing for patients with narcolepsy and that treatment of DNS warrants consideration. CONCLUSIONS Clinicians involved in the management of patients with narcolepsy should investigate patients' quality of nighttime sleep, give weight and consideration to patient reports of nighttime sleep experience, and consider DNS a target for treatment.
The impact of a repealed motorcycle helmet law in Miami-Dade County.

OBJECTIVE To study the impact of helmet nonuse in motorcycle crashes after the repeal of a mandatory helmet law in the state of Florida. METHODS We prospectively studied all patients evaluated at the University of Miami/Jackson Memorial Medical Center from July 1, 2000, through December 31, 2000, involved in motorcycle crashes, and compared them with those seen during the same time period the year before the helmet law change. RESULTS In 1999, before the repeal of the helmet law, there were 52 cases evaluated at our center compared with 94 after the law change. Helmet usage decreased from 1999 (83%) to 2000 (56%). The number of brain injuries (Abbreviated Injury Scale score > or = 2) during this same time period increased from 18 to 35, and the number of fatalities from 2 to 8. CONCLUSION The repeal of a motorcycle helmet law significantly increased the number and severity of brain injuries admitted to our trauma center.
Impedance in voltage-current relations description of the power system PCC - experimental investigations of the accuracy of the LTI system model

The paper presents experimental verification of the quality of LTI power grid model valid for the frequency range of 8 kHz. The single PCC was investigated so the paper is the local, University grid investigations oriented, however concerns two general important problems: one is the absolute accuracy of real grid impedance measurements to which no direct reference data are accessible, the second is the validity of the LTI model, which is used for description of the complex structure composed of nonlinear and switched power installations. The LTI models form very interesting and useful approximation of the complex reality and have meaningful time and frequency domain interpretation. When used for power grids they deal with their Norton/Thevenin equivalent models. Two components of such a model: impedance and system side sources describe the grid and are discussed in the paper. Rich experimental data were referenced to the structural model of the grid so the paper gives evaluative information on the quality of ad-choc grid modeling. Interesting, incremental method for the estimation of absolute impedance errors was proposed and used for improvement of the implemented DSP. Time varying nature of the investigated grid impedance was presented, and system errors with implementation of LTI model to such a time-varying PCC description are discussed.
Does Dog-Human Attachment Affect Their Inter-Specific Cooperation?

Leading a blind or blindfolded person is a complex cooperative task influenced by many factors. The aim of this study was to determine if quality of attachment affects the performance of dog and owner dyads showed on an Obstacle Course. Modified Ainsworth’s Strange Situation Test was used for assessing attachment quality. Only one dimension of the attachment, the ‘anxiety’ factor was found to correlate with behavioural measures of the Obstacle Course (e.g. number of mistakes, initialisation index that reflects which participant initiates more actions in a dyad). We found significant differences of performance between the three groups of dog-owner pairs (pet dog, guide dog and police dog dyads), but we could not show significant differences in the ‘attachment’ factor among these groups. We concluded that it is not the attachment type that causes the main differences in the leading behaviour of our three study groups. Dogs have an innate ability for cooperation with humans that was enhanced by selective breeding during domestication and this basic ability can be modified by training but seem to be less affected by the relationship with the owner.
An ultra-wideband metamaterial absorber with active frequency selective surface

We present an ultra-wideband metamaterial absorber with active frequency selective surface (AFSS). The metamaterial absorber consists of a periodic arrangement of AFSS patterns and a metallic back-plane, separated by 4 mm dielectric spacer. By adjusting the bias voltage of the PIN diodes embedded in the AFSS cells, we achieve three absorbing bands at different frequencies. Finite element method (FEM) simulation is carried out to discuss the absorbing properties of the absorber. The experimental results demonstrate that the metamaterial absorber has wideband absorption with a reflectivity below -8 dB over the microwave range from 2.43 to 14 GHz.
Turnover of Endogenous SsrA-tagged Proteins Mediated by ATP-dependent Proteases in Escherichia coli*

Formation and degradation of SsrA-tagged proteins enable ribosome recycling and elimination of defective products of incomplete translation. We produced an antibody against the SsrA peptide and used it to measure the amounts of SsrA-tagged proteins in Escherichia coli cells without interfering with tagging or altering the context of the tag added at the ends of nascent polypeptides. SsrA-tagged proteins were present in very small amounts unless a component of the ClpXP protease was missing. From the levels of tagged proteins in cells in which degradation is essentially blocked, we calculate that ≥1 in 200 translation products receives an SsrA tag. ClpXP is responsible for ≥90% of the degradation of SsrA-tagged proteins. The degradation rate in wild type cells is ≥1.4 min–1 and decreases to ∼0.10 min–1 in a clpX mutant. The rate of degradation by ClpXP is decreased ∼3-fold in mutants lacking the adaptor SspB, whereas degradation by ClpAP is increased 3–5-fold. However, ClpAP degrades SsrA-tagged proteins slowly even in the absence of SspB, possibly because of interference from ClpA-specific substrates. Lon protease degrades SsrA-tagged proteins at a rate of ∼0.05 min–1 in the presence or absence of SspB. We conclude that ClpXP, together with SspB, is uniquely adapted for degradation of SsrA-tagged proteins and is responsible for the major part of their degradation in vivo.
Two-dimensional MPPT for photovoltaic energy harvesting systems

This paper discusses a low power Maximum Power Point Tracker (MPPT) circuit specifically designed for wireless sensor node (hence effective, flexible, low cost and power-aware), that requires a power transferring circuit for conveying solar energy into rechargeable batteries even if it is not in optimal weather or orientation conditions. Depending on the operating conditions of the solar cell, the instantaneous generated power significantly changes requiring the adjustment not only of the working point of the solar panel but also of some other parameters and/or operating conditions of the converter itself in order to increase the conversion efficiency at different power level conditions. In this paper a two-dimensional MPPT algorithm that continuously changes both the converter switching frequency and the voltage on the solar panel is proposed, analyzed and experimentally verified.
Refining Our Understanding of Beta through

The Capital Asset Pricing Model (CAPM) has been a key theory in financial economics since the 1960s. One of its main contributions is to attempt to identify how the risk of a particular stock is related to the risk of the overall stock market using the risk measure Beta. If the relationship between an individual stock's returns and the returns of the market exhibit heteroskedasticity, then the estimates of Beta for different quantiles of the relationship can be quite different. The behavioral ideas first proposed by Kahneman and Tversky (1979), which they called prospect theory, postulate that: (i) people exhibit "loss-aversion" in a gain frame; and (ii) people exhibit "risk-seeking" in a loss frame. If this is true, people could prefer lower Beta stocks after they have experienced a gain and higher Beta stocks after they have experienced a loss. Stocks that exhibit converging heteroskedasticity (22.2% of our sample) should be preferred by investors, and stocks that exhibit diverging heteroskedasticity (12.6% of our sample) should not be preferred. Investors may be able to benefit by choosing portfolios that are more closely aligned with their preferences.
Design of Fixed-Width Multipliers With Linear Compensation Function

This paper focuses on fixed-width multipliers with linear compensation function by investigating in detail the effect of coefficients quantization. New fixed-width multiplier topologies, with different accuracy versus hardware complexity trade-off, are obtained by varying the quantization scheme. Two topologies are in particular selected as the most effective ones. The first one is based on a uniform coefficient quantization, while the second topology uses a nonuniform quantization scheme. The novel fixed-width multiplier topologies exhibit better accuracy with respect to previous solutions, close to the theoretical lower bound.
Joint Hybrid Tx–Rx Design for Wireless Backhaul With Delay-Outage Constraint in Massive MIMO Systems

This paper studies joint design of mixed-timescale hybrid precoding and combining to maximize the effective capacity for wireless backhaul in massive multiple-input multiple-output (MIMO) systems. Specifically, radio frequency (RF) analog processing is adaptive to statistical channel state information (CSI) while digital baseband processing is updated with instantaneous effective CSI. Equipped with traditional MIMO solutions at the baseband, the issue of RF design for both unconstrained-modulus and constant-modulus elements is addressed. Under the jointly correlated channel model, the objective function does not have a closed-form expression. In the unconstrained case, we derive the optimal RF solution structures, which lead to a combinatorial eigenmode selection formulation. Such an NP-hard problem is solved to near-optimality by semi-definite relaxation. In view of the additional difficulty posed by the non-convex modulus constraint, we exploit the problem structure to construct the constant-modulus design from the unconstrained-modulus solution which is cast as a problem of joint matrix approximation and solved by low-complexity Jacobi-like algorithms. Numerical results show that under loose and stringent delay-outage constraints, the mixed-timescale hybrid designs deliver effective rates comparable with other perfect CSI-based state-of-the-art baselines.
Big Corn and Soybean Crops Get Bigger is a Myth

There is a long-standing market saying that "big crops get bigger and small crops get smaller. " This statement refers to the yield forecasting cycle of the USDA’s National Agricultural Statistics Service (NASS). That cycle for corn and soybeans consists of monthly yield forecasts that begin in August and extend through November and culminate with the final yield estimate for the season that is released in January following harvest. Specifically, the statement implies that early NASS yield forecasts are “conservative” in years when yields are high and get larger as the forecast cycle progresses and are “optimistic” in years when yields are low and get smaller as the forecast cycle progresses. These notions are tied to the more general idea that NASS yield forecasts are “smoothed,” meaning that the final yield estimate results from cumulative monthly changes in forecasts in the same direction. Some tend to believe that smoothing of NASS yield forecasts, particularly in years of yield extremes, is intentional in order to minimize or spread the price impact of very large or small yields. Alternatively, yield forecasts may appear to be intentionally smoothed simply due to the fact that forecasts become more accurate during the forecast cycle as more actual yield information is incorporated into the forecasts.
Development of gelatin-chitosan-hydroxyapatite based bioactive bone scaffold with controlled pore size and mechanical strength

Hydroxyapatite–chitosan/gelatin (HA:Chi:Gel) nanocomposite scaffold has potential to serve as a template matrix to regenerate extra cellular matrix of human bone. Scaffolds with varying composition of hydroxyapatite, chitosan, and gelatin were prepared using lyophilization technique where glutaraldehyde (GTA) acted as a cross-linking agent for biopolymers. First, phase pure hydroxyapatite–chitosan nanocrystals were in situ synthesized by coprecipitation method using a solution of 2% acetic acid dissolved chitosan and aqueous solution of calcium nitrate tetrahydrate [Ca(NO3)2,4H2O] and diammonium hydrogen phosphate [(NH4)2H PO4]. Keeping solid loading constant at 30 wt% and changing the composition of the original slurry of gelatin, HA–chitosan allowed control of the pore size, its distribution, and mechanical properties of the scaffolds. Microstructural investigation by scanning electron microscopy revealed the formation of a well interconnected porous scaffold with a pore size in the range of 35–150 μm. The HA granules were uniformly dispersed in the gelatin–chitosan network. An optimal composition in terms of pore size and mechanical properties was obtained from the scaffold with an HA:Chi:Gel ratio of 21:49:30. The composite scaffold having 70% porosity with pore size distribution of 35–150 μm exhibited a compressive strength of 3.3–3.5 MPa, which is within the range of that exhibited by cancellous bone. The bioactivity of the scaffold was evaluated after conducting mesenchymal stem cell (MSC) – materials interaction and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay using MSCs. The scaffold found to be conducive to MSC’s adhesion as evident from lamellipodia, filopodia extensions from cell cytoskeleton, proliferation, and differentiation up to 14 days of cell culture.
Psychosocial Outcomes 3 to 10 Years After Donation in the Adult to Adult Living Donor Liver Transplantation Cohort Study

Background Studies of liver donors' psychosocial outcomes focus on the short term and rely largely on quality-of-life measures not specific to donation. We sought to examine long-term donation effects on 3 psychosocial domains: perceived physical, emotional, and socioeconomic outcomes. Methods Individuals donating 3 to 10 years previously at 9 centers were eligible for telephone surveys. Survey responses were examined descriptively. Cluster analysis was used to identify distinct donor groups based on response profiles across psychosocial domains. Potential predictors of response profiles were evaluated with regression analysis. Results Five hundred seventeen donors (66%) participated (M = 5.8 years postdonation, SD = 1.9). Fifteen percent to 48% of donors endorsed current donation-related physical health problems and concerns, and 7%-60% reported socioeconomic concerns (eg, insurance difficulties, financial expenditures). However, on average, donors experienced high psychological growth, and 90% felt positively about donation. Cluster analysis revealed 5 donor groups. One group showed high psychological benefit, with little endorsement of physical or socioeconomic concerns (15% of donors). Four groups showed less favorable profiles, with varying combinations of difficulties. The largest such group showed high endorsement of physical concerns and financial expenditures, and only modest psychological benefit (31% of donors). Men and nonHispanic whites were most likely to have unfavorable response profiles (Ps < 0.01). Compared with donors aged 19 to 30 years, older donors were less likely to have unfavorable profiles; these differences were significant for donors in the >40 to 50 year age group (Ps < 0.008). Conclusions Even many years postdonation, donors report adverse physical and socioeconomic effects, but positive emotional effects as well. Identification of response profiles and predictors may improve targeting of postdonation surveillance and care.
The Intraday Properties of the VIX and the VXO

This paper investigates daily and intraday properties of the VIX and its predecessor the VXO. Sampling data at a one-minute frequency, we document that both the VIX and VXO display a negative drift intraday. While this finding is expected in the VXO, given its constant 30-day maturity at a daily frequency, it is surprising to observe the same pattern in the VIX, which maintains the constant maturity at a one-minute frequency. In addition, we document that the VIX has a distinct intraweek pattern, declining during the week and surging over the weekend. We further observe that there is intraday and intraweek variation in the relation between the VIX and the S&P500 (the leverage/feedback effect) which appears to be most negative during the middle of the trading day. Similarly, there is a U-shape pattern in this relation during the week, with the leverage effect being most negative in the middle of the week.