bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extracting reliable empirical Green's functions using weighted cross-correlation functions of ambient seismic noise in west-central and southern Brazil
Authors: Shirzad Taghi , Safarkhani Mahsa , Assumpção Marcelo S 
Published: March 2022

SUMMARYAmbient seismic noise is now routinely used to study the Earth's interior. For an isotropic homogeneous medium, the basic assumption to extract seismic phases from a station pair is that the sources of seismic noise are distributed in such a way that there is a uniform energy flux around the station pair. In general, however, some particular azimuthal directions may dominate the energy flux, which directly affects the extracted interstation empirical Green's function (EGF). To solve this problem, we analysed synthetic cross-correlation functions (CCFs) from seismic pulses propagated in isotropic and anisotropic heterogeneous half-space media towards a station pair under the assumptions of uniformly and non-uniformly distributed sources of noise. A reliable EGF signal can be extracted by applying three processing steps: (1) normalizing the number of repeated stationary sources, (2) normalizing the energy of each excited source and (3) selecting coherent CCFs in the final stacking. In this way, three different classes of station pairs were identified based on the number of CCFs used in the stacking procedure. We introduced and applied a new method based on weighted root-mean-square stacking (WRMS) to the CCFs of more than 33 months of ambient noise recorded from January 2016 to September 2018 at 75 broad-band stations in West-Central Brazil. In the case of non-uniform distribution of source of noise, simple classical linear stacking of CCFs produces distorted EGFs. However, the waveform extracted by the WRMS method is very similar to the Rayleigh waves excited by an earthquake (on 2017 January 3) near one receiver observed at the other receiver. Moreover, synthetic tests and a comparison between extracted and earthquake signals show that although the WRMS method can extract the main part of the signal that is propagated on the shortest path, it cannot recover the energy parts propagated on multipath. Despite the N–W directionality in the geometry of the array, the rose-diagram results indicate no significant spatial variations in the energy level of EGFs extracted by the WRMS stacking, whereas the EGFs extracted by the classical linear stacking indicate the extreme directionality of energy flow in different period ranges. Rayleigh wave group and phase velocity tomographic maps resolved by the EGFs derived from the WRMS method indicate a clear boundary along the Asuncion and Rio Grande Arches between the Chaco-Paraná and the Paraná basins at the shorter period, while the tomographic maps in the same periods which were calculated by other stacking methods cannot clearly separate basins and arcs. Our tomographic maps at longer periods indicate variations of Moho depth and lithospheric velocities.
Does hormonal therapy improve sperm retrieval rates in men with non-obstructive azoospermia: a systematic review and meta-analysis
Authors: Tharakan Tharu , Corona Giovanni , Foran Daniel , Salonia Andrea , Sofikitis Nikolaos , Giwercman Aleksander , Krausz Csilla , Yap Tet , Jayasena Channa N , Minhas Suks 
Published: March 2022

AbstractBACKGROUNDThe beneficial effects of hormonal therapy in stimulating spermatogenesis in patients with non-obstructive azoospermia (NOA) and either normal gonadotrophins or hypergonadotropic hypogonadism prior to surgical sperm retrieval (SSR) is controversial. Although the European Association of Urology guidelines state that hormone stimulation is not recommended in routine clinical practice, a significant number of patients undergo empiric therapy prior to SSR. The success rate for SSR from microdissection testicular sperm extraction is only 40–60%, thus hormonal therapy could prove to be an effective adjunctive therapy to increase SSR rates.OBJECTIVE AND RATIONALEThe primary aim of this systematic review and meta-analysis was to compare the SSR rates in men with NOA (excluding those with hypogonadotropic hypogonadism) receiving hormone therapy compared to placebo or no treatment. The secondary objective was to compare the effects of hormonal therapy in normogonadotropic and hypergonadotropic NOA men.SEARCH METHODSA literature search was performed using the Medline, Embase, Web of Science and Clinicaltrials.gov databases from 01 January 1946 to 17 September 2020. We included all studies where hormone status was confirmed. We excluded non-English language and animal studies. Heterogeneity was calculated using I2 statistics and risk of bias was assessed using Cochrane tools. We performed a meta-analysis on all the eligible controlled trials to determine whether hormone stimulation (irrespective of class) improved SSR rates and also whether this was affected by baseline hormone status (hypergonadotropic versus normogonadotropic NOA men). Sensitivity analyses were performed when indicated.OUTCOMESA total of 3846 studies were screened and 22 studies were included with 1706 participants. A higher SSR rate in subjects pre-treated with hormonal therapy was observed (odds ratio (OR) 1.96, 95% CI: 1.08–3.56, P = 0.03) and this trend persisted when excluding a study containing only men with Klinefelter syndrome (OR 1.90, 95% CI: 1.03–3.51, P = 0.04). However, the subgroup analysis of baseline hormone status demonstrated a significant improvement only in normogonadotropic men (OR 2.13, 95% CI: 1.10–4.14, P = 0.02) and not in hypergonadotropic patients (OR 1.73, 95% CI: 0.44–6.77, P = 0.43). The literature was at moderate or severe risk of bias.WIDER IMPLICATIONSThis meta-analysis demonstrates that hormone therapy is not associated with improved SSR rates in hypergonadotropic hypogonadism. While hormone therapy improved SSR rates in eugonadal men with NOA, the quality of evidence was low with a moderate to high risk of bias. Therefore, hormone therapy should not be routinely used in men with NOA prior to SSR and large scale, prospective randomized controlled trials are needed to validate the meta-analysis findings.
Determinants of cryptococcal antigen (CrAg) screening uptake in Kampala, Uganda: An assessment of health center characteristics
Authors: Srishyla Diksha , Saemisch Gabriel , Turya Fred , Nalintya Elizabeth , Jjunju Samuel , Kagimu Enock , Rutakingirwa Morris K , Skipper Caleb P , Boulware David R , Meya David B , Rajasingham Radha 
Published: March 2022

Abstract

Cryptococcal antigen (CrAg) screening and pre-emptive antifungal therapy for people with CD4 cell counts &lt;100 cells/μl are recommended by the World Health Organization and several national HIV guidelines. We sought to evaluate CrAg screening program implementation across Uganda, in relation to health center level and distance from the capital. We conducted a cross-sectional study of 22 health centers across southern Uganda from April to June 2019. We reviewed laboratory records regarding number of CD4 cell count tests performed, proportion of outpatients with CD4 counts &lt;200 cells/μl, and number of CrAg screening tests performed. We administered surveys to health center staff to understand barriers to advanced HIV care. We observed no significant difference in health center level and performance of CrAg screening; with each subsequent health center level, there was 1.17-fold (95% CI: 0.92–1.41) higher odds of CrAg screening performed per level. CrAg screening uptake was not associated with distance from the capital city (odds ratio = 0.96, 95% CI: 0.89–1.04). Qualitative data from surveys indicated that limitations to uptake of CrAg screening were secondary to dysfunctional CD4 machines, lack of provider awareness of CrAg screening guidelines, and inadequate/intermittent supply of CrAg tests. There were no significant associations between CrAg screening uptake and level of health center or distance of health center from the capital city. We identified systemic barriers to CrAg screening related to inadequate CD4 testing, insufficient knowledge regarding national screening guidelines, and irregular laboratory testing supplies.

Lay summary
The objective of this study was to evaluate cryptococcal antigen (CrAg) screening program implementation in Uganda, by type of healthcare center and by distance from the capital city. CrAg screening uptake was not associated with distance from the capital city, or the type of healthcare center.
Determining the seismic age of the young open clusterα Per using δ Scuti stars
Authors: Pamos Ortega David , García Hernández Antonio , Suárez Juan Carlos , Pascual Granado Javier , Barceló Forteza Sebastià , Rodón José Ramón 
Published: March 2022

ABSTRACTIn this work, we aim at constraining the age of the young open cluster Melotte 20, known as α Per, using seismic indices. The method consists of the following steps: (1) Extract the frequency content of a sample of stars in the field of an open cluster. (2) Search for possible regularities in the frequency spectra of δ Sct stars candidates, using different techniques, such as the Fourier transform, the autocorrelation function, the histogram of frequency differences and the échelle diagram. (3) Constrain the age of the selected stars by both the physical parameters and seismic indices by comparing them with a grid of asteroseismic models representative of δ Sct stars. (4) Find possible common ages between these stars to determine the age of the cluster. We performed the pulsation analysis with MultiModes, a rapid, accurate and powerful open-source code, which is presented in this paper. The result is that the age of α Per could be between 96 and 100 Myr. This is an improvement over different techniques in the past. We therefore show that space astroseismology is capable of taking important steps in the dating of young open clusters.
X-ray selected narrow-line active galactic nuclei in the COSMOS field: Nature of optically dull active galactic nuclei
Authors: Fitriana Itsna K , Murayama Takashi 
Published: March 2022

Abstract
X-ray emission detection in a galaxy is one of the efficient tools for selecting active galactic nuclei (AGNs). However, many X-ray-selected AGNs are not easily selected as AGNs by their optical emission. These galaxies, so-called optically dull (OD) AGNs, are fascinating since their X-ray emission is bright even though the AGN signature in the optical regime is absent. In a deep multiwavelength survey over 2 deg2 of the Cosmic Evolution Survey (COSMOS) field, we have looked for the OD AGNs using photometric, spectroscopic, and X-ray data. We identified 310 non-broad line sources with optical spectra as AGNs using X-ray selection up to redshift z ∼ 1.5. We inspected the spectra to check for any AGN signature in their optical emission lines: [Ne v] forbidden emission line, Mass Excitation diagram (MEx), color excitation diagram (TBT), and excess in [O ii] emission line. Finally, we found 48 AGNs that show AGN signatures in the optical spectrum, classified as narrow-line AGN, and 180 AGNs that did not show any AGN signature as the OD AGN sample. Simple explanations of the nature of OD AGNe are a bright host galaxy that dilutes the AGN light or dust materials obscuring the AGN light. We found that the bright host galaxy dilution explains nearly $70\%$ of our OD AGN sample. At the same time, the dust material obscuration is unlikely to be the main reason. By estimating the Eddington ratio, we also found that 95 out of 180 of our OD AGNs have a lower accretion rate, (λEdd) ≲ 10−2, than the typical AGN value. We expected the lower accretion rate sources that suffer from neither host galaxy dilution nor obscuration to have radiatively inefficient flow (RIAF) in their accretion disk. Finally, nine sources have been identified to be most likely hosts of the RIAF disk.
Lattice Lindblad simulation
Authors: Hayata Tomoya , Hidaka Yoshimasa , Yamamoto Arata 
Published: March 2022

Abstract
We perform real-time lattice simulation of an open quantum system based on the Schwinger–Keldysh path integral representation of the Lindblad formalism. Although the real-time simulation generally suffers from the sign problem, a few exceptional cases exist. We focus on a sign-problem-free system of a non-relativistic spinless fermion and analyze the time evolution under driving and dissipation.
Patient Experiences of Self-Management for Chronic Low Back Pain: A Qualitative Study
Authors: Bourke Maurice John , Ferguson Diarmaid , Cooke Mary 
Published: March 2022

Abstract

Objective
Chronic low back pain (CLBP) is a lifelong condition causing disability and distress. One aim of treatment is to enhance self-management. To date, self-management interventions have had limited effectiveness. A greater understanding of self-management for CLBP has the potential to improve future interventional trials. The purpose of this study was to identify the experience of CLBP self-management for patients attending outpatient physical therapy and assess how the experience of CLBP self-management changes over time.

Methods
This qualitative study used constructivist grounded theory. Patients with CLBP who were attending an outpatient physical therapy department were recruited using convenience sampling. Each participant attended a semistructured interview. These were audio recorded and transcribed verbatim. The data were coded and thematically analyzed by the lead researcher. Recruitment continued until data saturation. Participants reviewed preliminary themes for validation.

Results
Six subthemes emerged from 9 interviews: (1) self-doubt, (2) coping day to day, (3) independent discovery, (4) developing resilience, (5) health care: opportunity and threat, and (6) living with pain differently. Two themes took on greatest significance. Self-doubt appeared most strongly and was prevalent in all experiences. However, living with pain differently appeared in those who had developed a level of pain acceptance. These themes formed a conceptual model, “Fluctuating Uncertainty.”

Conclusion
The experience of CLBP self-management is one of fluctuating self-doubt. Self-doubt is the predominant experience and is characterized by the perception of pain as a threat and low pain self-efficacy. During times of greater clarity, individuals develop strategies that increase pain self-efficacy and reinforce the perception of pain without threat. These are features of learning to live well with pain.

Impact
CLBP is a lifelong condition requiring self-management. The current study characterizes the self-management strategies used by patients attending physical therapy. The fluctuating nature of these strategies is dependent upon perception of pain and pain self-efficacy.

Lay Summary
People with CLBP who self-manage their pain fluctuate between attempting to control pain and learning to live with pain. People who understand their condition develop wider-ranging self-management strategies.
Should Central Banks Issue Digital Currency?
Authors: Keister Todd , Sanches Daniel 
Published: March 2022

Abstract
We study how introducing a central bank digital currency affects equilibrium allocations and welfare in an environment where both currency and bank deposits are used in exchange. We highlight an important policy tradeoff: while a digital currency tends to improve efficiency in exchange, it may also crowd out bank deposits, raise banks’ funding costs, and decrease investment. We derive conditions under which targeted digital currencies, which compete only with physical currency or only with bank deposits, raise welfare. If such targeted currencies are infeasible, we illustrate the policy tradeoffs that arise when issuing a single, universal digital currency.
Risk Assessment of Anterior Lumbar Interbody Fusion Access in Degenerative Spinal Conditions
Authors: Singh Kern , Cha Elliot D.K. , Lynch Conor P. , Nolte Michael T. , Parrish James M. , Jenkins Nathaniel W. , Jacob Kevin C. , Patel Madhav R. , Vanjani Nisheka N. , Pawlowski Hanna , Prabhu Michael C. , Myers Jonathan A. 
Published: March 2022

Study Design:
This was a retrospective cohort study.

Objective:
Develop an evidence-based preoperative risk assessment scoring system for patients undergoing anterior lumbar interbody fusion (ALIF).

Summary of Background Data:
ALIF may hold advantages over other fusion techniques in sagittal restoration and fusion rates, though it introduces unique risks to vascular and abdominal structures and thus possibly increased risk of operative morbidity.

Methods:
Primary, 1 or 2-level ALIFs were identified in a surgical registry. Baseline characteristics were recorded. Axial magnetic resonance imagings at L4–L5 and L5–S1 were reviewed for vascular confluence/bifurcation or anomalous structures, and measured for operative window size/slope. To assess favorable outcomes, a clinical grade was calculated: (clinical grade=blood loss×operative duration), higher value indicating poorer outcome. To establish a risk scoring system, a base risk score algorithm was established and stratified into 5 categories: high, high to intermediate, intermediate, intermediate to low, and low. Modifiers to base risk score included age, body mass index, operative level, history of bone morphogenic protein use, calcified vasculature, spondylolisthesis grade, working window size and slope, and abnormal vasculature. Modifiers were weighted for contribution to surgical risk. A total risk score was calculated and evaluated for strength of association with clinical outcome grades by Pearson correlation coefficient.

Results:
A total of 65 patients were included. Mean clinical outcome grade was 5.6, mean total risk score 21.3±21.5. Multilevel procedures (L4–S1) mean total risk score was 57.3±7.8. L4–L5 mean total risk score was 23.6±5.2; L5–S1 mean total risk score 8.3±6.6. Correlation analysis demonstrated a significant and strong relationship (|r|=0.753; P<0.001) between total risk scores and clinical outcome grades.

Conclusion:
Calculated ALIF risk scores significantly correlated with operative duration and blood loss. This scoring system represents a potential framework to facilitate clinical decision-making and risk assessment for potential ALIF candidates with degenerative spinal pathologies.
A Multicenter Evaluation of the Seraph 100 Microbind Affinity Blood Filter for the Treatment of Severe COVID-19
Authors: Chitty Stephen A. , Mobbs Sarah , Rifkin Brian S. , Stogner Steven W. , Lewis Michael S. , Betancourt Jaime , DellaVolpe Jeffrey , Abouzahr Fadi , Wilhelm Andrew M. , Szerlip Harold M. , Parikh Amay , Gaeta Robert M. , Rivera Ian , Park Caroline , Levi Benjamin , Anesi George L. , Alcover Karl C. , Arnold Thomas B. , Howard Jeffrey T. , Sharma Kumar , Pratt Kathleen P. , Stewart Ian J. , Chung Kevin K. ,   for the PURIFY Investigators
Published: March 2022

OBJECTIVES:
The Seraph100 Microbind Affinity Blood Filter (Seraph 100) (ExThera Medical, Martinez, CA) is an extracorporeal therapy that can remove pathogens from blood, including severe acute respiratory syndrome coronavirus 2. The aim of this study was to evaluate safety and efficacy of Seraph 100 treatment for COVID-19.

DESIGN:
Retrospective cohort study.

SETTING:
Nine participating ICUs.

PATIENTS:
COVID-19 patients treated with Seraph 100 (n = 53) and control patients matched by study site (n = 53).

INTERVENTION:
Treatment with Seraph 100.

MEASUREMENTS AND MAIN RESULTS:
At baseline, there were no differences between the groups in terms of sex, race/ethnicity, body mass index, and need for mechanical ventilation. However, patients in the Seraph 100 group were younger (median age, 54 yr; interquartile range [IQR], 41–65) compared with controls (median age, 64 yr; IQR, 56–69; p = 0.009). Charlson comorbidity index scores were lower in the Seraph 100 group (2; IQR, 0–3) compared with the control group (3; IQR, 2–4; p = 0.006). Acute Physiology and Chronic Health Evaluation II scores were also lower in Seraph 100 subjects (12; IQR, 9–17) compared with controls (16; IQR, 12–21; p = 0.011). The Seraph 100 group had higher vasopressor-free days with an incidence rate ratio of 1.30 on univariate analysis. This difference was not significant after adjustment. Seraph 100-treated subjects were less likely to die compared with controls (32.1% vs 64.2%; p = 0.001), a difference that remained significant after adjustment. However, no difference in mortality was observed in a post hoc analysis utilizing an external control group. In the full cohort of 86 treated patients, there were 177 total treatments, in which only three serious adverse events were recorded.

CONCLUSIONS:
Although this study did not demonstrate consistently significant clinical benefit across all endpoints and comparisons, the findings suggest that broad spectrum, pathogen agnostic, blood purification can be safely deployed to meet new pathogen threats while awaiting targeted therapies and vaccines.
Inspiratory Airway Resistance in Respiratory Failure Due to COVID-19
Authors: Nezami Bijan , Tran Hai V. , Zamora Kevin , Lowery Peter , Kantrow Stephen P. , Lammi Matt R. , deBoisblanc Bennet P. 
Published: March 2022

OBJECTIVES:
To measure inspiratory airflow resistance in patients with acute respiratory distress syndrome (ARDS) due to COVID-19.

DESIGN:
Observational cohort of a convenience sample.

SETTING:
Three community ICUs.

SUBJECTS:
Fifty-five mechanically ventilated patients with COVID-19.

INTERVENTIONS:
Measurements of ventilatory mechanics during volume control ventilation.

MEASUREMENTS:
Flow-time and pressure-time scalars were used to measure inspiratory airways resistance.

RESULTS:
The median inspiratory airflow resistance was 12 cm H2O/L/s (interquartile range, 10–16). Inspiratory resistance was not significantly different among patients with asthma or chronic obstructive pulmonary disease compared with those without a history of obstructive airways disease (median 12.5 vs 12 cm H2O/L/s, respectively; p = 0.66). Survival to 90 days among patients with inspiratory resistance above 12 cm H2O/L/s was 68% compared with 60% for patients below 12 cm H2O/L/s (p = 0.58). Inspiratory resistance did not correlate with C-reactive protein, ferritin, Pao
2/Fio
2 ratio, or static compliance.

CONCLUSIONS:
Inspiratory airflow resistance was normal to slightly elevated among mechanically ventilated patients with ARDS due to COVID-19. Airways resistance was independent of a history of obstructive airways disease, did not correlate with biomarkers of disease severity, and did not predict mortality.