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The main result in this paper is the failure of the finitely generated intersection property (FGIP) of ascending HNN extensions of non-cyclic finite rank free groups. This class of groups consists of free-by-cyclic groups and properly ascending HNN extensions of free groups. We also give a sufficient condition for the failure of the FGIP in the context of relative hyperbolicity, we apply this to free-by-cyclic groups of exponential growth.

Despite advances in the treatment of high energy proximal tibia fractures, including the utilization of staged management with external fixation, the infection rate remains high. Overlap between external fixator pin sites and definitive internal fixation has been proposed as a risk factor for infection.This retrospective study reviews 244 patients with staged knee-spanning external fixation followed by delayed definitive internal fixation at two separate level one trauma centers. Presence of pin-plate overlap as well as several other known risk factors for infection were recorded and measured to include open fractures, compartment syndrome, operative time and number of incisions. Development of deep infection was the primary outcome. Both univariate and multivariate statistics were applied to determine differences in rates of infection.65 (26.6%) patients had presence of pin-plate overlap while 179 (73.4%) patients had no overlap. There were no differences between overlapping and non-overlapping groups with respect to other infectious risk factors. Deep infection occurred in 34 (13.9%) total patients, 18 (27.7%) were in patients with pin-plate overlap and 16 (8.9%) in those without overlap. (P = 0.003; RR 3.01, 95% CI 1.51-4.76).This large, multicenter study demonstrated a statistically significant association between pin-plate overlap and the development of deep infection in tibial plateau fractures. On multivariate analysis, pin-plate overlap was identified as an independent risk factor for infection. When treating these complex injuries, surgeons should consider the definitive fixation construct when placing external fixation pins.

Background In 2016, the Centers for Disease Control and Prevention (CDC) changed the time frame for their definition of deep surgical site infection (SSI) from within 1 year to within 90 days of surgery. We hypothesized that a substantial number of infections in patients who have undergone fracture fixation present beyond 90 days and that there are patient factors that can predict who is more likely to present with SSI after 90 days. Methods A retrospective review yielded 452 deep SSI after fracture fixation. These patients were divided into two groups—those infected within 90 days of surgery (308 patients) and those infected beyond 90 days (144 patients). Data were collected on risk factors for infection. Univariate and multiple logistic regression analyses were performed to compare the two groups. A randomly selected control group was used to build infection prediction models for both outcomes. The two outcomes were then modeled against each other to determine whether differences in predictors for early versus late infection exist. Results Of the 452 infections, 144 occurred beyond 90 days (32%). No statistically significant patient factors were found in univariate analysis between the early and late infection groups. The need for flap coverage was the only injury characteristic that differed significantly between groups, with patients in the late infection group more likely to have needed a flap. In models of early versus late infection, there are no statistically significant predictors. When modeled against the control group and directly comparing the two models, predictors for early infection include male sex and fractures of the pelvis, acetabulum, or hip, whereas predictors of late infection include hepatitis C and/or human immunodeficiency virus (HIV) and admission to the intensive care unit (ICU). Conclusion Use of the recent CDC definition will underestimate the rate of actual postoperative infections when applied to orthopaedic trauma patients. Hepatitis C and/or HIV and ICU admission are predictors of late infection, whereas male sex and pelvis, acetabulum, or hip fractures are predictors of early infection. Patients who receive flap coverage may be more likely to present with late infection.

We study a family of finitely generated residually finite groups. These groups are doubles $F_2*_H F_2$ of a rank-$2$ free group $F_2$ along an infinitely generated subgroup $H$. Varying $H$ yields uncountably many groups up to isomorphism., Comment: 10 pages, 2 figures

We show that if G G is of type F n \mathcal {F}_n , and G G splits as a finite graph of groups, then the vertex groups are of type F n \mathcal {F}_n if the edge groups are of type F n \mathcal {F}_n .

The past few decades have seen major developments in the design and operation of cryogenic particle detectors. This technology offers an extremely good energy resolution - comparable to semiconductor detectors - and a wide choice of target materials, making low temperature calorimetric detectors ideal for a variety of particle physics applications. Rare event searches have continued to require ever greater exposures, which has driven them to ever larger cryogenic detectors, with the CUORE experiment being the first to reach a tonne-scale, mK-cooled, experimental mass. CUORE, designed to search for neutrinoless double beta decay, has been operational since 2017 at a temperature of about 10 mK. This result has been attained by the use of an unprecedentedly large cryogenic infrastructure called the CUORE cryostat: conceived, designed and commissioned for this purpose. In this article the main characteristics and features of the cryogenic facility developed for the CUORE experiment are highlighted. A brief introduction of the evolution of the field and of the past cryogenic facilities are given. The motivation behind the design and development of the CUORE cryogenic facility is detailed as are the steps taken toward realization, commissioning, and operation of the CUORE cryostat. The major challenges overcome by the collaboration and the solutions implemented throughout the building of the cryogenic facility will be discussed along with the potential improvements for future facilities. The success of CUORE has opened the door to a new generation of large-scale cryogenic facilities in numerous fields of science. Broader implications of the incredible feat achieved by the CUORE collaboration on the future cryogenic facilities in various fields ranging from neutrino and dark matter experiments to quantum computing will be examined., Comment: 45 pages, 14 figures

Failing to communicate a message in everyday settings can be a frustrating experience. However, miscommunication can lead to disaster in high-stakes situations. Yet in these contexts, under pressure to perform efficiently, speakers may also find themselves with limited resources to devote to message clarity. To understand how cognitive constraint affects communication and explore a possible low-cost solution, we investigated a method for moderating ambiguity production in the face of competing attentional demands: taking the perspective of the listener. Over two experiments, speakers labeled images (Experiment 1) or provided instructions (Experiment 2) to listeners in a non-interactive communication task. In both experiments, speakers were randomly assigned to cognitive constraint and perspective-taking conditions, such that some speakers were under higher cognitive constraint and some speakers received a simple perspective-taking directive. We replicated previous findings that additional cognitive constraint impairs speakers’ ability to avoid ambiguity. Additionally, we found that a simple directive can promote speaker clarity when labeling images, but not when providing instructions. These results suggest that a simple directive is likely insufficient to ensure speaker clarity in all cases.

To determine factors predictive of postoperative surgical site infection (SSI) after fracture fixation and create a prediction score for risk of infection at time of initial treatment.Retrospective cohort study.Level I trauma center.Study group, 311 patients with deep SSI; control group, 608 patients.We evaluated 27 factors theorized to be associated with postoperative infection. Bivariate and multiple logistic regression analyses were used to build a prediction model. A composite score reflecting risk of SSI was then created.Risk of postoperative infection.The final model consisted of 8 independent predictors: (1) male sex, (2) obesity (body mass index ≥ 30) (3) diabetes, (4) alcohol abuse, (5) fracture region, (6) Gustilo-Anderson type III open fracture, (7) methicillin-resistant Staphylococcus aureus nasal swab testing (not tested or positive result), and (8) American Society of Anesthesiologists classification. Risk strata were well correlated with observed proportion of SSI and resulted in a percent risk of infection of 1% for ≤3 points, 6% for 4-5 points, 11% for 6 to 8-9 points, and 41% for ≥10 points.The proposed postoperative infection prediction model might be able to determine which patients have fractures at higher risk of infection and provides an estimate of the percent risk of infection before fixation.Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

We show that certain right-angled Coxeter groups have finite index subgroups that quotient to $\mathbb Z$ with finitely generated kernels. The proof uses Bestvina-Brady Morse theory facilitated by combinatorial arguments. We describe a variety of examples where the plan succeeds or fails. Among the successful examples are the right-angled reflection groups in $\mathbb H^4$ with fundamental domain the $120$-cell or the $24$-cell., 30 pages, to appear in J. Inst. Math. Jussieu

OBJECTIVES To evaluate the association of admission blood glucose ≥200 mg/dL and surgical site infection in orthopaedic trauma surgery. DESIGN Retrospective, case control study. SETTING Academic trauma center. PATIENTS Four hundred sixty-five nondiabetic, noncritically ill orthopaedic trauma patients with an extremity, pelvic, or acetabular fracture and requiring open reduction and internal fixation or intramedullary nailing. INTERVENTION None. MAIN OUTCOME MEASUREMENTS Ninety-day deep surgical site infection. RESULTS Admission blood glucose ≥200 mg/dL was significantly associated with the primary outcome (8/128, 6.3% vs. 35/337, 1.8%; P = 0.01). Multivariable logistic regression modeling demonstrated that admission blood glucose ≥200 mg/dL was a significant risk factor for deep surgical site infections [odds ratio (OR): 4.7, 95% confidence interval (CI) 1.4-15.7], after controlling for male gender (OR: 1.8, 95% CI: 1.1-3.1), prior drug or alcohol abuse (OR: 1.9, 95% CI 0.9-4.0), open fracture (OR: 6.4, 95% CI 3.7-11.0), and fracture region (upper extremity OR: reference; pelvis/hip OR: 3.9, 95% CI 1.6-9.7; femur OR: 2.0, 95% CI 0.88-4.8; tibia/ankle OR: 3.3, 95% CI 1.7-6.2; and foot OR: 2.7, 95% CI 1.2-6.3). CONCLUSIONS Admission glucose ≥200 mg/dL was a significant independent risk factor for 90-day deep surgical site infections in orthopaedic trauma patients and may serve as an important marker for infection risk. LEVEL OF EVIDENCE Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

We show that certain graphs of groups with cyclic edge groups are aTmenable. In particular, this holds when each vertex group is either virtually special or acts properly and semisimply on ℍn.

The purpose of this study is to compare biomechanical properties of fully and partially threaded iliosacral screws. We hypothesise that fully threaded screws will have a higher yield force, and less deformation than partially threaded screws following axial loading. Twenty sawbone blocks were uniformly divided to simulate vertical sacral fractures. Ten blocks were affixed with fully threaded iliosacral screws in an over-drilled, lag-by-technique fashion whilst the remaining ten were fixed with partially threaded lag-by-design screws. All screws measured 7.3-mm x 145 mm, and were inserted to a 70% of calculated maximal insertional torque, ensuring uniform screw placement throughout across models. Continuous axial loads were applied to 3 constructs of each type to failure to determine baseline characteristics. Five hundred loading cycles of 500 N at 1 Hz were applied to 4 constructs of each type, and then axially loaded to failure. Force displacement curves, elastic, and plastic deformation of each construct was recorded. Fully threaded constructs had a 428% higher yield force, 61% higher stiffness, 125% higher ultimate force, and 66% lower yield deformation (p

We construct a finitely generated 2-dimensional group that acts properly on a locally finite CAT(0) cube complex but does not act properly on a finite dimensional CAT(0) cube complex., 3 pages, to appear in Geom. Ded

Background The area under the concentration-time curve over 24 hours (AUC24 ) is frequently utilized to monitor tobramycin exposure in children with cystic fibrosis (CF). An understanding of exposure target achievement during clinical implementation of an AUC24 based approach in children is limited. Methods A retrospective chart review was performed in children with CF treated with once daily tobramycin and drug concentration monitoring at a pediatric CF center. During clinical care AUC24 was estimated using a traditional log-linear regression approach (LLR). AUC24 was also estimated retrospectively using a pharmacokinetic model-based Bayesian forecasting approach (BF). AUC24 achievement after both approaches were compared. Results In 77 treatment courses (mean age, 12.7 ± 5.0 years), a target AUC24 100 to 125 mg h/L was achieved after starting dose in 21 (27%) and after initial dose adjustment in 35 (45%). In the first 7 days of treatment, 24 (32%) required ≥3 dose adjustments, and the mean number of drug concentrations measured was 7.1 ± 3.2. Examination of a BF approach demonstrated adequate prediction of measured tobramycin concentrations (median bias -2.1% [95% CI -3.1 to -1.4]; median precision 7.6% [95% CI, 7.1%-8.2%]). AUC24 estimates utilizing the BF approach were higher than the LLR approach with a mean difference of 6.4 mg h/L (95% CI, 4.8 to 8.0 mg h/L). Conclusions Achievement of a narrow AUC24 target is challenging during clinical care, and dose individualization is needed in most children with CF. Implementing a BF approach for estimating AUC24 in children with CF is supported.

Author(s): Dompe, V; Adams, DQ; Alduino, C; Alfonso, K; Avignone, FT; Azzolini, O; Bari, G; Bellini, F; Benato, G; Bersani, A; Biassoni, M; Branca, A; Brofferio, C; Bucci, C; Caminata, A; Campani, A; Canonica, L; Cao, XG; Capelli, S; Cappelli, L; Cardani, L; Carniti, P; Casali, N; Chiesa, D; Chott, N; Clemenza, M; Copello, S; Cosmelli, C; Cremonesi, O; Creswick, RJ; Cushman, JS; D'Addabbo, A; D'Aguanno, D; Dafinei, I; Davis, CJ; Dell'Oro, S; Domizio, SD; Drobizhev, A; Fang, DQ; Fantini, G; Faverzani, M; Ferri, E; Ferroni, F; Fiorini, E; Franceschi, MA; Freedman, SJ; Fujikawa, BK; Giachero, A; Gironi, L; Giuliani, A; Gorla, P; Gotti, C; Gutierrez, TD; Han, K; Heeger, KM; Huang, RG; Huang, HZ; Johnston, J; Keppel, G; Kolomensky, YG; Leder, A; Ligi, C; Ma, YG; Marini, L; Martinez, M; Maruyama, RH; Mei, Y; Moggi, N; Morganti, S; Napolitano, T; Nastasi, M; Nones, C; Norman, EB; Novati, V; Nucciotti, A; Nutini, I; O'Donnell, T; Ouellet, JL; Pagliarone, CE; Pallavicini, M; Pattavina, L; Pavan, M; Pessina, G; Pettinacci, V; Pira, C | Abstract: CUORE is a cryogenic experiment that focuses on the search of neutrinoless double beta decay in 130Te and it is located at the Gran Sasso National Laboratories. Its detector consists of 988 TeO2 crystals operating at a base temperature of ∼10 mK. It is the first ton-scale bolometric experiment ever realized for this purpose. Thanks to its large target mass and ultra-low background, the CUORE detector is also suitable for the search of other rare phenomena. In particular the low energy part of the spectra is interesting for the detection of WIMP-nuclei scattering reactions. One of the most important requirements to perform these studies is represented by the achievement of a stable energy threshold lower than 10 keV. Here, the CUORE capability to accomplish this purpose using a low energy software trigger will be presented and described.

OBJECTIVE To determine the risk factors for knee stiffness surgery after tibial plateau fixation. DESIGN Retrospective observational cohort study. SETTING Academic Level I trauma center. PATIENTS/PARTICIPANTS A study group of 110 patients who underwent knee stiffness surgery (manipulation while under anesthesia, arthroscopic lysis of adhesion, or quadricepsplasty) at a time remote from open reduction and internal fixation of tibial plateau fractures and a control group of 319 patients with tibial plateau fractures treated with open reduction and internal fixation who did not undergo knee stiffness surgery and who had either a minimum of 1 year of follow-up or clearly documented range of motion ≥110 degrees with a minimum of 90 days of follow-up. INTERVENTION Each case was assessed from the time of index admission through study event, end of minimum follow-up, or achievement of ≥110 degrees range of motion. MAIN OUTCOME MEASUREMENTS Knee stiffness surgery. RESULTS Total number of weeks in an external fixator (odds ratio, 1.5 per week; 95% confidence interval, 1.3-1.7; P < 0.001) and the presence of bilateral tibial plateau fractures (odds ratio, 3.3; 95% confidence interval, 1.2-9.1; P = 0.02) were significant predictors of knee stiffness intervention. CONCLUSION Clinicians should be aware that the time spent in external fixation and the presence of bilateral tibial plateau injuries are strong risk factors for requiring subsequent surgery to treat knee stiffness. LEVEL OF EVIDENCE Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Let M be a compact oriented irreducible 3-manifold which is neither a graph manifold nor a hyperbolic manifold. We prove that the fundamental group of M is virtually special., 29 pages, 4 figures

OBJECTIVE To develop a clinically useful prediction model of success at the time of surgery to promote bone healing for established tibial nonunion or traumatic bone defects. DESIGN Retrospective case controlled. SETTING Level 1 trauma center. PATIENTS Adult patients treated with surgery for established tibia fracture nonunion or traumatic bone defects from 2007 to 2016. Two hundred three patients met the inclusion criteria and were available for final analysis. INTERVENTION Surgery to promote bone healing of established tibia fracture nonunion or segmental defect with plate and screw construct, intramedullary nail fixation, or multiplanar external fixation. MAIN OUTCOME MEASURES Failure of the surgery to promote bone healing that was defined as unplanned revision surgery for lack of bone healing or deep infection. No patients were excluded who had a primary outcome event. RESULTS Multivariate logistic modeling identified 5 significant (P < 0.05) risk factors for failure of the surgery to promote bone healing: (1) mechanism of injury, (2) Increasing body mass index, (3) cortical defect size (mm), (4) flap size (cm), and (5) insurance status. A prediction model was created based on these factors and awarded 0 points for fall, 17 points for high energy blunt trauma (OR = 17; 95% CI, 1-286, P = 0.05), 22 points for industrial/other (OR = 22; 95% CI, 1-4, P = 0.04), and 28 points for ballistic injuries (OR = 28; 95% CI, 1-605, P = 0.04). One point is given for every 10 cm of flap size (OR = 1; 95% CI, 1-1.1, P < 0.001), 10 mm of mean cortical gap distance (OR = 1; 95% CI, 1-2, P = 0.004), and 10 units BMI, respectively (OR = 1.5; 95% CI, 1-3, P = 0.16). Two points are awarded for Medicaid or no insurance (OR = 2; 95% CI, 1-5, P = 0.035) and 3 points for Medicare (3; 95% CI, 1-9, P = 0.033). Each 1-point increase in risk score was associated with a 6% increased chance of requiring at least 1 revision surgery (P < 0.001). CONCLUSIONS This study presents a clinical score that predicts the likelihood of success after surgery for tibia fracture nonunions or traumatic bone defects and may help clinicians better determine which patients are likely to fail these procedures and require further surgery.

The disappearance of reactor $$\bar{\nu }_e$$ ν ¯ e observed by the Daya Bay experiment is examined in the framework of a model in which the neutrino is described by a wave packet with a relative intrinsic momentum dispersion $$\sigma _\mathrm{{rel}}$$ σ rel . Three pairs of nuclear reactors and eight antineutrino detectors, each with good energy resolution, distributed among three experimental halls, supply a high-statistics sample of $$\bar{\nu }_e$$ ν ¯ e acquired at nine different baselines. This provides a unique platform to test the effects which arise from the wave packet treatment of neutrino oscillation. The modified survival probability formula was used to fit Daya Bay data, providing the first experimental limits: $$2.38 \times 10^{-17}< \sigma _\mathrm{{rel}} < 0.23$$ 2.38 × 10 - 17 < σ rel < 0.23 . Treating the dimensions of the reactor cores and detectors as constraints, the limits are improved: $$10^{-14} \lesssim \sigma _\text {rel} < 0.23$$ 10 - 14 ≲ σ rel < 0.23 , and an upper limit of $$\sigma _\text {rel}

This work reports a precise measurement of the reactor antineutrino flux using 2.2 million inverse beta decay (IBD) events collected with the Daya Bay near detectors in 1230 days. The dominant uncertainty on the neutron detection efficiency is reduced by 56% with respect to the previous measurement through a comprehensive neutron calibration and detailed data and simulation analysis. The new average IBD yield is determined to be $(5.91\pm0.09)\times10^{-43}~\rm{cm}^2/\rm{fission}$ with total uncertainty improved by 29%. The corresponding mean fission fractions from the four main fission isotopes $^{235}$U, $^{238}$U, $^{239}$Pu, and $^{241}$Pu are 0.564, 0.076, 0.304, and 0.056, respectively. The ratio of measured to predicted antineutrino yield is found to be $0.952\pm0.014\pm0.023$ ($1.001\pm0.015\pm0.027$) for the Huber-Mueller (ILL-Vogel) model, where the first and second uncertainty are experimental and theoretical model uncertainty, respectively. This measurement confirms the discrepancy between the world average of reactor antineutrino flux and the Huber-Mueller model., 10 pages, 9 figures, and 2 tables

This Letter reports the first measurement of the ^{235}U ν[over ¯]_{e} energy spectrum by PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, operating 7.9 m from the 85 MW_{th} highly enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed 31678±304(stat) ν[over ¯]_{e}-induced inverse beta decays, the largest sample from HEU fission to date, 99% of which are attributed to ^{235}U. Despite broad agreement, comparison of the Huber ^{235}U model to the measured spectrum produces a χ^{2}/ndf=51.4/31, driven primarily by deviations in two localized energy regions. The measured ^{235}U spectrum shape is consistent with a deviation relative to prediction equal in size to that observed at low-enriched uranium power reactors in the ν[over ¯]_{e} energy region of 5-7 MeV.

The Precision Reactor Oscillation and Spectrum (PROSPECT) Experiment is a reactor neutrino experiment designed to search for sterile neutrinos with a mass on the order of 1 eV/c$^2$ and to measure the spectrum of electron antineutrinos from a highly-enriched $^{235}$U nuclear reactor. The PROSPECT detector consists of an 11 by 14 array of optical segments in $^{6}$Li-loaded liquid scintillator at the High Flux Isotope Reactor in Oak Ridge National Laboratory. Antineutrino events are identified via inverse beta decay and read out by photomultiplier tubes located at the ends of each segment. The detector response is characterized using a radioactive source calibration system. This paper describes the design, operation, and performance of the PROSPECT source calibration system.

We investigate the virtual specialness of a compact cube complex $X$ that splits as a graph of nonpositively curved cube complexes. We prove virtual specialness of $X$ when each vertex space of $X$ has word-hyperbolic $\pi_1$ and $\pi_1X$ has ``finite stature'' relative to its edge groups. The results generalize the motivating case when tree $\times$ tree lattices are virtual products., Comment: 27 pages

This Letter reports the first measurement of the ^{235}U ν[over ¯]_{e} energy spectrum by PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, operating 7.9 m from the 85 MW_{th} highly enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed 31678±304(stat) ν[over ¯]_{e}-induced inverse beta decays, the largest sample from HEU fission to date, 99% of which are attributed to ^{235}U. Despite broad agreement, comparison of the Huber ^{235}U model to the measured spectrum produces a χ^{2}/ndf=51.4/31, driven primarily by deviations in two localized energy regions. The measured ^{235}U spectrum shape is consistent with a deviation relative to prediction equal in size to that observed at low-enriched uranium power reactors in the ν[over ¯]_{e} energy region of 5-7 MeV.