Search

The Majorana collaboration is constructing the Majorana Demonstrator at the Sanford Underground Research Facility at the Homestake gold mine, in Lead, SD. The apparatus will use Ge detectors, enriched in isotope 76Ge, to demonstrate the feasibility of a large-scale Ge detector experiment to search for neutrinoless double beta decay. The long half-life of this postulated process requires that the apparatus be extremely low in radioactive isotopes whose decays may produce backgrounds to the search. The radioassay program conducted by the collaboration to ensure that the materials comprising the apparatus are sufficiently pure is described. The resulting measurements from gamma-ray counting, neutron activation and mass spectroscopy of the radioactive-isotope contamination for the materials studied for use in the detector are reported. We interpret these numbers in the context of the expected background for the experiment.

The Majorana Collaboration is constructing a system containing 40 kg of HPGedetectors to demonstrate the feasibility and potential of a future tonne-scaleexperiment capable of probing the neutrino mass scale in the inverted-hierarchyregion. To realize this, a major goal of the Majorana Demonstrator is todemonstrate a path forward to achieving a background rate at or below 1cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV.This goal is pursued through a combination of a significant reduction ofradioactive impurities in construction materials with analytical methods forbackground rejection, for example using powerful pulse shape analysistechniques profiting from the p-type point contact HPGe detectors technology.The effectiveness of these methods is assessed using simulations of thedifferent background components whose purity levels are constrained fromradioassay measurements.

The Majorana Demonstrator will search for the neutrinoless double-beta (β β 0 ) decay of the isotope Ge with a mixed array of enriched and natural germanium detectors. The observation of this rare decay would indicate that the neutrino is its own antiparticle, demonstrate that lepton number is not conserved, and provide information on the absolute mass scale of the neutrino. The Demonstrator is being assembled at the 4850-foot level of the Sanford Underground Research Facility in Lead, South Dakota. The array will be situated in a low-background environment and surrounded by passive and active shielding. Here we describe the science goals of the Demonstrator and the details of its design. © 2014 N. Abgrall et al.

A low-background, high-purity germanium detector has been used to search forevidence of low-energy, bremsstrahlung-generated solar axions. An upper boundof $1.36\times 10^{-11}$ $(95% CL)$ is placed on the direct coupling of DFSZmodel axions to electrons. The prospects for the sensitivity of the MajoranaDemonstrator array of point-contact germanium detectors to solar axions arediscussed in the context of the model-independent annual modulation due to theseasonal variation of the earth-sun distance.

The {\sc Majorana Demonstrator will search for the neutrinoless double-betadecay of the isotope Ge-76 with a mixed array of enriched and natural germaniumdetectors. The observation of this rare decay would indicate the neutrino isits own antiparticle, demonstrate that lepton number is not conserved, andprovide information on the absolute mass scale of the neutrino. The {\scDemonstrator} is being assembled at the 4850-foot level of the SanfordUnderground Research Facility in Lead, South Dakota. The array will be situatedin a low-background environment and surrounded by passive and active shielding.Here we describe the science goals of the {\sc Demonstrator} and the details ofits design.

The Majorana Collaboration is building the Majorana Demonstrator, a 60 kg array of high purity germanium detectors housed in an ultra-low background shield at the Sanford Underground Laboratory in Lead, SD. The Majorana Demonstrator will search for neutrinoless double-beta decay of 76Ge while demonstrating the feasibility of a tonne-scale experiment. It may also carry out a dark matter search in the 110 GeV/c2 mass range. We have found that customized Broad Energy Germanium (BEGe) detectors produced by Canberra have several desirable features for a neutrinoless double-beta decay experiment, including low electronic noise, excellent pulse shape analysis capabilities, and simple fabrication. We have deployed a customized BEGe, the Majorana Low-Background BEGe at Kimballton (MALBEK), in a low-background cryostat and shield at the Kimballton Underground Research Facility in Virginia. This paper will focus on the detector characteristics and measurements that can be performed with such a radiation detector in a low-background environment. © 2010 Elsevier B.V.

Neutrinoless double-beta decay experiments can potentially determine theMajorana or Dirac nature of the neutrino, and aid in understanding the neutrinoabsolute mass scale and hierarchy. Future 76Ge-based searches target ahalf-life sensitivity of >10^27 y to explore the inverted neutrino masshierarchy. Reaching this sensitivity will require a background rate of ~5200 mwe is required for atonne-scale experiment with a compact shield similar to the planned 40-kgMAJORANA DEMONSTRATOR. The required overburden is highly dependent on thechosen shielding configuration and could be relaxed significantly if, forexample, a liquid cryogen and water shield, or an active neutron shield wereemployed. Operation of the MAJORANA DEMONSTRATOR and GERDA detectors will serveto reduce the uncertainties on cosmic-ray background rates and will impact thechoice of shielding style and location for a future tonne-scale experiment. 4/2013: The peer review process revealed that one of the veto rejectionfactors (the factor-of-4 described on p12) needs to be better established. Ourreevaluation of this parameter to date has not yielded strong support for thevalue stated in the manuscript, and we require further study to develop a solidestimate. This further study will supersede the work described in thismanuscript, and may or may not lead to the same conclusion regarding the ~>5200mwe requirement for future tonne-scale 76Ge neutrinoless double beta decayexperiments.

Background: Allergic diseases are triggered by signaling through the high-affinity IgE receptor, FcεRI. In both mast cells (MCs) and basophils, FcεRI is a tetrameric receptor complex comprising a ligand-binding α subunit (FcεRIα), a tetraspan β subunit (FcεRIβ, MS4A2) responsible for trafficking and signal amplification, and a signal transducing dimer of single transmembrane γ subunits (FcεRIγ). However, FcεRI also exists as presumed trimeric complexes that lack FcεRIβ and are expressed on several cell types outside the MC and basophil lineages. Despite known differences between humans and mice in the presence of the trimeric FcεRI complex, questions remain as to how it traffics and whether it signals in the absence of FcεRIβ. We have previously reported that targeting FcεRIβ with exon-skipping oligonucleotides eliminates IgE-mediated degranulation in mouse MCs, but equivalent targeting in human MCs was not effective at reducing degranulation., Results: Here, we report that the FcεRIβ-like protein MS4A6A exists in human MCs and compensates for FcεRIβ in FcεRI trafficking and signaling. Human MS4A6A promotes surface expression of FcεRI complexes and facilitates degranulation. MS4A6A and FcεRIβ are encoded by highly related genes within the MS4A gene family that cluster within the human gene loci 11q12-q13, a region linked to allergy and asthma susceptibility., Conclusions: Our data suggest the presence of either FcεRIβ or MS4A6A is sufficient for degranulation, indicating that MS4A6A could be an elusive FcεRIβ-like protein in human MCs that performs compensatory functions in allergic disease., (© 2022 The Authors. Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

The leading cause of treatment failure in Staphylococcus aureus infections is the development of biofilms. Biofilms are highly tolerant to conventional antibiotics which were developed against planktonic cells. Consequently, there is a lack of antibiofilm agents in the antibiotic development pipeline. To address this problem, we developed a platelet-rich plasma (PRP)-derived biologic, termed BIO-PLY (for the BIOactive fraction of Platelet-rich plasma LYsate) which has potent in vitro bactericidal activity against S. aureus synovial fluid free-floating biofilm aggregates. Additional in vitro studies using equine synoviocytes and chondrocytes showed that BIO-PLY protected these cells of the joint from inflammation. The goal of this study was to test BIO-PLY for in vivo efficacy using an equine model of infectious arthritis. We found that horses experimentally infected with S. aureus and subsequently treated with BIO-PLY combined with the antibiotic amikacin (AMK) had decreased bacterial concentrations within both synovial fluid and synovial tissue and exhibited lower systemic and local inflammatory scores compared to horses treated with AMK alone. Most importantly, AMK+BIO-PLY treatment reduced the loss of infection-associated cartilage proteoglycan content in articular cartilage and decreased synovial tissue fibrosis and inflammation. Our results demonstrate the in vivo efficacy of AMK+BIO-PLY and represents a new approach to restore and potentiate antimicrobial activity against synovial fluid biofilms., Competing Interests: The contents of this manuscript are the subject of a patent filed by NC State University and the University of Pennsylvania by the authors (JG, TS, and LS). The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Gilbertie, Schaer, Engiles, Seiler, Deddens, Schubert, Jacob, Stefanovski, Ruthel, Hickok, Stowe, Frink and Schnabel.)

Infectious arthritis is difficult to treat in both human and veterinary clinical practice. Recent literature reports Staphylococcus aureus as well as other gram-positive and gram-negative isolates forming free-floating biofilms in both human and equine synovial fluid that are tolerant to traditional antimicrobial therapy. Using an in vitro equine model, we investigated the ability of platelet-rich plasma (PRP) formulations to combat synovial fluid biofilm aggregates. Synovial fluid was infected, and biofilm aggregates allowed to form over a 2-hour period. PRP was collected and processed into different formulations by platelet concentration, leukocyte presence, and activation or lysis. Infected synovial fluid was treated with different PRP formulations with or without aminoglycoside cotreatment. Bacterial load (colony-forming unit/mL) was determined by serial dilutions and plate counting at 8 hours posttreatment. All PRP formulations displayed antimicrobial properties; however, formulations containing higher concentrations of platelets without leukocytes had increased antimicrobial activity. Lysis of PRP and pooling of the PRP lysate (PRP-L) from multiple horses as compared to individual horses further increased antimicrobial activity. This activity was lost with the removal of the plasma component or inhibition of the proteolytic activity within the plasma. Fractionation of pooled PRP-L identified the bioactive components to be cationic and low-molecular weight (<10 kDa). Overall, PRP-L exhibited synergism with amikacin against aminoglycoside tolerant biofilm aggregates with greater activity against gram-positive bacteria. In conclusion, the use of PRP-L has the potential to augment current antimicrobial treatment regimens which could lead to a decrease in morbidity and mortality associated with infectious arthritis., (© 2020 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)

Platelet-rich plasma (PRP) preparations are being used with moderate success to treat osteoarthritis (OA) in humans and in veterinary species. Such preparations are hindered, however, by being autologous in nature and subject to tremendous patient and processing variability. For this reason, there has been increasing interest in the use of platelet lysate preparations instead of traditional PRP. Platelet lysate preparations are acellular, thereby reducing concerns over immunogenicity, and contain high concentrations of growth factors and cytokines. In addition, platelet lysate preparations can be stored frozen for readily available use. The purpose of this study was to evaluate the effects of a pooled allogeneic platelet-rich plasma lysate (PRP-L) preparation on equine synoviocytes and chondrocytes challenged with inflammatory mediators in-vitro to mimic the OA joint environment. Our hypothesis was that PRP-L treatment of inflamed synoviocytes would protect chondrocytes challenged with synoviocyte conditioned media by reducing synoviocyte pro-inflammatory cytokine production while increasing synoviocyte anti-inflammatory cytokine production. Synoviocytes were stimulated with either interleukin-1β (IL-1β) or lipopolysaccharide (LPS) for 24 h followed by no treatment or treatment with platelet-poor plasma lysate (PPP-L) or PRP-L for 48 h. Synoviocyte growth was evaluated at the end of the treatment period and synoviocyte conditioned media was assessed for concentrations of hyaluronic acid (HA), IL-1β, tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6). Chondrocytes were then challenged for 48 h with synoviocyte conditioned media from each stimulation and treatment group and examined for gene expression of collagen types I (COL1A1), II (COL2A1), and III (COL3A1), aggrecan (ACAN), lubricin (PRG4), and matrix metallopeptidase 3 (MMP-3) and 13 (MMP-13). Treatment of inflamed synoviocytes with PRP-L resulted in increased synoviocyte growth and increased synoviocyte HA and IL-6 production. Challenge of chondrocytes with conditioned media from PRP-L treated synoviocytes resulted in increased collagen type II and aggrecan gene expression as well as decreased MMP-13 gene expression. The results of this study support continued investigation into the use of pooled PRP-L for the treatment of osteoarthritis and warrant further in-vitro studies to discern the mechanisms of action of PRP-L.

The Majorana Collaboration is operating an array of high purity Ge detectors to search for neutrinoless double-β decay in ^{76}Ge. The Majorana Demonstrator comprises 44.1 kg of Ge detectors (29.7 kg enriched in ^{76}Ge) split between two modules contained in a low background shield at the Sanford Underground Research Facility in Lead, South Dakota. Here we present results from data taken during construction, commissioning, and the start of full operations. We achieve unprecedented energy resolution of 2.5 keV FWHM at Q&#95;{ββ} and a very low background with no observed candidate events in 9.95 kg yr of enriched Ge exposure, resulting in a lower limit on the half-life of 1.9×10^{25}  yr (90% C.L.). This result constrains the effective Majorana neutrino mass to below 240-520 meV, depending on the matrix elements used. In our experimental configuration with the lowest background, the background is 4.0&#95;{-2.5}^{+3.1}  counts/(FWHM t yr).

Context: A high number of recreational runners sustain a running-related injury each year. To reduce injury risk, alterations in running form have been suggested. One simple strategy for running stride frequency or length has been commonly advocated., Objective: To characterize how running mechanics change when stride frequency and length are manipulated., Data Sources: In January 2012, a comprehensive search of PubMed, CINAHL Plus, SPORTDiscus, PEDro, and Cochrane was performed independently by 2 reviewers. A second search of the databases was repeated in June 2012 to ensure that no additional studies met the criteria after the initial search., Study Selection: Inclusion criteria for studies were an independent variable including manipulation of stride frequency or length at a constant speed with outcome measures of running kinematics or kinetics., Study Design: Systematic review., Level of Evidence: Level 3., Data Extraction: Two reviewers independently appraised each article using a modified version of the Quality Index, designed for assessing bias of nonrandomized studies., Results: Ten studies met the criteria for this review. There was consistent evidence that increased stride rate resulted in decreased center of mass vertical excursion, ground reaction force, shock attenuation, and energy absorbed at the hip, knee, and ankle joints. All but 1 study had a limited number of participants, with several methodological differences existing among studies (eg, overground and treadmill running, duration of test conditions). Although speed was held constant during testing, it was individually self-selected or fixed. Most studies used only male participants., Conclusion: Despite procedural differences among studies, an increased stride rate (reduced stride length) appears to reduce the magnitude of several key biomechanical factors associated with running injuries.

We report results of air monitoring started due to the recent natural catastrophe on 11 March 2011 in Japan and the severe ensuing damage to the Fukushima Dai-ichi nuclear reactor complex. On 17-18 March 2011, we registered the first arrival of the airborne fission products (131)I, (132)I, (132)Te, (134)Cs, and (137)Cs in Seattle, WA, USA, by identifying their characteristic gamma rays using a germanium detector. We measured the evolution of the activities over a period of 23 days at the end of which the activities had mostly fallen below our detection limit. The highest detected activity from radionuclides attached to particulate matter amounted to 4.4 ± 1.3 mBq m(-3) of (131)I on 19-20 March., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: There is little published information regarding postoperative management of patients with Chronic Exertional Compartment Syndrome (CECS). Reports of recurrence of symptoms following surgical decompression exist, and are not uncommon depending on the specific technique used. Recurrence suggests that more time and effort may need to be spent on implementing strategic post-operative rehabilitation management in order to avoid repeat surgical intervention or prolonged symptoms., Objective: To summarize relevant literature regarding CECS and propose scientifically-based guidelines for rehab following compartment release with the rationale based on tissue healing, muscle loading, and scar tissue formation and consideration of all tissues contained in the involved compartment., Literature Review: A LITERATURE SEARCH WAS PERFORMED IN PUBMED, SPORTDISCUS, CINAHL, PEDRO, AND GOOGLE SCHOLAR USING THE PHRASE: "chronic exertional compartment syndrome.", Results: No specific rehabilitation guidelines following surgical compartment release for lower extremity CECS were found in the literature search performed for this clinical commentary., Discussion: The development of the proposed post-operative guidelines may allow for improved long-term outcomes following anterior compartment release., Summary: Adequate description of long-term follow-up of outcomes following compartment release for CECS is lacking in current literature. The proposed guidelines for rehab following compartment release include consideration of tissue healing, muscle loading, scar tissue formation, and consideration of soft tissues contained in the involved compartment. Utilization of the proposed guidelines may allow for future research to be performed in order to assess outcomes following surgical intervention for CECS.

Study Objective: To evaluate the onset of spinal anesthesia with power spectral heart rate analysis to determine the influence of the block on the autonomic nervous system., Design: Prospective, clinical evaluation., Setting: Tertiary-care teaching hospital., Patients: 27 ASA physical status I and II patients scheduled for lower extremity orthopedic surgery and free of major cardiac disease or cardiac drugs with direct influence of heart rate (HR) or blood pressure (BP)., Interventions: Prior to anesthesia, a baseline power spectral heart rate reading was taken in the supine position. Spinal anesthesia was established in the sitting position with 15 mg of bupivacaine and 0.2 mg epinephrine introduced at the L3-L4 interspace with a 22-gauge Quincke needle. The patient was returned supine, and power spectral heart rate data were again collected at 5-minute intervals throughout the procedure. Level of the spinal block was checked at 5-minute intervals until 30 minutes and considered complete when two consecutive readings were unchanged., Measurements and Main Results: Heart rate and BP were recorded at baseline and at five-minute intervals after injection. Power spectral heart rate data included low-frequency activity (LFa), high-frequency activity (HFa), and the ratio (LFa/HFa). Spinal level achieved was recorded by thoracic dermatome at complete onset. Heart rate and BP remained within 20% of control in all cases. Complete onset of the spinal block was present by 30 minutes in all cases. The average level of spinal anesthesia was T8. Compared with baseline, LFa activity decreased, HFa activity remained unchanged, and the ratio was decreased. During endoprosthesis insertion, 9 of 14 total hip patients had a transient ten-fold increase in LFa activity, without HFa change, and a corresponding increase in the ratio., Conclusions: Power spectral heart rate analysis during low thoracic bupivacaine spinal anesthesia is compatible with decreased sympathetic activity during stable hemodynamic intervals. Insertion of hip endoprosthesis resulted in a dramatic, transient increase in sympathetic activity, indicating that sympathetic activation was still possible despite the presence of surgical anesthesia from the subarachnoid block.