bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimal Softening for Gravitational Force Calculations in N-body Dynamics
Authors: Das Hirakjyoti , Deb Sukanta , Baruah Amiya 
Published: April 2021

Abstract
The choice of the optimal value of the softening length (ϵ

i
) of each particle dealing with N-body simulations has a profound impact on error values in the gravitational force calculation. A slight deviation from its exact optimal value may result in a large error in the calculation. In this paper we augment the accuracy of the existing gravitational force calculation methods by providing a new technique to calculate the individual optimal values of ϵ

i
for various configurations of the Plummer density model. We have proposed an expression

that relates each particle by considering the average characteristic length (λ

i
) and density (ρ

i
), unlike previous studies that considered ϵ

i
as an exclusive function of ρ

i
. We have performed gravitational force calculations for each and every particle from the Plummer density model using compact as well as noncompact gravitational force methods based on smoothed particle hydrodynamics. We have tested our new equation for the entire range of numerical simulations performed during the study. It is found that the errors in our force calculations are not only lower than those estimated from previous studies but also remain flat for various considerations of nearest neighboring particles (N
neigh). The adjusted expression of ϵ

λ,i
in our study has less dependence on N
neigh in the Plummer sphere. Finally, based on the results obtained using the method proposed in this study, we find that it remarkably improves both the accuracy as well as the stability of the gravitational force calculation.
Magnetic Helicity Flux across Solar Active Region Photospheres. II. Association of Hemispheric Sign Preference with Flaring Activity during Solar Cycle 24
Authors: Park Sung-Hong , Leka K. D. , Kusano Kanya 
Published: April 2021

Abstract
In our earlier study (Paper I) of this series, we examined the hemispheric sign preference (HSP) of magnetic helicity flux dH/dt across photospheric surfaces of 4802 samples of 1105 unique active regions (ARs) observed during solar cycle 24. Here, we investigate any association of the HSP, expressed as a degree of compliance, with flaring activity, analyzing the same set of dH/dt estimates as used in Paper I. The AR samples under investigation are assigned to heliographic regions (HRs) defined in the Carrington longitude–latitude plane with a grid spacing of 45° in longitude and 15° in latitude. For AR samples in each of the defined HRs, we calculate the degree of HSP compliance and the average soft X-ray flare index. The strongest flaring activity is found to be in one distinctive HR with an extremely low-HSP compliance of 41% as compared to the mean and standard deviation of 62% and 7%, respectively, over all HRs. This sole HR shows an anti-HSP (i.e., <50%) and includes the highly flare-productive AR NOAA 12673, however this AR is not uniquely responsible for the HR’s low HSP. We also find that all HRs with the highest flaring activity are located in the southern hemisphere, and they tend to have lower degrees of HSP compliance. These findings point to the presence of localized regions of the convection zone with enhanced turbulence, imparting a greater magnetic complexity and a higher flaring rate to some rising magnetic flux tubes.
The JAGWAR Prowls LIGO/Virgo O3 Paper I: Radio Search of a Possible Multimessenger Counterpart of the Binary Black Hole Merger Candidate S191216ap
Authors: Bhakta D. , Mooley K. P. , Corsi A. , Balasubramanian A. , Dobie D. , Frail D. A. , Hallinan G. , Kaplan D. L. , Myers S. T. , Singer L. P. 
Published: April 2021

Abstract
We present a sensitive search with the Karl G. Jansky Very Large Array for the radio counterpart of the gravitational wave candidate S191216ap, which is classified as a binary black hole merger and suggested to be a possible multimessenger event, based on the detection of a high-energy neutrino and a TeV photon. We carried out a blind search at C band (4–8 GHz) over 0.3 deg2 of the gamma-ray counterpart of S191216ap reported by the High-Altitude Water Cerenkov Observatory (HAWC). Our search, spanning three epochs over 130 days of postmerger and having a mean source-detection threshold of 75 μJy beam−1 (4σ), yielded five variable sources associated with active galactic nucleus activity and no definitive counterpart of S191216ap. We find <2% (3.0% ± 1.3%) of the persistent radio sources at 6 GHz to be variable on a timescale of <1 week (week–months), consistent with previous radio variability studies. Our 4σ radio luminosity upper limit of ∼1.2 × 1028 erg s−1 Hz−1 on the afterglow of S191216ap, within the HAWC error region, is 5–10 times deeper than previous binary black hole (BBH) radio afterglow searches. Comparing this upper limit with theoretical expectations given by Perna et al. for putative jets launched by BBH mergers, for on-axis jets with energy ≃1049 erg, we can rule out jet opening angles ≲ 20° (assuming that the counterpart lies within the 1σ HAWC region that we observed).
« Inverser les imaginaires en écrivant un récit commun, mobilisateur et positif »
Authors: Servigne Pablo , Moncond’huy Léonore , Fourreau Éric 
Published: April 2021

À des endroits différents, ils incarnent la nouvelle génération de l’engagement écologique et solidaire face aux crises climatique, biologique (biodiversité, pandémies), sociale et démocratique que nous traversons. Maire de Poitiers à 30 ans, Léonore Moncond’huy expérimente à l’échelle d’une ville moyenne un nouveau logiciel politique, en rupture avec les pratiques descendantes, patriarcales et dirigistes du siècle passé. Initiateur de la collapsologie, chercheur et co-fondateur du magazine Yggdrasil , Pablo Servigne s’est imposé comme une figure majeure de la pensée radicale sur l’effondrement et le changement de modèle de société. DARD/DARD les a fait se rencontrer pour nourrir le nouveau récit à construire. Autant le dire d’emblée : entre eux, ça a « matché » !
« La psychanalyse dans la rue » : contributions de la psychodynamique du travail
Authors: Tarouquela Brasil Katia 
Published: April 2021

Ce texte présente une expérience de clinique du travail dans le contexte d’une « clinique publique » éphémère installée au cœur même de l’espace urbain, dans les rues de Brasília. Un tel espace propose et promeut une écoute de leur souffrance à des sujets fragilisés par un système social basé sur l’oppression des travailleurs comme des chômeurs. La réflexion, ici proposée, se structurera autour d’un certain nombre de questions : qu’apporte la référence à la pdt dans l’écoute telle qu’elle se déploie dans ce cadre ? Comment comprendre la souffrance sociopolitique à la lumière de la psychanalyse et de la psychodynamique du travail ? À partir d’un regard critique posé sur le dispositif, il s’agira de réfléchir à ses limites et aux possibilités qu’il permet, et de discuter l’intérêt d’un tel dispositif en référence à l’éthique et à l’engagement social de la psychanalyse et de la psychodynamique du travail.
Self-Assessment via Videotaping to Maximize Teaching Effectiveness
Authors: Jeffers Jeanette M , Guthrie Diana W 
Published: April 2021

ABSTRACT
The educator's behavior can influence the learner's responsiveness more effectively than any other teaching strategy. To enhance one's teaching presentation, the educator must assume responsibility for self-improvement and direction. Videotaped experience with self-directed assessments provide an effective strategy for nurses to enhance learning and impact patient education, continuing education, and inservice opportunities for nurses. Using the Performance Video Assessment Guide, the nurse educator can observe, focus, evaluate, and perfect teaching outcomes by viewing videotaped performances.
Care of the Aging Person: A Nursing Specialty-An Educational Series Developed by Staff Nurses
Authors: Davidson Bonnie , Tiivel Judy , Fevez Lynn , Gladish Karren , Sexsmith Pat , Telfer Sarah , Trotter Carolyn , Wabin Doris 
Published: April 2021

ABSTRACT
The increased focus on the needs of elderly people in the acute-care setting is a reflection of the interest and concern shown by society at this time. Not only is there an increasing number of elders in the population, but also an increased number of hospital beds are occupied by older adults (Gross & Schwenger 1981). On many acute-care units 35% to 50% of the patients are over 65.
In acute-care settings there is a need to increase professional awareness of the special needs of elderly patients. Elderly people with an acute illness are especially vulnerable because of age-related changes, multiple chronic diseases and the unfamiliar, fast-paced environment (Davidson, 1986). We all need to know more about the specific nursing needs of older patients and to recognize their full potential so we can help them to improve their functional ability and increase their independence. A series of 10 gerontological education seminars was developed in a large university teaching hospital to provide information that would foster positive attitudes about aging and that would enhance nursing care of elderly people. This paper will describe the successful development of a gerontological educational series by a committee largely composed of staff nurses.
ARTHROPLASTY USING ACETABULAR IMPLANTS IN SECONDARY PROTRUSIONED HIPS
Authors: Udvarhelyi I 
Published: April 2021

ABSTRACT
From 1979 to 1987, 102 operations were performed at the author's institution. The technique is simple and does not use any heterogenic material. There were no complications, except for one suppuration. Results are classified according to Charnley.
RESULTS OF ULTRASTRUCTURAL ANALYSIS OF THE CALF MUSCLES IN CLUBFOOT
Authors: Kránicz J , Trombitás K , Szatbó Gy 
Published: April 2021

ABSTRACT
Open biopsies were carried out on the muscles of 23 clubfoot patients, ages 9 months to 4 years. Electron microscopic analyses of the so-called "clubfoot muscles" and the peroneal muscles were performed. The changes found were not present in every area of the muscles, but were surrounded by fields of normal structure. Fatty degeneration with fibrosis was observed as the consequence of immobilization. More marked loss was found in the contractile elements. The authors believe that neuromuscular atrophy is a primary cause of congenital clubfoot. The most seriously affected muscles in this study were the tibialis posterior and peroneal muscles. The material failed to prove correlation with age. Based on their observations, the authors suggest finishing all types of immobilization before 1 year of age, when children begin to walk.
PRIMARY CERAMIC HIP REPLACEMENT: A PROSPECTIVE STUDY OF 119 HIPS
Authors: Hoffinger Scott A , Keggi Kristaps J , Zatorski Laurine E 
Published: April 2021

Abstract
A prospective study of 119 consecutive primary ceramic total hip arthroplasties (Autophor, Smith & Nephew) was performed. Follow up was 100% at a minimum of 3 years. Six hips were revised during the course of the study (5%). Harris hip scores were 29.0 preoperatively, 78.7 at 6 weeks, and 92.6 at 3.4 years (range: 62 to 100). Ninety-one percent of the 107 surviving hips at follow up had a good or excellent hip score. The clinical results matched those of Mittelmeier. Thigh pain was a frequent finding, but rarely presented a clinical problem. Our incidence of thigh pain may be higher than that of others because no patients were lost to follow up. The ceramic portion of the Autophor Ceramic Hip was well tolerated clinically and radiographically. The femoral component was responsible for 2% to 4% of the revisions, and we have now replaced it with a stem designed for bony stabilization.
DYNAMIC ELECTROMYOGRAPHY IN ACTIVE AND LIMITED WALKING BELOW-KNEE AMPUTEES
Authors: Pinzur Michael S , Asselmeier Marc , Smith Douglas 
Published: April 2021

ABSTRACT
Walking electromyography was performed in 12 below-knee amputees, who were amputated for peripheral vascular insufficiency. All were at least 1 year post-surgery and had no problems with the fit of their prostheses. Seven were coinmunity walkers and five were limited household ambulators. The quadriceps and hamstring muscles exhibited electrical activity during 60% and 64.7% of the gait cycle, respectively, in the active walkers, compared with 44.6% and 53.8% in the limited walkers. Quadriceps muscle activity was initiated almost 10% earlier in the active walkers, while hamstring muscle initiation was similar in both groups. The active walkers were able to maintain quadriceps and increase hamstring muscle activity to compensate for their absent ankle motors, while the limited walkers showed decreased activity in both muscle groups. The results of this preliminary study suggest that the dysvascular limited walking below-knee amputee does not use the quadriceps and hamstring muscles for propulsion during walking, and does not appear to reap the benefits of knee joint preservation.
INTRATHECAL MORPHINE: DOSAGE AND EFFICACY IN YOUNGER PATIENTS FOR CONTROL OF POSTOPERATIVE PAIN FOLLOWING SPINAL FUSION
Authors: Blackman Ronald G , Reynolds James , Shively James 
Published: April 2021

ABSTRACT
Intrathecal morphine in an average dose of 0.01 mg/kg was given to 33 patients between ages 11 and 16 years who had spinal arthrodesis for idiopathic scoliosis. The morphine was administered intrathecally as a 10-cc bolus at the conclusion of the arthrodesis, but before closure. The goal was to study safety in terms of respiratory depression and pain relief Respirations occurred spontaneously in 30 of the 33 patients within 15 minutes of cessation of anesthesia. Respiratory depression occurred in five patients, four of whom had arterial blood pC02 levels >60 mm Hg. Thirty-one patients had relief of pain for 8 to >40 hours, averaging 18 hours. Two patients had no noticeable pain relief There appeared to be no relation between dose and pain relief in this limited dose range. We were unable to duplicate the long duration of pain relief reported elsewhere. We also were unable to decrease the side effects of respiratory depression and nausea to a level reported by others. It may be that the 10 cc bolus injected intrathecally circulates to the brain and ventricles faster than desired, or that factors relating to type of anesthesia or dose need to be considered. Low-dose intrathecal morphine does provide noticeable pain relief in younger patients undergoing spinal fusion. The side effects of nausea and respiratory depression can be managed safely with medication.
CLINICAL EXPERIENCE WITH AUTOMATED PERCUTANEOUS DISCECTOMY: THE NUCLEOTOME® SYSTEM
Authors: Gill Kevin , Blumenthal Scott L 
Published: April 2021

ABSTRACT
The Nucleotome® system was used to treat contained herniated nucleus pulposus of the lumbar spine over a 2-year period. The results were categorized as successful or unsuccessful according to patient perception and anticipated result. The overall success rate was 79%; 93% in private pay and 65% in workers' compensation. The causes of failure were three free fragments not identified in the preoperative scanning technique and 10 cases with significant back pain failing to respond to percutaneous techniques. Overall, percutaneous lumbar discectomy is believed to be an acceptable treatment technique for those patients with contained herniated nucleus pulposus.
INDUCTION OF OSTEOCHONDROMAS BY PERIOSTEAL RESECTION
Authors: Hwang Sung Kwan , Park Byeong Mun 
Published: April 2021

ABSTRACT
Forty immature and 40 mature rabbits which received periosteal resection from the proximal metaphyses or diaphyses of tibiae were evaluated for the occurrence of osteochondromas at the sites of periosteal defects. Thirteen of 20 immature tibiae with the periosteal defects at their proximal metaphyses showed osteochondromas covered by hyaline cartilage caps. We assume that the occurrence of osteochondroma at the metaphyseal region of growing long bone, where the periosteal defects were made, is due primarily to a decrease in the power of the periosteum to control the circumferential growth of the metaphysis, and is due secondarily to an abnormal proliferation of cartilage progenitors located in Ranvier's groove.
DEEP VEIN THROMBOSIS PROPHYLAXIS IN THE OUTPATIENT SETTING: PREVENTING COMPLICATIONS FOLLOWING HOSPITAL DISCHARGE
Authors: Turpie Alexander G G 
Published: April 2021

ABSTRACT
Venous thromboembolism is an important complication in patients undergoing major orthopedic surgery. Without prophylaxis, there is a 50% to 60% incidence of deep vein thrombosis (DVT), a 10% to 30% incidence of proximal vein thrombosis, and a 1% to 2% rate of fatal pulmonary embolism after total hip replacement. The incidence of DVT after knee arthroplasty is even higher, ranging from 55% to 70% and, although there are no accurate figures on the incidence of fatal pulmonary embolism, it is likely to be similar to that following hip arthroplasty. Low molecular weight heparins (LMWHs) have been shown to be effective and safe in the prevention of venous thromboembolism in patients undergoing major orthopedic procedures. In comparative studies, LMWHs are more effective than adjusted dose heparin or warfarin without increased risk of bleeding.
CONSORTIUM DATA: COMPARATIVE EFFICACY OF LOW MOLECULAR WEIGHT HEPARIN AND WARFARIN FOLLOWING TOTAL HIP REPLACEMENT
Authors: Colwell Clifford W 
Published: April 2021

ABSTRACT
The Consortium Study is a prospective, randomized research project designed to extend the medical community's understanding of the incidence of thromboembolic disease following hip replacement surgery. The study's methodology of assessing deep vein thrombosis (DVT) and pulmonary embolism (PE) is by clinical symptomatology. Once clinical symptoms occur, diagnostic confirmation includes noninvasive techniques such as duplex ultrasonography, venography, VQ lung scan, and/or lung angiography. The study is designed to recruit a cohort of 4500 patients and will involve 150 medical centers in the United States. The final conclusion and definitive data of the incidence of DVT and PE, when comparing enoxaparin with warfarin, will be available after the full complement of 4500 patients is recruited. This study will demonstrate the incidence of thromboembolic disease during the acute hospital phase and the medium-term phase for the patient undergoing elective hip replacement.
Is Ultrasonography a Reliable Way to Confirm the Diagnosis of Morton's Neuroma?
Authors: Kaminsky Sean , Griffin Letha , Milsap James , Page Debbie 
Published: April 2021

ABSTRACT
The diagnosis of Morton's neuroma is based on patient history and clinical findings. Occasionally, however, the diagnosis still remains in doubt despite careful examination. While magnetic resonance imaging (MRI) has been used to evaluate such cases, its specificity remains unproven and its availability is not universal. Ultrasonography may offer a reasonable alternative to MRI. Eight patients clinically diagnosed with neuromas who had not responded to conservative care underwent ultrasonography. Sonography in each demonstrated a round or oval echogenic mass where a neuroma was believed to be present. Sonography on a control group of 10 asymptomatic patients (20 feet) revealed no such mass. Pathologic inspections of surgically resected specimens confirmed the diagnosis of Morton's neuroma. With no false positive results, this preliminary study indicates ultrasonography may be a specific diagnostic test for Morton's neuroma.
The Efficacy and Safety of the Hematoma Block for Fracture Reduction in Closed, Isolated Fractures
Authors: Furia John P , Alioto Richard J , Marquardt John D 
Published: April 2021

ABSTRACT
Fracture manipulation in the emergency department often requires some method of anesthesia. This study evaluates the efficacy and safety of the hematoma block in patients with closed, isolated fractures requiring manipulative reduction. Sixty-one patients treated with a hematoma block (HB group) prior to fracture manipulation were compared with 53 patients treated with either intravenous sedation or "conscious sedation" (NHB group). Using a pain analog scale, patients rated their pain from 1 (no pain) to 10 (severe pain) both prior to and during fracture manipulation. A pain differential score was calculated for each group. Results demonstrated pain differential scores of 2.7 and 0.8 for the HB and NHB groups, respectively. There were no complications associated with any of the procedures. Based on these results, we conclude that the hematoma block is an effective and safe method of providing anesthesia for fracture reduction in select patients.
Orderly Oriented Wire Mesh: A Novel Porous Coating
Authors: Naidu Sanjiv H , Moulton Mark J R , Cuckler J M , Ducheyne P 
Published: April 2021

ABSTRACT
As an alternative to commercially available porous beads and fiber metal mesh, a new porous coating, orderly oriented wire mesh (OOWM), was developed. Rectangular plugs, 10×5×5 mm with porous-coated beads, and four different OOWM configurations were inserted into bilateral femoral condyles of adult beagles. Dogs were sacrificed immediately after implantation, and at 4 weeks, 8 weeks, and 12 weeks postimplantation. Mechanical pullout strength of plugs revealed that porous beads are equivalent to the simplest OOWM at 12 weeks postimplantation. Of the four OOWMs tested, the 257×25 single layer was significantly more stable than others at 4 weeks postimplantation. These results indicate that in an in vivo unloaded model, OOWM is just as effective as the porous beads in achieving early bone ingrowth and stability.
Mechanical Evaluation of a Soft Cast Material
Authors: Zmurko Matthew G , Belkoff Stephen M , Herzenberg John E 
Published: April 2021

ABSTRACT
In this study, the structural and material properties of a new semi-rigid material, Scotchcast SoftCast (SCS), were compared to the properties of two rigid materials, plaster of pans (POP) and Scotchcast Plus (SCP). Cylinders and flat beams made from 4, 6, 8, and 10 layers of each casting material were tested in three-point bending and diametrical compression. Initial stiffness and yield force values of SCS casts were significantly lower than for casts of SCP and POP made of the same number of layers. Casts made from SCS may be indicated for non-rigid applications, but not where rigid immobilization is required.
Clinical Experience With the Molteno Implant in Advanced Infantile Glaucoma
Authors: Munoz Michelle , Tomey Karim F , Traverso Carlo , Day Susan H , Senft Susan H 
Published: April 2021

ABSTRACT
The alternatives in the management of infantile glaucoma refractory to conventional treatment are quite limited and unrewarding. We did a retrospective study of 49 patients (53 eyes) under 12 years of age with advanced, uncontrolled glaucoma who each underwent implantation of a single-plate Molteno implant in one stage. Over the follow-up period ranging from 6 months to 3 years (mean 18 months), 36 of the 53 eyes (68%) had an intraocular pressure « 21 mm Hg and were considered a success. Fourteen eyes (26%) required further glaucoma surgery, 2 eyes developed severe chronic hypotony, and 1 eye lost light perception following endophthalmitis. The number of anti-glaucoma medications was decreased from a mean of 2 (± 1) to 1 (± 1). The probability for success of the Molteno implant in controlling glaucoma increased with the age of the patient.
Six eyes (11%) were late failures, most probably due to fibrous encapsulation of the bleb. Complications observed were: prolonged hypotony and flat anterior chamber, retinal detachment, migration of the tube, erosion of the tube through the conjunctiva, and an ingrowth of fibrous tissue in the anterior chamber.
We consider the Molteno implant to be a reasonable option in the management of difficult cases of infantile glaucoma.