bluuebunny/crossref_metadata_2025 huggingface dataset:
Aquatic physiotherapy in the functional capacity of elderly with knee osteoarthritis
Authors: Garbi Fernando Pereira , Rocha Júnior Paulo Roberto , Pontes Natália de Souza , Oliveira Andressa de , Barduzzi Glauber de Oliveira , Boas Paulo José Fortes Villas
Published: September 2021

Abstract Introduction: Physicaltherapy in patients with osteoarthritis (OA) acts to decrease pain, increase joint functionality and to promote improvement in quality of life. Objective: To analyze the effect of a structured program of aquatic physiotherapy (AP) on functional capacity (FC) and mobility of elderly people with OA. Methods: Prospective, quantitative and analytical, randomized control study. The sample consisted of 29 patients, aged 60 years or over, diagnosed with OA, randomly allocated to the intervention group (IG), composed of 17 participants who underwent BP for two months, and to the control group (CG) of 12 participants. The primary outcome was measured by the WOMAC instruments and six-minute walk test. As a secondary endpoint, the Timed Up and Go Test measured mobility. Descriptive statistical analysis was used to present the data, with mean and standard deviation values. The comparison between groups for potential confounding factors and in relation to evolution was performed using the non-parametric chi-square test, Fisher's exact test and the Kruskal-Wallis test, and Dunn's test for multiple comparisons. The differences were considered statistically significant when p < 0.05. Results: There was a significant difference in physical and functional parameters related to pain (p < 0.001), stiffness (p < 0.001) physical activity (p < 0.001), distance covered in six minutes (p = 0.001), and mobility (p < 0.001) when comparing IG to CG. Conclusion: The structured AP program effectively contributed to the improvement of FC and mobility of elderly people with knee OA.
Saúde quilombola: percepções em saúde em um quilombo do agreste de Pernambuco/Brasil
Authors: Gomes Wanessa da Silva , Gurgel Idê Gomes Dantas , Fernandes Saulo Luders
Published: September 2021

Resumo Este estudo analisa a percepção de saúde dos quilombolas de uma comunidade no agreste de Pernambuco à luz da determinação social da saúde. A comunidade apresenta uma população de aproximadamente 250 famílias, sendo a agricultura e o trabalho na casa de farinha suas principais fontes de subsistência. Trata-se de uma pesquisa-ação, de caráter analítico, baseada na abordagem qualitativa na coleta e análise dos dados, a partir de entrevistas em profundidade, círculo de cultura e observação participante. Os dados foram analisados pela técnica do discurso do sujeito coletivo. Destaca-se, nos resultados, que a compreensão da saúde se insere num contexto de complexidade integrando a qualidade da alimentação, o trabalho desenvolvido e a relação com a terra. O olhar por meio da perspectiva sistêmica proporcionada pela determinação social da saúde, contribuiu para a compreensão da saúde em sua totalidade, onde o território aparece como elemento central na reprodução dos modos de vida e de saúde da população quilombola, estando esta, em constante luta pela demarcação e titulação de suas terras, condição fundamental para o viver saudável na comunidade quilombola.
Internationalization of Higher Education Institutions: perceptions of scholars
Authors: Costa Rejane Pinto , Canen Alberto Gabbay
Published: September 2021

Abstract This study aims to contribute to Brazilian Higher Education Institutions (HEIs) within an international perspective. Our main argument is that when HEIs value international research and students’/academics’ international mobility, such institutions contribute to enlarge the view of internationalization throughout Brazil and push HEIs far beyond political, economic and commercialization processes considered to be, today, key drivers for Higher Education changes in terms of internationalization. To achieve this aim, the most recent tendencies in literature concerning the concepts of HEIs and International Management (IM) were gauged to realize the extent to which they may contribute to alternative perceptions in global Higher Education in Brazil. The theoretical framework was based on the articulation of such concepts, and data were connected to the interviews held with highly skilled scholars of three different public Brazilian HEIs using the methodology of oral histories. Data pointed traits and suggestions toward expanding internationalization in Brazilian HEIs, among which fostering international researchers and resource allocation systems for international research funding.
Co-creating social value in placemaking: the grand balancing act
Authors: Raiden Ani , King Andrew , Peace Sir John , Osbon Kevin , Sousa Sophia de , Alvarez Laura
Published: September 2021

Social value in the built environment refers to the social impact any organisation or project in that sector makes on its many and varied stakeholders. This involves different agents, such as design and planning professionals, engineering and construction professionals and workers, trades, facilities management providers and their personnel and community groups and their members. This paper examines social value activities with a focus on placemaking and shows how in the Midlands, UK, regional strategic influence, consultant, design and planning efforts relate to the Useful Projects Social Value Maturity Framework and align with the UN Sustainable Development Goals (SDGs). The authors highlight how the agents collectively help ensure that Nottingham is one exemplar city with a direct participation structure of civil society in urban planning and management that operates regularly and democratically; how their activities help improve education, awareness-raising and human and institutional capacity on climate change mitigation, adaptation, impact reduction and early warning; and how they together ensure responsive, inclusive, participatory and representative decision making at all levels. The paper presents a transformative case study of social value in practice, which has a partnerships model at its heart, and the potential to inform future methodologies for business and community engagement to improve social outcomes
The influence of particle size distribution on the stress distribution in granular materials
Authors: Liu Deyun , O'Sullivan Catherine , Carraro J. Antonio H.
Published: September 2021

This study systematically explores the effect of the shape of the particle size distribution (PSD) on stress transmission in granular materials using three-dimensional discrete-element method simulations. Extending prior studies that have focused on bimodal mixtures of coarser and finer grains, a broad range of isotropically compressed specimens with spherical particles and linear, fractal and gap-graded particle size distributions is considered. Considering isotropic stress conditions, the nature of stress distribution was analysed by determining the mean effective particle stresses and considering the proportion of this stress transmitted by particles with different sizes. For gap-graded materials a contact-based perspective was adopted to consider the stress transmission both within and between the different size fractions. A clear correlation emerged between the cumulative distribution of particle sizes by volume and the cumulative distribution of particle sizes by mean effective stress for specimens with continuous PSDs. This correlation does not hold universally for gap-graded materials. In gap-graded materials the distribution of effective stress between the different size fractions depends upon the size ratio and the percentage of finer grains in the specimen. In contrast to specimens with continuous gradings, in gap-graded specimens the distribution of effective stress among the different size fractions exhibits a marked sensitivity to density. Basic network analysis is shown to provide a useful insight into effective stress transmission in bimodal gap-graded materials.
“Reversal” ALPPS in patient with hepatocellular carcinoma and liver cirrhosis. First clinical case in Russia
Authors: Voskanyan S. E. , Rudakov V. S. , Shabalin M. V. , Artemyev A. I. , Bashkov A. N. , Kolyshev I. Yu. , Zhurbin A. S. , Naidenov E. V. , Popov M. V.
Published: September 2021

Liver resection in patients with HCC is the treatment of choice. In patients with insufficient future liver remnant (FLR) and compensated liver function performing the Associated Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) is possible. The classic version of ALPPS consists in ligation of the right branch of the portal vein with transection of the parenchyma and then performing right hepatectomy or right trisegmentectomy. This paper describes the first case in Russia of performing ligation of the left portal branch with transection of the parenchyma and then performing left trisegmentectomy (“reversal” ALPPS) in a patient with HCC and cirrhosis. Reversal ALPPS can be successfully performed in patients with insufficient future liver remnant in well-selected patients.
New possibilities for testing direct arterial liver perfusion after liver transplantation
Authors: Moiseenko A. V. , Polikarpov A. A. , Tarazov P. G. , Kozlov A. V. , Tileubergenov I. I. , Granov D. A.
Published: September 2021

The aim of the study was to show new promising possibilities of direct perfusion test for the transplanted liver.

Materials and methods. We have performed 246 liver transplantations (1998–2020). Since 2015 arterial complications were detected in 24 (23%) patients after 105 transplantations complicated by liver hypoperfusion: splenic artery steal syndrome (n = 8), hepatic artery thrombosis (n = 7), combination of hepatic artery stenosis and steal syndrome (n = 6), hepatic artery stenosis (n = 3). Endovascular interventions were performed in these cases for revascularization. Direct perfusion test was performed in 8 patients.

Results. The liver perfusion index increased from 0.27 (0.13–0.45) to 0.62 (0.33–0.89) after endovascular procedures. Sufficient perfusion was ≥0.65.

Conclusion. Direct liver perfusion test makes possible to identify and objectify graft blood supply, timely and adequate correction, and reduces the risk of developing biliary ischemic complications.
Interventional radiology in rendezvous technique for choledocholitiasis in elderly patients
Authors: Okhotnikov O. I. , Lutsenko V. D. , Yakovleva M. V. , Gorbacheva O. S. , Grigoriev S. N , Okhotnikov O. O.
Published: September 2021

Aim. Define the safety and effectiveness of rendezvous technique for choledocholithiasis.

Material and methods. We performed a retrospective and prospective analysis of the results in percutaneous transhepatic access to the bile ducts and endoscopic intervention in the rendezvous technique for choledocholithiasis in 100 elderly patients. The patients were divided into 2 groups for 50 people. The implementation of the rendezvous began from the antegrade stage in patients from group I; in patients of group II – from the retrograde stage. Postmanipulation complications and failures were When analyzed. The control point of the study is the identification of complications associated with manipulation from the next stages of the rendezvous technique.

Results. We revealed a direct dependence of the results in sequence of rendezvous technique for elderly patients with choledocholithiasis and obstructive jaundice. This fact allows recommending percutaneous transhepatic access before endoscopic intervention for these patients with statistical significance. The frequency of complications and failures in patients of group I was 18%, in group II – 52%. This allows for such patients percutaneous transhepatic access before endoscopic intervention in the rendezvous technique. The frequency of complications and failures in patients of group I was 18%, in group II – 52%.

Conclusion. Dilatation of intrahepatic segmental and subsegmental 2 and 3 biliary ducts with moderate and severe obstructive jaundice is a predictor of complications with ineffective endoscopic approach. In such situations, preventive antegrade drainage of the biliary tract with rendezvous technique makes possible to prevent cholangitis, effectively eliminate biliary hypertension, clarify the severity of stenosis of the papilla with antegrade balloon revision, and also secure delayed endoscopic resolution of biliary pathology.
Technical aspects of minimally invasive percutaneous approach for local complications of acute pancreatitis
Authors: Novikov S. V. , Rogal M. L. , Yartsev R. A. , Teterin Yu. S.
Published: September 2021

Aim. To improve the results of treatment for patients with acute pancreatitis by optimizing the technique of performing percutaneous methods of drainage and sequestrectomy.

Material and methods. We have considered experience of treating pancreatic necrosis in 257 patients, confirmed by computed tomography, intraoperatively, and postmortem examinations. Moderate severity pancreatitis was detected in 159 (61.9%) patients, severe – in 98 (38.1%) cases.

Results. Small focal pancreatic necrosis was detected in 99 (62.3%) patients with moderate pancreatitis, large focal pancreatitis – in 60 (37.7%). Small-focal pancreatic necrosis was in 23 (23.5%) patients, large-focal – in 43 (43.9%), subtotal – in 29 (29.6%), total – in 3 (3.1%) among patients with severe acute pancreatitis. Percutaneous approach was used in combination with transluminal and open surgery in 59 (23%) patients. Infected necrosis was detected in 6 (3.8%) patients with acute moderate pancreatitis and in 44 (44.9%) patients with severe pancreatitis, sepsis – in 12 (12.2%) patients. 27 (10.5%) patient have died from septic shock in the first phase of pancreatitis, included 14 (5.4%) cases after surgery. Overall 41 (16%) patients with pancreatic necrosis have died.

Conclusion. Compliance of stages in surgical treatment technology allows optimally combine it with transluminal sequestrectomy, reduces surgical trauma, eliminates additional risks of open approach associated with complications and deaths.
Sorbents based on mesoporous silica modified by amidic functional groups
Authors: Batueva Tatyana D. , Shcherban Marina G. , Brukhanova Maria V. , Kondrashova Natalya B.
Published: September 2021

Synthesized sorbents based on silica with a pore structure of MCM-41, modified with amide groups. Using the low-temperature sorption of nitrogen, X-ray phase analysis (XRD), IR spectroscopy, and scanning electron microscopy, the textural and structural properties of the studied silica sorbents were determined. The kinetics of sorption of copper (II), nickel (II), cobalt (II) from aqueous solutions by the obtained reagents was studied, the dependence of the sorption ability of the reagents on the method of modifying the silica base and the monomer concentration during joint sorption of metals was determined. The possibility of separation of the investigated non-ferrous metals by the obtained reagents is shown.
Current state and prospects for the development of the chemical faculty of Perm State National Research University (on the 90th anniversary of the education of the faculty)
Authors: Mashevskaya Irina V. , Rogozhnikov Sergey I.
Published: September 2021

The article is devoted to the current stage of development of the chemical faculty of Perm State National Research University and strategic plans for its further development. It is a continuation of a series of articles published for the 90th anniversary of the Faculty of Chemistry. In the previous issue, an article was published on the emergence and formation of the Faculty of Chemistry of PSU
Pornografija, stav o uporabi kondoma i uporaba kondoma kod riječkih adolescenata
Authors: Koletić Goran , Mehulić Jasmina
Published: September 2021

Jednostavnost pristupa internetskoj pornografiji izazvala je zabrinutost odgojnih stručnjaka i opće javnosti zbog negativnih učinaka pornografije na psihosocijalno i seksualno sazrijevanje adolescenata. Pretpostavljena povezanost između uporabe pornografije i rizičnog seksualnog ponašanja, posebice nezaštićenog spolnog odnosa, često se nalazi u središtu pozornosti. Prema dosadašnjim istraživanjima, stav o uporabi kondoma važan je prediktor stvarne uporabe kondoma. Međutim, razmjerno je malo studija analiziralo povezanost između uporabe pornografije, stava o uporabi kondoma i uporabe kondoma među adolescentima. Konceptualni okvir ove studije čini nedavno razvijeni model akvizicije, aktivacije i aplikacije (3AM). Cilj je ove studije analiza longitudinalne povezanosti između učestalosti uporabe pornografije te stava o uporabi kondoma i uporabe kondoma pri posljednjem spolnom odnosu. Podaci su prikupljeni metodom ankete u dva vala među učenicima/ama 14 riječkih srednjih škola od 2015. do 2018. godine (N=227; Mdob=17,3; SD=0,5). Kontrolirajući traženje uzbuđenja i permisivne stavove o seksualnosti, provedena je višegrupna ukrižena analiza primjenom strukturalnog modeliranja. Utvrđena je longitudinalna povezanost između učestalosti uporabe pornografije i negativnijeg stava o uporabi kondoma, ali samo kod mladića. Nije utvrđena longitudinalna povezanost između uporabe pornografije i uporabe kondoma. Povrh rasprave o rezultatima, zaključno se razmatraju preporuke za daljnja istraživanja i praktične implikacije. Dobiveni nalazi mogu poslužiti stručnjacima iz područja obrazovanja, medijske pismenost i javnog zdravstva, ali i široj javnosti.
PERCEPTIONAL DIFFERENCES IN ARCHITECTURAL FACADE PERCEPTION DUE TO ARCHITECTURAL EDUCATION
Authors: YILDIZ KUYRUKÇU Emine , ÖZDEMİR ERDOĞAN Tuğba
Published: September 2021

Aim: In this study, the façades of tourism buildings designed with different currents (universalism, regionalism, syncreticism, contextualism, neovernakularism) on the Antal-ya coastline, in terms of 'taste', 'chaos', 'affection', 'familiarity', by groups of architects and non-architects. It is aimed to examine how it is perceived. Method: For this purpo-se, the fronts of 20 tourism buildings from 5 different styles, designed with a modern and postmodern approach, were analyzed by 60 people through a questionnaire. In the survey, adjective pairs such as impressive / ordinary, original / imitation, coarse / elegant, modest / flamboyant, complex / plain, familiar / unfamiliar, modern / outdated, questio-ning the façade features for tourism buildings were evaluated with a five-digit semantic differentiation scale. The analysis of the data sets obtained through the questionnaire was performed with the IBM Statistical Package For The Social Sciences (SPSS) 23 For Windows statistical software package program. At the beginning of the study, it was thought that the subjects would have perception-behavioral performance differences depending on the architectural education. Results: Unlike the non-architect profession, the architect group liked the universalism, neo-natalism and regionalism movements, found it impressive and original; It was determined that he did not like the synchterism and contextualism movements as complex, rude and outdated. Conclusion: In the analysis, it was seen that the differences between architects and non-architects are statis-tically significant. As a result of the study, it was determined that there are significant differences between architects and non-architects in evaluating the adjectives of expres-siveness, complexity, familiarity and originality. İndividuals who do not have an archi-tectural education are familiar with the traditional inspired structures, and they find the-se structures impressive It is for the individuals who study architecture to find modern and regionalist structures impressive and original.
DNA Extract was from filter paper stored at room temperature v1
Authors: Izenour Katie , Kalalah Anwar , Salib Fayez , Zohdy Sarah
Published: September 2021

Preservation of samples requiring cold-chain storage is an often unavoidable challenge especially when doing laboratory work outside the western world. Samples are a precious commodity and it is imperative to maintain their viability. One method for collection and storage of samples in a liquid form (blood, saliva, serum) at room temperature is on filter paper cards like the Cellabs Tropbio Filter Paper Blood Collection Disks™. Methods and protocols exist for the use and recovery of whole blood from filter paper discs. This protocol describes the wash and recovery of DNA extracted from whole blood using the Qiagen DNeasy Extraction kit and dried on filter paper, re-suspended after several months of room temperature storage and use in conventional PCR. This protocol was used to suspend DNA extracted from the wholeblood of Dogs in Cairo, Egypt. The DNA was extracted using the Qiagen DNEasy Extraction Kit and placed on Cellabs Tropbio Filter Paper Blood Collection Disks™ (filter paper). The DNA dried on the filter paper overnight and was stored in plastic self-closure baggies for several months before being washed off and used in Conventional PCR. The use case described here is of a dog who was PCR positive for Babesia spp. using a sample of whole blood washed from the filter paper as well as dried DNA from filter paper.
Reconstitution of Parkin ubiquitin ligase activity using mouse and human mitochondria v1
Authors: Antico Odetta , Ordureau Alban
Published: September 2021

Analysis of Parkinson’s linked genes PINK1 and Parkin has uncovered a mechanism by which upon loss of mitochondrial membrane potential, Parkin E3 ubiquitin ligase activity is activated by PINK1 kinase activity, to trigger mitochondrial membrane protein ubiquitylation, leading to removal of damaged mitochondria (mitophagy). We and other groups have previously reported in vitro assays of Parkin E3 ligase activity using recombinant Parkin and PINK1 expressed in E. coli. This provided evidence of Parkin activation by PINK1 phosphorylation of Ser65 in both ubiquitin and UBL domain of Parkin. Herein, we report a reconstitution assay in which addition of recombinant Parkin to mitochondria isolated from cells after treatment by combination of Antimycin A and Oligomycin (to induce PINK1 activation on the outer mitochondrial membrane), enables robust ubiquitylation of multiple substrates at the mitochondria. This assay represents a powerful tool to study Parkin E3 ligase activity and the functional interplay between ubiquitylation and phosphorylation mediated by PINK1 and Parkin and their role in reshaping the endogenous mitochondrial proteome.
SDS-PAGE Using TGX Acrylamide Kit--CHEM 584 v1
Authors: Christensen Ken
Published: September 2021

Prepare and run your SDS-PAGE gel using the Bio-Rad TGX gel system and the mini-PROTEAN gel box.
MODELING OF A VENTILATED CAVITY BEHIND A STREAMLINED BODY
Authors: Voropaiev G. O. , Korobov V. I. , Dimitrieva N. F.
Published: September 2021

The results of physical and numerical modeling of a ventilated air cavity behind a streamlined body are presented. The results of laboratory experiments to determine the amount of gas flowing from the ventilated cavity are presented. It is formed behind the cavitator depending on a number of geometric and dynamic parameters. Numerical simulation of non-stationary 3D two-phase flow was performed on the basis of open source software OpenFOAM. The influence of gas blowing parameters on the formation of an air cavity, size, shape and stability has been investigated. Good qualitative agreement with experimental data was obtained. It is shown that the thickness of the ventilated cavity is determined by the diameter of the cavitator regardless of the diameter of the blow hole, and the increase in velocity or gas flow rate has a positive effect on the length and stability of the formed cavity.
Yeni Yapılacak Betonarme Bir Binanın TBDY 2018’e göre Deprem Performansının Belirlenmesi
Authors: İBİŞ Tolunay , ULUTAŞ Hakan
Published: September 2021

Bu çalışmada, tasarımı TBDY (2018)’e göre yapılan ve yapımı devam eden betonarme bir binanın incelenmek üzere proje verileri elde edilmiştir. Binanın doğrusal elastik olmayan değerlendirme yöntemlerinden tek modlu statik itme analizi ile performans düzeyi belirlenmiştir. Elde edilen performans analizinin sonucu TBDY 2018’de verilen hedef performans seviyesi ile kıyaslanmıştır. Bina daha yapım aşamasında olduğundan yeni yapılacak bir bina gibi değerlendirilip performans analizi bu kapsamda yapılmıştır. Kesitlerin moment eğrilik analizleri ile plastik mafsal özelliklerinin belirlenmesi için SAP 2000’in Section Desinger arayüzünde faydalanılmıştır. Yapılan statik itme analizi sonucu kolon ve betonarme perdelerde herhangi bir hasar meydana gelmemiş, kirişlerin ise bazıları belirgin hasar bölgesinde kalmıştır. Düşey taşıyıcı elemanlarda hasar oluşmadığı için bina performans seviyesi kiriş hasarlarına bakılarak karar verilmiştir. Binanın yönetmelikte verilen hedef performans seviyesini sağladığı belirlenmiştir.
Poli(4-vinilbenzil-g-stiren) Aşı Kopolimerinin RAFT ve SRP Yöntemleriyle Sentezi ve Karakterizasyonu
Authors: SAVAŞ Bedrettin , ÖZTÜRK Temel , MEYVACI Ergül
Published: September 2021

Poli(4-vinilbenzil-g-stiren) [poli(VB-g-S)] aşı kopolimeri tersinir katılmalı/ayrışmalı zincir transfer (RAFT) ve serbest radikal polimerizasyon (FRP) teknikleri kullanılarak sentez edildi. Bu amaç için, 4-vinilbenzil klorür monomeri kullanılarak FRP yöntemiyle poli(4-vinilbenzil klorür) [poli-4-VBC] polimeri sentezlendi. İkinci aşamada, poli-4-VBC polimeri ile potasyum etil ksantat reaksiyona sokularak makro-RAFT ajanı oluşturuldu. Son aşamada, RAFT tekniğiyle makro-RAFT ajanı varlığında stiren monomeriyle poli(VB-g-S) aşı kopolimeri sentez edildi. Sentezlenen ürünler 1H-NMR, FT-IR, TGA, SEM ve Dinamik Işık Saçılım (DLS) cihazları gibi spektroskopik ve termal analiz teknikleri kullanılarak karakterize edildi.
Imaging the Ice Sheet and Uppermost Crustal Structures with a Dense Linear Seismic Array in the Larsemann Hills, Prydz Bay, East Antarctica
Authors: Fu Lei , Guo Jingxue , Li Junlun , Deng Bao , Liu Guofeng , Xiao Enzhao , Chen Xiaofei
Published: September 2021

Comprehensive geophysical surveys including magnetotelluric, seismic, and aerial gravity–magnetic surveys are essential for understanding the history of Antarctic tectonics. The ice sheet and uppermost structure derived from those geophysical methods are relatively low resolution. Although ice-penetrating radar can provide high-resolution reflectivity images of the ice sheet, it cannot provide constraints on subice physical properties, which are important for geological understanding of the Antarctic continent. To obtain high-resolution images of the ice sheet and uppermost crustal structure beneath the Larsemann Hills, Prydz Bay, East Antarctica, we conduct an ambient noise seismic experiment with 100 short-period seismometers spaced at 0.2 km intervals. Continuous seismic waveforms are recorded for one month at a 2 ms sampling rate. Empirical Green’s functions are extracted by cross correlating the seismic waveform of one station with that of another station, and dispersion curves are extracted using a new phase-shift method. A high-resolution shear-velocity model is derived by inverting the dispersion curves. Furthermore, body waves are enhanced using a set of processing techniques commonly used in seismic exploration. The stacked body-wave image clearly shows a geological structure similar to that revealed by the shear-wave velocity model. This study, which is the first of its kind in Antarctica, possibly reveals a near-vertical intrusive rock covered by an ice sheet with a horizontal extent of 4 km. Our results help to improve the understanding of the subice environment and geological evolution in the Larsemann Hills, Prydz Bay, East Antarctica.
Magnitude Estimation for Earthquake Early Warning with Multiple Parameter Inputs and a Support Vector Machine
Authors: Zhu Jingbao , Li Shanyou , Song Jindong
Published: September 2021

Accurately estimating the magnitude within the initial seconds after the P-wave arrival is of great significance in earthquake early warning (EEW). Over the past few decades, single-parameter approaches such as the τc and Pd methods have been applied to EEW magnitude estimation studies considering the first 3 s after the P-wave onset. However, these methods present considerable scatter and are affected by the signal-to-noise ratio (SNR) and epicentral distance. In this study, using Japanese K-NET strong-motion data, we propose a machine-learning method comprising multiple parameter inputs, namely, the support vector machine magnitude estimation (SVM-M) model, to determine earthquake magnitudes and resolve the aforementioned problems. Our results using a single seismological station record show that the standard deviation of the magnitude prediction errors of the SVM-M model is 0.297, which is less than those of the τc (1.637) and Pd (0.425) methods. The magnitudes estimated by the SVM-M model within 3 s after the P-wave arrival are not obviously affected by the SNR or epicentral distance, and not overestimated for MJMA≤5. In addition, in an offline EEW application, the magnitude estimation error of the SVM-M model gradually decreases with increasing time after the first station is triggered, and the underestimation of event magnitudes for 6.5≤MJMA gradually improves. These results demonstrate that the proposed SVM-M model can robustly estimate earthquake magnitudes and has potential for EEW.
The 6 May 1947 Milwaukee, Wisconsin, Earthquake
Authors: Hough Susan E.
Published: September 2021

The State of Wisconsin is not known for earthquake activity. The authoritative public-facing U.S. Geological Survey Comprehensive Catalog of earthquakes includes only three small (magnitude < 2) earthquakes in the state, all instrumentally recorded. Although other catalogs include more events in Wisconsin, experience has shown that many types of events, such as explosions and cryoseisms, have made their way into earthquake catalogs in this region. In this short report, I summarize available information about an earthquake that was felt in eastern Wisconsin at 15:27 local time on 6 May 1947. As what appears to be the largest historical earthquake in the State of Wisconsin, it is of public interest, its modest size notwithstanding. It appears that no useful instrumental records exist, due in part to a teleseismic event that occurred approximately 3 min later, generating surface waves that were recorded on early long-period instruments in the region. Instrumental data may exist for this event but have not been found. Comparing the felt area with information from recent earthquakes in the region, I estimate an intensity magnitude of 3.8 for the event, with a subjectively estimated uncertainty range 3.5–4.1. Relatively strong effects, including reports of broken dishes in Milwaukee, and shaking described as short but especially sharp, suggest that the event may have been among the sprinkling of shallow earthquakes now known to occur in the upper Great Lakes region.
Structure of a fault segment boundary in the Lost River fault zone, Idaho, and possible effect on the 1983 Borah Peak earthquake rupture
Authors: Susong David D. , Janecke Susanne U. , Bruhn Ronald L.
Published: September 2021

The 1983 Borah Peak earthquake (Ms 7.3) initiated within the southern part of the Thousand Springs segment in the Lost River fault zone, east-central Idaho. The earthquake rupture propagated unilaterally to the northwest over a distance of 36 km and was accompanied by sinistral-normal slip within the fault zone. At the surface, the southern-most part of the rupture zone is marked by a bend in the Lost River fault zone at the intersection between the Thousand Springs segment to the north and the Mackay segment of the fault zone to the southeast. The intersection between the two fault segments is a lens-shaped area that contains numerous NW- and NE-striking faults that cut the Paleozoic bedrock. Several of the faults within the intersection zone ruptured at the surface during the 1983 earthquake.

A three-dimensional geometrical model of the intersection zone between the Thousand Springs and Mackay fault segments was constructed from geological mapping in conjunction with previously published interpretations of geodetic and seismological data. The longitudinal axis of the intersection zone plunges to the southwest, where its projected position in the subsurface roughly coincides with the location of the 1983 earthquake's hypocenter at a depth of 15 to 16 km. The intersection zone between the two fault segments may have played a dual role during the Borah Peak earthquake, both marking the site of rupture nucleation, but also acting to arrest spread of the rupture to the southeast onto the adjacent Mackay segment.
Polarization and coherence of 5 to 30 Hz seismic wave fields at a hard-rock site and their relevance to velocity heterogeneities in the crust
Authors: Menke William , Lerner-Lam Arthur L. , Dubendorff Bruce , Pacheco Javier
Published: September 2021

Except for its very onset, the P wave of earthquakes and chemical explosions observed at two narrow-aperture arrays on hard-rock sites in the Adirondack Mountains have a nearly random polarization. The amount of energy on the vertical, radial, and transverse components is about equal over the frequency range 5 to 30 Hz, for the entire seismogram. The spatial coherence of the seismograms is approximately exp(−cfΔx), where c is in the range 0.4 to 0.7 km−1Hz−1, f is frequency and Δx is the distance between array elements. Vertical, radial, and transverse components were quite coherent over the aperture of the array, indicating that the transverse motion of the compressional wave is a property of relatively large (106 m3) volumes of rock, and not just an anomaly caused by a malfunctioning instrument, poor instrument-rock coupling, or out-crop-scale effects. The spatial coherence is approximately independent of component, epicentral azimuth and range, and whether P- or S-wave coda is being considered, at least for propagation distances between 5 and 170 km. These results imply a strongly and three-dimensionally heterogeneous crust, with near-receiver scattering in the uppermost crust controlling the coherence properties of the waves.
Rupture process of the 1987 Superstition Hills earthquake from the inversion of strong-motion data
Authors: Wald David J. , Helmberger Donald V. , Hartzell Stephen H.
Published: September 2021

A pair of significant earthquakes occurred on conjugate faults in the western Imperial Valley involving the through-going Superstition Hills fault and the Elmore Ranch cross fault. The first event was located on the Elmore Ranch fault, Ms = 6.2, and the larger event on the Superstition Hills fault, Ms = 6.6. The latter event is seen as a doublet teleseismically with the amplitudes in the ratio of 1:2 and delayed by about 8 sec. This 8-sec delay is also seen in about a dozen strong-motion records. These strong-motion records are used in a constrained least-squares inversion scheme to determine the distribution of slip on a 2-D fault. Upon closer examination, the first of the doublets was found to be itself complex requiring two episodes of slip. Thus, the rupture model was allowed to have three separate subevents, treated as separate ruptures, with independent locations and start times. The best fits were obtained when all three events initiated at the northwestern end of the fault near the intersection of the cross-fault. Their respective delays are 2.1 and 8.6 sec relative to the first subevent, and their moments are 0.4, 0.9, and 3.5 × 1025 dyne-cm, which is about half of that seen teleseismically. This slip distribution suggests multi-rupturing of a single asperity with stress drops of 60, 200, and 15 bars, respectively. The first two subevents were confined to a small area around the epicenter while the third propagated 18 km southwestward, compatible with the teleseismic and afterslip observations.
Seismic site effects and the spatial interpolation of earthquake seismograms: Results using aftershocks of the 1986 North Palm Springs, California, earthquake
Authors: Spudich Paul , Miller David P.
Published: September 2021

We address the following two questions. Can a microearthquake's ground motions be modeled by incident P and S waves that excite a site transfer-function that is a smooth function of incidence angle? Given recorded ground motions from a set of earthquakes having known locations and mechanisms, can we derive such a site transfer-function and use it to obtain the ground motions that would result from an earthquake source occurring somewhere in the same volume but having a location and mechanism that are different from the recorded events? Although many factors will cause two distinct microearthquake sources to have different seismograms at a common station, in this paper we concentrate only upon the differences caused by source mechanisms, P- and S-wave travel-time variations and by variations in the site transfer-function. We specifically exclude the effects of waves scattered from heterogeneities in the geologic structure away from the seismic site. We express the site transfer-function as a sum of several terms having simple dependences upon incidence angle and azimuth. Each term is an independent function of time. Given a set of seismograms observed at the site, we solve a linear system of equations for the time dependences of each term. These time series may be used to calculate the seismograms that would have resulted from an earthquake having arbitrary mechanism and location. This step is an interpolation. We have applied this technique to seismograms after aftershocks of the 1986 North Palm Springs earthquake. Our interpolation technique works fairly well within the volume occupied by the recorded events, but the method is not very successful at providing accurate seismograms for sources located outside the aftershock volume. The primary causes of the inaccuracy are the inadequacy of our chosen angular functions to model the site response fully and the likely scattering of seismic waves by geological heterogeneities (in this case, the Banning and Mission Creek faults) near the seismic stations. Our methods could be used to determine the effects of single scattering from lateral heterogeneities in geologic structure.
A fault model for the Nahanni earthquakes from aftershock studies
Authors: Horner R. B. , Wetmiller R. J. , Lamontagne M. , Plouffe M.
Published: September 2021

Relative locations of 323 large aftershocks (M 3.0 or greater) in the period from 5 October 1985 to 25 March 1988 show that the Ms 6.6 event on 5 October 1985 initiated at 62.208°N, 124.217°W, about 2.5 km northeast of the Ms 6.9 main shock on 23 December 1985. The overall aftershock distribution suggests the October rupture was primarily a west-dipping, low-angle thrust. In subsequent aftershock activity, the main rupture plane was marked by a distinct quiescent area of about 200 km2 that persisted until the 23 December event. Most of the stress drop and slip occurred in this area. Following the 23 December rupture, a similar sized quiescent zone was also observed; however, it was only evident during the first 24 hr of the aftershock sequence, and the area was about 50 per cent too small to yield the overall stress drop. The additional area appeared to come from secondary rupture zones that developed coincident with the main shock rupture. Precise locations of 182 small (M 3.0 or less) aftershocks recorded during a third field survey from 12 to 21 September 1986 indicated at least one and probably three high-angle faults. Composite mechanism solutions showed thrust faulting except in a region directly south of the main shock rupture areas where there is a bend in one of the secondary fault zones and a concentration of aftershock activity. Mechanism solutions calculated for five of the largest aftershocks in the same region also indicated a similar variability. Development of secondary fault zones explained the increased complexity of the December event and may also provide an explanation for the vertical peak acceleration exceeding 2 g that was recorded about 10 sec after the December rupture initiated.
Variations in broadband seismic noise at IRIS/IDA stations in the USSR with implications for event detection
Authors: Given Holly K.
Published: September 2021

Ambient noise conditions at four IRIS/IDA sites in the USSR are characterized from 0.01 to 100 Hz as part of a study to ascertain the utility of broadband three-component seismic stations in monitoring regional Eurasian seismicity. Estimates of the power spectral density of noise levels were computed for a 5-day period in two seasons (winter and summer), at two times of the day. Of these periods, lower noise conditions were found at night in the summer. In general, at 1 Hz and above, noise levels and their variations correlate predictably with the soundness of vault construction and the proximity of the station to civilization. Absolute noise levels at the IRIS/IDA/USSR sites range from a high of about −120 dB to a low of −155 dB relative to (1 m/s2)2/Hz, between 1 and 5 Hz. A time-of-day variation in noise was observed at all sites, with noise levels during the work day ranging from 7 to 14 dB higher than night levels, depending on the site. This effect was observed only for frequencies above about 1 Hz. Observed seasonal variations (winter versus summer) are highly station dependent, although the seasonal effect is restricted to frequencies below 1 Hz and is in general centered on the microseism peak (0.1 to 0.2 Hz). Below 0.1 Hz, noise levels are influenced by the thermal and barometric isolation of the site. Low-frequency levels were not studied below 0.01 Hz. Minimum detectable magnitudes are estimated for the IRIS/IDA stations using the observed noise levels over 1 Hz. In general, a magnitude 3 event should be detectable at 1,000 km by all stations under night noise conditions if the dominant signal frequency is 1 Hz; the magnitude estimates increase with increasing frequency. These detectability estimates assume a conservative signal-to-noise ratio of 6.

High-frequency data recorded by independent equipment co-located with the IRIS/IDA system during a 2-week experiment allow estimation of noise levels at the sites up to 100 Hz. Borehole versus surface noise levels recorded during the high-frequency experiment showed significant noise reduction (20 dB) can be achieved by borehole deployment at sites with exposed surface vaults. With well-isolated surface vaults, borehole noise reduction is about a factor of 2. Absolute noise levels between 1 to 10 Hz observed at IRIS/IDA/USSR sites are systematically higher than average NORESS noise by about 7 dB to 25 dB, depending on the station.
Frequency-dependent attenuation in eastern Kazakhstan and implications for seismic detection thresholds in the Soviet Union
Authors: Sereno Thomas J.
Published: September 2021

The frequency-dependent attenuation of regional seismic phases recorded by three stations near the nuclear explosion test site in eastern Kazakhstan is estimated by inverting spectra from 21 events with magnitudes between 2.3 and 4.6 at distances between 200 and 1300 km. The Pn spectra are inverted between 1 and 10 Hz, and the Lg spectra are inverted between 0.5 and 2.5 Hz. The motivation for this study is that previous estimates of detection capability in the Soviet Union are based on data recorded in other regions (eastern North America and Scandinavia) and therefore have large uncertainty. The data recently recorded in eastern Kazakhstan provide an excellent opportunity to compare regional wave propagation and noise characteristics at these sites to conditions assumed in previous detection capability simulations. It is found that attenuation in eastern Kazakhstan is not much different from attenuation in Scandinavia, but it is greater than attenuation in eastern North America. This implies that estimates of detection thresholds that assume attenuation like that observed in eastern North America will be lower than estimates of detection thresholds that assume attenuation like that observed in eastern Kazakhstan or Scandinavia. However, it is not known how well data recorded in eastern Kazakhstan represent conditions in other areas of the Soviet Union.
An automatic means to discriminate between earthquakes and quarry blasts
Authors: Hedlin Michael A. H. , Minster J. Bernard , Orcutt John A.
Published: September 2021

In this article we discuss our efforts to use the NORESS array to discriminate between regional earthquakes and ripple-fired quarry blasts (events that involve a number of subexplosions closely grouped in space and time). The method we describe is an extension of the time versus frequency “pattern-based” discriminant proposed by Hedlin et al. (1989b). At the heart of the discriminant is the observation that ripple-fired events tend to give rise to coda dominated by prominent spectral features that are independent of time and periodic in frequency. This spectral character is generally absent from the coda produced by earthquakes and “single-event” explosions. The discriminant originally proposed by Hedlin et al. (1989b) used data collected at 250 sec−1 by single sensors in the 1987 NRDC network in Kazakhstan, U.S.S.R. We have found that despite the relatively low digitization rate provide by the NORESS array (40 sec−1) we have had good success in our efforts to discriminate between earthquakes and quarry blasts by stacking all vertical array channels to improve signal-to-noise ratios.

We describe our efforts to automate the method, so that visual pattern recognition is not required, and to make it less susceptible to spurious time-independent spectral features not originating at the source. In essence, we compute a Fourier transform of the time-frequency matrix and examine the power levels representing energy that is periodic in frequency and independent of time. Since a double Fourier transform is involved, our method can be considered as an extension of “cepstral” analysis (Tribolet, 1979). We have found, however, that our approach is superior since it is cognizant of the time independence of the spectral features of interest. We use earthquakes to define what cepstral power is to be expected in the absence of ripple firing and search for events that violate this limit. The assessment of the likelihood that ripple firing occurred at the source is made automatically by the computer and is based on the extent to which the limit is violated.