bluuebunny/crossref_metadata_2025 huggingface dataset:
Novos temas para Santo Domingo: observações sobre o “Documento de Trabalho”
Authors: Antoniazzi Alberto
Published: September 2021

Acaba de ser publicado o “Documento de Trabalho” da IV Conferência Geral do Episcopado Latino-Americano, a ser realizada em outubro, em Santo Domingo. O Documento (doravante = DT) retoma muitas das contribuições das Conferências Episcopais, que o CELAM reunira em fevereiro num extenso volume chamado “Secunda Relatio”. Supera significativamente, em conteúdo e abertura pastoral, os documentos anteriores “Elementos para uma reflexão” (fevereiro de 1990) e “Documento de Consulta” (abril de 1991). Está tendo uma acolhida favorável por parte de muitos teólogos e agentes de pastoral. Em suma, parece constituir um progresso significativo rumo a Santo Domingo e reacende a esperança de que o Documento Final expresse os anseios da grande maioria das comunidades eclesiais católicas da América Latina, continuando Medellín e Puebla.

Em artigo recente (cf. Os temas de Santo Domingo, Perspectiva Teológica 24, 1992: 227-236), escrito em março p. p., tive a oportunidade de apresentar algumas reflexões sobre a “Secunda Relatio”, procurando apontar perspectivas por ela não consideradas, especialmente na análise da realidade (o ‘Ver”) e na reflexão teológica (o “julgar”). Minha intenção era indicar alguns temas que Santo Domingo deveria levar em conta, sobretudo se quisesse não simplesmente refletir o estágio atual da Igreja latino-americana, mas apontar perspectivas de futuro.

Retomo aqui algumas dessas observações, para verificar em que medida foram atendidas pelo DT ou poderiam ainda ser consideradas na reflexão que prepara a realização da Conferência e a elaboração do Documento Final.
Indagações sobre a Pastoral da Juventude no Brasil
Authors: Gasques Jerônimo
Published: September 2021

Por ocasião da Campanha da Fraternidade com o tema JUVENTUDE (1992), gostaria de levar o caro leitor a uma reflexão, em termos gerais, sobre a realidade da Pastoral da Juventude (PJ) na Igreja do Brasil. Considerarei, em igual medida, o Estudo da CNBB sobre a PJ no Brasil. Pela primeira vez na história da Igreja do Brasil, a CNBB aprovou um ESTUDO sobre a Pastoral da Juventude no Brasil. O mesmo estudo ainda não tem caráter de documento, como normalmente é convencionado chamar os documentos da CNBB. No entanto, esse Estudo nos leva às indagações que seguem, como preocupação, entusiasmo, possibilidade e desafio. Em igual medida a CF/92 trará uma sugestiva oportunidade para uma ulterior reflexão sobre a caminhada da PJ no Brasil.
Mathematical Modeling of the Problem of Locating Temporary Accommodation Centers and Assigning Victims After a Possible Earthquake to Safe Places and Solving Using Meta-Heuristic Algorithms
Authors: Mardaninejad Farideh , Nastaran Mahin
Published: September 2021

Introduction: Earthquakes, one of the most important natural disasters of the earth, have always caused irreparable damage to human settlements in short time. One of the most important issues that we face after an earthquake is the transfer of earthquake victims and traumatized civilians to safe places and medical centers. The city of Mashhad with different geographical faults and the presence of enormous religious, cultural, historical and industrial assets make Mashhad the most dangerous city in terms of earthquake hazards. In the 9th district of this city, the existence of worn-out structures along the narrow passages and the importance to save time in providing relief proves the need to locate temporary accommodation centers and allocate the injured to safe places.Material and Methods:The process of optimizing the accommodation of people includes 2 main steps 1) Determining candidate locations for temporary accommodation 2) Optimal allocation of population blocks (origin).The weight of criteria was calculated using the pairwise comparison method. Then suitable places for deployment are identified. Criterion in the form of giving a specific weight to each, in order to prepare the final map, is of importance. Accordingly, the opinions of experts in the field of urban crisis management have been utilized. Subsequently, using GAMS software and 7 super-innovative algorithms such as SA, PSO, ICA, ACO, ABC, FA, LAFA.Results:The average process time and cost of 7 algorithms out of ten random problems with 1000 repetitions, and an average of 10 execution times show, that the 3 algorithms ACO, ABC and LAFA have lower cost and process time than the other meta-innovative algorithms. Therefore, we use the above three algorithms to solve the case studyConclusion: Finally, the LAFA optimization algorithm had obtained a better and more appropriate result due to its execution time and cost being less than the other two algorithms.
Performance Analysis of Data Mining Techniques for the Prediction Breast Cancer Risk on Big Data
Authors: Sohrabei Solmaz , Atashi Alireza
Published: September 2021

Introduction: Early detection breast cancer Causes it most curable cancer in among other types of cancer, early detection and accurate examination for breast cancer ensures an extended survival rate of the patients. Risk factors are an important parameter in breast cancer has an important effect on breast cancer. Data mining techniques have a growing reputation in the medical field because of high predictive capability and useful classification. These methods can help practitioners to develop tools that allow detecting the early stages of breast cancer.Material and Methods: The database used in this paper is provided by Motamed Cancer Institute, ACECR Tehran, Iran. It contains of 7834 records of breast cancer patients clinical and risk factors data. There were 4008 patients (52.4%) with breast cancers (malignant) and the remaining 3617 patients (47.6%) without breast cancers (benign). Support vector machine, multi-layer perceptron, decision tree, K nearest neighbor, random forest, naïve Bayesian models were developed using 20 fields (risk factor) of the database because database feature was restrictions. Used 10-fold crossover for models evaluate. Ultimately, the comparison of the models was made based on sensitivity, specificity and accuracy indicators.Results: Naïve Bayesian and artificial neural network are better models for the prediction of breast cancer risks. Naïve Bayesian had accuracy of 93%, specificity of 93.32%, sensitivity of 95056%, ROC of 0.95 and artificial neural network had accuracy of 93.23%, specificity of 91.98%, sensitivity of 92.69%, and ROC of 0.8.Conclusion: Strangely the different artificial intelligent calculations utilized in this examination yielded close precision subsequently these techniques could be utilized as option prescient instruments in the bosom malignancy risk considers. The significant prognostic components affecting risk pace of bosom disease distinguished in this investigation, which were approved by risk, are helpful and could be converted into choice help devices in the clinical area.
The Role of Information Dashboards as a Business Intelligence Tool for Managing the Corona Virus Pandemic
Authors: Farrahi Razieh , Nabovati Ehsan , Ebnehoseini Zahra
Published: September 2021

Information dashboards were one of the best ways to manage Covid disease. The concept of information dashboards and their important benefits are explained in the present study.
Risk assessment of a solar attack according to ISO 31000 standard
Authors: Lavrnić Igor , Bašić Ana , Viduka Dejan
Published: September 2021

Energy supply remains the greatest challenge for many of Eastern European countries and their economy. In post-soviet and ex-Yugoslavian countries, till today there exists a system where some of the power plants rely on high voltage (HV) and medium voltage (MV) power grids in the process of distribution of electric energy (EE) to final consumers. This makes them vulnerable to solar storms due to HV power transformers which are especially sensitive to geomagnetic induced current (GIC). The acquisition of electrical power infrastructure could put the electrical infrastructure out of service from a couple of months to a year or more. Loss of income, for ordinary families, is a primary hazard of a long power outage. Business continuity of industry and other critical infrastructures (CI) is important in this scenario, but it is a significant challenge for small businesses and enterprises as well. This paper introduces ISO 31000 standard to such scenarios with the primary goal of achieving resilience of companies against such disaster as a new method of vial response to avoid scope of similar hazards.
“Oeconomicus” of Xenophon: Its Significance for Modern Economic Science
Authors:   Institute of Economics of the Ural Branch of RAS, Bochko V. S.
Published: September 2021

The article analyzes Xenophon’s ‘Oeconomicus’, where he traced the emergence of economic science. In his work, Xenophon offers a broader understanding of the subject field of economics, including the ethical aspect. The article argues that it was in fact Xenophon rather than Aristotle who was the first economic theorist. Xenophon’s idea about the ethical foundations of economics was developed during the Renaissance and in the age of Enlightenment. Thus, economics went beyond the science of household management to the science about the quality of life and its enhancement. By looking at the origins of economic science (theory) and connecting them to the modern agenda we can ensure the methodological completeness of approaches to including ethics into economic theorizing. The article makes a special focus on strategic planning, which is one of the ways of combining ethics and economic practice.
Long Covid/Post-Acute-Covid Syndrome as a ‘hybrid condition’ - A common framework for patients’ experience and pathophysiology
Authors: Richter Dirk , Theodoridou Anastasia
Published: September 2021

While hundreds of thousands of patients suffer from Long Covid/Post-Acute Covid-Syndrome, the condition still remains a medical conundrum. Patients’ experiences and symptoms cannot always be linked to a pathophysiological mechanism. We present a hypothesis that depicts Long Covid as a hybrid condition, which means that pathophysiology and patients’ experience are partly due to different causal pathways. On the background of neuroscience and philosophy of science research, we propose to consider the infection per se as an ‘indifferent kind’ and patients’ experiences as an ‘interactive kind’. Interactive kinds represent the interactions between the human brain, psychological experiences and sociocultural factors. This approach allows the integration of the subjective experience of Long Covid patients and the pathophysiology into a common framework. Practically, this framework may help to prevent sufferers from experiencing a devaluation of their perspective. Long Covid/Post-Acute Covid Syndrome is a real medical condition and affected patients are truly sick.
Shallow soil effects for contrasting PGAs at nearby strong-motion stations during the 2017, Mj 5.2, southern Akita Prefecture earthquake
Authors: P. Dhakal Yadab , Suzuki Wataru , Kimura Takeshi , Kunugi Takashi , Aoi Shin
Published: September 2021

On September 8, 2017, an earthquake of Mj 5.2 occurred with the epicenter in southern Akita Prefecture, Japan, at 22:23 local time. According to the Japan Meteorological Agency (JMA), the focal depth was 9 km. Many strong-motion stations of K-NET and KiK-net recorded ground motions from the earthquake. The maximum horizontal vector peak ground acceleration (PGA) of approximately 136 cm/s2 was recorded at one of the KiK-net stations at an epicentral distance of about 8 km. However, despite being 37 km and 53 km far from the epicenter, two stations recorded PGAs of approximately 126 and 113 cm/s2, respectively, similar to that near the epicenter. Even though these PGAs are not rare, we found that the PGAs at the two sites strongly deviated from the median values suggested by a ground motion prediction equation (GMPE), while the nearby sites generally followed the GMPE. Available velocity models showed that shallow shear wave velocities, especially in the top 5 m, were lower (i.e., the soils were softer) at the two sites compared to those at their nearest neighboring sites. We compared the ratios of the PGAs and peak ground velocities (PGVs) at the two sites with respect to their neighboring sites for many earthquakes covering a wide range of magnitudes and azimuths. We found that the PGAs and PGVs at the two sites were systematically larger than those at the adjacent sites. Linear theoretical site amplifications using the available soil models gave peak frequencies around 6-8 Hz at the larger PGA sites. Bandpass-filtered records showed significantly larger PGAs around these frequencies at the larger PGA sites. The above results showed that local site condition is one of the major contributing factors to induce large PGAs. Furthermore, softer sites experience more substantial nonlinear site amplification than the stiffer sites when input motions exceed some threshold PGAs. This latter effect means that the softer sites can produce a variety of ground motion spectra. Nevertheless, the degree of damage to built structures depends on several factors, including the design and quality of construction. We expect that this study contributes to developing improved microzonation maps for earthquake disaster mitigation.
Hydro-torrential hazard vs. anthropogenic activities along the Seti valley, Kaski, Nepal: Assessment and recommendations from a risk perspective
Authors: Gurung Narayan , Fort Monique , Bell Rainer , Arnaud-Fassetta Gilles , Maharjan Narayan Raj
Published: September 2021

The Seti River originates from the Annapurna Massif in the Higher Himalaya of Nepal and flows through the Pokhara valley in the Lesser Himalaya. The Seti River witnessed a disastrous flash flood on May 5th, 2012 causing the death of 72 people, obliterating dozens of homes and damaging infrastructures worth millions of dollars. Despite the 2012 flood event and several warnings by scientists for more yet bigger scale future floods in the Seti valley, fluvial risk is being aggravated by anthropogenic activities such as unplanned human settlement, encroachment of riverbanks, haphazard construction of road, drinking water, and hydropower projects in potential flood hazard areas in addition to the increased impacts of climate change on geological and hydro-metrological hazards as in other parts of Hindu Kush Himalayan Range. Covering some 40-km distance from the Seti headwater (Sabche Cirque) down to Pokhara city, the study is carried out based on hydro-geomorphological mapping, analysis of land-use and land-cover change, hydrological analysis including HEC-RAS modelling, historical archives, and interviews with local people. The study shows a significant change on the land use and land cover of the Seti catchment, mainly the urban/built-up area, which is increased by 405% in 24 years period (1996 to 2020) and by 47% in 7 years period (2013 to 2020). Further the study reveals that anthropogenic activities along the Seti valley have increased fluvial risk and are likely to invite more disasters. From the HEC-RAS analysis, two motor bridges built over Seti River were found to have insufficient freeboard to safely pass the highest flood discharge for 100 years return-period. Instead of relocating people to safer places, the government and local authorities rather seem to have encouraged people to live in the floodplain by providing basic amenities such as drinking water, electricity and access road. Given the context of climate change and Pokhara valley and the Seti catchment being in a high-seismic gap zone, there is a strong possibility of similar flood to the scale of 2012 or even greater in Seti River. Though the fluvial risk can be managed in a sustainable way through the application of functional space concept, i.e., by allowing more space (freedom) for rivers, this economic and environment friendly approach of the fluvial risk management has not been implemented yet in the Seti valley nor in Nepal. Rather the encroachment of floodplains by anthropogenic activities along the Seti valley is on an increasing trend. Many settlements and infrastructures along the valley have been identified vulnerable to hydro-torrential hazards, therefore it is utmost necessity to implement functional space river concept, land use and land plan policy, early warning system and public awareness education in order to mitigate and manage the future impact of fluvial hazards along the Seti valley.
“The Advent of Civilization Amongst Them Will Not Tend to Their Betterment”: Understanding Representations of Colonial Contact in the Kitikmeot
Authors: McLean Scott
Published: September 2021

Between 1915 and 1920, members of the Royal Northwest Mounted Police (RNWMP) wrote four major narratives of making contact with Inuit living in territory now known as the Kitikmeot region of Nunavut. The authors were the first representatives of the Canadian state to enter the region, and their narratives positioned Inuit as “better off without civilization.” Various members of the Royal Canadian Mounted Police (RCMP) stationed in the region over the subsequent three decades reproduced such discourse. While, at first glance, this discourse seems to attribute a nobility to traditional ways of life, upon closer inspection it actually positions Inuit as incapable of adapting successfully to changing socio-economic circumstances. Methodologically, this article critically reinterprets archival documents from the early agents of colonization in the Kitikmeot. While advancing historical scholarship concerning relations between Inuit and the Canadian state, the article contributes to contemporary agendas of decolonization and reconciliation by enabling a more complete understanding of the origins and nature of colonial rule in the Arctic. By arguing that colonial discourses have roots in local and specific relations of production, the article also contributes to postcolonial theories of efforts to legitimize colonization and represent colonized Others in essentialist and paternalistic terms.
“Merely to See and Touch It”: On Service, McCrae, and Literary Tourism in Canada
Authors: Zacharias Robert
Published: September 2021

Long dismissed as a “critical error” ( Booth 2016 ) and still capable of inciting “embarrassment palpable” ( Watson 2006 ) among scholars otherwise happy to emphasize the material contexts that inform the circulation of texts, literary tourism has recently become the focus of serious academic inquiry. Recent work has begun to disaggregate the various forms of literary tourist sites ( Fawcett and Cormack 2001 ), but continues to have a methodological gap surrounding the specifically literary aspects of the practice itself, and—with the notable exception of Green Gables (Squire 1992; Devereux 2001 )—has left Canada predictably unexamined. This essay begins with a brief introduction to literary tourism in Canada before moving into a comparative analysis of two National Historic Sites associated with Canadian literary authors: the Robert Service cabin in Dawson City, Yukon, and the John McCrae House in Guelph, Ontario. The sites offer a compelling comparison as the former homes of two of the best-known Canadian poets of the early twentieth century whose works have become popularly synonymous with two of Canada’s most heavily mythologized eras. The enduring popularity of poems like “The Cremation of Sam McGee” reflect not only Service’s central role in mythologizing Canada’s north but also a strategic “cultural commoditization” of the area’s gold rush heritage ( Jarvenpa 1994 ; Grace 2001 ), while McCrae’s “In Flanders Fields” retains its status not only as the “most popular poem” of the First World War in Canada and beyond ( Fussell 2000 ), but also as a primary example of the ideological function of Great War literature within Canada ( Holmes 2005 ; Gordon 2014 ). Although the two author houses may initially appear a study in contrasts, I draw on recent work in literary tourist studies to argue they are linked in their function as “materialized fictions” ( Hendrix 2008 ), or concrete interpretative frames that aim to offer tangible evidence of the Canadian myths their former inhabitants helped to fashion.
Laparoscopic Treatment of Annular Pancreas Causing Duodenal Obstruction in an Adult: A Case Report
Authors: Laohawiriyakamol Suphawat , Wangkulangkul Piyanun , Wanitsuwan Worrawit , Cheewatanakornkul Siripong , Laohawiriyakamol Teeranan , Kanjanapradit Kanet
Published: September 2021

Annular pancreas is a rare congenital anomaly characterized by the presence of a pancreatic tissue of variable amount which completely or partially obstructs the second part of duodenum. It usually affects infancy, but in adulthood it can mimic a wide range of clinical entity. Gastrojejunostomy or duodenojejunostomy are common operations in adults because the duodenum is less mobile. We report a case of annular pancreas in a 60-year-old male that presented with clinical condition of gastric outlet obstruction and was successfully treated with a laparoscopic Roux-en-Y gastrojejunostomy.
A new species of Cryptopleurum Mulsant, 1844 from China (Coleoptera: Hydrophilidae)
Authors: Ryndevich S.K.
Published: September 2021

A new species of the Hydrophilidae subfamily Sphaeridiinae, Cryptopleurum sichuanicum sp. n., is described from China.
Internetowy hejt wobec chorych oraz pracowników służby zdrowia w czasach pandemii wirusa SARS-CoV-2 w Polsce
Authors: Dąbrowska Ilona Anna
Published: September 2021

Przedmiotem rozważań w niniejszym artykule jest kwestia publikowania na polskich stronach internetowych treści (komentarzy) hejterskich wobec osób dotkniętych wirusem SARS-CoV-2, a także pracowników służby zdrowia – lekarzy, pielęgniarek, ratowników medycznych. W publikacji dokonuję analizy zawartości wybranych serwisów informacyjnych, w których na przestrzeni kilku pierwszych miesięcy walki z epidemią publikowano artykuły dotyczące osób chorych bądź pracowników służby zdrowia. Refleksje na temat omawianego zagadnienia wzbogacone zostały o konkretne przykłady – przypadki wyjątkowo brutalnych i okrutnych w skutkach e-ataków. Artykuł stanowi próbę odpowiedzi na pytanie o skalę hejtu, poziom brutalności opublikowanych w wybranych serwisach informacyjnych komentarzy, a także możliwości obrony przed mową nienawiści oraz zachowaniami hejterskimi w polskiej cybersferze. Istotnym aspektem jest pytanie o podejście systemowe – możliwości rozwiązań, które skutecznie zniechęciły lub wręcz uniemożliwiłyby stosowanie mowy nienawiści w sieci. Publikacja akcentuje zagrożenia związane z rozprzestrzenianiem się agresywnych komentarzy, a także weryfikuje funkcjonujące obecnie rozwiązania, mające na celu minimalizowanie hejtu online.
Komunikacja naukowa w oczach polskich młodych naukowców w świetle międzynarodowych badań ankietowych z 2019 roku
Authors: Świgoń Marzena , Nicholas David
Published: September 2021

W artykule omówiono wyniki międzynarodowych badań nad komunikacją naukową prowadzonych w 2019 roku wśród naukowców na wczesnym etapie kariery. Szczególną uwagę poświęcono polskim respondentom, na co zabrakło miejsca w zbiorczych artykułach wieńczących międzynarodowy projekt Harbingers i opublikowanych w zagranicznych czasopismach. Polscy badacze z pokolenia millenialsów, podobnie do ich zagranicznych rówieśników z Francji, Hiszpanii, Wielkiej Brytanii, Stanów Zjednoczonych, Malezji, Chin i Rosji, posiadają potencjał do zmiany komunikacji naukowej, głównie poprzez szerokie wykorzystywanie mediów społecznościowych oraz zaangażowanie w ruch otwartego dostępu i otwartej nauki. Znacznie ograniczające są jednakże czynniki systemowe, zarówno w Polsce, jak i w innych krajach.
Women’s Work and Men
Authors: Jarska Natalia
Published: September 2021

Through the use of selected contemporary sociological research and prolific collections of largely unpublished memoirs, this article analyzes men’s attitudes toward the paid employment of women—particularly married women—in post-Stalinist Poland. The personal narratives reveal an increasing acceptance of women’s work outside the household over time and across generations. A significant shift in Polish men’s attitudes to a greater acceptance of women’s paid employment took place in the younger generation, born in the 1930s and 1940s and socialized after World War II. However, hostile attitudes of working-class men toward working women persisted, based on a continuing aspiration to uphold the male breadwinner family model.
Introduction
Authors: Cohen Mathilde , Mazouz Sarah
Published: September 2021

France is an overwhelmingly majority-White nation. Yet the French majority is reluctant to identify as White, and French social science has tended to eschew Whiteness as an object of inquiry. Inspired by critical race theory and critical Whiteness studies, this interdisciplinary special issue offers a new look at White identities in France. It does so not to recenter Whiteness by giving it prominence, but to expose and critique White dominance. This introduction examines the global and local dimensions of Whiteness, before identifying three salient dimensions of its French version: the ideology of the race-blind universalist republic; the past and present practice of French colonialism, slavery, and rule across overseas territories; and the racialization of people of Muslim or North African backgrounds as non-White.
Laos and China's Belt and Road Initiative – Gains and Losses
Authors:   IMEMO RAS, Russia, Moscow, Rogozhina Natalia G.
Published: September 2021

The article analyzes the consequences of Laos' participation in the Chinese Belt and Road Initiative. The benefits acquired and possible losses are assessed. The construction of a railway in Laos, linking it to China, is the most successful Belt and Road project in Southeast Asia, which has a special place in China's strategic plans. The railway construction project is of great economic importance for Laos and in the future can stimulate its economic growth. At the same time, there is a risk of falling into debt dependence on China. The ability of Laos to meet its debt obligations will depend on the profitability of the project, which, however, raises many questions, since the project is more focused on the short-term interests of China than on the long-term interests of Laos. Whether Laos will be able to economically benefit from the construction of the railway remains questionable. But there is no doubt that China will benefit. China will not only strengthen economic presence in this country, relying on the support of the local elite, but also use Laos as a springboard to move deeper into Southeast Asia.
Reduction of Gain and Time Constant of Vestibulo-Ocular Reflex in Man Induced by Diazepam and Thiopental
Authors: Padoan Serge , Korttila Kari , Magnusson Mans , Pyykkö Ilmari , Schalén Lucyna
Published: September 2021

The effect of intravenous administration of two sedatives, diazepam (0.3 mg/kg) and thiopental (6.0 mg/kg), on the vestibulo-ocular reflex (VOR) in man was investigated on 9 volunteers. The VOR was evoked with a velocity step rotation test and gain and time constant of perrotatory and postrotatory nystagmus were measured. Both drugs reduced VOR gain. Diazepam-induced reduction lasted 8 h and thiopental-induced reduction 1 h. A reduction of the VOR time constant was found lasting about 1 h for both drugs, but with a tendency for the thiopental effect to last longer. These findings, not previously described in man, differ from what has been found in macaques and rabbits injected with diazepam. The reduction of gain and time constant were not correlated with the blood concentration of either drug.

The present results suggest that in man the VOR gain and time constant are both reduced by different types of sedatives although with different time courses. On the basis of previously shown effect of alertness on the VOR, it is hypothesized that diazepam and thiopental, besides having a specific effect on central nervous system structures important to the VOR, also induce reduction of the VOR through a general sedation of the CNS.
A Multidimensional Model of the Effect of Gravity on the Spatial Orientation of the Monkey
Authors: Merfeld Daniel M. , Young Laurence R. , Oman Charles M. , Shelhamert Mark J.
Published: September 2021

A “sensory conflict” model of spatial orientation was developed. This mathematical model was based on concepts derived from observer theory, optimal observer theory, and the mathematical properties of coordinate rotations. The primary hypothesis is that the central nervous system of the squirrel monkey incorporates information about body dynamics and sensory dynamics to develop an internal model. The output of this central model (expected sensory afference) is compared to the actual sensory afference, with the difference defined as “sensory conflict”. The sensory conflict information is, in turn, used to drive central estimates of angular velocity (“velocity storage”), gravity (“gravity storage”), and linear acceleration (“acceleration storage”) toward more accurate values. The model successfully predicts “velocity storage” during rotation about an earth-vertical axis. The model also successfully predicts that the time constant of the horizontal vestibulo-ocular reflex is reduced and that the axis of eye rotation shifts toward alignment with gravity following postrotatory tilt. Finally, the model predicts the bias modulation, and decay components that have been observed during off-vertical axis rotations (OVAR).
Rhythmical eye-head-torso rotation alters fore-aft head stabilization during treadmill locomotion in humans*
Authors: Paquet Nicole , Watt Douglas G.D. , Lefebvre Luc
Published: September 2021

A repetitive manoeuvre called torso rotation (TR) is known to temporarily reduce the gain of the horizontal vestibulo-ocular reflex by 10–15% consists of a series of rhythmical rotations of the eyes, head and upper body executed continuously for 30 minutes while standing. Our aim was to investigate whether TR affects the ability to hold the head in a fixed fore-aft position relative to space while walking on a treadmill with eyes closed. Ten healthy subjects stood in a carefully standardized position on a stationary treadmill. The treadmill started unexpectedly and ran for 4 s at 29 cm/s. The test stimulus was a linear acceleration in the fore-aft direction at the moment of treadmill start-up. Linear head position (i.e., ability to stabilize the head) was measured during and following the stimulus. A mechanical system prevented head rotation. Two series of 60 trials were performed before TR (control 1 and control 2 series) and one after TR. Before TR, subjects drifted rearward at an average drift velocity ± S.D. = 3.1 ± 0.9 cm / s. This drift was reasonably stable over time within and between the two control series. After TR, head holding ability was further impaired, with subjects having more difficulty to stabilize their head after treadmill start-up. In the first 10 trials after the arrest of TR, the average drift velocity was significantly larger than before TR ( 6.1 ± 1.5 cm / sec, p < 0.01). Recovery to control values followed a roughly exponential time course, with 67% impairs the ability to sense and/or respond to fore-aft linear accelerations of the head following treadmill start-up in the absence of vision.
The influence of light on modulation of the human vestibulo-ocular reflex
Authors: Das Vallabh E. , Yaniglos Stacy , Leigh R. John
Published: September 2021

The goal of this study was to investigate the influence of light, without retinal slip information, on the ability to generate eye movements to compensate for head rotations. Subjects were rotated sinusoidally at 1.0, 2.0 or 3.0 Hz at a peak velocity of 30 deg/sec while they: 1) performed mental arithmetic in darkness; 2) attempted to view the remembered location of a stationary target in darkness; 3) attempted to view the remembered location of the stationary target through translucent contact lenses that allowed the passage of light but did not provide any target information (ganzfeld stimulus); 4) directly viewed the illuminated stationary target. The gain of compensatory eye movements was least while subjects viewed through the translucent contact lenses (median = 0.76), intermediate while subjects either performed mental arithmetic in darkness (median = 0.84) or attempted to view the remembered location of the target in darkness (median = 0.84), and greatest if they actually viewed the target (median = 0.95). Our findings suggest that factors other than light alone account for the increased gain of compensatory eye movements that occurs when subjects view rather than imagine a stationary target.
Otolith dysfunction in skew deviation after brain stem lesions
Authors: Tilikete C. , Ventre-Dominey J. , Denise P. , Nighoghossian N. , Vighetto A.
Published: September 2021

We investigated the horizontal and the vertical otolith-ocular reflex induced by off-vertical-axis rotation and subjective visual vertical in 14 patients with skew deviation due to brain stem lesion. Patients were divided into two groups: the group C ([Formula: see text]) with caudal brain stem lesions and the group R ([Formula: see text]) with rostral brain stem lesions as defined by the midpons level. The patient group was compared to a control group of 20 healthy subjects. The otolith-ocular reflex was evoked by constant velocity rotation in yaw plane around an axis tilted at 15 deg with respect to gravity. In group C, the horizontal off-vertical-axis nystagmus bias was negative i.e. anticompensatory to chair rotation, when directed toward the lesioned side. Furthermore, patients of group C were presenting with a significant tilt of subjective visual vertical. In group R, a vertical downward offset was induced predominantly in the hypotropic eye and in the direction of rotation away from the lesion. Finally, in patients of group R, horizontal and vertical modulation was increased for rotation away from the lesion.

These results are discussed in terms of 1) asymmetrical horizontal and vertical dynamic otolith signals feeding the velocity storage network after brain stem lesion, 2) possible involvement of cerebellar function in OVAN modulation.
The role of ocular oscillations upon visually dependent postural stabilization in patients affected by congenital nystagmus
Authors: Savino Gustavo , Dickmann Anna , Ottaviani Fabrizio , Di Nardo Walter , Scullica Luigi , Di Girolamo Stefano
Published: September 2021

Visually dependent postural stabilization decreases as a consequence of a long-standing reduction of visual cues in patients affected by congenital nystagmus. The aim of the present study was to verify whether the changes in postural control in this group of patients are due to ocular oscillations or to reduced visual acuity. Therefore, postural control was evaluated when the nystagmus was blocked by the blocking position or by prisms and compared with the postural score observed in a group of normal controls whose visual acuity had been artificially reduced to the same level as that of the patients using Bangerter's filters. The results show a statistically significant improvement of visually dependent postural stabilization when ocular oscillations are inhibited either by the gaze blocking position or by prisms. They also show that postural control in normal subjects with Bangerter's filters is reduced, but is still significantly better than that observed when ocular oscillations are inhibited in patients affected by congenital nystagmus. Our data strongly support the role of ocular oscillations in visually dependent postural control, since postural impairment recovered under any condition in which ocular oscillations were abolished, despite differences in visual acuity. Our data also show that reduced visual acuity decreases visually dependent postural control to a lesser degree than ocular oscillations. This could be due to the fact that ocular oscillations are a disturbing input, usually inhibited centrally, in order to avoid oscillopsia. This mechanism is probably responsible for the reduced role of visual cues in the postural control in this group of patients. The reduction of visual acuity, by comparison, merely causes a decrease in visual cues, depending on the degree of visual loss. It can be concluded that the impaired postural control in patients affected by congenital nystagmus is mainly due to ocular oscillations, with reduced visual acuity creating a secondary effect.
Idiothetic orientation and path integration in unilateral hippocampal atrophy and sclerosis
Authors: Wiest Gerald , Müller Christian , Glück Judith , Deecke Lüder , Baumgartner Christoph
Published: September 2021

We determined the effects of hippocampal lesions on idiothetic spatial orientation by exposing 14 patients with unilateral hippocampal atrophy and/or sclerosis (HAS) and 10 normal controls to random rotational displacements ( ± 30 ∘ – 180 ∘ ) in darkness and examined their ability to rotate themselves back to the initial position. In comparison to controls, the patients responses were distinctly hypometric ( p < 0.005). Patients with right hippocampal lesions showed a trend towards higher come back errors ( p = 0.08). Normal controls could maintain their accuracy over five consecutive trials. Patients, beginning with less accuracy, showed significant improvement after each trial ( p < 0.001). The findings suggest that unilateral HAS impair the immediate recall of idiothetic spatial information, but does not affect long-term spatial learning.
Finite element modeling of the 3D otolith structure
Authors: Kondrachuk Alexander V.
Published: September 2021

A 3D finite element model (FEM) of the mammalian utricular otolith corresponding to spatial structure, shape and size of the otolith from the guinea pig was developed. The otolithic membrane (OM) was considered as consisting of gel and otoconial layers. The macular surface was approximated as a plane. The deformation of the OM under static loads such as gravity and the change of endolymphatic pressure was analyzed using the FEM for different mechanical parameters of the OM and for different gravity vector orientations. The analytical dependence of OM displacements caused by the acceleration parallel to the macular plane was obtained. By comparison of the results of calculations with the known experimental data Young’s modulus of the gel layer was estimated to be of order of 10 N/m 2 . It was shown that static loads result in 3D local otolith displacements inhomogeneously distributed along the macular surface and across otolith thickness. Their distribution depends on the geometrical and mechanical parameters of the otolith components. The influences of the finite size of the OM, the Young’s modulus, Poisson’s ratio and thickness of the gel layer on the local displacements distribution of the OM were analyzed. The results of simulation suggest that: a) the Young’s modulus of the thin lowest part of the gel layer adjacent to the macular surface is much smaller than that of the rest of the OM; b) the structure of the border is designed to reduce the spatial inhomogeneity of the gel layer displacement; c) a change of the endolymphatic pressure may result in significant deformation of the OM.
Models of the dynamics of otolithic membrane and hair cell bundle mechanics*
Authors: Kondrachuk Alexander V.
Published: September 2021

Dynamic behavior of an otolithic membrane (OM) was studied analytically using simplified homogeneous viscoelastic (Kelvin-Voight body) model of the OM. The OM was represented by a thin plate attached to a macular plane. Viscoelastic properties of the OM determine the specific times ( T 1 and T 2 ) and frequency-dependent behavior of the local displacements of the membrane caused by the inertial time-dependent forces. Two kinds of an otolith stimulation were analyzed: step-function and harmonic accelerations of the membrane. Results of the modeling were compared with the known experimental data to estimate the Young’s modulus E and viscosity μ of a gel layer: E is of order of 10 N/m 2 , μ is of order of 1 poise in the range of frequency 0.2–2 Hz. It has allowed us to estimate the values of T 1 ( 10 − 5 – 10 − 6 sec) and T 2 ( ∼ 3 · 10 − 2 sec). A relationship of the motion equation of the OM with well-known overdamped pendulum model of the otolith was discussed. The model of stereocilia tip-links deformation in the case, when the HCBs passively follow gel deformation, was proposed and analyzed. It was shown that for slender and long HCBs with the lengths comparable to a thickness of effective gel layer, a relative deformation of the tip-links of stereocilia caused by OM acceleration depends on time and the distance from the macular plane. The results of the modeling suggest that this type of the HCB may be responsible for analysis of fine temporal (frequency) structure of the OM acceleration.
Effect of aging on the otolith-ocular reflex
Authors: Furman Joseph M. , Redfern Mark S.
Published: September 2021

We assessed the influence of age on the otolith-ocular reflex and semicircular canal-otolith interaction. Healthy young (n=30) and healthy older (n=60) subjects were rotated about an earth vertical axis, and about a 30 degree off-vertical axis. Eye movements during and following rotation were recorded using electro-oculography. Results indicated that there were statistically significant changes in the otolith-ocular reflex and semicircular canal-otolith interaction as a function of age. The modulation component during off-vertical axis rotation (OVAR) was greater in the older group compard to the young adults, whereas the bias component was smaller with advanced age. The foreshortening of the vestibulo-ocular reflex time constant induced by post-rotatory head tilt following cessation of rotation was less prominent in the older group. There were no consistent changes in the semicircular canal-ocular reflex. Overall, response parameters showed more variability in the older subjects. We conclude that age related changes in the otolith-ocular reflex and semicircular canal-otolith interaction are a result primarily of a degradation of central vestibular processing of otolith signals rather than a decline of peripheral vestibular function.
Multivariate vestibular testing: Thresholds for bilateral Ménière's disease and aminoglycoside ototoxicity
Authors: Dimitri P.S. , Wall C. , Rauch S.D.
Published: September 2021

Although patient symptoms and an audiogram can typically identify the affected ear or ears in Ménière's disease, there are some cases where this differentiation is problematic. This paper concentrates on the sole use of vestibular test data to discriminate between unilateral and bilateral Ménière's disease. Patients that were known to have peripheral unilateral vestibular hypofunction (n = 104) were used as learning groups to define a region in multidimensional measurement space consisting of four vestibular test scores which summarized data from electronystagmography, sinusoidal harmonic acceleration, and computerized dynamic posturography tests. A multivariate boundary was created from the unilateral learning group that determined thresholds for identifying bilateral vestibular hypofunction. Patients with bilateral Ménière's disease (n = 23) and with bilateral ototoxicity (n = 19) were then used as test subjects to determine the sensitivity of the multivariate boundary. Results showed up to a increase in estimated test sensitivity (specificity = 95%) bilateral vestibular hypofunction.
Spatial orientation of postrotatory nystagmus during static roll tilt in cats
Authors: Yasuda Keiko , Fushiki Hiroaki , Wada Rinnosuke , Watanabe Yukio
Published: September 2021

While the stimulation of otolith inputs reduces the duration of postrotatory nystagmus (PRN), there is still room for dialogue about the effect of static tilt on the orientation of PRN. We studied one possible influence of static roll tilt on the spatial orientation of PRN in cats. The animal was rotated about an earth-vertical axis (EVA) at a constant velocity of 100 deg/s with an acceleration and deceleration of 120 deg / s 2 . Within two seconds after stopping EVA rotation, the animal was passively tilted at 45 deg/s about its longitudinal axis by as much as ± 90 deg in steps of 15 deg. Eye movements were measured with magnetic search coils. The angle of the PRN plane and its slow phase eye velocity were measured. The time constant of PRN decreased with an increase in roll tilt. The PRN plane remained earth horizontal within a range of ± 30 deg roll tilt. Beyond this range, the velocity of PRN decreased too rapidly to measure any change in orientation. Our results indicate a spatially limited and temporally short interaction of the semicircular canal and otolith signals in the velocity storage mechanism of cat PRN. Our data, along with previous studies, suggest that different species show different solutions to the problem of the imbalance and spatial disorientation during contradictory stimuli.
Modeling head tracking of visual targets
Authors: Chen K.J. , Keshner E.A. , Peterson B.W. , Hain T.C.
Published: September 2021

Control of the head involves somatosensory, vestibular, and visual feedback. The dynamics of these three feedback systems must be identified in order to gain a greater understanding of the head control system. We have completed one step in the development of a head control model by identifying the dynamics of the visual feedback system. A mathematical model of human head tracking of visual targets in the horizontal plane was fit to experimental data from seven subjects performing a visual head tracking task. The model incorporates components based on the underlying physiology of the head control system. Using optimization methods, we were able to identify neural processing delay, visual control gain, and neck viscosity parameters in each experimental subject.
Remodeling of synaptic connections in the deafferented vestibular nuclear complex
Authors: Li Hongyan , Dokas Linda A. , Godfrey Donald A. , Rubin Allan M.
Published: September 2021

To determine if synaptic remodeling in the vestibular nuclear complex (VNC) may be involved in vestibular compensation, expressions of growth-associated protein-43 (GAP-43) and synaptosome-associated protein of 25~kDa (SNAP-25) were examined by immunoblotting and immunocytochemistry after unilateral vestibular ganglionectomy (UVG) in rats. GAP-43 expression increased bilaterally in the VNC after UVG, but more rapidly on the lesioned side, and remained high through 60 days. It was mainly associated with boutons at all survival times but was also present in some axonal processes and, at 7 days after UVG, in some somata. SNAP-25 expression also increased bilaterally, more rapidly on the lesioned side, but decreased bilaterally after peaking at 14 days. Its distribution in the VNC resembled that of GAP-43 but was more completely localized to boutons. Comparisons were made with auditory centers of the same rats, since the lesion also deafferented that system. Our results combined with those of previous studies suggest that degeneration of the vestibular nerve fibers is required for increased expression of GAP-43 in the VNC. The results suggest that axonal sprouting and synaptogenesis are involved in synaptic remodeling bilaterally in the rat VNC after UVG.