Configuración Territorial de la pesca comercial ribereña en la Reserva de la Biosfera Los Petenes, Estado de Campeche (México)

Small-scale fishing is a significant activity from a socioeconomic, environmental and alimentary perspective; and is considered in the goal number 14 of the Agenda 2030 for Sustainable Development. In this global context, it is relevant to reveal its territorial traits in natural protected areas, which participate in international trade, as in the case of the Los Petenes Biosphere Reserve (282,858 ha). In order to reach this objective, the following aspects are recognized: infrastructure, the organization of the fishermen, the use of the resources and the commercial flows. The investigation, which uses both qualitative and quantitative data, is substantiated by the theory on the spatial organization of the economy. The results show a sector with good access to national and international commercialization channels, but with multiple territorial imbalances.La pesca a pequeña escala tiene una significativa perspectiva socioeconómica, ambiental y alimentaria; está conside­rada en la meta número 14 de la Agenda 2030 de Desarrollo Sostenible. En este marco global, resulta pertinente develar los rasgos territoriales de mencionada actividad en áreas protegidas que participan en el comercio internacional: tal es el caso de la Reserva de la Biosfera Los Petenes (282.858 ha). Para alcanzar dicho objetivo se reconocen: las infraestructuras, la organización de los pescadores, la explotación de los recursos y los flujos comerciales. La teoría de la Organización Espacial de la Economía funda­menta esta investigación que utiliza datos cuantitativos y cualitativos. Los resultados muestran un sector con buen acceso a los canales de comercialización nacional e internacional, pero con múltiples desajustes territoriales

RADIONUCLIDE EVALUATION OF CONTRACTILITY OF THE RIGHT HEART IN MITRAL VALVE STENOSIS

Aim. With the use of radionuclide weight-adjusted tomoventriculography (RTVG), to assess the condition of the right heart chambers in mitral valve stenosis (MV) of rheumatic origin.Material and methods. Totally, 20 patients studied (mean age — 54,2±8,22 y.) with rheumatic mitral valve lesion, of those 13 were investigated before and after correction of the defect. All patients, before and after correction of the defect were examined with the RTVG.Results. In all patients with the MV defect, we found a decrease of regional contractility of the RV. Patients with MV defects, related to the comparison group, had significantly more statistically decreased EF, MCI and SSN/Z, EF and higher values of EDV of the RV. Valve defect correction led to statistically more significant decrease of ESV, increase of MCI and EF RV. The sizes of the right atrium, measured with RTVG, were significantly higher comparing to the controls, and after correction of the defect, they reduced.Conclusion. The RTVG method could be applied for non-invasive assessment of the right heart chambers function in patients with MV stenosis of rheumatic origin

Feasibility of use of coheneration in boiler installations

The article describes an arrangement of co-generation technologies based on boiler installation. This paper analyses the operation of back-pressure steam turbine. Economical efficiency of the steam turbine using was calculated. The obtained data proves the feasibility of using cogeneration.В статье изложен способ применения когенерационной технологии на базе котельной установки. Также проанализирована работа паровой противодавленческой турбины. Рассчитана экономическая эффективность внедрения паровой турбины. Полученные данные доказывают целесообразность использования когенерации для автономного электроснабжения котельной

Totalitarianism and geography: L.S. Berg and the defence of an academic discipline in the age of Stalin

In considering the complex relationship between science and politics, the article focuses upon the career of the eminent Russian scholar, Lev Semenovich Berg (1876–1950), one of the leading geographers of the Stalin period. Already before the Russian Revolution, Berg had developed a naturalistic notion of landscape geography which later appeared to contradict some aspects of Marxist–Leninist ideology. Based partly upon Berg's personal archive, the article discusses the effects of the 1917 revolution, the radical changes which Stalin's cultural revolution (from the late 1920s) brought upon Soviet science, and the attacks made upon Berg and his concept of landscape geography thereafter. The ways in which Berg managed to defend his notion of geography (sometimes in surprisingly bold ways) are considered. It is argued that geography's position under Stalin was different from that of certain other disciplines in that its ideological disputes may have been regarded as of little significance by the party leaders, certainly by comparison with its practical importance, thus providing a degree of ‘freedom’ for some geographers at least analogous to that which has been described by Weiner (1999. A little corner of freedom: Russian nature protection from Stalin to Gorbachev. Berkeley: University of California Press) for conservationists. It is concluded that Berg and others successfully upheld a concept of scientific integrity and limited autonomy even under Stalinism, and that, in an era of ‘Big Science’, no modernizing state could or can afford to emasculate these things entirely

Relaxation of residual stresses in surface-hardened rotating prismatic elements of structures under creep conditions

A method for solving boundary problems of relaxation of residual stresses in a rotating surface-hardened prismatic specimen under high-temperature creep conditions has been developed. The problem models the stress-strain state of a surface-hardened prismatic rod with one end fixed to an infinitely rigid disk rotating at a constant angular velocity. In the first stage, we solve the problem of reconstructing fields of residual stresses and plastic deformations after the hardening procedure, which play the role of the initial stress-strain state, is solved. In the second stage, we address  the problem of relaxation of residual stresses under creep conditions is addressed. A detailed study of the influence of angular velocity on the intensity of residual stress relaxation in different sections along the axial coordinate is carried out for a $10{\times}10{\times}150$ mm prismatic specimen made of EP742 alloy at a temperature of 650$^\circ$C, following ultrasonic mechanical hardening of one of its faces. The analysis of the calculation results revealed that for angular velocities ranging from 1500 rpm to 2500 rpm, a non-trivial effect is observed. The relaxation of residual stresses in more stressed sections experiencing axial tensile stresses due to rotation occurs less intensively than in the “tail” section, where the axial load is zero. The obtained results from this study can be useful in assessing the effectiveness of surface-hardened rotating components under high-temperature creep conditions

Scientific, institutional and personal rivalries among Soviet geographers in the late Stalin era

Scientific, institutional and personal rivalries between three key centres of geographical research and scholarship (the Academy of Sciences Institute of Geography and the Faculties of Geography at Moscow and Leningrad State Universities) are surveyed for the period from 1945 to the early 1950s. It is argued that the debates and rivalries between members of the three institutions appear to have been motivated by a variety of scientific, ideological, institutional and personal factors, but that genuine scientific disagreements were at least as important as political and ideological factors in influencing the course of the debates and in determining their final outcome

Changes in aortic root dimensions after ascending aortic repair with concomitant aortic valve replacement

The issue of ascending aortic repair with concomitant aortic valve replacement in pa-tients with ascending aortic aneurysm (AscAA) and aortic valve stenosis is still debatable.Aim. To analyze the dimension changes of the preserved aortic root after simultaneous ascending aorta repair and aortic valve replacement.Material and methods. This retrospective study included 102 patients who, from December 2012 to May 2022, underwent simultaneous aortic valve replacement and ascending aorta repair with hemiarch replacement. Patients were divided into 2 following groups based on the aortic valve morphology: group 1 — patients with bicuspid aortic valve (BAV) and AscAA (n=75), group 2 — patients with tricuspid aortic valve (TAV) and AscAA (n=27). Depending on the presence of aortic root dilatation (maximum diameter (d) >40 mm), each of the groups was additionally stratified into 2 more subgroups as follows: patients without aortic root dilatation (d≤40 mm) and patients with its dilatation (d>40 mm). The dynamics of the aortic root diameter was assessed by computed tomography angiography.Results. The mean follow-up period for patients was 36,2±14,6 months. Survival rate in the BAV+AscAA and TAV+AscAA groups was 96% and 100%, respectively (p=0,380). Freedom from aortic root resurgery was 100% in both study groups. In patients with dilated and non-dilated aortic root of the BAV+AscAA group, an increase in aortic root dimension was noted at a rate of 0,65±0,51 mm/year and 0,32±0,27 mm/year, respectively. In patients of the TAV+AscAA group, a regression in dilated and non-dilated aortic root diameter was observed as follows: 0,93±0,48 mm/year and 0,56±0,43 mm/year, respectively.Conclusion. In patients with AscAA in combination with BAV stenosis after a singlestep surgical intervention, a weak negative dynamics of non-dilated and dilated aortic root is observed in the mid-term follow-up period. In patients with AscAA and TAV, there is involutive alterations of the aortic root dimension during 3-year follow-up

АТОМНО-АБСОРБЦИОННЫЙ СПЕКТРОМЕТР «КОЛИБРИ-ААС» ДЛЯ ОДНОВРЕМЕННОГО МНОГОЭЛЕМЕНТНОГО АНАЛИЗА

A desktop continuum source electrothermal atomic absorption spectrometer for the simultaneous multielement determination was developed based on a “Kolibri-2” polychromator and a MAES multichannel spectrum analyzer with a photodetector linear array. The device provided rapid monitoring of absorption spectra in the wavelength range of 190–360 nm with a single exposure time of 5 ms and atomization pulses of 1–2 seconds. The high luminosity of the spectrometer made it possible to use a low-power deuterium lamp as a continuum source. The heat treatment and the atomization of the samples was carried out in a longitudinally heated tube furnace with programmable heating. The processing of the spectral data, including the recording of the absorption, subtraction of the spectral background, linearization of the dependence of absorption on the concentration of atomic vapor, and the construction of the calibration graphs was performed automatically using a modified “Atom” software algorithm. The analysis of the series of multielement solutions had shown that, despite the relatively low spectral resolution, the device allowed for the direct simultaneous determination of elements by resonance lines in a concentration range of up to 4 orders of magnitude. Furthermore, the detection limits of the elements were comparable to or lower than those for the sequential flame atomic absorption spectrometry or the inductively coupled plasma atomic emission analysis. The comparison of the results of direct determination of micro and macro components in water from the rivers of Gorny Altai and the Laboratory of Isotope-Geochemical Methods of Analysis of the Institute of Geology and Mineralogy (IGM), SB RAS confirmed the correctness of the analysis. At this stage of the development, “Kolibri-AAS” spectrometers could replace flame AAS instruments for the sequential determination of elements in solutions in analytical laboratories. In the future, as the atomization technique and software are improved, the spectrometer could be used to analyze solid and liquid organic and inorganic substances.Keywords: atomic absorption spectrometry, spectrometer, electrothermal atomizer, simultaneous multi-element analysis, continuum sourceDOI: http://dx.doi.org/10.15826/analitika.2018.22.4.002(Russian)S.S. Boldova1,2, *V.A. Labusov1,2,3, D.A. Katskov4, D.O. Selyunin1,2, M.S. Saushkin1,2, I.A. Zarubin1,2,3 and Z.V. Semenov1,21Institute of Automation and Electrometry, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga, 1, Novosibirsk,  630090, Russian Federation2VMK-Optoelektronika, pr. Akademika Koptyuga, 1, Novosibirsk, 630090, Russian Federation3Novosibirsk State Technical University, pr. K. Marksa, 20, Novosibirsk, 630073, Russian Federation4 Tshwane University of Technology, Pretoria, 0001, South AfricaНастольный атомно-абсорбционный спектрометр с источником непрерывного спектра и электротермическим атомизатором для одновременного определения элементов сконструирован на базе полихроматора «Колибри-2» и многоканального анализатора спектров МАЭС с линейкой фотодетекторов. Прибор осуществляет быстрый мониторинг спектра поглощения в диапазоне длин волн 190-360 нм с временем однократной экспозиции 5 мс при 1-2 секундных импульсах атомизации пробы. Высокая светосила спектрометра позволяет использовать в качестве источника излучения непрерывного спектра дейтериевую лампу малой мощности. Термообработка и атомизация пробы проводятся в продольно нагреваемой трубчатой печи с программируемым нагревом. Обработка спектральных данных, включающая регистрацию абсорбции, учет спектрального фона, линеаризацию зависимости абсорбции от концентрации атомного пара и построение градуировочных графиков, производится автоматически с помощью модифицированной программы «Атом». На примере анализа серии многоэлементных растворов показано, что, несмотря на сравнительно низкое спектральное разрешение, прибор позволяет осуществлять прямое одновременное определение элементов по резонансным линиям в диапазоне концентраций до 4 порядков. При этом пределы обнаружения элементов оказываются сравнимыми или ниже аналогичных показателей для последовательного атомно-абсорбционного анализа с пламенной атомизацией или атомно-эмиссионного анализа с индуктивно связанной плазмой. Сопоставление результатов прямого определения микро- и макрокомпонентов в водах рек Горного Алтая с данными лаборатории изотопно-геохимических методов анализа Института геологии и минералогии СО РАН подтвердило правильность анализа. На данном этапе разработки спектрометр «Колибри-ААС» может заменить в аналитических лабораториях пламенные ААС приборы для последовательного определения элементов в растворах. В перспективе, по мере усовершенствования технологии атомизации и программного обеспечения, предполагается использовать спектрометр для анализа твердых и жидких органических и неорганических веществ.Ключевые слова: атомно-абсорбционная спектрометрия, спектрометр, электротермический атомизатор, одновременный многоэлементный анализ, источник непрерывного спектраDOI: http://dx.doi.org/10.15826/analitika.2018.22.4.00

Трудности диагностики метастатического рака молочной железы у пациентки после минимально инвазивного протезирования аортального клапана: клинический случай

HighlightsThe article describes a clinical case of a patient with metastatic breast cancer detected after aortic valve replacement. The case was initially treated as sternal osteomyelitis due to ministernotomy performed during aortic valve surgery. However, the diagnosis of metastatic breast cancer with sternal and spinal (third thoracic vertebra) metastatses, and ribs lesion was established upon further study. Adjuvant endocrine therapy was prescribed to the patient due to her age and previous surgery. AbstractBreast cancer is an urgent problem in oncology as it remains the most frequent type of cancer in the Russian Federation and world wide. Long-term treatment success and survival of patients depend on selected treatment modality, and long-term postopertive monitoring of patients as the means of the early detection of metastatic recurrence. Furthermore, concominant somatic ilness could change or mask the symptoms of local recurrence or metastasis, resulting in difficulties with establishing the proper diagnosis. We report a clinical case of metastatic breast cancer in a patient with severe aortic stenosis who underwent aortic valve replacement. We have not found analogious cases in domestic and foreign literature.Основные положенияВ статье описан клинический случай метастатического рака молочной железы у пациентки после протезирования аортального клапана. Ввиду выполненной министернотомии при операции на аортальном клапане данный случай изначально трактовался, как подозрение на остеомиелит грудины, однако при детальном изучении диагностирован метастатический рак молочной железы с поражением грудины, ребер и тела третьего грудного позвонка. С учетом возраста и перенесенной операции пациентке назначена адъювантная гормональная терапия. АннотацияРак молочной железы представляет серьезную проблему современной онкологии, занимая лидирующую позицию среди всех злокачественных новообразований не только в РФ, но и мире. Долгосрочный успех в лечении и выживаемость данной категории пациентов зависят не только от выбранного варианта терапии, но и дальнейшего длительного мониторирования состояния больных с целью своевременной диагностики рецидивирующего или метастатического процесса. Кроме того, сопутствующие соматические заболевания могут менять или маскировать симптомы развития локальных рецидивов и метастазов, что ведет к затруднению интерпретации клинической картины и поздней диагностике прогрессирования опухоли. В данной статье описан клинический случай сочетания метастатического рака молочной железы с ранее выполненным протезированием аортального клапана биопротезом по поводу тяжелого аортального стеноза. Наличие стернотомного доступа в анамнезе сыграло решающую роль в трудности дифференциальной диагностики в амбулаторном звене. При анализе отечественной и зарубежной литературы не обнаружено подобных публикаций