The neutron dose equivalent rate measurements by R3DR/R2 spectrometers on the international space station.

The data from two Bulgarian-German instruments with the basic name "Radiation Risk Radiometer-Dosimeter" (R3D) are discussed. The R3DR instrument worked inside the ESA EXPOSE-R facility (2009-2010), while R3DR2 worked inside the ESA EXPOSE-R2 facility (2014-2016). Both were outside the Russian Zvezda module on the International Space Station (ISS).

Observation of the radiation environment and solar energetic particle events in Mars orbit in May 2018- June 2022.

The dosimeter Liulin-MO for measuring the radiation environment onboard the ExoMars Trace Gas Orbiter (TGO) is a module of the Fine Resolution Epithermal Neutron Detector (FREND). Here we present results from measurements of the charged particle fluxes, dose rates and estimation of dose equivalent rates at ExoMars TGO Mars science orbit, provided by Liulin-MO from May 2018 to June 2022. The period of measurements covers the declining and minimum phases of the solar activity in 24th solar cycle and the rising phase of the 25th cycle.

Solar modulation of the GCR flux and dose rate, observed in space between 1991 and 2019.

The paper presents the solar modulation of the long-term galactic cosmic rays (GCR) flux and dose rates variations, observed during 14 space experiments by 10 Bulgarian build Liulin-type spectrometers (LTS) (Dachev et al., 2015a). They worked in near Earth space and in the interplanetary radiation environment between January 1991 and January 2019.

Checklist of -dwelling testate amoebae in Bulgaria.

Background: Until now, a complete checklist of -dwelling testate amoebae in Bulgaria has never been published. Records for species diversity and distribution in the country were scattered in many faunistic and ecological publications. The aim of the present study is to summarise all data for the species distribution at the level of country by reviewing the existing literature and by additional data obtained in our research over the past two years.

High dose rates obtained outside ISS in June 2015 during SEP event.

The R3DR2 instrument performed measurements in the European Space Agency (ESA) EXPOSE-R2 platform outside the Russian "Zvezda" module of the International Space Station (ISS) in the period 24 October 2014-11 January 2016. It is the Liulin-type deposited energy spectrometer (DES) (Dachev et al., 2015a).

Overview of the Liulin type instruments for space radiation measurement and their scientific results.

Ionizing radiation is recognized to be one of the main health concerns for humans in the space radiation environment. Estimation of space radiation effects on health requires the accurate knowledge of the accumulated absorbed dose, which depends on the global space radiation distribution, solar cycle and local shielding generated by the 3D mass distribution of the space vehicle. This paper presents an overview of the spectrometer-dosimeters of the Liulin type, which were developed in the late 1980s and have been in use since then.

[Psychophysiological and clinical criteria in predicting possibilities of vocational training of adolescents with mild mental retardation: use of instrumental methods].

The paper deals with the topical aspects of using instrumental psychophysiological means of assessing higher cortical functions during a medical and pedagogical process of vocational training of psychoneurological disabled individuals.

The dose rate observed on 19-21 October 1989 and its modulation by geophysical effects.

The Liulin dosimeter-radiometer on the MIR space station detected the 19 October 1989 high energy solar proton event. These results show that the main particle increase contains protons with energies up to about 9 GeV. After the main particle onset the Liulin dosimeter observed a typical geomagnetic cutoff modulation of the dose rate from the solar particles as the MIR space station traversed magnetic latitudes.

"Mir" radiation dosimetry results during the solar proton events in September-October 1989.

Using data from dosimetry-radiometry system "Liulin" on board of "Mir"-space station the particle flux and doserate during September-October, 1989 has been studied. The orbit of the station was 379 km perigee, 410 km apogee and 51.6 degrees inclination.

Modeling of the radiation exposure during the flight of the second Bulgarian cosmonaut on board the Mir Space Station.

An experiment involving active detection of space radiation was carried out in the Space Research Institute (SRI) of Bulgarian Academy of Sciences, in preparation of the flight of the second Bulgarian cosmonaut. The radiations that would be encountered on the flight were modelled including solar and galactic cosmic rays and the particle radiation in the Earth's radiation belts. The dose rate was calculated for these different radiations behind the shielding of the space station.

[Transplantation of embryos in sheep breeding].

Intra- and inter-breed transplantations were carried out with Bulgarian fresh embryos and with frozen embryos imported from Poland. A complex biotechnology was worked out, including methods of estrus synchronization, of inducing superovulation, and of producing, morphologic evaluation, storing, and transplantation of sheep embryos. Discussed are the possibilities of using embryo transplantation in sheep breeding for the fuller use of the reproductive potential of elite ewes as donors of embryos, for the introduction of new genotypes by means of importing frozen embryos as well as a modern model for fundamental investigations in the reproductive and cell biology.

[Possibilities of inducing superovulation and obtaining zygotes for transplantation in sheep].

The possibilities were explored of inducing superovulation and obtaining of zygotes from ewes of the Romanov and Tsigai breeds. The pattern used of inducing superovulation included stimulation with the serum gonadotropin preparation Gravohormone applied at the rates of 750 and 1000 IU, estrus synchronization with Estrumate (ICI, England), and ovulation with the use of the choriogonadotropin preparation Gonabion (Jenapharm, DDR). With Romanov sheep both doses of Gravohormone did not affect essentially the ovarian activity--3.

[Experiments with embryo transplantation in cattle in Bulgaria].

Summarized are the results of the first attempts to transplant embryos in cattle in this country over the 1979-1982 period. An average of 6.4 ovulations have been obtained by the induction of superovulation in 48 donor heifers with the use of gonadotropic preparations (Gestyl, Anteron, Folligon) in the middle of the luteal phase at dose of 2000-2500 IU as well as with prostaglandine preparations (Estrumate, Oestrophan) injected 48 hours later.

[Control of sex cycle functions in sheep using cloprostenol, an analog of prostaglandin F2a].

Studied was the synchronizing effect of the prostaglandin F2a analague - estrumate (ICI, England). with the Tsigai sheep. The investigations included observations on the clinical characteristics of the estrus, determination of the hormonal profile in naturally manifested estrus and in estrus induced with prostaglandin, and the conception rate with the first two successive estrus cycles along with the total conception.

Changes in plasma oestradiol-17beta, progesterone, testosterone, LH and fertility after treatment with I.C.I. 80, 996.

Fifty heifers were twice injected with I.C.I.

[Estrogenic activity of some lucerne varieties].

Studies was the estrogenic activity of lucerne--the local population Dounavka, the zonated French variety Du Puits, the promising Bulgarian variety. Pleven 1, the population Boinitsa, and the French variety Du Poitou. The estrogenic activity was determined by the biologic method based on the increase in the uterus weight of infantile mice after treatment with estrogens.

[Effect of several factors on the estrogen activity of lucerne].

Investigations were carried out on the estrogen activity of lucerne from various mowings harvested in years of different climate, studying the effect of age and yield of the crop. The observations were made during three successive years on local populations of lucerne grown under nonirrigation conditions. The estrogen activity was determined ny Bikov's biologic method, and the presence of cumestrol and genestein was established through chromatography.

[Effect of a gestagen used for the induction of synchronous estrus and fertilization of cattle].

The preparations Synchrosyn, Gestafortin, and Bovisynchron, having chlormadinonacetate as a common active ingredient, were used to induce synchronous estrus and fertilization in heifers. A total of 254 animals were involved belonging to the following breeds: Bulgarian Simmental, Bulgarian Red, Bulgarian Brown, and Black Pied. All three preparations were administered orally: Synchrosyn and Gestafortin were given with the forage at the rate of 10 mg chlormadinonacetate, and Bovisynchron was offered twice daily at an interval of 12 hours, rated 1 cu.