Restoration of spermatogenesis after transplantation of c-Kit positive testicular cells in the fowl

Transplantation of male germ line cells into sterilized recipients has been used in mammals for conventional breeding as well as for transgenesis. We have previously adapted this approach for the domestic chicken and we present now an improvement of the germ cell transplantation technique by using an enriched subpopulation of c-Kit-positive spermatogonia as donor cells. Dispersed c-Kit positive testicular cells from 16 to 17 week-old pubertal donors were transplanted by injection directly into the testes of recipient males sterilized by repeated gamma irradiation. We describe the repopulation of the recipient’s testes with c-Kit positive donor testicular cells, which resulted in the production of functional heterologous spermatozoa. Using manual semen collection, the first sperm production in the recipient males was observed about nine weeks after the transplantation. The full reproduction cycle was accomplished by artificial insemination of hens and hatching of chickens

Restoration of spermatogenesis after transplantation of c-Kit positive testicular cells in the fowl

Transplantation of male germ line cells into sterilized recipients has been used in mammals for conventional breeding as well as for transgenesis. We have previously adapted this approach for the domestic chicken and we present now an improvement of the germ cell transplantation technique by using an enriched subpopulation of c-Kit-positive spermatogonia as donor cells. Dispersed c-Kit positive testicular cells from 16 to 17 week-old pubertal donors were transplanted by injection directly into the testes of recipient males sterilized by repeated gamma irradiation. We describe the repopulation of the recipient’s testes with c-Kit positive donor testicular cells, which resulted in the production of functional heterologous spermatozoa. Using manual semen collection, the first sperm production in the recipient males was observed about nine weeks after the transplantation. The full reproduction cycle was accomplished by artificial insemination of hens and hatching of chickens

Temporal Trends of Persistent Organic Pollutants across Africa after a Decade of MONET Passive Air Sampling

The Global Monitoring Plan of the Stockholm Convention on Persistent Organic Pollutants (POPs) was established to generate long-term data necessary for evaluating the effectiveness of regulatory measures at a global scale. After a decade of passive air monitoring (2008-2019), MONET is the first network to produce sufficient data for the analysis of long-term temporal trends of POPs in the African atmosphere. This study reports concentrations of 20 POPs (aldrin, chlordane, chlordecone, DDT, dieldrin, endrin, endosulfan, HBCDD, HCB, HCHs, heptachlor, hexabromobiphenyl, mirex, PBDEs, PCBs, PCDDs, PCDFs, PeCB, PFOA, and PFOS) monitored in 9 countries (Congo, Ghana, Ethiopia, Kenya, Mali, Mauritius, Morocco, Nigeria, and Sudan). As of January 1, 2019, concentrations were in the following ranges (pg/m(3)): 0.5-37.7 (Sigma 6PCB), 0.006-0.724 (Sigma 17PCDD/F), 0.05-5.5 (Sigma 9PBDE), 0.6-11.3 (BDE 209), 0.1-1.8 (Sigma 3HBCDD), 1.8-138 (Sigma 6DDT), 0.1-24.3 (Sigma(3)endosulfan), 0.6-14.6 (Sigma 4HCH), 9.1-26.4 (HCB), 13.8-18.2 (PeCB). Temporal trends indicate that concentrations of many POPs (PCBs, DDT, HCHs, endosulfan) have declined significantly over the past 10 years, though the rate was slow at some sites. Concentrations of other POPs such as PCDD/Fs and PBDEs have not changed significantly over the past decade and are in fact increasing at some sites, attributed to the prevalence of open burning of waste (particularly e-waste) across Africa. Modeled airflow back-trajectories suggest that the elevated concentrations at some sites are primarily due to sustained local emissions, while the low concentrations measured at Mt. Kenya represent the continental background level and are primarily influenced by long-range transport

The Characterization of Fixation of Ba, Pb, and Cu in Alkali-Activated Fly Ash/Blast Furnace Slag Matrix

The fixation of heavy metals (Ba, Cu, Pb) in an alkali-activated matrix was investigated. The matrix consisted of fly ash and blast furnace slag (BFS). The mixture of NaOH and Na-silicate was used as alkaline activator. Three analytical techniques were used to describe the fixation of heavy metals—X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), and X-ray powder diffraction (XRD). All heavy metals formed insoluble salts after alkaline activation. Ba was fixed as BaSO4, and only this product was crystalline. EDS mapping showed that Ba was cumulated in some regions and formed clusters. Pb was present in the form of Pb(OH)2 and was dispersed throughout the matrix on the edges of BFS grains. Cu was fixed as Cu(OH)2 and also was cumulated in some regions and formed clusters. Cu was present in two different chemical states; apart from Cu(OH)2, a Cu–O bond was also identified

Response of green reflectance continuum removal index to the xanthophyll de-epoxidation cycle in Norway spruce needles

A dedicated field experiment was conducted to investigate the response of a green reflectance continuum removal-based optical index, called area under the curve normalized to maximal band depth between 511nm and 557nm (ANMB511-557), to light-induced transformations in xanthophyll cycle pigments of Norway spruce [Picea abies (L.) Karst] needles. The performance of ANMB511-557 was compared with the photochemical reflectance index (PRI) computed from the same leaf reflectance measurements. Needles of four crown whorls (fifth, eighth, 10th, and 15th counted from the top) were sampled from a 27-year-old spruce tree throughout a cloudy and a sunny day. Needle optical properties were measured together with the composition of the photosynthetic pigments to investigate their influence on both optical indices. Analyses of pigments showed that the needles of the examined whorls varied significantly in chlorophyll content and also in related pigment characteristics, such as the chlorophyll/carotenoid ratio. The investigation of the ANMB511-557 diurnal behaviour revealed that the index is able to follow the dynamic changes in the xanthophyll cycle independently of the actual content of foliar pigments. Nevertheless, ANMB511-557 lost the ability to predict the xanthophyll cycle behaviour during noon on the sunny day, when the needles were exposed to irradiance exceeding 1000 µmol m-2 s-1. Despite this, ANMB511-557 rendered a better performance for tracking xanthophyll cycle reactions than PRI. Although declining PRI values generally responded to excessive solar irradiance, they were not able to predict the actual de-epoxidation state in the needles examine

The Effect Of Plyometric Training (Depth Jump) On Running Economy And Cycling Economy

Vytrvalostní sportovní výkon je ovlivňován mnoha faktory. Jedním z nich je ekonomika pohybu. V našem výzkumu se věnujeme ekonomice běžecké a cyklistické. Účastníky výzkumu byli studenti prvního ročníku Fakulty sportovních studií Masarykovy univerzity. Výzkum dokončilo 28 testovaných osob (věk 20,29 ± 0,94 let, výška 182,32 ± 7,98 cm, hmotnost 76,98 ± 10,03 kg), které byly náhodně rozděleny do experimentální a kontrolní skupiny. Před tréninkovým programem i po něm probíhalo vstupní testování zaměřené na zjišťování RE (ekonomika běhu) a CE (cyklistická ekonomika). Intervenční tréninkový program plyometrického charakteru trval 8 týdnů, probandi trénovali 2× v týdnu (8 sérií po 10 opakováních cviku depth jump v každém tréninku). Výsledky ukázaly, že realizací krátkodobého plyometrického tréninku prostřednictvím cviku depth jump nedošlo k signifikantnímu zlepšení RE při běhu rychlostí 10 a 12 km.hod.–1 Stejně tak nedošlo k signifikantnímu zlepšení CE při zátěži 1,5 W.kg–1 a 2 W.kg–1. Z hlediska výstupů pro praxi nedoporučujeme při uvedených rychlostech a intenzitě šlapání aplikovat plyometrický trénink daného charakteruEndurance sport performance is influenced by many factors, such as motor economies. In this research we focused on running and cycling economies. Twenty-eight first year students of Faculty of Sport science of Masaryk University (age 20.29 ± 0.94 years, height 182.32 ± 7.98 cm, weight 76.98 ± 10.03 kg) were selected to participate as subjects. The test subjects were randomised into an experimental group (n = 17) and a control group (n = 11). Pre-test and post-test were taken on RE and CE. The PI protocol was eight weeks, twice a week, eight sets per day, and ten repetitions per set. The results showed that short-term plyometric training using depth jump had no significant effect on RE when running at 10 and 12 km.h–1. Similarly, there was no significant effect on CE using strain of 1.5 W.kg–1 and 2 W.kg–1. From the point of view of practical use, we do not recommend apply analogous plyometric training using the declared running speed and cycling intensity

Cement Kiln By-Pass Dust: An Effective Alkaline Activator for Pozzolanic Materials

Cement kiln by-pass dust (CKD) is a fine-grained by-product of Portland clinker manufacturing. Its chemical composition is not suitable for returning back into feedstock and, therefore, it has to be discharged. Such an increasing waste production contributes to the high environmental impact of the cement industry. A possible solution for the ecological processing of CKD is its incorporation into alkali-activated blast furnace slag binders. Thanks to high alkaline content, CKD serves as an effective accelerator for latent hydraulic substances which positively affect their mechanical properties. It was found out that CKD in combination with sodium carbonate creates sodium hydroxide in situ which together with sodium water glass content increases the dissolution of blast furnace slag particles and subsequently binder phase formation resulting in better flexural and compressive strength development compared to the sample without it. At the same time, the addition of CKD compensates the autogenous shrinkage of alkali-activated materials reducing the risk of material cracking. On the other hand, this type of inorganic admixture accelerates the hydration process causing rapid loss of workability

Plant-based and immunostimulant-enhanced diets modulate oxidative stress, immune and haematological indices in rainbow trout (Oncorhynchus mykiss)

The aim of this study was to investigate the effects of three commercial diets, standard, immunostimulant-supplemented (β-glucan, vitamins C and E) and plant-based, on the degree of oxidative stress in tissues of rainbow trout (Oncorhynchus mykiss). Selected immune and haematological indices were measured and challenge with Aeromonas salmonicida was conducted. The plant-based diet systemically modulated all oxidative stress biomarkers (thiobarbituric acid reactive substances; reduced and oxidised glutathione and their ratio) in the intestine. The ratio was elevated in all organs (liver, kidney, muscle and intestine) and an enhancement of respiratory burst and complement activity was observed even in the control fish. With the standard diet, an elevation of thiobarbituric acid reactive substances in the intestine and a decrease in some immune indices appeared after challenge. Less distinctive changes and the lowest mortality rate (the highest being with the plant-based feed) were obtained with immunostimulants. Increased total immunoglobulin, relative lymphocytosis and a decrease in the phagocyte count were observed. This study contributes especially by a thorough examination of oxidative stress indices in different tissues. The exact composition of these commercial diets is a trade secret; however, knowledge of their effects is extremely important for fish farmers using them; therefore, this study has a great practical impact

The Effect of Biochar Application on Soil Properties and Growth of the Model Plant Zea Mays

The classic way of land cultivation means the use of inorganic fertilizers that are salts that dissolve rapidly in a short time and improve soil fertility. This process negatively affects soil salinity and the life of microorganisms. The use of biochar as a soil conditioner is a promising solution. The aim of the work is to enrich the properties of less fertile soils and to enhance the growth of the model plant Zea mays (corn) by biochar application. We used four different soil types commonly spread in the Czech Republic – regosol, chernozem, cambisol and fluvisol representing a broad range of organic matter content. Also, we applied two different EBC (The European Biochar Certificate) certified biochars for use in agriculture. Corn seeds were germinated and cultivated for 3 months in repeated plant life cycles. Soils and biochar samples were characterized before and after cultivation by TGA, EA, BET, SEM, extraction of organic matter. The effect of biochar application was observed continuously through the measurement of plant height, the number of leaves and cobs. After the finalization of cultivation experiments, the dry mass of individual plants was measured, and root image analysis of every plant was performed. Fluvisol and cambisol have much higher organic matter content than regosol and chernozem. The application of biochar had the most significant impact on regosol regardless of the application dose; these results are in good agreement with the root image analysis. Furthermore, plants in soils treated with biochar had more corn cobs. The analysis on biochar samples showed the continual leaching of both organic and inorganic molecules from biochar to surrounding soil, which is crucial for its possible use as a soil conditioner and confirms the long-timescale positive effect on soil properties