Number of results to display per page
Search Results
31162. The canopy rainfall interception in actual and potential distribution of Qinghai spruce (Picea crassifolia) forest
- Creator:
- Xu, Zhonglin, Feng, Zhaodong, Zhao, Chuanyan, Zheng, Jianghua, Yang, Jianjun, Tian, Fengxia, Peng, Huanhua, Wang, Chao, Peng, Shouzhang, and Sher, Hassan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Qinghai spruce, actual interception, potential interception, potential distribution, and ecohydrology
- Language:
- Slovak
- Description:
- Interception is one of the most underestimated processes in hydrological cycle in arid and semiarid regions. In Qilian Mountains of northwestern arid and semiarid China, the Qinghai spruce (Picea crassifolia) forest plays an important role in the hydrological cycle of the inland Heihe River basin. The historical disturbance of Qinghai spruce forest has resulted in various ecological problems. In order to realize the sustainable development of Heihe River basin, the Chinese government implemented restoration practices for Qinghai spruce in the past three decades. In this study, we estimated the rainfall interception in the actual and potential distribution of Qinghai spruce forest. Some of the important findings include: (1) The interception ratio of rainfall events ranged from 11-51% with a mean value of 27.02%; (2) Totally, 147 Mt of rainfall is intercepted by canopy of actual Qinghai spruce forest, in the projected potential distribution of the forest, totally 407 Mt of rainfall will be intercepted.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31163. The Capsalidae (Monogenea: Monopisthocotylea): a review of diversity, classification and phylogeny with a note about species complexes
- Creator:
- Whittington, Ian D.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Platyhelminthes, Monogenea, Capsalidae, Entobdellinae, Entobdella, Benedeniinae, Neobenedenia melleni, subfamilies, systematics, and morphology
- Language:
- English
- Description:
- The Capsalidae are monogeneans parasitizing ''skin'', fins and gills of marine fishes. Some capsalids are pathogenic to cultivated fish and a few have caused epizootic events. It is a cosmopolitan family with broad host associations (elasmobranchs and teleosts, including sturgeons). Approximately 200 capsalid species are placed in nine subfamilies and 44-46 genera, some of which are well known (Benedenia, Capsala, Entobdella, Neobenedenia). Sturgeons host two capsalid species (Nitzschiinae) and 15 species in five genera are reliably reported from elasmobranchs. The combination of ancient (shark, ray, sturgeon) and modern (teleost) host fish lineages indicates that capsalid evolution is likely a blend of coevolution and host-switching, but a family phylogeny has been lacking due to deficient knowledge about homologies. The current phenetic subfamilial classification is discussed in detail using a preliminary phylogeny generated from large subunit ribosomal DNA sequence data from representatives of five subfamilies. Monophyly of the Capsalidae is supported by possession of accessory sclerites. Hypotheses are proposed for the possible radiation of capsalids. A suggestion that Neobenedenia melleni, a pathogenic species atypical due to its broad host-specificity (>100 host teleost species from >30 families in five orders), may be a complex of species is supported from genetic evidence. This may explain peculiarities in biology, taxonomy, host associations and geographic distribution of N. 'melleni' and has implications for fish health. Holistic studies using live and preserved larval and adult capsalid specimens and material for genetic analysis are emphasised to further determine identity, phylogeny and details of biology, especially for pathogenic species.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31164. The cardiovascular effects of central hydrogen sulfide are related to K(APT) channels activation
- Creator:
- Liu, W.-Q., Chai, C., Li, X.-Y., Yuan, W.-J., Wang, W.-Z., and Lu, Y.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, sulfan, krevní tlak, srdeční rytmus, hydrogen sulphide, blood pressure, heart rate, rat, hydrogen sulfide, central, 14, and 612
- Language:
- English
- Description:
- Hydrogen sulfide (H2S), an endogenous “gasotransmitter”, exists in the central nervous system. However, the central cardiovascular effects of endogenous H2S are not fully determined. The present study was designed to investigate the central cardiovascular effects and its possible mechanism in anesthetized rats. Intracerebrovent ricular (icv) injection of NaHS (0.17~17 μ g) produced a significant and dose-dependent decrease in blood pressure (BP) and heart rate (HR) (P<0.05) compared to control. The higher dose of NaHS (17 μ g, n=6) decreased BP and HR quickly of rats and 2 of them died of respiratory paralyse. Icv injection of the cystathionine beta-synthetase (CBS) activator s-adenosyl-L-methionine (SAM, 26 μ g) also produced a significant hypotension and bradycardia, which were similar to the results of icv injection of NaHS. Furthermore, the hypotension and bradycardia induced by icv NaHS were effectively attenuated by pretreatment with the KATP channel blocker glibenclamide but not with the CBS inhibitor hydroxylamine. The present study suggests that icv injection of NaHS produces hypotension and bradycardia, which is dependent on the KATP channel activation., W.-Q. Liu ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31165. The cardiovascular response to lower body negative pressure in humans depends on seal location
- Creator:
- Goswami, Nandu, Grasser, E., Roessler, A., Schneditz, D., and Helmut Hinghofer-Szalkay
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, vnitřní orgány, abdom, physiology, internal organs, abdominal compression, central blood volume, orthostasis, splanchnic blood flow, thoracic electrical impedance, 14, and 612
- Language:
- English
- Description:
- We tested whether seal location at iliac crest (IC) or upper abdomen (UA), before and during lower body negative pressure (LBNP), would affect thoracic electrical impedance, hepatic blood flow, and central cardiovascular responses to LBNP. After 30 min of supine rest, LBNP at -40 mmHg was applied for 15 min, either at IC or UA, in 14 healthy males. Plasma density and indocyanine green concentrations assessed plasma volume changes and hepatic perfusion. With both sealing types, LBNP-induced effects remained unchanged for mean arterial pressure (-3.0±1.1 mm Hg), cardiac output (-1.0 l min-1), and plasma volume (-11 %). Heart rate was greater during UA (80.6±3.3 bpm) than IC (76.0±2.5 bpm) (p<0.01) and thoracic impedance increased more using UA (3.2±0.2 Ω) than IC (1.8±0.2 Ω) (p<0.0001). Furthermore, during supine rest, UA was accompanied by lower thoracic impedance (26.9±1.1 vs 29.0±0.8 Ω , p<0.001) and hepatic perfusion (1.6 vs 1.8 l.min-1, p<0.05) compared to IC. The data suggest that the reduction in central blood volume in response to LBNP depends on location of the applied seal. The sealing in itself altered blood volume distribution and hepatic perfusion in supine resting humans. Finally, application of LBNP with the seal at the upper abdomen induced a markedly larger reduction in central blood volume and greater increases in heart rate than when the seal was located at the iliac crest., N. Goswami ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31166. The care collective: the care manifesto: the politics of interdependence
- Creator:
- Meyer, Jan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31167. The cause of the difference in leaf net photosynthetic rate between two soybean cultivars
- Creator:
- Jiang, Hua and Xu, Da-Quan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- carboxylation efficiency, chlorophyll fluorescence, electron transport, Glycine max, photochemical efficiency, photophosphorylation, photosystem 2, quantum yield, and ribulose-1,5-bisphosphate carboxylase
- Language:
- Multiple languages
- Description:
- To explore the cause of difference in photosynthetic performance between different cultivars of crops, leaf net photosynt rate (PN) and photosystem 2 (PS2) photochemical efficiency (Fv/Fm), apparent quantum yield of carbon assimilation (φc), electron transport rate, photophosphorylation activity, etc. were measured in two soybean cultivars, Heinong 42 and Heinong 37. At pod setting and filling, significant differences in PN between them were observed. The former with a higher PN (from 7 to 38 %) had a significantly higher leaf thickness, leaf dry mass/area (LMA), chlorophyll content, soluble protein content, apparent quantum yield of electron transport through PS2 (φe), carboxylation efficiency (CE), and ribulose-1,5-bisphosphate carboxylase (RuBPC) activity. The significantly higher PN of Heinong 42 is mainly due to its higher content and activity of RuBPC. and Hua Jiang, Da-Quan Xu.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31168. The cell body space occupied by the nucleus during the cell differentiation in human lymphocytic, granulocytic and erythroid cell lineages
- Creator:
- Smetana, Karel, Klamová, Hana, Mikulenková, Dana, Čermák, Jaroslav, Otevřelová, Petra, Karban, Josef, and Trněný, Marek
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- diferenciace buněk, cell differentiation, nucleus, cell space, 14, and 612
- Language:
- English
- Description:
- The present nuclear and cell body diameter measurements demonstrated size differences of the approximate cell space estimate occupied by the cell nucleus during the cell differentiation in lymphocytic, granulocytic and erythroid cell lineages. These lineages were used as convenient models because all differentiation steps were easily identified and accessible in diagnostic peripheral blood or bone marrow smears of blood donors (BDs), patients suffering from chronic lymphocytic leukemia (CLL), patients with chronic myeloid leukemia (CML) and refractory anemia (RA) of the myelodysplastic syndrome (MDS). The cell space occupied by the nucleus was constant and did not change during the cell differentiation in the lymphocytic cell lineages of BDs and CLL patients despite the decreased cell size. In contrary, the cell space occupied by the nucleus markedly decreased in differentiating cells of granulocytic and erythroid lineages of patients suffering from CML. In the erythroid cell lineage in patients with RA of MDS the small reduction of the cell space occupied by the nucleus during the differentiation was not significant. The measurements also indicated that in progenitor cells of all studied cell lineages nuclei occupied more than 70 % of the cell space. Thus, the nucleus-cytoplasmic morphological and functional equilibrium appeared to be characteristic for each differentiation step and each specific cell lineage., Karel Smetana, Hana Klamová, Dana Mikulenková, Jaroslav Čermák, Petra Otevřelová, Josef Karban, Marek Trněný., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31169. The chamber exposure of laboratory rats to metal oxides originating from metal producing industry
- Creator:
- Kováčiková, Z. and Chorvatovičová, D.
- Type:
- article, model:article, and TEXT
- Subject:
- inhalation exposure, metal oxides, lung, cardiac Mg2* ATPase, and genotoxic effect
- Language:
- English
- Description:
- Laboratory rats were exposed to the inhalation of dust from an agglomeration unit which is the greatest contributor to dust pollution in the vicinity of a mercury producing plant. The exposure lasted for 6 months (4 hours daily, 5 days per week), the concentration of aerosol in the chamber was 10 mg.m-3. After finishing the exposure, the animals were examined and compared with the controls which were held under standard laboratory conditions. The number of alveolar macrophages was highly elevated (P<0.001) in the exposed animals, Mg24 ATPase activity in the heart muscle was decreased. The alanine aminotransferase activity in the serum was not changed, the aspartate aminotransferase was slightly enhanced. No differences in the frequency of abnormal sperm and in the frequency of polychromatic erythrocytes in bone marrow were detected.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
31170. The changes in pineal N-acetyltransferase activity, pineal and serum melatonin concentration in rats after irradiation of the head
- Creator:
- Kassayová, M., Ahlersová, E., Ahlers, I., and Milárová, R.
- Type:
- article, model:article, and TEXT
- Subject:
- head gamma irradiation, rats, pineal N-acetyltransferase activity, and pineal melatonin content
- Language:
- English
- Description:
- Male Wistar rats adapted to a light/dark cycle (LD) 12:12 h were exposed in the darkness to a single dose of 14.35 Gy gamma rays on the head with the body shielded. Irradiated and sham-irradiated rats were kept again in the 12 h LD cycle with a free access to food and water till the analysis performed in the darkness. Pineal N-acetyltransferase activity and melatonin content, the serum concentration of the melatonin, corticosterone, thyrotropin and thyroid hormones were determined. N-acetyltransferase activity was lower 2-24 h after irradiation non-significantly whereas between 3-10 days it did not differ from the controls. Radiation decreased the pineal melatonin content and its serum concentration 2 h after exposure and increased them significantly 1-3 days after irradiation. No changes in melatonin levels were found on postirradiation days 5-10. The corticosterone concentration was increased 2 h after exposure only. Local head irradiation changed neither thyrotropin nor thyroid hormone levels.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public