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1.
One hundred nineteen pen-raised wild turkeys (Meleagris gallopavo) from 12 locations in nine states in the United States were examined for coccidia by sugar flotation of intestinal contents and mucosa or by subinoculating the contents into uninfected domestic turkeys. Seventy-eight (66%) of the turkeys were positive for coccidia. There were no differences in the frequency of coccidia among adult, sub-adult or juvenile turkeys. More females (75%) were infected than males (48%). The species of coccidia from 30 of the turkeys were identified based on microscopic examination of oocysts, fresh scrapings, stained sections and inoculations of bobwhites (Colinus virginianus). The frequency of each species was Eimeria meleagrimitis (97%), E. gallopavonis (47%), E. meleagridis (27%), E. dispersa (17%), E. innocua-E. subrotunda (13%), E. adenoeides (7%) and an undescribed species (3%). Of the 30 turkeys in which the species of coccidia was determined, 30% had a single species infection, 40% had two species, 20% had three species and 10% had four species. 相似文献
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The composition of the amino acid pool during spherulation was determined. It changes in size and in composition, the concentration of each amino acid behaving individually. The first response to the onset of spherulation either by starvation or osmotic shock (0.5 M mannitol) always is a decrease of the pool's size, which during further starvation expands for a short period and then decreases again. During development induces by mannitol in the presence of external amino acids, the pool size increases continuously after the initial depletion.As shown by radioactive labeling, amino acids were actively released from the plasmodium into a medium containing amino acids, but retained by the microplasmodia in an amino acid-free medium. The kinetics of the uptake of radioactive amino acids from the medium is biphasic, indicating the existence of multiple pools. Even after a labeling period of 8 h the amino acid pool is not yet in equilibrium with the medium. The possibility of a compartimentation of the pool was confirmed by density labeling of two different enzymes.Whereas the turnover of total protein is only very low during growth, it is rather high in spherulating microplasmodia. At least 70% of the originally existing protein is degraded during this development, while, simultaneously, at least 50% of the protein present after 24 h starvation is newly synthesized during that period. 相似文献
4.
Wilma?Gertrud?Charlotte?HunekeEmail author Oliver?Huhn Michael?Schr?eder 《Polar Biology》2016,39(5):789-798
The Bransfield Strait is a semi-enclosed sea located in the northern part of the West Antarctic Peninsula region, which is subject to strong climatic changes. The bathymetry is complex and comprises three basins that are separated from each other by shallow sills. Oceanographic measurements of the Bransfield Strait region are available since the first half of the twentieth century. In this study, hydrographic data from the ANT-XXIX/3 expedition of RV Polarstern in 2013 are presented to describe the actual physical state of the art, particularly for biological work done during that cruise. The general hydrographic situation of the Bransfield Strait in 2013 is found to be similar to observations from the early twentieth century. The Bransfield Strait’s water masses are modified versions of the water masses from the adjacent seas. The different water masses within the Bransfield Strait are separated by two fronts, the so-called Bransfield and Peninsula Front. While the Bransfield Front is most pronounced in the central and southwestern Bransfield Strait, the Peninsula Front can be identified from the northeastern to the central part of the study domain. Based on an analysis of water mass properties around the Antarctic Peninsula and close to the Antarctic Sound, a notable inflow of Shelf Water from the Weddell Sea through the Antarctic Sound appears unlikely. 相似文献
5.
Marian C. Cheung Gertrud Wolfbauer Hiroshi Deguchi José A. Fernández John H. Griffin John J. Albers 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2009,1791(3):206-211
To gain further insights into the relationship between plasma phospholipid transfer protein (PLTP) and lipoprotein particles, PLTP mass and phospholipid transfer activity were measured, and their associations with the level and size of lipoprotein particles examined in 39 healthy adult subjects. No bivariate correlation was observed between PLTP activity and mass. PLTP activity was positively associated with cholesterol, triglyceride, apo B and VLDL particle level (rs = 0.40–0.56, p ≤ 0.01) while PLTP mass was positively associated with HDL-C, large HDL particles, and mean LDL and HDL particle sizes (rs = 0.44–0.52, p < 0.01). Importantly, plasma PLTP specific activity (SA) was significantly associated with specific lipoprotein classes, positively with VLDL, IDL, and small LDL particles (rs = 0.42–0.62, p ≤ 0.01) and inversely with large LDL, large HDL, and mean LDL and HDL particle size (rs = − 0.42 to − 0.70, p ≤ 0.01). After controlling for triglyceride levels, the correlation between PLTP mass or SA and HDL size remained significant. In linear models, HDL size explained 45% of the variability of plasma PLTP SA while triglyceride explained 34% of the PLTP activity. Thus, in healthy adults a significant relationship exists between HDL size and plasma PLTP SA (rs = − 0.70), implying that HDL particle size may modulate PLTP SA in the vascular compartment. 相似文献
6.
To investigate the factors governing the accumulation of sucroseand amino acids in the taproots of sugar beet, their contentswere measured in the leaves, phloem sap and the taproots ofsugar beet, fodder beet and a hybrid between both, grown oneither 3.0 or 0.5 mM nitrate. In the taproots the contents ofmalate, citrate and inorganic ions were also determined. Forthe high sucrose accumulation in sugar beet as compared to theother varieties three factors were found. (a) In sugar beet,less amino acids and more sucrose are taken up into the phloemthan in fodder beet. (b) In sugar beet, the sucrose and aminoacid syntheses are less sensitive to the nitrate concentrationsthat are required for optimal plant growth than in other varieties.In fodder beet, upon raising the nitrate concentration from0.5 mM to 3 mM, the synthesis and storage of sucrose is decreasedand that of amino acids increased. The corresponding valuesin sugar beet (0.5 mM) are similar to those in fodder beet andare not much affected by an increase of nitrate. (c) The sucroseaccumulation is limited by the accumulation of inorganic ionsin the taproots. The sucrose content in the taproots is negativelycorrelated to the total ion content. Whereas sucrose representstwo-third of all solutes in the taproots of sugar beet, it amountsto only one-third of the solutes in fodder beet taproots. Key words: Amino acids, Beta vulgans L, phloem sap, potassium, sucrose storage, sugar beet, taproots, transport 相似文献
7.
Egbert Hoiczyk Michael W. Ring Colleen A. McHugh Gertrud Schwär Edna Bode Daniel Krug Matthias O. Altmeyer Jeff Zhiqiang Lu Helge B. Bode 《Molecular microbiology》2009,74(2):497-517
Cell differentiation is widespread during the development of multicellular organisms, but rarely observed in prokaryotes. One example of prokaryotic differentiation is the Gram-negative bacterium Myxococcus xanthus . In response to starvation, this gliding bacterium initiates a complex developmental programme that results in the formation of spore-filled fruiting bodies. How the cells metabolically support the necessary complex cellular differentiation from rod-shaped vegetative cells into spherical spores is unknown. Here, we present evidence that intracellular lipid bodies provide the necessary metabolic fuel for the development of spores. Formed at the onset of starvation, these lipid bodies gradually disappear until they are completely used up by the time the cells have become mature spores. Moreover, it appears that lipid body formation in M. xanthus is an important initial step indicating cell fate during differentiation. Upon starvation, two subpopulations of cells occur: cells that form lipid bodies invariably develop into spores, while cells that do not form lipid bodies end up becoming peripheral rods, which are cells that lack signs of morphological differentiation and stay in a vegetative-like state. These data indicate that lipid bodies not only fuel cellular differentiation but that their formation represents the first known morphological sign indicating cell fate during differentiation. 相似文献
8.
Kirchengast S Knogler W Hauser G 《Anthropologischer Anzeiger; Bericht über die biologisch-anthropologische Literatur》2002,60(2):187-197
The effect of weight, classified by body mass index (BMI), on bone mass (BMC) of the whole body and on bone mineral density BMD of the hip joint was analysed in a sample of 120 Austrians of Vienna and surroundings. The 68 females and 52 males of this cross sectional study ranged in age between 60 and 92 years (x = 71.7 +/- 7.7). Age distribution was not significantly different between sexes. The WHO (1997) classification of body mass index (BMI) was used for weight classification, i.e. normal weight (BMI 18.5-24.99) and moderate overweight (BMI 25.0-29.99). Obese subjects (BMI 30+) were not included in this study. Bone mass of the whole body as well as bone density of the hip joint were determined by Dual-energy-X-ray absorptiometry (DEXA) using a hologic 2000 scanner. As expected BMC and BMD values were significantly higher in males than in females. While in both females and males moderately overweight BMD of the hip was significantly higher than in those with normal BMI, statistically significant differences of BMC were restricted to females only. Such positive association between body weight and BMC and BMD is in agreement with previous studies on mature subjects, and menopausal and postmenopausal women in particular. In addition, this study demonstrates corresponding positive associations between moderate overweight and bone mass and -density in the elderly and old aged. 相似文献
9.
Zusammenfassung Der Kurztag wurde fürKalanchoë Bloßfeldiana auf 2 Stunden bis hinab zu 1 Sek. abgekürzt. Bei Anwendung von natürlichem Tageslicht oder elektrischem Licht von 60–80 000 Lux bei Zimmertemperatur kamen die Pflanzen bei allen diesen Tageslängen zum Blühen.Man kann die Pflanzen also täglich 23 Stunden, 59 Min. und 59 Sek. im Dunkeln halten und braucht sie nur 1 Sek. zu belichten, um die Blütenbildung herbeizuführen.Alle Blütenstände waren völlig normal ausgebildet, unverlaubt und relativ reichblütig.Mit abnehmender Belichtungszeit ging die Blütenzahl zurück, und der Zeitpunkt des ersten Sichtbarwerdens der Infloreszenzen sowie des Aufblühens der Knospen wurde hinausgeschoben. Von 20 Min. abwärts trat diese Abnahme des Blühimpulses aber nicht mehr klar ein, so daß bei den längeren Belichtungszeiten wohl auch die Menge der Assimilate — die bei den sehr kurzen Zeiten überall wohl als gleich unbedeutend angesehen werden darf—mit eine Rolle spielte.Mit 3 Textabbildungen. 相似文献
10.
Synchronously and normally grown Chlorella pyrenoidosa cell populations were analysed by countercurrent distribution in aqueous two-polymer phase systems and by a multiple sedimentatation technique. Partition of cells in aqueous phases reflects the surface properties of cells (primarily surface charge) and multiple sedimentation reflects the cells' size-density parameters. It was found that:
- 1. 1. Synchronized cells that have just divided have the lowest partition of any in the population. Surface charge (as reflected by partition) increases with time after cell division. Cells have the highest partition just prior to division.
- 2. 2. Synchronized cells that have just divided are the smallest of any in the population. Since size and sedimentation rate increase with time after cell division multiple sedimentation permits the separation of cells of different ages.
- 3. 3. Both countercurrent distribution and multiple sedimentation studies reveal considerable heterogeneity of synchronized Chlorella populations. The increase in both surface charge and size with cell age does not appear to proceed in a continuous fashion. Rather, it seems to go in a stepwise manner.
- 4. 4. Non-synchronized cells examined by either countercurrent distribution or multiple sedimentation show two distinct sub-populations. One of these corresponds to the youngest, just divided cells; and the other to cells just prior to cell division. It is suggested that a lag time just prior to cell division and just after cell division explains these results.
- 5. 5. Countercurrent distribution in two-polymer phases and multiple sedimentation at unit gravity in a suspension medium best suited for the cell under investigation seem to be methods of choice for tracing cell changes during division, maturation and aging and for sub-fractionating such cell populations.