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1.
Genomic constitution and taxonomy of the Chinese hexaploids Elymus cylindricus and E. breviaristatus (Poaceae: Triticeae)
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Cai‐Rong Yang Bernard‐R. Baum Wei‐Huan Chen Hai‐Qin Zhang Xiao‐Yan Liu Xing Fan Li‐Na Sha Hou‐Yang Kang Yi Wang Yong‐Hong Zhou 《Botanical journal of the Linnean Society. Linnean Society of London》2016,182(3):650-657
Elymus cylindricus (2n = 6x = 42) and E. breviaristatus (2n = 6x = 42) are distributed in grasslands and deserts of northern and north‐western China. Their genomic constitution and taxonomic status are unclear. Elymus cylindricus was crossed with E. wawawaiensis J.R.Carlson & Barkworth ( StH ), Roegneria grandis Keng ( StY ) and Campeiostachys dahurica (Turcz. ex Griseb.) B.R.Baum, J.L. Y ang & C. Y en var. dahurica ( StYH ). Meiotic pairing in the hybrids E. cylindricus × E. wawawaiensis ( StH ), E. cylindricus × R. grandis ( StY ) and E. cylindricus × C. dahurica var. dahurica ( StYH ) showed on average 10.00, 11.30 and 20.92 bivalents per cell, respectively. Elymus breviaristatus was crossed with C. dahurica var. dahurica ( StYH ) and E. cylindricus. Chromosome pairing in the hybrids of E. breviaristatus × C. dahurica var. dahurica and E. breviaristatus × E. cylindricus showed on average 19.60 and 19.27 bivalents, respectively. Genomic in situ hybridization (GI SH ) revealed the presence of St , Y and H genomes in E. cylindricus and E. breviaristatus. An intergenomic rearrangement was observed in E. cylindricus using GI SH . Meiotic pairing data and GI SH indicated that both E. cylindricus and E. breviaristatus are allohexaploids containing the StYH genomes. Elymus cylindricus and E. breviaristatus should be treated as Campeiostachys dahurica var. cylindrica and Campeiostachys breviaristata, respectively. 相似文献
2.
Vegetation of arid and semiarid environments has in general a patchy distribution. Our objective was to (a) determine several
qualitative and quantitative analytical characteristics of vegetation patches in an arid zone of Patagonia, Argentina, and
(b) investigate relationships between them. Annual precipitation in this area was 200 mm during 1999–2005. Eight transects
involving ten patches each were studied within a 15 × 15 km area. Mean (±1 SE) values (n = 80) in the vegetation patches were 315 ± 25 and 207 ± 16 cm for the greatest and lowest patch diameter, respectively; 23 ± 2 cm
for mound height; 113 ± 12 cm for maximum vegetation height; and 170 ± 18 cm and 58 ± 2% for distance to the next vegetation
patch and vegetation patch cover within a transect, respectively. Correlations between greatest and lowest diameters, mound
height, maximum plant height and distance to the closest vegetation patch were all significant (P < 0.01; n = 80). In all vegetation patches, the greatest and lowest frequencies were found for the grass Stipa spp. (71.2%) and the shrub Grindelia chiloensis (Cornel.) Cabrera (12.5%). Stipa spp. and the shrub Atriplex lampa (Moq.) D. Dietr. showed the highest simultaneous frequency (50%). A reasonable association among species (>45%) was found
for Stipa spp., Atriplex lampa and the shrubs Larrea divaricata Cav., Lycium chilense Miers ex Bertero and Junellia ligustrina (Lag.) Moldenke. Larrea divaricata and Atriplex lampa contributed more than 84% of the total patch standing crop (5,777 ± 435 g). Average patch size and specific diversity were
5.93 ± 0.33 m2 and 1.31 ± 0.11, respectively. Aboveground standing crop of the two dominant shrubs decreased as plant species diversity
increased (P < 0.05). Conservation of vegetation patches is crucial to prevent increased soil erosion and desertification in the study
ecological system. 相似文献
3.
BackgroundSpecific tumor markers have yet to be identified in rectal cancer. This study aims to identify a novel genetic signature in rectal cancer to provide clues for survival and immunotherapy.MethodsDEGs were obtained from two GEO datasets of rectal cancer. By using data from TCGA and GSE133057, two cohorts of rectal cancer were applied to establish and evaluate the signature. A nomogram was constructed for training and validation. We integrated the risk-score with clinicopathological features and assessed its interplay with immune cells and molecules. Finally, our study performed functional annotations, gene-targeted miRNAs, and single-cell analysis.ResultsA total of 468 DEGs were identified, and a signature consisting of 5 genes (CLIC5, ENTPD8, PACSIN3, HGD, and GNG7) was selected to calculate the risk-score. The model exhibited high performance in time-dependent ROC and a nomogram. Further results showed that overall survival was significantly worse in the high-risk group. As an independent prognostic factor, the risk-score was associated with vascular invasion. There was a dramatic difference in nonregulatory CD4+ and CD8+ T cells between the high and low-risk groups, and the 5 genes were correlated with immune inhibitors. There was a considerable difference in autophagy, immune, cell cycle, infection, and apoptosis-associated terms and pathways in GO and KEGG. The functional states of differentiation, apoptosis, and quiescence were closely related to the 5-gene signature in single-cell analysis.ConclusionOur results suggest that the signature could serve as a novel prognostic biomarker in rectal cancer, which might benefit decision-making regarding immunotherapy. 相似文献
4.
Delorme M Thomas DW 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1999,169(2):123-132
Nitrogen (N) and energy (E) requirements of the phyllostomid fruit bat, Artibeus jamaicensis, and the pteropodid fruit bat Rousettus aegyptiacus, were measured in adults that were fed on four experimental diets. Mean daily food intake by A. jamaicensis and R. aegyptiacus ranged from 1.1–1.6 times body mass and 0.8–1.0 times body mass, respectively. Dry matter digestibility and metabolizable
E coefficient were high (81.1% and 82.4%, respectively) for A. jamaicensis and (77.5% and 78.0%, respectively) for R. aegyptiacus. Across the four diets, bats maintained constant body mass with mean metabolizable E intakes ranging from 1357.3 kJ · kg−0.75 · day−1 to 1767.3 kJ · kg−0.75 · day−1 for A. jamaicensis and 1282.6–1545.2 kJ · kg−0.75 · day−1 for R. aegyptiacus. Maintenance E costs were high, in the order of 3.6–5.4 times the basal metabolic rate (BMR). It is unlikely that the E intakes
that we observed represent a true measure of maintenance E requirements. All evidence seems to indicate that fruit bats are
E maximizers, ingesting more E than required and regulating storage by adjusting metabolic output. We suggest that true maintenance
E requirements are substantially lower than what we observed. If it follows the eutherian norm of two times the BMR, fruit
bats must necessarily over-ingest E on low-N fruit diet. Dietary E content did affect N metabolism of A. jamaicensis. On respective low- and high-E diets, metabolic fecal N were 0.492 mg N · g−1 and 0.756 mg N · g−1 dry matter intake and endogenous urinary N losses were 163.31 mg N · kg−0.75 · day−1 and 71.54 mg N · kg−0.75 · day−1. A. jamaicensis required 332.3 mg · kg−0.75 · day−1 and 885.3 mg · kg−0.75 · day−1 of total N on high- and low-E diets, respectively, and 213.7 mg · kg−0.75 · day−1 of truly digestible N to achieve N balance. True N digestibilities were low (29% and 49%) for low- and high-E diets, respectively.
For R. aegyptiacus, metabolic fecal N and endogenous urinary N losses were 1.27 mg N · g−1 dry matter intake and 96.0 mg N · kg−0.75 · day−1, respectively, and bats required 529.8 mg · kg−0.75 · day−1 (total N) or 284.0 mg · kg−0.75 · day−1 (truly digestible N). True N digestibility was relatively low (50%). Based on direct comparison, we found no evidence that
R. aegyptiacus exhibits a greater degree of specialization in digestive function and N retention than A. jamaicensis. When combined with results from previous studies, our results indicate that all fruit bats appear to be specialized in their
ability to retain N when faced with low N diet.
Accepted: 24 November 1998 相似文献
5.
Autotrophic and heterotrophic respiration in needle fir and Quercus-dominated stands in a cool-temperate forest, central Korea 总被引:3,自引:0,他引:3
Na-yeon Lee Jin-Woo Koo Nam Jin Noh Joon Kim Yowhan Son 《Journal of plant research》2010,123(4):485-495
To investigate annual variation in soil respiration (R
S) and its components [autotrophic (R
A) and heterotrophic (R
H)] in relation to seasonal changes in soil temperature (ST) and soil water content (SWC) in an Abies holophylla stand (stand A) and a Quercus-dominated stand (stand Q), we set up trenched plots and measured R
S, ST and SWC for 2 years. The mean annual rate of R
S was 436 mg CO2 m−2 h−1, ranging from 76 to 1,170 mg CO2 m−2 h−1, in stand A and 376 mg CO2 m−2 h−1, ranging from 82 to 1,133 mg CO2 m−2 h−1, in stand Q. A significant relationship between R
S and its components and ST was observed over the 2 years in both stands, whereas a significant correlation between R
A and SWC was detected only in stand Q. On average over the 2 years, R
A accounted for approximately 34% (range 17–67%) and 31% (15–82%) of the variation in R
S in stands A and Q, respectively. Our results suggested that vegetation type did not significantly affect the annual mean
contributions of R
A or R
H, but did affect the pattern of seasonal change in the contribution of R
A to R
S. 相似文献
6.
There are four species of Gymnetron in China recorded to date including Gymnetron
miyoshii Miyoshi, 1922, Gymnetron
villosipenne Roelofs, 1875, Gymnetron
auliense Reitter, 1907 and Gymnetron
vittipenne Marseul, 1876, of which the last two are new country records. The pre-imaginal stages including eggs, mature larvae and pupae of Gymnetron
miyoshii, Gymnetron
auliense and Gymnetron
vittipenne are described and illustrated. In addition, their diagnostic characters (larvae and pupae) are discussed and differentiated, and notes on some of their biological parameters are provided. Potential ecological impacts between Gymnetron weevils and their host Veronica spp. also are provided. 相似文献
7.
S. Walsh C.J. Haddad M.A. Kostek T.J. Angelopoulos P.M. Clarkson P.M. Gordon N.M. Moyna P.S. Visich R.F. Zoeller R.L. Seip S. Bilbie P.D. Thompson J. Devaney H. Gordish-Dressman E.P. Hoffman Thomas B. Price L.S. Pescatello 《Gene》2012
Purpose
We investigated the influence of Leptin (LEP) and leptin receptor (LEPR) SNPs on habitual physical activity (PA) and body composition response to a unilateral, upper body resistance training (RT) program.Methods
European-derived American volunteers (men = 111, women = 131, 23.4 ± 5.4 yr, 24.4 ± 4.6 kg·m− 2) were genotyped for LEP 19 G>A (rs2167270), and LEPR 326 A>G (rs1137100), 668 A>G (rs1137101), 3057 G>A (rs1805096), and 1968 G>C (rs8179183). They completed the Paffenbarger PA Questionnaire. Arm muscle and subcutaneous fat volumes were measured before and after 12 wk of supervised RT with MRI. Multivariate and repeated measures ANCOVA tested differences among phenotypes by genotype and gender with age and body mass index as covariates.Results
Adults with the LEP 19 GG genotype reported more kcal/wk in vigorous intensity PA (1273.3 ± 176.8, p = 0.017) and sports/recreation (1922.8 ± 226.0, p < 0.04) than A allele carriers (718.0 ± 147.2, 1328.6 ± 188.2, respectively). Those with the LEP 19 GG genotype spent more h/wk in light intensity PA (39.7 ± 1.6) than A allele carriers (35.0 ± 1.4, p = 0.03). In response to RT, adults with the LEPR 668 G allele gained greater arm muscle volume (67,687.05 ± 3186.7 vs. 52,321.87 ± 5125.05 mm3, p = 0.01) and subcutaneous fat volume (10,599.89 ± 3683.57 vs. − 5224.73 ± 5923.98 mm3, p = 0.02) than adults with the LEPR 668 AA genotype, respectively.Conclusion
LEP19 G>A and LEPR 668 A>G associated with habitual PA and the body composition response to RT. These LEP and LEPR SNPs are located in coding exons likely influencing LEP and LEPR function. Further investigation is needed to confirm our findings and establish mechanisms for LEP and LEPR genotype and PA and body composition associations we observed. 相似文献8.
Toxoplasma gondii and Neospora caninum are two closely related protozoan parasites which can cause abortion and significant economic losses in sheep and goats. However, it is yet to know whether black-bone sheep and goats are infected with T. gondii and N. caninum in China. In the present investigation, the seroprevalence and risk factors of T. gondii and N. caninum infections in black-boned sheep and goats were investigated in Yunnan Province, subtropical southwest China between July and August of 2017. A total of 481 serum samples were tested for T. gondii antibodies using the Modified Agglutination Test (MAT), and 468 serum samples were examined for N. caninum antibodies by indirect Enzyme-Linked Immunosorbent Assay (iELISA). The overall seroprevalence of T. gondii in black-boned sheep and goats was 36.80% (177/481, 95% CI 32.49–41.11), and 40 out of 468 serum samples were N. caninum-seropositive (8.55%, 95% CI 6.02–11.08). There was significant difference in the seroprevalence of T. gondii infection in different regions (χ2 = 19.869, df = 2, P<0.01). As for the seroprevalence of N. caninum infection, region (χ2 = 8.558, df = 2, P<0.05), age (χ2 = 16.631, df = 3, P < 0.01), gender (χ2 = 11.219, df = 1, P < 0.01) and species (χ2 = 8.673, df = 1, P < 0.01) were the risk factors. In addition, the seroprevalence of coinfection of T. gondii and N. caninum in black-boned sheep and goats was 3.63% (17/468, 95% CI 1.94–5.32). To our knowledge, this is the first report of T. gondii and N. caninum seroprevalence in black-boned sheep and goats in China, which provided base-line data for the execution of control strategies and measures against T. gondii and N. caninum infection in black-boned sheep and goats. 相似文献
9.
The concentration-dependence of the diffusion and sedimentation coefficients (kD and ks, respectively) of a protein can be used to determine the second virial coefficient (B2), a parameter valuable in predicting protein-protein interactions. Accurate measurement of B2 under physiologically and pharmaceutically relevant conditions, however, requires independent measurement of kD and ks via orthogonal techniques. We demonstrate this by utilizing sedimentation velocity (SV) and dynamic light scattering (DLS) to analyze solutions of hen-egg white lysozyme (HEWL) and a monoclonal antibody (mAb1) in different salt solutions. The accuracy of the SV-DLS method was established by comparing measured and literature B2 values for HEWL. In contrast to the assumptions necessary for determining kD and ks via SV alone, kD and ks were of comparable magnitudes, and solution conditions were noted for both HEWL and mAb1 under which 1), kD and ks assumed opposite signs; and 2), kD ≥ ks. Further, we demonstrate the utility of kD and ks as qualitative predictors of protein aggregation through agitation and accelerated stability studies. Aggregation of mAb1 correlated well with B2, kD, and ks, thus establishing the potential for kD to serve as a high-throughput predictor of protein aggregation. 相似文献
10.
11.
Kaido SoosaarÜlo Mander Martin MaddisonArno Kanal Ain KullKrista Lõhmus Jaak TruuJürgen Augustin 《Ecological Engineering》2011,37(1):40-53
We studied greenhouse gas (GHG) fluxes in two differently loaded riparian Alnus incana-dominated forests in agricultural landscapes of southern Estonia: a 33-year-old stand in Porijõgi, in which the uphill agricultural activities had been abandoned since the middle of the 1990s, and a 50-year-old stand in Viiratsi, which still receives polluted lateral flow from uphill fields fertilized with pig slurry. In Porijõgi, closed-chamber based sampling lasted from October 2001 to October 2009, whereas in Viiratsi the sampling period was from November 2003 to October 2009. Both temporal and spatial variations in all GHG gas fluxes were remarkable. Local differences in GHG fluxes between micro-sites (“Edge”, “Dry” and “Wet” in Porijõgi, and “Wet”, “Slope” and “Dry” in Viiratsi) were sometimes greater than those between sites. Median values of GHG fluxes from both sites over the whole study period and all microsites did not differ significantly, being 45 and 42 mg CO2-C m−2 h−1, 8 and 0.5 μg CH4-C m−2 h−1, 1.0 and 2.1 mg N2-N m−2 h−1, and 5 and 9 μg N2O-N m−2 h−1, in Porijõgi and Viiratsi, respectively. The N2:N2O ratio in Viiratsi (40-1200) was lower than in Porijõgi (10-7600). The median values-based estimation of the Global Warming Potential of CH4 and N2O was 19 and 185 kg CO2 equivalents (eq) ha−1 yr−1 in Porijõgi and −14 and 336 kg CO2 eq ha−1 yr−1 in Viiratsi, respectively. A significant Spearman rank correlation was found between the mean monthly air temperature and CO2, CH4 and N2 fluxes in Porijõgi, and N2O flux in Viiratsi, and between the monthly precipitation and CH4 fluxes in both study sites. Higher groundwater level significantly increases CH4 emission and decreases CO2 and N2O emission, whereas higher soil temperature significantly increases N2O, CH4 and N2 emission values. In Porijõgi, GHG emissions did not display any discernable trend, whereas in Viiratsi a significant increase in CO2, N2, and N2O emissions has been found. This may be a result of the age of the grey alder stand, but may also be caused by the long-term nutrient load of this riparian alder stand, which indicates a need for the management of similar heavily loaded riparian alder stands. 相似文献
12.
Sandblom E Axelsson M Davison W 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2009,179(2):165-173
Catecholamines increase arterial pressure by increasing cardiac output (Q) and stroke volume (V
s), while angiotensin II (ang II) also increases vascular resistance (R
sys) in the Antarctic fish Pagothenia borchgrevinki. Adrenaline, phenylephrine and ang II (Asn1, Val5) were injected into P. borchgrevinki. Cardiovascular variables, including central venous pressure (P
cv) and mean circulatory filling pressure (P
mcf; an index of venous capacitance), were recorded to investigate if venous vasoconstriction can explain the increased V
s and Q and the arterial pressor response in this species. Routine P
cv and P
mcf were 0.11 ± 0.01 and 0.18 ± 0.02 kPa, respectively. All of the drugs caused moderate increases in P
cv and P
mcf and the responses were attenuated after α-adrenergic blockade with prazosin. Although dorsal aortic pressure (P
da) also increased in response to all agonists, the mechanisms differed. Adrenaline caused sustained increases in V
s and Q, while R
sys only rose transiently. Ang II had a slower effect than adrenaline and increased both R
sys and Q, while phenylephrine only increased R
sys. This study demonstrates that P
cv is positive and controlled by an α-adrenergic mechanism in P. borchgrevinki. However, given the relatively small venous response to adrenaline it seems more likely that the increases in V
s and Q from this agonist are due to direct effects on the heart. 相似文献
13.
Décio Luis Semensatto-Jr. Rogério Hideki Ferreira Funo Dimas Dias-Brito 《Revue de Micropaléontologie》2009,52(1):67
Two foraminiferal associations comprising only arenaceous species define two distinct environments in a 340 m-long mangrove transect at Cardoso Island, Trapandé Bay (Cananéia-Iguape estuarine system, SP, Brazil). The “lower muddy flat” (LMF), from the outer mangrove fringe inwards towards land (100 m), is positioned in the lower plain between 0.04 and 0.23 m above the mean sea level (msl), and remains subaerially exposed between 48.5 and 65.6% of the time. This environment is characterized by higher foraminiferal diversity and evenness (McIntosh's D = 0.54 ± 0.21 and Pielou's E = 0.68 ± 0.25, respectively) and is dominated by Arenoparrella mexicana and Trochammina inflata, and to a lesser extent by Ammotium directum and Textularia earlandi. The mangrove plant of this segment is a Rhizophoretum with average height of 8.4 ± 1.2 m. The sediment is characterized by higher concentration of organic matter (93.5 ± 32.3 g dm−3) and metals (e.g. V = 53.4 ± 21.8 ppm and Zn = 46.4 ± 21.3 ppm). The “upper sandy flat” (USF), 240 m wide along the transect, is positioned in the upper plain between 0.28 and 0.89 m above the msl, and remains subaerially exposed between 69.7 and 98.5% of the time. This environment is characterized by a lower diversity and evenness (D = 0.33 ± 0.17 and E = 0.49 ± 0.20, respectively). The association is dominated by species T. inflata and Miliammina fusca. The Rhizophoretum exhibits a lower average height of 3.6 ± 0.6 m. The sediment is poorer in organic matter (39.3 ± 15.0 g dm−3) and metals (e.g. V = 13.0 ± 6.8 ppm and Zn = 6.9 ± 3.7 ppm). Whereas “elongate” tests (uniserial, biserial and planospiral followed by a uniserial portion) are restricted to the LMF, “spiraled” species dominate the USF. Subaerial exposure time seems to exert a primary influence on species distribution, in addition to salinity and sediment type. Species may be adapted to different exposure times, a factor dependent on their position on the intertidal zone and the tidal regime, which should be taken into account in relative sea level reconstructions based on intertidal foraminifera. These patterns have important implications for studies investigating the ecology and paleoecology of foraminifera and subtle fluctuations in relative sea level during the Quaternary. 相似文献
14.
Gout patients have a high incidence of atherosclerotic coronary heart disease. Low serum paraoxonase (PON) activity is considered
a risk factor for atherosclerosis. The relationships among paraoxonase-1 (PON1) activity, oxidative stress parameters, and
atherosclerosis in gout is not known. Therefore, we determined the plasma levels of malondialdehyde (MDA), oxidized low-density
lipoprotein (Ox-LDL), and activities of PON1/superoxide dismutase (SOD) activities in 49 gout patients (mean age 44.2 ± 7.0 years)
and 42 healthy, age-matched controls (mean age 45.0 ± 9.3 years). PON1 was measured spectrophotometrically, MDA by thiobarbituric
acid method, SOD by Griess reaction, and Ox-LDL by sandwich ELISA. Lipid and other biochemical parameters were determined
by routine laboratory methods. In gout patients, PON1/SOD activities and MDA/Ox-LDL levels were 131.3 ± 25.3/75.3 ± 28.9 kU l−1 and 6.12 ± 1.67 nmol ml−1/690.1 ± 180.2 μg l−1, respectively. In controls, these were 172.5 ± 27.8/94.0 ± 26.3 kU l−1 and 4.10 ± 1.25 nmol ml−1/452.3 ± 152.1 μg l−1, respectively. Thus, in gout patients, there was a significant decrease in PON1 (P < 0.01) and SOD (P < 0.05) activities, and an increase in MDA (P < 0.01) and Ox-LDL (P < 0.01) levels compared with controls. PON1 activity correlated positively with SOD (P < 0.05), and negatively with MDA (P < 0.01) and Ox-LDL (P < 0.01). These results suggest that gout patients were in a state of oxidative stress and the protective effects of HDL against
atherosclerosis maybe dependent on PON1 activity. These findings may explain in part the reported increase in cardiovascular
mortality in gout patients. 相似文献
15.
We determined the interactive effects of irradiance, elevated CO2 concentration (EC), and temperature in carrot (Daucus carota var. sativus). Plants of the cv. Red Core Chantenay (RCC) were grown in a controlled environmental plant growth room and exposed to 3
levels of photosynthetically active radiation (PAR) (400, 800, 1 200 μmol m−2 s−1), 3 leaf chamber temperatures (15, 20, 30 °C), and 2 external CO2 concentrations (C
a), AC and EC (350 and 750 μmol mol−1, respectively). Rates of net photosynthesis (P
N) and transpiration (E) and stomatal conductance (g
s
) were measured, along with water use efficiency (WUE) and ratio of internal and external CO2 concentrations (C
i/C
a). P
N revealed an interactive effect between PAR and C
a. As PAR increased so did P
N under both C
a regimes. The g
s
showed no interactive effects between the three parameters but had singular effects of temperature and PAR. E was strongly influenced by the combination of PAR and temperature. WUE was interactively affected by all three parameters.
Maximum WUE occurred at 15 °C and 1 200 μmol m−2 s− 1 PAR under EC. The C
i
/C
a
was influenced independently by temperature and C
a. Hence photosynthetic responses are interactively affected by changes in irradiance, external CO2 concentration, and temperature. EC significantly compensates the inhibitory effects of high temperature and irradiance on
P
N and WUE. 相似文献
16.
Tracy B. L.; Ivey F. M.; Hurlbut D.; Martel G. F.; Lemmer J. T.; Siegel E. L.; Metter E. J.; Fozard J. L.; Fleg J. L.; Hurley B. F. 《Journal of applied physiology》1999,86(1):195-201
To determine theeffects of strength training (ST) on muscle quality (MQ,strength/muscle volume of the trained muscle group), 12 healthy oldermen (69 ± 3 yr, range 65-75 yr) and 11 healthy older women (68 ± 3 yr, range 65-73 yr) were studied before and after aunilateral leg ST program. After a warm-up set, four sets ofheavy-resistance knee extensor ST exercise were performed 3 days/wk for9 wk on the Keiser K-300 leg extension machine. The men exhibitedgreater absolute increases in the knee extension one-repetition maximum(1-RM) strength test (75 ± 2 and 94 ± 3 kg before andafter training, respectively) and in quadriceps muscle volume measuredby magnetic resonance imaging (1,753 ± 44 and 1,955 ± 43 cm3) than the women (42 ± 2 and 55 ± 3 kg for the 1-RM test and 1,125 ± 53 vs.1,261 ± 65 cm3 forquadriceps muscle volume before and after training, respectively, inwomen; both P < 0.05). However,percent increases were similar for men and women in the 1-RM test (27 and 29% for men and women, respectively), muscle volume (12% forboth), and MQ (14 and 16% for men and women, respectively).Significant increases in MQ were observed in both groups in the trainedleg (both P < 0.05) and in the 1-RMtest for the untrained leg (both P < 0.05), but no significant differences were observed between groups,suggesting neuromuscular adaptations in both gender groups. Thus,although older men appear to have a greater capacity for absolutestrength and muscle mass gains than older women in response to ST, the relative contribution of neuromuscular and hypertrophic factors to theincrease in strength appears to be similar between genders. 相似文献
17.
Bukhari SA Rajoka MI Ibrahim Z Jalal F Rana SM Nagra SA 《Molecular biology reports》2011,38(4):2703-2710
Maternal oxidative stress during pregnancy may impair fetal growth and help in the development of diseases in adulthood. The
aim of current study was to assess total oxidation status (TOS), related parameters and their relationship to DNA damage (%)
and homocysteine level in normal pregnant women in low-income participants. In a cross-sectional study healthy women were
grouped as normal, while age matched nulliparous and singleton pregnancies were included for first, second and third trimester
groups. TOS (P < 0.01), melanodialdehyde (MDA) (P < 0.001), aspartate aminotransferase (AST) (P < 0.01), triiodothyronine (T3) (P < 0.01), thyroxine (T4) (P < 0.01), and homocysteine (P < 0.001), in pregnant women were significantly higher as compared to normal healthy women. While serum total proteins (P < 0.01), albumin (P < 0.01) and total antioxidant status (TAS) (P < 0.001) decreased significantly as compared to normal healthy women. Women in third trimester showed a significantly high
level of body temperature (P < 0.01), triglyceride (P < 0.01), LDL-cholesterol (P < 0.05), AST (P < 0.01), T3 (P < 0.01), homocysteine (P < 0.001), TOS (P < 0.01) and MDA (P < 0.001) but a lower concentration of serum proteins, albumin and TAS at the end of the pregnancy. Pearson correlation indicated
a positive relationship of homocysteine with triglycerides (P < 0.027), TOS (P < 0.01), MDA (P < 0.035) and had a negative relationship with total protein (P < 0.026). DNA damage was strongly related with T3 (P < 0.008), TOS (P < 0.02), MDA (P < 0.037) and MBI (P < 0.048) profiles of pregnant women. These changes were considered normal for pregnant women having optimum blood pressure
and normal child birth. Hormonal influences and hemodilution may contribute towards the observed changes in this study. 相似文献
18.
《Journal of Asia》2022,25(2):101918
The cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is one of the polyphagous and destructive pests in the world. It has caused a lot of damage in cotton fields and settles on other host plants, especially Chinese hibiscus shrubs Hibiscus rosa-sinensis L. and causes irrecoverable damages to these ornamental plants and urban landscape. Midge fly Dicrodiplosis manihoti Harris (Dip.: Cecidomiidae) is one of the most common fly species which was collected in mealybugs colonies. In this study, the biology and age-stage, two-sex life table parameters of Dicrodiplosis manihoti, was evaluated at four constant temperatures (22, 27, 32 and 37 ± 1 °C, 65 ± 5 % RH and a photoperiod of 16: 8 (L: D) h) in the laboratory conditions. The developmental pre-adult period was found as 36.12 ± 0.38, 24.09 ± 0.41, 14.96 ± 0.34 and 12.68 ± 0.26 days and the average egg produced by females was 23.65 ± 2.86, 11.14 ± 2.09, 12.32 ± 3.94 and 8.57 ± 0.67 at those temperatures, respectively which decreased as the temperature increased from 22 to 37 °C, respectively. The population intrinsic rate of increase (rm) was 0.0247 ± 0.0051, 0.0291 ± 0.0099, 0.0374 ± 0.0206 and 0.0103 ± 0.0129 (d-1), and the population finite rate of increase (λ) for the above mentioned temperatures was 1.0249 ± 0.0052, 1.0295 ± 0.0101, 1.0384 ± 0.0212 and 1.0104 ± 0.0130 (d-1), respectively. Also, the net reproductive rate (R0) at the above mentioned temperatures was 2.62 ± 0.5, 2.19 ± 0.53, 2.05 ± 0.73 and 1.18 ± 0.22 offspring respectively. The shortest (T = 14.88 ± 0.45 days) and the longest (T = 38.28 ± 0.65 days) mean generation time was recorded at 37 and 22 °C, respectively. According to the results of this study D. manihoti has a good potential to control of Ph. solenopsis and the temperature of around 32 °C is the best for mass rearing this predator. 相似文献
19.
Luca Vitale Paul Di Tommasi Carmen Arena Angelo Fierro Amalia Virzo De Santo Vincenzo Magliulo 《Acta Physiologiae Plantarum》2007,29(4):317-326
Zea mays is cultivated in the Mediterranean regions where summer drought may lead to photoinhibition when irrigation is not available.
In this work the response of maize to water stress was evaluated by gas exchange measurements at the canopy and leaf level.
Leaf gas exchange was assessed before, during and after water stress, while canopy turbulent fluxes of mass and energy were
performed on a continuous basis. In the early growth period, a linear increment of net ecosystem photosynthetic rate (P
NE) to incoming of photosynthetic photon flux density (PPFD) was found and net leaf photosynthetic rate (P
NL) showed the tendency to saturate under high irradiance. During water stress, the relationship between P
NE and PPFD became curvilinear and both P
NE and P
NL saturated in a range between 1,000 and 1,500 μmol (photons) m−2 s−1. Leaf water potential (ψl) dropped from −1.50 to −1.88 MPa during water stress, indicating that leaf and canopy gas exchanges were limited by stomatal
conductance. With the restoration of irrigation, P
NE, P
NL and ψl showed a recovery, and P
NE and P
NL reached the highest values of whole study period. Leaf area index (LAI) reached a value of 3.0 m2 m−2. The relationship between P
NE and PPFD remained curvilinear and P
NE values were lower than those of a typical well-irrigated maize crop. The recovery in P
NE and P
NL after stress, and ψl values during stress indicate that the photosynthetic apparatus was not damaged while soil moisture stress after-effects
resulted in a sub-optimal LAI values, which in turn depressed P
NE. 相似文献
20.
Tatiana P. Soares da Costa Andrew C. Muscroft-Taylor Renwick C.J. Dobson Sean R.A. Devenish Geoffrey B. Jameson Juliet A. Gerrard 《Biochimie》2010
Dihydrodipicolinate synthase (DHDPS, E.C. 4.2.1.52), a validated antibiotic target, catalyses the first committed step in the lysine biosynthetic pathway: the condensation reaction between (S)-aspartate β-semialdehyde [(S)-ASA] and pyruvate via the formation of a Schiff base intermediate between pyruvate and the absolutely conserved active-site lysine. Escherichia coli DHDPS mutants K161A and K161R of the active-site lysine were characterised for the first time. Unexpectedly, the mutant enzymes were still catalytically active, albeit with a significant decrease in activity. The kcat values for DHDPS-K161A and DHDPS-K161R were 0.06 ± 0.02 s−1 and 0.16 ± 0.06 s−1 respectively, compared to 45 ± 3 s−1 for the wild-type enzyme. Remarkably, the KM values for pyruvate increased by only 3-fold for DHDPS-K161A and DHDPS-K161R (0.45 ± 0.04 mM and 0.57 ± 0.06 mM, compared to 0.15 ± 0.01 mM for the wild-type DHDPS), while the KM values for (S)-ASA remained the same for DHDPS-K161R (0.12 ± 0.01 mM) and increased by only 2-fold for DHDPS-K161A (0.23 ± 0.02 mM) and the Ki for lysine was unchanged. The X-ray crystal structures of DHDPS-K161A and DHDPS-K161R were solved at resolutions of 2.0 and 2.1 Å respectively and showed no changes in their secondary or tertiary structures when compared to the wild-type structure. The crystal structure of DHDPS-K161A with pyruvate bound at the active site was solved at a resolution of 2.3 Å and revealed a defined binding pocket for pyruvate that is thus not dependent upon lysine 161. Taken together with ITC and NMR data, it is concluded that although lysine 161 is important in the wild-type DHDPS-catalysed reaction, it is not absolutely essential for catalysis. 相似文献