Eight male collegiate weightlifters (age: 21.2 +/- 0.9 years; height: 177.6 +/- 2.3 cm; and body mass: 85.1 +/- 3.3 kg) participated in this study to compare isometric to dynamic force-time dependent variables. Subjects performed the isometric and dynamic mid-thigh clean pulls at 30-120% of their one repetition maximum (1RM) power clean (118.4 +/- 5.5 kg) on a 61 x 121.9-cm AMTI forceplate. Variables such as peak force (PF) and peak rate of force development (PRFD) were calculated and were compared between isometric and dynamic conditions. The relationships between force-time dependent variables and vertical jump performances also were examined. The data indicate that the isometric PF had no significant correlations with the dynamic PF against light loads. On the one hand, there was a general trend toward stronger relationships between the isometric and dynamic PF as the external load increased for dynamic muscle actions. On the other hand, the isometric and dynamic PRFD had no significant correlations regardless of the external load used for dynamic testing. In addition, the isometric PF and dynamic PRFD were shown to be strongly correlated with vertical jump performances, whereas the isometric PRFD and dynamic PF had no significant correlations with vertical jump performances. In conclusion, it appears that the isometric and dynamic measures of force-time curve characteristics represent relatively specific qualities, especially when dynamic testing involves small external loads. Additionally, the results suggest that athletes who possess greater isometric maximum strength and dynamic explosive strength tend to be able to jump higher. 相似文献
The chromoblastomycosis is a subcutaneous mycosis with a high morbidity rate, Fonsecaea pedrosoi being the largest etiologic agent of this mycosis, usually confined to the skin and subcutaneous tissues. Rarely people get the cure, because the therapies shown to be deficient and few studies report the host–parasite relationship. Dendritic cells (DCs) are specialized in presenting antigens to naïve T lymphocytes inducing primary immune responses. Therefore, we propose to study the migratory capacity of DCs after infection with conidia of F. pedrosoi. The phenotype of DCs was evaluated using cells obtained from footpad and lymph nodes of BALB/c mice after 12, 24 and 72 h of infection. After 24 and 72 h of infection, we found a significant decrease in DCs in footpad and a significant increase in the lymph nodes after 72 h. The expression of surface markers and co-stimulatory molecules were reduced in cells obtained from footpad. To better assess the migratory capacity of DCs migration from footpad, CFSE-stained conidia were injected subcutaneously. We found that after 12 and 72 h, CD11c+ cells were increased in regional lymph nodes, leading us to believe that DCs (CD11c+) were able to phagocytic conidia present in footpad and migrated to regional lymph nodes.
While attention on logging in the tropics has been increasing, studies on the long-term effects of silviculture on forest dynamics and ecology remain scare and spatially limited. Indeed, most of our knowledge on tropical forests arises from studies carried out in undisturbed tropical forests. This bias is problematic given that logged and disturbed tropical forests are now covering a larger area than the so-called primary forests. A new network of permanent sample plots in logged forests, the Tropical managed Forests Observatory (TmFO), aims to fill this gap by providing unprecedented opportunities to examine long-term data on the resilience of logged tropical forests at regional and global scales. TmFO currently includes 24 experimental sites distributed across three tropical regions, with a total of 490 permanent plots and 921 ha of forest inventories. 相似文献
Gametophytic apomixis in Kentucky bluegrass (Poa pratensis L.) involves the parthenogenetic development of unreduced eggs from aposporic embryo sacs. Marker-assisted selection for the mode of reproduction in P. pratensis would avoid costly and time-consuming phenotypic progeny tests. We developed and tested two SCAR primer pairs that are associated with the mode of reproduction in P. pratensis. The SCAR primers identified the apomictic and sexual genotypes among progenies of sexual x apomictic crosses with very low bias. Furthermore, when tested on a wide range of Italian and exotic P. pratensis germplasm, they were able to unequivocally distinguish sexual from apomictic genotypes. This system should, therefore, allow new selection models to be set up in this species. 相似文献
The olive is considered one of the most important fruit crops of the Mediterranean basin where it shows a wide range of variability,
with about 2,000 cultivars. Italy, with about 500 cultivars, plays a fundamental role. The ability to discriminate olive cultivars
and estimate genetic variability are important factors in better management of genetic resources and in helping to understand
how genetic diversity is partitioned among cultivars. The two main objectives of the present investigation were to evaluate
the identity of cultivars grown in Abruzzo region, central Italy, and to study their genetic structure. We applied amplified
fragment length polymorphism (AFLP) methodology on 84 genotypes belonging to the most relevant and oldest varieties cultivated
in Abruzzo and on six unknown genotypes. The information content of data was evaluated using the Marker Ratio index and the
Polymorphic Index Content. Moreover, STRUCTURE software was used to investigate the genetic population structure. The analysis
enabled us to clearly distinguish eight cultivars within seven clusters. Additionally, one cluster was found to have various
minor cultivars and showed a relatively high level of diversity. The partitioning of genetic diversity showed that the largest
amount of molecular variance was within groups. Our data suggest that both sexual and clonal propagation have played an important
role in the evolution of olive cultivars. In our hypothesis, some ancestral population spread in central Italy with a relevant
role of seed propagation, followed by a selection of superior clones from which more traditional varieties originated. In
a few cases, hybridization should be taken into consideration to explain the diffusion of recently developed cultivars. 相似文献