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131.
132.
With populations of land snails of very small size like Vertiginidae,questions have arisen as to whether populations of relativelydistant islands in archipelagos are really isolated from eachother. Apart from other flight agencies, airborne transportof loose specimens is not improbable in stormy weather conditions.Currently, mechanisms of wind-borne transport of sand particlesover short and long distances have been intensively studied.The results are available in the literature on sediments, allowingthe calculation of probable flight distances for particles insuspension. For living snails of the Aegean species Truncatel-lina rothi,an average fall velocity of 2.62.7 m s1 has beendetermined in experiments under laboratory conditions. Applyingthese results, Truncatellina living on an island at 100 m altitudeand close to the coast could be transported up to several kilometersin heavy storms, which are not uncommon in the Aegean archipelago(Greece). This would imply that many of the Aegean islands arenot effectively isolated for minute snail species, and thatgenetic interchange between island populations is probably frequent. (Received 3 April 1996; accepted 27 January 1997) 相似文献
133.
A. IOAKIM-LIOSSI P. KARAKITSOS CH. MARKOPOULOS† K. ARONI‡ K. DELIVELIOTI J. GOGAS† K. KYRKOU 《Cytopathology》1997,8(5):322-327
DNA content and p53 protein expression in ductal breast cancer
The DNA content of 85 ductal breast cancers of different histological grades was evaluated using static cytometry and correlated with immunocytochemical expression of p53 protein in tumour cells in cytological material. A statistically significant difference was observed between p53 protein expression and grade of malignancy ( P <0.001). The percentage of euploid tumours significantly decreased from grade I through grade II to grade III tumours ( P <0.001). Clonal DNA heterogeneity was observed in 26.6% of cases analysed and was correlated with p53 protein expression ( P <0.001). These changes probably reflect genomic alterations which may affect potential malignancy of breast cancer. 相似文献
The DNA content of 85 ductal breast cancers of different histological grades was evaluated using static cytometry and correlated with immunocytochemical expression of p53 protein in tumour cells in cytological material. A statistically significant difference was observed between p53 protein expression and grade of malignancy ( P <0.001). The percentage of euploid tumours significantly decreased from grade I through grade II to grade III tumours ( P <0.001). Clonal DNA heterogeneity was observed in 26.6% of cases analysed and was correlated with p53 protein expression ( P <0.001). These changes probably reflect genomic alterations which may affect potential malignancy of breast cancer. 相似文献
134.
Acaricidal activity of Metarhizium anisopliae isolated from paddocks in the Mexican tropics against two populations of the cattle tick Rhipicephalus microplus
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A. FERNÁNDEZ ‐SALAS M. A. ALONSO‐DÍAZ R. A. ALONSO‐MORALES R. LEZAMA‐GUTIÉRREZ J. C. RODRÍGUEZ‐RODRÍGUEZ J. A. CERVANTES‐CHÁVEZ 《Medical and veterinary entomology》2017,31(1):36-43
The acaricidal effects of 55 strains of Metarhizium anisopliae (Metschnikoff) Sorokin, 1883 (Hypocreales: Clavicipitaceae) isolated from paddocks of cattle farms were evaluated in two Rhipicephalus microplus (Canestrini 1887) (Ixodida: Ixodidae) populations, of which one was multi‐resistant and one was susceptible to chemical acaricides. Percentage mortality and reproductive efficiency indices in R. microplus were evaluated by adult immersion tests at a dose of 1 × 108 conidia/mL for each fungal strain. Some strains were selected to calculate lethal concentrations to kill 50% (LC50) and 99% (LC99) of engorged ticks. Strains MaV22, MaV26 and MaV55 induced 100% mortality in R. microplus on day 14. Strains MaV05, MaV09 and MaV22 caused mortality of >90% from day 12 onward in both tick populations. The most effective acaricidal fungal strain, MaV55, inhibited egg laying by 54.86 and 55.86% in acaricide‐resistant and ‐susceptible R. microplus populations, respectively. None of the fungal strains had statistically significant effects on larval hatching. In conclusion, nine strains of M. anisopliae demonstrated high acaricidal effects against R. microplus and reduced its egg laying. No differences in acaricidal effects were observed between the two populations of ticks tested. 相似文献
135.
Cyprinus curpio is usually dioecious, with well–developed paired gonads (ovaries or testes) of which the two parts are approximately equal in weight. However, a few instances of abnormal development have been observed. In one male fish, the right testis developed normally to maturity, while the left testis was vestigial. In a female fish, only the right component of the ovary was present. Some monoecious, synchronous hermaphrodite specimens have also been observed, and self fertilization demonstrated experimentally. It has been shown (Kossmann, 1971) that the progeny of such synchronous hermaphrodites may also have this characteristic. These studies demonstrate that even such a highly evolved teleost as the Carp may retain the primitive characteristic of hermaphroditism. 相似文献
136.
The discovery of green fluorescent protein (GFP) from jellyfish Aequorea victoria has provoked numerous studies to unveil the myriads of biomedical applications. Consequently, several studies also revealed the prevalence of fluorescence in different marine and terrestrial organisms. However, since GFP's discovery or the Nobel prize award on GFP, the fluorescence has not been explored so far from India. The current study presents the widespread fluorescent organisms resources available in India for biomedical and toxicological applications. Fluorescence emission from different plant and animal components were examined by direct observations using UV torchlight. Investigation revealed that blue light excited fluorescence in several organisms. For the first time, this study observed GFP like fluorescence in many terretrial and marine organisms of India. Observations are indicating that fluorescent proteins have essential ecological functions that are yet to be determined. The examined plant and animal components were not bioluminescent. In comparison, the potential untouched research areas on fluorescence aspects are detailed. A thorough review of fluorescent organisms reported hitherto is also provided to spread the current knowledge on fluorescence. 相似文献
137.
Biotic filtering and mass effects in small shrub patches: is arthropod community structure predictable based on the quality of the vegetation?
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VOJTĚCH LANTA KAI NORRDAHL SONJA GILBERT GUY SÖDERMAN VEIKKO RINNE 《Ecological Entomology》2018,43(2):234-244
1. Community assembly is affected by four processes: dispersal, filtering effects (selection), ecological drift and evolution. The role of filtering relative to dispersal and drift should decline with patch size, hampering possibilities to predict which organisms will be observed within small‐sized patches. However, vegetation structure is known to have a marked impact on species assemblages, and plant quality may act as a biotic filter. This challenges the assumption of unpredictable species assemblages in small‐sized vegetation patches. 2. Using 32 stands of five shrub species in south‐west Finland, this study investigated whether biotic filtering effects caused by patch‐forming plants are strong enough to overcome the mixing of mobile arthropod assemblages across small patches. 3. Stochastic variation did not hide the signals of biotic filtering and dispersal in the small shrub patches. Habitat richness around the patches explained a three times larger share of variation in the species composition than did the identity of the patch‐forming plant, but it had less effect on the abundance of arthropods. A radius of 50–100 m around a patch explained the species composition best. 4. Abundance patterns varied between the feeding guilds; the patch‐forming shrub influenced the abundances of detritivores and leaf‐feeding herbivores, whereas the abundances of flower‐visiting herbivores appeared to track the flowering phenology of the plants. Shrub identity had little effect on omnivores or predators. Predator abundances were correlated with the abundance of potential prey. 5. The results of this study suggest that community composition within a vegetation patch may be predictable even if dispersal overrides local filtering effects, as suggested by the mass‐effects paradigm. 相似文献
138.
139.
Christiaan H. Vinkers Herm J. Lamberink Joeri K. Tijdink Pauline Heus Lex Bouter Paul Glasziou David Moher Johanna A. Damen Lotty Hooft Willem M. Otte 《PLoS biology》2021,19(4)
Many randomized controlled trials (RCTs) are biased and difficult to reproduce due to methodological flaws and poor reporting. There is increasing attention for responsible research practices and implementation of reporting guidelines, but whether these efforts have improved the methodological quality of RCTs (e.g., lower risk of bias) is unknown. We, therefore, mapped risk-of-bias trends over time in RCT publications in relation to journal and author characteristics. Meta-information of 176,620 RCTs published between 1966 and 2018 was extracted. The risk-of-bias probability (random sequence generation, allocation concealment, blinding of patients/personnel, and blinding of outcome assessment) was assessed using a risk-of-bias machine learning tool. This tool was simultaneously validated using 63,327 human risk-of-bias assessments obtained from 17,394 RCTs evaluated in the Cochrane Database of Systematic Reviews (CDSR). Moreover, RCT registration and CONSORT Statement reporting were assessed using automated searches. Publication characteristics included the number of authors, journal impact factor (JIF), and medical discipline. The annual number of published RCTs substantially increased over 4 decades, accompanied by increases in authors (5.2 to 7.8) and institutions (2.9 to 4.8). The risk of bias remained present in most RCTs but decreased over time for allocation concealment (63% to 51%), random sequence generation (57% to 36%), and blinding of outcome assessment (58% to 52%). Trial registration (37% to 47%) and the use of the CONSORT Statement (1% to 20%) also rapidly increased. In journals with a higher impact factor (>10), the risk of bias was consistently lower with higher levels of RCT registration and the use of the CONSORT Statement. Automated risk-of-bias predictions had accuracies above 70% for allocation concealment (70.7%), random sequence generation (72.1%), and blinding of patients/personnel (79.8%), but not for blinding of outcome assessment (62.7%). In conclusion, the likelihood of bias in RCTs has generally decreased over the last decades. This optimistic trend may be driven by increased knowledge augmented by mandatory trial registration and more stringent reporting guidelines and journal requirements. Nevertheless, relatively high probabilities of bias remain, particularly in journals with lower impact factors. This emphasizes that further improvement of RCT registration, conduct, and reporting is still urgently needed.Many randomized controlled trials (RCTs) are biased and difficult to reproduce due to methodological flaws and poor reporting. Analysis of 176,620 RCTs published between 1966 and 2018 reveals that the risk of bias in RCTs generally decreased. Nevertheless, relatively high probabilities of bias remain, showing that further improvement of RCT registration, conduct, and reporting is still urgently needed. 相似文献
140.
SYNOPSIS. In various ciliates the contractile vacuole is a permanent organelle, delimited by a differentiated cortex.
The cortex is made up of a dense reticulum of anastomosing tubules limited by a smooth membrane, and vesicles. This "spongiome" can be considered as a localized and specialized condensation of the endoplasmic reticulum. 相似文献
The cortex is made up of a dense reticulum of anastomosing tubules limited by a smooth membrane, and vesicles. This "spongiome" can be considered as a localized and specialized condensation of the endoplasmic reticulum. 相似文献