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排序方式: 共有479条查询结果,搜索用时 15 毫秒
471.
Diego Gil-Tapetado Carmen D. Soria Jose F. Gómez Jose Manuel Sesma Francisco José Cabrero-Sañudo 《Ecological Entomology》2023,48(1):40-54
- Identifying which species are being negatively impacted by climate change and the mechanisms driving their decline is essential to effectively protect biodiversity.
- Coenonympha pamphilus is a common and generalist butterfly, widely distributed throughout the Western Palearctic, being multivoltine in southern Europe. Previous studies indicate that it will not be substantially affected by climate change; however, it has seemingly disappeared from the southeast of the Iberian Peninsula in the last decades.
- Here, we aim to determine if it has effectively disappeared from this area, as well as identify the environmental conditions limiting its distribution and the potential causes behind this a priori local extinction.
- We downloaded all the occurrence records of C. pamphilus and analysed their spatial and temporal trends. To identify the climatic variables driving the distribution of this butterfly in the Iberian Peninsula, we performed an ensemble species distribution model (SDM), combining 600 individual models produced with 6 algorithms.
- We confirmed that C. pamphilus has not been observed in the southeast of the Iberian Peninsula since 2008. Aridity was the main factor limiting the distribution of C. pamphilus in our ensemble SDM, with areas with high aridity being unsuitable for this species.
- We hypothesise that multivoltinism is the mechanism driving this local extirpation, as high aridity is causing host plants (Poaceae) to wither prematurely, precluding the development of the second and/or third generations of the butterfly. Even though generalist species are theoretically more resilient to climate change, other traits such as multivoltinism may increase their vulnerability and need to be further investigated.
472.
Natalia M López Fernando di Sciascio Carlos M Soria Max E Valentinuzzi 《Biomedical engineering online》2009,8(1):5-13
Background
Myoelectric control of a robotic manipulator may be disturbed by failures due to disconnected electrodes, interface impedance changes caused by movements, problems in the recording channel and other various noise sources. To correct these problems, this paper presents two fusing techniques, Variance Weighted Average (VWA) and Decentralized Kalman Filter (DKF), both based on the myoelectric signal variance as selecting criterion. 相似文献473.
H Tuschi W Klein F Kocsis E Bernat H Altmann 《Environmental physiology & biochemistry》1975,5(2):84-91
The inhibition of semi-conservative DNA replication and unscheduled DNA synthesis by three different detergents was investigated in mouse spleen cells. The investigations were made by following the kinetics of the incorporation of 3H-thymidine into the DNA, as well as by autoradiographic studies. At various concentrations different inhibition patterns were found and the significance of these findings is discussed. 相似文献
474.
Summary A method of artificial mass-breeding ofCeratitis capitata has been developped after the results obtained byFinney andChristenson. The breeding of the larvae is obtained on a medium made of powdered atomised carrot and brewer's yeast, the development
of molds and bacteria being inhibited by benzo?c and hydrochloric acids. Nearly 80 per cent of the eggs give adult flies.
An original method for obtaining the eggs in an artificial egg-laying apparatus is described. The development of the insect
is completed in 21 days at the temperature of 26°C. A daily production of 20 000 flies or more is easily obtained, at very
low cost, by the work of a single person.
Travail réalisé avec la collaboration technique de MlleM. Barthes.
Station de Zoologie agricole du Centre de recherches agronomiques du Sud-Est. 相似文献
Travail réalisé avec la collaboration technique de MlleM. Barthes.
Station de Zoologie agricole du Centre de recherches agronomiques du Sud-Est. 相似文献
475.
P C Montecucchi A M Lazzarini L Barbieri F Stirpe M Soria D Lappi 《International journal of peptide and protein research》1989,33(4):263-267
The N-terminal portion of some type 1 ribosome-inactivating proteins (RIPs) isolated from the seeds of Gelonium multiflorum, Momordica charantia, Bryonia dioica, Saponaria officinalis and from the leaves of Saponaria officinalis are reported in the present paper. Their relationship with other RIPs is discussed. 相似文献
476.
477.
478.
E. Mocé M.L. Mocé S.A. Lozano-Palazón J. Bernácer M.M. Martínez-Granell I.C. Esteve F. Bernat S.J. Contreras I. Villalba E.A. Gómez 《Animal : an international journal of animal bioscience》2022,16(5):100525
Fertility is one of the most economically important traits in farm animals, due to the direct and indirect costs associated to low pregnancy rates. Thus, one of the priority goals in animal reproduction is to predict the performance that the semen doses will have in vivo based on the quality values obtained in laboratory assays. Attempts have been made for getting a predictive model of fertility of frozen-thawed sperm in dairy goats, but similar studies have not been conducted for chilled goat buck sperm doses that are mostly used for artificial insemination in many countries including Spain. We study how parameters of in vitro sperm quality and characteristics of Murciano-Granadina dairy goats may affect the in vivo fertility obtained after artificial insemination with semen doses chilled at 4 °C. Moreover, this information was used for obtaining predictive models of the fertility. Sixty-three ejaculates from 13 males were used to prepare chilled doses for the insemination of 495 goats over 13 sessions. Fresh and chilled sperm were evaluated for motility and plasma membrane integrity with a computer-assisted sperm analysis system and flow cytometry, respectively. Fertility was determined at parturition, according to the kidding goats. Overall fertility was 59.6%. Pearson’s correlation coefficients between in vivo fertility and quality variables of fresh sperm were not significant and were low (below 0.34 in absolute value) for chilled sperm. Females’ characteristics had a low negative impact on fertility (correlation coefficients of ?0.19 with age, ?0.20 with parturitions and ?0.11 with total milk yield obtained in the best lactation). Fixed and mixed logistic regression procedures were used trying to explain the fertility results. None of the models accurately predicted fertility, but the best models included the percentage of total motile sperm or average path velocity from fresh semen, age of the females and the session effect (uncontrolled environmental effects). These analyses showed that primiparous goats were 2.42 times more likely to get pregnant than goats that had kidded four or more times. Our field assay data on fertility in Murciano-Granadina dairy goats highlighted the importance of making quality controls of sperm, of choosing the doses presenting high percentages of motile sperm exhibiting regular trajectories and of selecting the youngest goats for AI, after their first kidding. Efforts should continue to obtain better predictive models for improving fertility in goat dairy herds. 相似文献
479.
Summary Soft-sediment deformation structures in Tortonian turbiditic deposits of the Guadix Basin (southern Spain) have been described.
The most common structures are asymmetrical pillow structures and elongated sets of loadcasts. The structures are metric in
scale and have been interpreted as the result of liquefaction and/or fluidization processes triggered by the rapid sedimentation
of single high concentration turbidites.
Final morphology of soft-sediment deformation structures is related to two main driving force systems: unstable density gradient
and lateral shear stress. The latter is probably induced by the downslope component of the sediment weight. The asymmetry
of deformational structures (in horizontal and vertical cross-section) allows a clarification of the relationship between
morphology of deformation and direction of lateral shear stress: this relationship seems ambiguous and confused in the literature.
The interpretations both of deformation mechanism and trigger agent have been supported with:-field analyses;-calculations
on the liquefaction processes induced by rapid sedimentation;-qualitative models in laboratory. 相似文献