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101.
Piotr Matyjasiak Paweł Boniecki Maciej Fuszara Mateusz Okołowski Izabela Olejniczak 《Animal cells and systems.》2018,22(2):124-131
Feather holes are small (0.5–1?mm in diameter) deformities that appear on the vanes of flight feathers. Such deformities were found in many bird species, including galliforms and passerines. Holey flight feathers may be more permeable to air, which could have a negative effect on their ability to generate aerodynamic forces. However, to date the effects of feather holes on flight performance in birds remained unclear. In this study we investigated the relationship between the number of feather holes occurring in the wing or tail feathers and short term flight performance traits – aerial manoeuvrability, maximum velocity and maximum acceleration – in barns swallows, which are long distance migrating aerial foragers. We measured short-term flight performance of barn swallows in a standardized manner in flight tunnels. We found that acceleration and velocity were significantly negatively associated with the number of holes in the wing flight feathers, but not with those in the tail feathers. In the case of acceleration the negative relationship was sex specific – while acceleration significantly decreased with the number of feather holes in females, there was no such significant association in males. Manoeuvrability was not significantly associated with the number of feather holes. These results are consistent with the hypothesis that feather holes are costly in terms of impaired flight. We discuss alternative scenarios that could explain the observed relationships. We also suggest directions for future studies that could investigate the exact mechanism behind the negative association between the number of feather holes and flight characteristics. 相似文献
102.
103.
Izabela Kołodziejczyk Katarzyna Dzitko Rafał Szewczyk Małgorzata M. Posmyk 《Acta Physiologiae Plantarum》2016,38(6):146
Melatonin (N-acetyl-5-methoxytryptamine) has a great potential for plant biostimulation. Its role in plant physiology is intensively explored, and its important function in plant stress defence frequently underlined. Melatonin is particularly effective when applied as an additional factor of seed priming. In the presented research, hydroconditioning was chosen experimentally as optimal for maize (Zea mays L.) seeds. The following seed variants were compared: controlled non-treated, hydroprimed with water and hydroprimed with melatonin solutions 50 and 500 μM. To identify modifications in proteome of maize seeds caused by the applied hydroconditioning techniques, protein extracts of germinated seed embryos (24 h, 25 °C) were separated by 2D-PAGE. Next, obtained maps of proteomes were compared (statistically and graphically) using PDQuest software, and characteristic spots of proteins were analysed qualitatively by mass-spectrometric techniques and identified in the Mascot protein databases. Research helped to identify hydropriming-associated proteins, and for the first time those which were expressed only in the presence of melatonin. Study confirmed that suitably selected pre-sowing treatment with melatonin, by embryo proteome modification, effectively prepares plants to adverse environmental conditions. In melatonin treated seeds during the initial state of embryos growth, even under optimal conditions, additional antioxidative, detoxifying, anti-stresses proteins were synthesized. Moreover, the supply of energy from seed storage substances was pretty intensified. The presented results partially explain how melatonin acts in plant stress defence, and why plants with higher melatonin content have exhibited increased capacity for stress tolerance. 相似文献
104.
Joanna Kabat-Koperska Agnieszka Kolasa-Wołosiuk Irena Baranowska-Bosiacka Krzysztof Safranow Danuta Kosik-Bogacka Izabela Gutowska Anna Pilutin Edyta Gołembiewska Karolina Kędzierska Kazimierz Ciechanowski 《Apoptosis : an international journal on programmed cell death》2016,21(11):1240-1248
Pregnancy puts a significant additional strain on kidneys. The aim of our study was to investigate the impact of immunosuppressive drugs on changes in native kidneys in female Wistar rats after exposure during pregnancy. The study was conducted on 32 dams, subjected to immunosuppressive regimens commonly used in the therapy of human kidney transplant recipients (cyclosporine A, mycophenolate mofetil and prednisone; tacrolimus, mycophenolate mofetil and prednisone; cyclosporine A, everolimus and prednisone). The animals received drugs for 2 weeks before pregnancy and during 3 weeks of pregnancy. In all treated dams lower body weight (but not kidney mass) and alterations in serum sodium and chloride ions were found; serum creatinine concentration was increased in dams treated with cyclosporine A, everolimus and prednisone. All treatment groups of dams showed increased apoptosis in the distal tubules. In histological examination the changed intensity of acidophilic or basophilic cytoplasm of epithelial cells was found in kidneys of rats treated with calcineurin inhibitors, mycophenolate mofetil and prednisone. All immunosuppressive regimens caused abnormalities affecting nephron tubules. Regimens containing calcineurin inhibitors and mycophenolate mofetil caused higher rate of apoptosis and more pronounced histopathological changes. Regimen based on everolimus despite the lower rate of apoptosis in the proximal tubules and lower accumulation of kidney injury markers revealed higher serum creatinine concentration. Thus, interpretation which combination of drugs is better or worse for long-lasting functioning of kidneys in pregnant females requires further studies. 相似文献
105.
The induction of thymocyte apoptosis through the Nur77-mediated intrinsic pathway can be of physiological importance in the clonal deletion of autoreactive thymocytes during negative selection in the thymus and/or in thymocytes undergoing oncogenic transformation. Ionomycin treatment induces endogenous Nur77 expression as well as apoptosis and cytochrome c release in thymocytes. Here it is shown for the first time that in normal thymocytes undergoing apoptosis, ionomycin induces translocation of endogenous Nur77 not only to the nucleus, but also to mitochondria. Immunosuppressant FK506 inhibits Nur77 NBRE and NurRE binding activity but has no effect on thymocytes apoptosis, the subcellular localization of Nur77, or cytochrome c release. This indicates that thymocytes can undergo apoptosis through the intrinsic Nur77-mediated mitochondrial pathway and that the transactivation activity of Nur77 monomers or dimers is not necessary for thymocyte apoptosis. 相似文献
106.
Trade‐offs between reproduction and self‐maintenance (immune function and body mass) in a small seabird,the little auk
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Izabela Kulaszewicz Katarzyna Wojczulanis‐Jakubas Dariusz Jakubas 《Journal of avian biology》2017,48(3):371-379
Breeding season is the most energetically and physiologically demanding phase in the avian annual cycle, challenging adults' physiology and survival. However, the timing and extent that self‐maintenance of breeding adults is compromised during the breeding season is poorly understood. We investigated the trade‐off between reproduction and self‐maintenance in relation to breeding phase (prelaying, incubation, chick rearing) and sex in a small Arctic seabird, the little auk Alle alle. To measure a bird's allocation of time for self‐maintenance, we examined size‐adjusted body mass and immunocompetence expressed by bacteria (Escherichia coli) killing capacity (BKC) of blood plasma, heterophils/lymphocyte ratio (H/L) and their numbers of particular leucocytes per 10 000 red blood cells (RBC). We found that size‐adjusted body mass decreased as the breeding season progressed. BKC, number of heterophils and H/L values were all was significantly higher at prelaying when compared to all other phases. Interestingly, we found that heavier individuals had higher BKC and number heterophils at the prelaying and chick rearing phases than light individuals. There were no differences by sex in any studied variables. Our results indicate that immunocompetence and body mass of breeding adults decreases over the course of breeding season. The efficiency of the immune system appears to be dependent on the bird's body reserves. Our results suggest that little auks allocation of resources into reproduction negatively affects their self‐maintenance. 相似文献
107.
Microstructure and nanomechanical properties of single stalks from diatom Didymosphenia geminata and their change due to adsorption of selected metal ions
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Izabela Zgłobicka Adrian Chlanda Michał Woźniak Maciej Łojkowski Robert Szoszkiewicz Marta Mazurkiewicz‐Pawlicka Wojciech Święszkowski Elżbieta Wyroba Krzysztof J. Kurzydłowski 《Journal of phycology》2017,53(4):880-888
We present topographical and nanomechanical characterization of single Didymosphenia geminata stalk. We compared the samples before and after adsorption of metal ions from freshwater samples. Transmission electron microscopy studies of single stalk cross‐sections have shown three distinct layers and an additional thin extra coat on the external layer (called “EL”). Using scanning electron microscopy and atomic force microscopy (AFM), we found that topography of single stalks after ionic adsorption differed significantly from topography of pristine stalks. AFM nanoindentation studies in ambient conditions yielded elastic moduli of 214 ± 170 MPa for pristine stalks and 294 ± 108 MPa for stalks after ionic adsorption. Statistical tests showed that those results were significantly different. We conducted only preliminary comparisons between ionic adsorption of several stalks in air and in water. While the stalks with ions were on average stiffer than the pristine stalks in air, they became more compliant than the pristine stalks in water. We also heated the stalks and detected EL softening at 50°C ± 15°C. AFM nanoindentation in air on the softened samples yielded elastic moduli of 26 ± 9 MPa for pristine samples and 43 ± 22 MPa for stalks with absorbed metal ions. Substantial decrease of the EL elastic moduli after heating was expected. Significantly different elastic moduli for the samples after ionic adsorption in both cases (i.e., for heated and nonheated samples), as well as behavior of the stalks immersed in water, point to permanent structural EL changes due to ions. 相似文献
108.
Katarzyna Juzoń Ilona Czyczyło-Mysza Izabela Marcińska Michał Dziurka Piotr Waligórski Edyta Skrzypek 《Acta Physiologiae Plantarum》2017,39(9):202
Polyamines (PAs) are related to many physiological processes, including soil drought stress. Two yellow lupin ‘Morocco 4’ (drought tolerant) and ‘Taper’ (drought sensitive) were exposed to soil drought for 2 weeks. The half of the examined plants were additionally sprayed with a solution of polyamine biosynthesis inhibitor—dl-α-difluoromethylarginine (DFMA). Yellow lupin leaves showed a 19% increase and seeds a 54% decrease in the total PA contents. The seeds contained fourfold less PAs than the leaves under drought conditions. The highest amount of spermidine and lack of agmatine were found in the leaves, while in the seeds the highest content of spermine and the presence of agmatine was confirmed. The use of DFMA under drought conditions decreased the content of spermine in ‘Morocco 4’ and ‘Taper’ (41 and 19%, respectively) and spermidine in ‘Taper’ (by 13%), as well as reduced two out of three of the yield components. More tolerant ‘Morocco 4’, after DFMA treatment was characterized by a higher spermidine and spermine content and a smaller decrease in yield components compared to the less tolerant ‘Taper’. Simultaneously subjecting plants to soil drought and DFMA treatment caused in ‘Morocco 4’ a decline in the number of pods and seeds per plant and seeds dry weight per plant (64, 50 and 54%, respectively), while in ‘Taper’ a reduction of the number of pods per plant and seeds per pod (32 and 27%, respectively) was observed. These results confirm that PAs are involved in yellow lupin tolerance and may play a protective function under soil drought conditions. 相似文献
109.
Jamie Sheren Siriwimon Saichaemchan Witthawat Ariyawutyakorn Izabela Avolio Ethan Cabral Magdelena Glogowska Carol Amato Steven Robinson Jennifer Hintzsche Allison Applegate Eric Seelenfreund Rita Gonzalez Keith Wells Stacey Bagby John Tentler Aik‐Choon Tan Joshua Wisell Marileila Varella‐Garcia William Robinson 《Pigment cell & melanoma research》2017,30(1):53-62
Genomic rearrangements resulting in activating kinase fusions have been increasingly described in a number of cancers including malignant melanoma, but their frequency in specific melanoma subtypes has not been reported. We used break‐apart fluorescence in situ hybridization (FISH) to identify genomic rearrangements in tissues from 59 patients with various types of malignant melanoma including acral lentiginous, mucosal, superficial spreading, and nodular. We identified four genomic rearrangements involving the genes BRAF, RET, and ROS1. Of these, three were confirmed by Immunohistochemistry (IHC) or sequencing and one was found to be an ARMC10‐BRAF fusion that has not been previously reported in melanoma. These fusions occurred in different subtypes of melanoma but all in tumors lacking known driver mutations. Our data suggest gene fusions are more common than previously thought and should be further explored particularly in melanomas lacking known driver mutations. 相似文献
110.
Katarzyna Golan Cezary Sempruch Edyta Górska-Drabik Paweł Czerniewicz Bożena Łagowska Izabela Kot Katarzyna Kmieć Klaudia Magierowicz Bogumił Leszczyński 《Arthropod-Plant Interactions》2017,11(5):675-682
The study aimed at comparing the changes in the content of free amino acids, phenolic compounds and the activity of PAL and TAL caused by two piercing-sucking arthropods: the grape mealybug (Pseudococcus maritimus Ehrh.) and the two-spotted spider mite (Tetranychus urticae Koch) in the leaves of orchid and strawberry, respectively. The obtained results show that the amino acid content and the ratio of amino acids to phenolic compounds increased in both plant species infested by the mealybug and the mite. However, such response was weakly dependent on changes in activity of the analysed enzymes. The pest feeding affected accumulation of the phenolic compounds, since the induction of the PAL activity in mealybug-infested orchid leaves during the first 5 h of the experiment preceded the increase in phenolic compounds during the first week of insect feeding. Instead, the increased activity of TAL was accompanied by elevated levels of phenolic compounds in the leaves of strawberry infested by mites. Mechanisms of biochemical plant responses induced by infestation of the studied herbivorous arthropods are discussed. 相似文献