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Nando Sigona 《Ethnic and racial studies》2018,41(3):456-460
How we label, categorize and, in turn, differentiate between those on the move, for example those who cross the Mediterranean on unseaworthy boats, has enormous implications on the kind of legal and moral obligations receiving states and societies feel towards them. This is perhaps even more salient nowadays in the context of the process of reform of the global governance of migration initiated with the 2016 New York Declaration for Refugees and Migrants. 相似文献
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G.L. Nuechterlein 《Animal behaviour》1981,29(4):985-989
Of 38 western grebe (Aechmophorus occidentalis) colonies initiated on the Delta Marsh, Lake Manitoba, in 1973 through 1979, over half (53%) included breeding Forster's terns (Sterna forsteri). Tern-associated colonies included 12 of the 13 largest colonies, incorporating 83% of the total nesting effort (N=2821 nests). Such colonies were impossible to approach undetected, because grebes used the tern's aerial alarm system to warn of danger. Playbacks showed that grebes recognized the tern's alarm call, and responded by immediately leaving their nests. This essentially constitutes a form of ‘information parasitism,’ which probably is widespread in many nesting associations. This work suggests a broadening of the ‘information centre’ hypothesis to include transfer of information about any reproductive requisite, not just food. 相似文献
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aneta Wareczak-Florczak Bartosz Urbaski 《Reports of Practical Oncology and Radiotherapy》2022,27(3):566
The war in Ukraine has led to a massive influx of refugees into Poland, posing a major challenge for the health care system. The large number of refugees will undoubtedly lead to a substantial increase in the number of patients requiring treatment for a wide range of conditions, including cancer. In the present article, we describe and discuss the many difficulties faced by cancer treatment centres in Poland due to these circumstances. Key issues include the lack of proper diagnostic testing in this population and differences in oncological practices between Poland and Ukraine. Other problems include difficulties in obtaining patients’ medical records and communication issues caused by the language barrier. In addition, in the context of the ongoing COVID-19 pandemic, the low vaccination rate among Ukrainian refugees is also a significant risk factor. Addressing these challenges will require a comprehensive approach involving the national health care agency and individual cancer centres. This is especially important in oncology due to the interdisciplinary nature of the field, which requires the contribution of specialists from many different fields as well as appropriate funding. 相似文献
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A. V. Alessenko 《Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry》2013,7(2):108-123
The review discusses the functional role of sphingolipids in the pathogenesis of Alzheimer’s disease (AD). Certain evidence exists that the imbalance of sphingolipids such as sphingomyelin, ceramide, sphingosine, sphingosine-1-phosphate and galactosylceramide in the brain of animals and humans, in the cerebrospinal fluid and blood plasma of AD patients plays a crucial role in neuronal function by regulating growth, differentiation and cell death in CNS. Activation of sphingomyelinase (Smase), which leads to the accumulation of the proapoptotic agent, ceramide, can be considered as a new mechanism for AD and may be a prerequisite for the treatment of this disease by using drugs that inhibit SMase activity. The role of sphingolipids as biomarkers for the diagnosis of the early stage of Alzheimer’s disease and monitoring the effectiveness of treatment with new drugs is discussed. 相似文献
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Fuke Yusuke Satoh Takashi P. Kano Yuichi Watanabe Katsutoshi 《Ichthyological Research》2021,68(4):556-560
Ichthyological Research - 相似文献
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An inexpensive and easily automated flow injection method for determination of urea in cow’s milk was evaluated. Urea is hydrolysed by urease and in a gas diffusion cell the ammonia formed passes a membrane into an indicator solution. The resulting colour change of the indicator is measured at 590 nm. The repeatability of the analysis, expressed as the coefficient of variation (C.V.), was between 0.5 and 1.2%. Measured (y) and expected (x) milk urea concentrations after addition of known amounts of urea were related according to the equation y = 1.00× – 0.12 with a C.V. for the regression of 1.8%. Recommended amounts (0.02 %) of the preservative bronopol (2-bromo-2-nitropropane-1,3-diol) added to the milk did not affect the results (P > 0.05). 相似文献
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Kamal Abuhassan Damien Coyle Ammar Belatreche Liam Maguire 《Journal of computational neuroscience》2014,36(1):19-37
Confirming that synaptic loss is directly related to cognitive deficit in Alzheimer’s disease (AD) has been the focus of many studies. Compensation mechanisms counteract synaptic loss and prevent the catastrophic amnesia induced by synaptic loss via maintaining the activity levels of neural circuits. Here we investigate the interplay between various synaptic degeneration and compensation mechanisms, and abnormal cortical oscillations based on a large-scale network model consisting of 100,000 neurons exhibiting several cortical firing patterns, 8.5 million synapses, short-term plasticity, axonal delays and receptor kinetics. The structure of the model is inspired by the anatomy of the cerebral cortex. The results of the modelling study suggest that cortical oscillations respond differently to compensation mechanisms. Local compensation preserves the baseline activity of theta (5–7 Hz) and alpha (8–12 Hz) oscillations whereas delta (1–4 Hz) and beta (13–30 Hz) oscillations are maintained via global compensation. Applying compensation mechanisms independently shows greater effects than combining both compensation mechanisms in one model and applying them in parallel. Consequently, it can be speculated that enhancing local compensation might recover the neural processes and cognitive functions that are associated with theta and alpha oscillations whereas inducing global compensation might contribute to the repair of neural (cognitive) processes which are associated with delta and beta band activity. Compensation mechanisms may vary across cortical regions and the activation of inappropriate compensation mechanism in a particular region may fail to recover network dynamics and/or induce secondary pathological changes in the network. 相似文献
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Transport of ethanol in baker’s yeast 总被引:1,自引:0,他引:1
Ethanol is transported into various strains of baker's yeast by simple diffusion (no effect of inhibitors and a linear concentration dependence of the initial rate of uptake and final distribution in cells). It distributes itself in 96.6 +/- 16.2% of intracellular water. 相似文献
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Environmental influences affecting genetically susceptible individuals seem to contribute significantly to the development of Parkinson’s disease (PD). Xenobiotic exposure including transitional metal deposition into vulnerable CNS regions appears to interact with PD genes. Such exposure together with mitochondrial dysfunction evokes a destructive cascade of biochemical events, including oxidative stress and degeneration of the sensitive dopamine (DA) production system in the basal ganglia. Recent research indicates that the substantia nigra degeneration can be decelerated by treatment with iron binding compounds such as deferiprone. Interestingly compounds known to decrease PD risk including caffeine, niacin, nicotine and salbutamol also possess iron binding properties. Adequate function of antioxidative mechanisms in the vulnerable brain cells can be restored by acetylcysteine supplementation to normalize intracellular glutathione activity. Other preventive measures to reduce deterioration of dopaminergic neurons may involve life-style changes such as intake of natural antioxidants and physical exercise. Further research is recommended to identify therapeutic targets of the proposed interventions, in particular protection of the DA biosynthesis by oxygen radical scavengers and iron binding agents. 相似文献
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Zhiyou Cai Nannuan Liu Chuanling Wang Biyong Qin Yingjun Zhou Ming Xiao Liying Chang Liang-Jun Yan Bin Zhao 《Cellular and molecular neurobiology》2016,36(4):483-495
Receptor for advanced glycation end products (RAGE) is a receptor of the immunoglobulin super family that plays various important roles under physiological and pathological conditions. Compelling evidence suggests that RAGE acts as both an inflammatory intermediary and a critical inducer of oxidative stress, underlying RAGE-induced Alzheimer-like pathophysiological changes that drive the process of Alzheimer’s disease (AD). A critical role of RAGE in AD includes beta-amyloid (Aβ) production and accumulation, the formation of neurofibrillary tangles, failure of synaptic transmission, and neuronal degeneration. The steady-state level of Aβ depends on the balance between production and clearance. RAGE plays an important role in the Aβ clearance. RAGE acts as an important transporter via regulating influx of circulating Aβ into brain, whereas the efflux of brain-derived Aβ into the circulation via BBB is implemented by LRP1. RAGE could be an important contributor to Aβ generation via enhancing the activity of β- and/or γ-secretases and activating inflammatory response and oxidative stress. However, sRAGE–Aβ interactions could inhibit Aβ neurotoxicity and promote Aβ clearance from brain. Meanwhile, RAGE could be a promoting factor for the synaptic dysfunction and neuronal circuit dysfunction which are both the material structure of cognition, and the physiological and pathological basis of cognition. In addition, RAGE could be a trigger for the pathogenesis of Aβ and tau hyper-phosphorylation which both participate in the process of cognitive impairment. Preclinical and clinical studies have supported that RAGE inhibitors could be useful in the treatment of AD. Thus, an effective measure to inhibit RAGE may be a novel drug target in AD. 相似文献
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In the present paper we demonstrate the use of inverse Broyden’s algorithm (IBA) in the simulation of fracture in single iron
crystals. The iron crystal structure is treated as a truss system, while the forces between the atoms situated at the nodes
are defined by modified Morse inter-atomic potentials. The evolution of lattice structure is interpreted as a sequence of
equilibrium states corresponding to the history of applied load/deformation, where each equilibrium state is found using an
iterative procedure based on IBA. The results presented demonstrate the success of applying the IBA technique for modeling
the mechanisms of elastic, plastic and fracture behavior of single iron crystals. 相似文献
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We examined the affects of selected water quality variables on the presence of subadult sharks in six of nine Georgia estuaries.
During 231 longline sets, we captured 415 individuals representing nine species. Atlantic sharpnose shark (Rhizoprionodon terranovae), bonnethead (Sphyrna tiburo), blacktip shark (Carcharhinus limbatus) and sandbar shark (C. plumbeus) comprised 96.1% of the catch. Canonical correlation analysis (CCA) was used to assess environmental influences on the assemblage
of the four common species. Results of the CCA indicated Bonnethead Shark and Sandbar Shark were correlated with each other
and with a subset of environmental variables. When the species occurred singly, depth was the defining environmental variable;
whereas, when the two co-occurred, dissolved oxygen and salinity were the defining variables. Discriminant analyses (DA) were
used to assess environmental influences on individual species. Results of the discriminant analyses supported the general
CCA findings that the presence of bonnethead and sandbar shark were the only two species that correlated with environmental
variables. In addition to depth and dissolved oxygen, turbidity influenced the presence of sandbar shark. The presence of
bonnethead shark was influenced primarily by salinity and turbidity. Significant relationships existed for both the CCA and
DA analyses; however, environmental variables accounted for <16% of the total variation in each. Compared to the environmental
variables we measured, macrohabitat features (e.g., substrate type), prey availability, and susceptibility to predation may
have stronger influences on the presence and distribution of subadult shark species among sites. 相似文献
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《Ostrich》2013,84(3):241-246
The North African population of Bonelli’s Eagle Aquila fasciata (Vieillot, 1822) is limited to the south by the northern fringe of the Sahara Desert. This study provides the first data on the spatial distribution and density of breeding Bonelli’s Eagles in south-west Morocco, at the southern limit of their breeding distribution in the Western Palearctic. We used broad-scale sampling to investigate spatial patterns in occupancy of territorial pairs of Bonelli’s Eagles in an area of ~29 715 km2 in the western Anti-Atlas Mountains, southern Morocco, during 2016–2018. We found 28 nesting territories containing 40 used nests, heterogeneously distributed in areas of high topographic variation, from 60 to 1 890 m asl. The average nearest-neighbour nest distance was 14.12 ± 9.90 km and varied from 2.65 km in the north-west to 37.80 km in the pre-Saharan lands in the south-west portion of the study area. This work shows the importance of the western Anti-Atlas Mountains as one of the most significant strongholds of the species in Morocco. However, there is a need for systematic analyses of the different factors affecting the distribution of the species to implement conservation actions of this peripheral population. 相似文献
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Funmilola A. Ayeni Bolanle A. Adeniyi Samuel T. Ogunbanwo Raquel Tabasco Torsten Paarup Carmen Peláez Teresa Requena 《Archives of microbiology》2009,191(8):639-648
A total of 96 lactic acid bacteria (LAB) were isolated from African indigenous fermented products and cow’s intestines to
study their inhibitory capability against multi-drug-resistant uropathogens. Escherichia coli accounted for approximately 45% of isolated uropathogens, followed by Staphylococcus spp. (20%). The Gram negative uropathogens were highly resistant to quinolones, co-trimoxazole, teicoplanin and some β-lactams,
while the Staphylococcus spp. showed high resistance to aminoglycosides, β-lactams and macrolides. Twenty-four LAB isolates were selected based on
their antimicrobial activity against two uropathogenic Staphylococcus aureus strains and bacteriocin production. LAB strains showing antimicrobial activity were grouped into smaller groups through amplified
ribosomal DNA restriction analysis (ARDRA). Representative strains were identified as Weissella spp., Enterococcus
faecium, Lactococcus lactis and Lactobacillus brevis through sequencing of 16S rDNA. The Weissella spp. and L. brevis strains demonstrated remarkable inhibitory activity against seven strains of Gram negative uropathogens. Two strains of L. lactis produced a bacteriocin-like inhibitory substance active against Lactobacillus sakei. In this study, an unusual high rate of co-trimoxazole, quinolones and macrolides resistance among uropathogens from south
west Nigeria was discovered. Based on their sensitivity to Weissella spp., there is a potential for using these LAB as a natural approach for the protection against the uropathogens assayed. 相似文献
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PurposeIt is vital to appropriately power clinical trials towards discovery of novel disease-modifying therapies for Parkinson’s disease (PD). Thus, it is critical to improve prediction of outcome in PD patients.MethodsWe systematically probed a range of robust predictor algorithms, aiming to find best combinations of features for significantly improved prediction of motor outcome (MDS-UPDRS-III) in PD. We analyzed 204 PD patients with 18 features (clinical measures; dopamine-transporter (DAT) SPECT imaging measures), performing different randomized arrangements and utilizing data from 64%/6%/30% of patients in each arrangement for training/training validation/final testing. We pursued 3 approaches: i) 10 predictor algorithms (accompanied with automated machine learning hyperparameter tuning) were first applied on 32 experimentally created combinations of 18 features, ii) we utilized Feature Subset Selector Algorithms (FSSAs) for more systematic initial feature selection, and iii) considered all possible combinations between 18 features (262,143 states) to assess contributions of individual features.ResultsA specific set (set 18) applied to the LOLIMOT (Local Linear Model Trees) predictor machine resulted in the lowest absolute error 4.32 ± 0.19, when we firstly experimentally created 32 combinations of 18 features. Subsequently, 2 FSSAs (Genetic Algorithm (GA) and Ant Colony Optimization (ACO)) selecting 5 features, combined with LOLIMOT, reached an error of 4.15 ± 0.46. Our final analysis indicated that longitudinal motor measures (MDS-UPDRS-III years 0 and 1) were highly significant predictors of motor outcome.ConclusionsWe demonstrate excellent prediction of motor outcome in PD patients by employing automated hyperparameter tuning and optimal utilization of FSSAs and predictor algorithms. 相似文献
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Linas Balčiauskas Laima Balčiauskienė Uudo Timm 《Central European Journal of Biology》2014,9(12):1147-1154
The body size of Palearctic Sorex shrews decreases at higher latitudes, and as such the Bergmann’s rule does not work. However, no analysis has ever been done for water shrew (Neomys fodiens) in the middle of distribution range. Analysis of available literature data showed that some body and skull measurements of N. fodiens are negatively correlated to latitude. Measurements of 158 water shrews from Estonia and Lithuania were also analyzed with respect to the short scale latitudinal pattern. We found that populations are separated (Wilk’s lambda = 0.363, p<0.0001). Differences are related to PC1 (skull size), explaining 49.80% of the variance and PC2 (body size), explaining 10.06% of the variance. Estonian shrews are smaller in their body and skull (most differences significant) and their skulls are relatively shorter and wider in the area of the brain case. Thus, the negative correlation of body and skull size to latitude in N. fodiens is applicable even over quite short latitudinal distances. Further analysis of diagnostic characters between N. fodiens and N. anomalus is required. 相似文献
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Oudin’s principle of single immunodiffusion in agar gel was modified for quantitative determination of IgA in bronchoalveolar lavage (BAL) of normal 20–25 g mice. The reaction took place at 25 °C in 0.3 % agarose with 16.7 % pig serum against mouse IgA, and was evaluated on the basis of a relationship between the progress of the precipitin zone and the square root of time. The linear dependence of the derived constantk on the logarithmic concentration of antibody in the sample permitted to express the results as titre, corresponding to a dilution wherek = 0. Examination of seven samples of pooled blood serum of normal mice shoved taht (1) the IgA level was practically constant, (2) serum IgA possessed under given conditions similar properties as IgA from the bronchoalveolar secretion; it is therefore possible to employ pooled sera as a reliable control of the immunodiffusion system in ease of lack of reference standards with defined IgA content. Examination of 82 individual BAL samples of normal mice revealed that the mean IgA concentration in 2.5 mL samples was almost 1000 times lower than in blood serum. 相似文献