The ancestors of marine mammals once roamed the land and independently committed to an aquatic lifestyle. These macroevolutionary transitions have intrigued scientists for centuries. Here, we ...generated high-quality genome assemblies of 17 marine mammals (11 cetaceans and six pinnipeds), including eight assemblies at the chromosome level. Incorporating previously published data, we reconstructed the marine mammal phylogeny and population histories and identified numerous idiosyncratic and convergent genomic variations that possibly contributed to the transition from land to water in marine mammal lineages. Genes associated with the formation of blubber (
), vascular development (
), and heat production by brown adipose tissue (
) had unique changes that may contribute to marine mammal thermoregulation. We also observed many lineage-specific changes in the marine mammals, including genes associated with deep diving and navigation. Our study advances understanding of the timing, pattern, and molecular changes associated with the evolution of mammalian lineages adapting to aquatic life.
Understanding the factors that cause endangered populations to either grow or decline is crucial for preserving biodiversity. Conservation efforts often address extrinsic threats, such as ...environmental degradation and overexploitation, that can limit the recovery of endangered populations. Genetic factors such as inbreeding depression can also affect population dynamics but these effects are rarely measured in the wild and thus often neglected in conservation efforts. Here we show that inbreeding depression strongly influences the population dynamics of an endangered killer whale population, despite genomic signatures of purging of deleterious alleles via natural selection. We find that the 'Southern Residents', which are currently endangered despite nearly 50 years of conservation efforts, exhibit strong inbreeding depression for survival. Our population models suggest that this inbreeding depression limits population growth and predict further decline if the population remains genetically isolated and typical environmental conditions continue. The Southern Residents also had more inferred homozygous deleterious alleles than three other, growing, populations, further suggesting that inbreeding depression affects population fitness. These results demonstrate that inbreeding depression can substantially limit the recovery of endangered populations. Conservation actions focused only on extrinsic threats may therefore fail to account for key intrinsic genetic factors that also limit population growth.
Development of sharing economy has brought new opportunities to the development of green logistics. Pallet pooling is a typical type of sharing economy. It has been recently promoted in almost every ...country in the world. Researchers have reached a common agreement that establishing an effective pallet pool is of great importance to the pallets use efficiency. It is also believed that the implementation of pallet pool will substantially contribute to the economic and social development. Detailed analysis of pallet pooling such as benefit analysis, mode choose, pallet allocation model & algorithm, quality control, etc. are discussed in this paper. Based on literature review, several important problems are listed for future study. These problems are information management, supply chain management, rental pricing, pallets tracking and allocation, quality control, sustainable development (carbon emissions), and “internet plus pallet pooling”. Some suggestions on China’s pallet pooling development are proposed as well.
The question about correlation between organic and functional changes in persons, exposed to radiation is still insufficiently studied. Dynamics of morbidity for different forms and classes of ...non-tumour diseases periodisation, proposed by epidemiologists, suggests the identification of three main periods: «early» (the first 6 post-Chornobyl accident years); «distant» (12-21 years) and «late» (22-30 years). However, the correspondence this periodisation to the results of epidemiological data, without taking into account the clinical features of the diseases, may contribute to the impression, that in the first period after a radiation disaster functional disorders (or autonomic regulation disorders, etc.) prevail in all cases. Meanwhile, the data from ophthalmological and neurological studies, which we aim to demonstrate in this paper, rather indicate the presence of a significant morphological basis for the development of functional disorders in early period after a radiation disaster. The objective of this work is analyse modern experimental, epidemiological and clinical data on the correlation between organic and functional changes, characteristic of radiation cerebro-ophthalmological effects - radiation cataracts, age-related macular degeneration, cerebral small vessel disease, and neurocognitive deficits. Materials and methods. The criteria for inclusion in the analytical review were peer-reviewed publications in PubMed/MEDLINE, Scopus, Web of Science, and manually selected papers; the results of our own research were also used. An additional analysis of the results of examinations conducted in 1991-2004 was performed, which included a total of 11 123 persons irradiated as the result of catastrophy at the Chornobyl NPP. Results. In the first period of radiation cataract development, which is a specific consequence of radiation exposure, morphological changes (lens opacities) are observed, which lead to a decrease in visual function only later. Analysing the correlation between organic and functional changes in the development of diseases, for which ionising radiation exposure is a significant risk factor, we observe a similar picture. For example, CSVD associated with arterial hypertension may be a manifestation of accelerated aging associated with exposure to ionising radiation.Similarly, the initial signs of age-related macular degeneration in radiation-exposed individuals are usually manifested by changes in the morphology of the retina, choroid, and pigment epithelium in the macular area, while functional disorders in the form of decreased central vision and metamorphopsia, etc., occur later.
Climate change has become one of the most important topics in each country’s government agendas. The current effects demand quicker actions in order to decrease the speed at which the global warming ...and climate is changing, which are commonly seen in global agreements to reduce pollution. However, the main changes to face and mitigate such phenomena depends on each country´s decision and not on global agreements as the causes are continent-wide although the effects and magnitudes may be local. One of the key components for an effective adaption and mitigation is the role that the population have over national decisions. For this reason, the level of awareness and knowledge about what is occurring in their surroundings vital, thus the importance of a correct information broadcast and education. For the aforementioned reasons, the current study compares the recent perception of a well-educated Ecuadorean community regarding the climate change worldwide and in Ecuador with the scientific evidence and historical facts, and how it affects its vulnerability to the climate change effects.
The discovery and utility of clinically relevant circulating biomarkers depend on standardized methods that minimize preanalytical errors. Despite growing interest in studying extracellular vesicles ...(EVs) and cell-free messenger RNA (cf-mRNA) as potential biomarkers, how blood processing and freeze/thaw impacts the profiles of these analytes in plasma was not thoroughly understood. We utilized flow cytometric analysis to examine the effect of differential centrifugation and a freeze/thaw cycle on EV profiles. Utilizing flow cytometry postacquisition analysis software (FCMpass) to calibrate light scattering and fluorescence, we revealed how differential centrifugation and post-freeze/thaw processing removes and retains EV subpopulations. Additionally, cf-mRNA levels measured by RT-qPCR profiles from a panel of housekeeping, platelet, and tissue-specific genes were preferentially affected by differential centrifugation and post-freeze/thaw processing. Critically, freezing plasma containing residual platelets yielded irreversible ex vivo generation of EV subpopulations and cf-mRNA transcripts, which were not removable by additional processing after freeze/thaw. Our findings suggest the importance of minimizing confounding variation attributed to plasma processing and platelet contamination.
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