202 research outputs found
Evolution Of Feeding Shapes Swimming Kinematics Of Barnacle Naupliar Larvae: A Comparison Between Trophic Modes
A central goal in evolutionary biology is connecting morphological features with ecological functions. For marine invertebrate larvae, appendage movement determines locomotion, feeding, and predator avoidance ability. Barnacle larvae are morphologically diverse, and the morphology of non-feeding lecithotrophic nauplii are distinct from those that are planktotrophic. Lecithotrophic larvae have a more globular body shape and simplified appendages when compared with planktotrophs. However, little is known about whether and how such morphological changes affect kinematics, hydrodynamics, and ecological functions. Here, we compared the nauplii kinematics and hydrodynamics of a lecithotrophic Rhizocephalan species, Polyascus planus, against that of the planktotrophic nauplii of an intertidal barnacle, Tetraclita japonica. High-speed, micro-particle image velocimetry analysis showed that the Polyascus nauplii swam faster and had higher amplitude and more synchronous appendage beating than the Tetraclita nauplii. This fast swimming was accompanied by a faster attenuation of induced flow with distance, suggesting reduced predation risk. Tetraclita nauplii had more efficient per beat cycles with less backward displacement during the recovery stroke. This âanchoring effectâ resulted from the anti-phase beating of appendages. This movement, together with a high-drag body form, likely helps direct the suction flow toward the ventral food capturing area. In sum, the tradeoff between swimming speed and predation risks may have been an important factor in the evolution of the observed larval forms
A Tailâs Tale: Biomechanical Roles Of Dorsal Thoracic Spine Of Barnacle Nauplii
Many marine invertebrates have complex life histories that begin with a planktonic larval stage. Similar to other plankton, these larval invertebrates often possess protruding body extensions, but their function beyond predator deterrence is not well-documented. For example, the planktonic nauplii of crustaceans have spines. Using the epibiotic pedunculate barnacle Octolasmis spp., we investigated how the dorsal thoracic spine affects swimming and fluid disturbance by comparing nauplii with their spines partially removed against those with intact spines. Our motion analysis showed that amputated Octolasmis spp. swam slower, in jerkier trajectories, and were less efficient per stroke cycle than those with intact spines. Amputees showed alterations in limb beat pattern: larger beat amplitude, increased phase lag, and reduced contralateral symmetry. These changes might partially help increase propulsive force generation and streamline the flow, but were insufficient to restore full function. Particle image velocimetry further showed that amputees had a larger relative area of influence, implying elevated risk by rheotactic predator. Body extensions and their interactions with limb motion play important biomechanical roles in shaping larval performance, which likely influences the evolution of form
An intelligent swarm based-wavelet neural network for affective mobile phone design
In this paper, an intelligent swarm based-wavelet neural network for affective mobile designed is presented. The contribution on this paper is to develop a new intelligent particle swarm optimization (iPSO), where a fuzzy logic system developed based on human knowledge is proposed to determine the inertia weight for the swarm movement of the PSO and the control parameter of a newly introduced cross-mutated operation. The proposed iPSO is used to optimize the parameters of wavelet neural network. An affective design of mobile phones is used to evaluate the effectiveness of the proposed iPSO. It has been found that significantly better results in a statistical sense can be obtained by the iPSO comparing with the existing hybrid PSO methods
O Serviço Social numa Comissão Social de Freguesia: uma abordagem preliminar deste novo espaço sócio ocupacional
Aprofundar o conhecimento do Serviço Social no Ăąmbito das ComissĂ”es Sociais de Freguesia, refletindo sobre a prĂĄtica do Serviço Social, nomeadamente na ComissĂŁo Social de Freguesia da Guia, Ă© o objetivo deste relatĂłrio. O processo de criação e implementação do Programa Rede Social, como polĂtica social baseada nos fundamentos da descentralização de poderes e responsabilidades do Estado e a sua intensificação em parcerias entre o setor pĂșblico e o setor privado, assentam numa lĂłgica de desenho de polĂticas sociais neoliberais. O Serviço Social revela ser um importante recurso profissional para as autarquias, nomeadamente para as freguesias, desempenhando um trabalho de proximidade com as populaçÔes, facilitando-lhes o acesso a alguns direitos sociais e executando os seus deveres cĂvicos. No entanto, esta atuação de natureza assistencialista, pretende a resolução emergencial da situação de pobreza e das desigualdades sociais da população de determinada freguesia. Ora, estes fenĂłmenos nĂŁo estĂŁo circunscritos a uma pequena ĂĄrea territorial, sĂŁo problemas estruturais e universais, como tal nĂŁo podem ser tratados apenas como locais. Tendo como ponto de partida, a experiĂȘncia vivenciada pela assistente social que fez parte da organização da ComissĂŁo Social de Freguesia da Guia e que desenhou o seu modelo de intervenção social, Ă© feita uma anĂĄlise a este novo espaço. Conclui-se, atestando que para a efetivação como espaço sĂłcio profissional e que legitime a profissĂŁo, a polĂtica social que define as CSF terĂĄ que sofrer algumas alteraçÔes e melhorias, partindo ao encontro do projeto profissional do Serviço Social, ao mesmo tempo que potencia o enfrentamento Ă pobreza e desigualdades sociais ao nĂvel local
Influenza H5N1 and H1N1 Virus Replication and Innate Immune Responses in Bronchial Epithelial Cells Are Influenced by the State of Differentiation
Influenza H5N1 virus continues to be enzootic in poultry and transmits zoonotically to humans. Although a swine-origin H1N1 virus has emerged to become pandemic, its virulence for humans remains modest in comparison to that seen in zoonotic H5N1 disease. As human respiratory epithelium is the primary target cells for influenza viruses, elucidating the viral tropism and host innate immune responses of influenza H5N1 virus in human bronchial epithelium may help to understand the pathogenesis. Here we established primary culture of undifferentiated and well differentiated normal human bronchial epithelial (NHBE) cells and infected with highly pathogenic influenza H5N1 virus (A/Vietnam/3046/2004) and a seasonal influenza H1N1 virus (A/Hong Kong/54/1998), the viral replication kinetics and cytokine and chemokine responses were compared by qPCR and ELISA. We found that the in vitro culture of the well differentiated NHBE cells acquired the physiological properties of normal human bronchi tissue which express high level of α2-6-linked sialic acid receptors and human airway trypsin-like (HAT) protease, in contrast to the low expression in the non-differentiated NHBE cells. When compared to H1N1 virus, the H5N1 virus replicated more efficiently and induced a stronger type I interferon response in the undifferentiated NHBE cells. In contrast, in well differentiated cultures, H5N1 virus replication was less efficient and elicited a lower interferon-beta response in comparison with H1N1 virus. Our data suggest that the differentiation of bronchial epithelial cells has a major influence in cells' permissiveness to human H1N1 and avian H5N1 viruses and the host innate immune responses. The reduced virus replication efficiency partially accounts for the lower interferon-beta responses in influenza H5N1 virus infected well differentiated NHBE cells. Since influenza infection in the bronchial epithelium will lead to tissue damage and associate with the epithelium regeneration, the data generated from the undifferentiated NHBE cultures may also be relevant to disease pathogenesis
Peroxisome division in the yeast Yarrowia lipolytica is regulated by a signal from inside the peroxisome
We describe an unusual mechanism for organelle division. In the yeast Yarrowia lipolytica, only mature peroxisomes contain the complete set of matrix proteins. These mature peroxisomes assemble from several immature peroxisomal vesicles in a multistep pathway. The stepwise import of distinct subsets of matrix proteins into different immature intermediates along the pathway causes the redistribution of a peroxisomal protein, acyl-CoA oxidase (Aox), from the matrix to the membrane. A significant redistribution of Aox occurs only in mature peroxisomes. Inside mature peroxisomes, the membrane-bound pool of Aox interacts with Pex16p, a membrane-associated protein that negatively regulates the division of early intermediates in the pathway. This interaction inhibits the negative action of Pex16p, thereby allowing mature peroxisomes to divide
Parentage Influence On Gene Expression Under Acidification Revealed Through Single-Embryo Sequencing
The dissolution of anthropogenic carbon dioxide (CO2) in seawater has altered its carbonate chemistry in the process of ocean acidification (OA). OA affects the viability of marine species. In particular, calcifying organisms and their early planktonic larval stages are considered vulnerable. These organisms often utilize energy reserves for metabolism rather than growth and calcification as supported by bulk RNA-sequencing (RNA-seq) experiments. Yet, transcriptomic profiling of a bulk sample reflects the average gene expression of the population, neglecting the variations between individuals, which forms the basis for natural selection. Here, we used single-embryo RNA-seq on larval sea urchin Heliocidaris crassispina, which is a commercially and ecologically valuable species in East Asia, to document gene expression changes to OA at an individual and family level. Three paternal half-sibs groups were fertilized and exposed to 3 pH conditions (ambient pHâ8.0, 7.7 and 7.4) for 12âh prior to sequencing and oxygen consumption assay. The resulting transcriptomic profile of all embryos can be distinguished into four clusters, with differences in gene expressions that govern biomineralization, cell differentiation and patterning, as well as metabolism. While these responses were influenced by pH conditions, the male identities also had an effect. Specifically, a regression model and goodness of fit tests indicated a significant interaction between sire and pH on the probability of embryo membership in different clusters of gene expression. The single-embryo RNA-seq approach is promising in climate stressor research because not only does it highlight potential impacts before phenotypic changes were observed, but it also highlights variations between individuals and lineages, thus enabling a better determination of evolutionary potential
Do people feel they belong? Socioâpolitical factors shaping the place attachment of Hong Kong citizens
Hong Kong citizensâ sense of belonging has gone through a period of fluctuation during the period of rapid socioâpolitical and legal change since the outbreak of the AntiâExtradition Law Amendment Bill Movement in 2019. This study explored how multiple dimensions of the place attachment of Hong Kong citizens have been shaped by factors associated with these changes. Six socioâpolitical variables were incorporated into the three dimensions of the personâprocessâplace (PPP) framework. Based on a representative survey of the local population (n = 768), we found that political inclination and identity were significantly associated with the sense of place, with citizens identifying as Chinese and aligning with the proâestablishment camp showing higher levels of place attachment. Mobility was negatively associated with place attachment, whereas the correlation between attachment and perceptions of the law and legal system was positive. The study has implications for Hong Kongâs current socioâpolitical and institutional environment and for emigration. It also demonstrates the wider applicability of the PPP framework for identifying and clarifying the various predictors of different dimensions of place attachment
Selective scattering between Floquet-Bloch and Volkov states in a topological insulator
The coherent optical manipulation of solids is emerging as a promising way to
engineer novel quantum states of matter. The strong time periodic potential of
intense laser light can be used to generate hybrid photon-electron states.
Interaction of light with Bloch states leads to Floquet-Bloch states which are
essential in realizing new photo-induced quantum phases. Similarly, dressing of
free electron states near the surface of a solid generates Volkov states which
are used to study non-linear optics in atoms and semiconductors. The
interaction of these two dynamic states with each other remains an open
experimental problem. Here we use Time and Angle Resolved Photoemission
Spectroscopy (Tr-ARPES) to selectively study the transition between these two
states on the surface of the topological insulator Bi2Se3. We find that the
coupling between the two strongly depends on the electron momentum, providing a
route to enhance or inhibit it. Moreover, by controlling the light polarization
we can negate Volkov states in order to generate pure Floquet-Bloch states.
This work establishes a systematic path for the coherent manipulation of solids
via light-matter interaction.Comment: 21 pages, 6 figures, final version to appear in Nature Physic
Depression literacy among Australians of Chinese-speaking background in Melbourne, Australia
<p>Abstract</p> <p>Background</p> <p>This study investigated the knowledge of depression and preference for professional help, medications and treatment methods among Australians of Chinese-speaking background, and the perceptions of this population of the causes of mental illness.</p> <p>Methods</p> <p>Adopting a cluster convenience sampling method, the study recruited 200 Chinese-speaking subjects from four major areas in metropolitan Melbourne where many Chinese live. The respondents were presented with a vignette describing an individual with depression and then asked questions to assess their understanding of depression and preference for professional help, medications and treatment methods. A comparative approach was used to compare the findings with those of a previous study of the mental health literacy of Australian and Japanese adults.</p> <p>Results</p> <p>Compared to the Australian and Japanese samples, a much lower percentage of Chinese-speaking Australians (14%) could correctly identify major depression described in the vignette, and a higher percentage believed that counseling professionals could be helpful. Higher percentages of those who believed that close family members could be helpful were found in the Chinese-speaking Australian and Japanese samples, and these two groups also expressed more uncertainty about the usefulness or harmfulness of certain medications compared to the Australian sample. Higher percentages of respondents in both the Chinese-speaking Australian and the Australian sample considered "lifestyle changes" to be helpful compared to the Japanese sample. In the Chinese-speaking sample, 30%, 17.4%, 33% and 27% of the respondents rated "traditional Chinese medicine doctors," "Chinese herbal medications," "taking Chinese nutritional foods/supplements" and "<it>qiqong</it>" as helpful. Many perceived "changing <it>fungshui</it>" and "traditional Chinese worship" to be harmful. Regarding the perception of causes of mental illness, items related to psychosocial perspectives including "life stress" and "interpersonal conflict" were rated highly by the respondents, whereas traditional beliefs including "punishment for misdeeds conducted by ancestors" and "demon possession" had the lowest ratings.</p> <p>Conclusions</p> <p>Campaigns to increase the mental health literacy of Chinese-speaking Australians are needed. The abovementioned socially and culturally driven beliefs need to be taken into consideration in the development of culturally relevant education programs.</p
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