scholarly journals Do positive interactions between marine invaders increase likelihood of invasion into natural and artificial habitats?

Oikos ◽  
2020 ◽  
Author(s):  
Louise B. Firth ◽  
Lois Duff ◽  
Paul E. Gribben ◽  
Antony M. Knights
1981 ◽  
Vol 12 (4) ◽  
pp. 216-232 ◽  
Author(s):  
Suzanne Evans Morris

The mealtime setting can be creatively used by the speech-language pathologist to increase the positive interactions between the child and caregiver and to establish the basic prerequisites for the development of communication. Specific program suggestions are provided to enable the speech-language pathologist to utilize the mealtime setting to integrate both vocal and nonvocal communicative objectives. The roots of interaction and communication which underly both vocal and nonvocal systems are described.


2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster

AbstractCarbon nanofibers possess excellent conductivity properties, which may be beneficial in the design of more effective neural prostheses, however, limited evidence on their cytocompatibility properties exists. The objective of the present in vitro study was to determine cytocompatibility and material properties of formulations containing carbon nanofibers to predict the gliotic scar tissue response. Poly-carbonate urethane was combined with carbon nanofibers in varying weight percentages to provide a supportive matrix with beneficial bulk electrical and mechanical properties. The substrates were tested for mechanical properties and conductivity. Astrocytes (glial scar tissue-forming cells) were seeded onto the substrates for adhesion. Results provided the first evidence that astrocytes preferentially adhered to the composite material that contained the lowest weight percentage of carbon nanofibers. Positive interactions with neurons, and, at the same time, limited astrocyte functions leading to decreased gliotic scar tissue formation are essential for increased neuronal implant efficacy.


1992 ◽  
Vol 26 (9-11) ◽  
pp. 2345-2348 ◽  
Author(s):  
C. N. Haas

A new method for the quantitative analysis of multiple toxicity data is described and illustrated using a data set on metal exposure to copepods. Positive interactions are observed for Ni-Pb and Pb-Cr, with weak negative interactions observed for Ni-Cr.


1995 ◽  
Vol 269 (4) ◽  
pp. R739-R748 ◽  
Author(s):  
C. De Rouffignac

The kidney is the main organ regulating composition of body fluids. A considerable number of hormones control the activity of renal cells to maintain hydromineral equilibrium. It becomes more and more difficult to interpret this multihormonal control in terms of regulatory processes. To illustrate this complexity, the hormonal regulation of electrolyte transport in the nephron thick ascending limb is taken as an example. This nephron segment is largely responsible for two kidney functions: the urinary-concentrating ability (by its capacity to deliver hypertonic sodium chloride into the medullary interstitium) and regulation of magnesium excretion into final urine. Six hormones are presently identified as acting on the transport of both sodium chloride and magnesium ions in this nephron segment. Therefore, the pertinent question is how the thick ascending limb and, hence, the kidney, is capable of regulating water balance independently from magnesium balance. It is proposed that the hormones act in combination: circulating levels of the individual hormones acting on these cells may determine the configuration of the paracellular and transcellular transport pathways of the epithelium either in the “sodium” or “magnesium” mode. The configuration would depend on the distribution and activity of the receptor at the surface of the basolateral membrane in contact with the circulating hormones. This distribution along with stimulation of respective signal transduction pathways would lead to the final biological effects. It is already known that the distribution of cell receptors may vary according to factors such as age, nutritional variability, hormonal status, degree of desensitization of the receptors, etc. The modulation of hormonal responses would depend therefore on the degree of coupling of hormone-receptor complexes to different intracellular transduction pathways and on the resulting negative and/or positive interactions between these pathways.


2021 ◽  
Vol 168 (2) ◽  
Author(s):  
Alice E. Hall ◽  
Roger J. H. Herbert ◽  
Richard Stafford

AbstractCoastal habitats are important for commercially exploited and protected species of fish and larger mobile invertebrates. The addition of artificial structures within the marine environment has the potential to alter the connectivity between habitats and to affect metapopulations of a region. Baited remote underwater videos (BRUV) were used to investigate the spatial and seasonal variation in abundance of adult and juvenile mobile species associated with subtidal natural and artificial habitats within Poole Bay on the south coast of England in 2019. Metrics included the relative maximum abundance (MaxN), number of species seen (S), assemblage structure and size range of fish. Higher values of MaxN and S were recorded on artificial structures in the spring and early summer; however, this pattern was reversed by mid-summer and early autumn when more fish were recorded on the natural reefs. Yet overall differences in MaxN and S between habitats were not significant. Differences in assemblage composition between habitats varied monthly, but this was mostly driven by particular sites. Although most fish observed were juveniles, there were some seasonal differences in the size of fish using natural and artificial sites, especially bib (Trisopterus luscus), black bream (Spondyliosoma cantharus), bass (Dicentrarchus labrax) and pollack (Pollachius pollachius). The artificial habitats in this region appeared to be important in certain months, so temporal studies of this type need to be incorporated within surveys, particularly those in proximity to protected areas.


2020 ◽  
pp. 1-44
Author(s):  
CHRISTOF DEJUNG

Abstract This article examines the history of the Swiss merchant house Volkart Bros., which was one of the most important exporters of Indian raw cotton and one of the biggest trading firms in South Asia during the colonial period. The study allows for a fresh look at Indian economic history by putting forth two main arguments. First, it charts the history of a continental European firm that was active in South Asia to offer a better understanding of the economic entanglements of the subcontinent with the wider world, which often had a reach beyond the empire. This ties in with recent research initiatives that aim to examine the history of imperialism from a transnational perspective. Second, the history of a private company helps in developing a micro-perspective on the often ambiguous relation between the business goals of individual enterprises and colonial rule. The article argues that this may be evidence of the fact that capitalism and imperialism were two different, although sometimes converging, spatial structures, each with a distinct logic of its own. What is more, the positive interactions between European and Indian businessmen, fostered by a cosmopolitan attitude among business elites, point to the fact that even in the age of empire, the class background of actors could be more important for the establishing of cooperative ventures than the colour of their skin or their geographical origin. It is argued that this offers the possibility of examining the history of world trade in terms of global social history.


2021 ◽  
pp. 002200272110130
Author(s):  
Robert A. Blair ◽  
Benjamin S. Morse

How does violence during civil war shape citizens’ willingness to trust and rely on state security providers in the post-conflict period? Can post-conflict security sector reform restore perceptions of state security forces among victims of wartime state predation? Using a survey and field experiment in Liberia, we show that rebel-perpetrated violence is strongly positively correlated with trust and reliance on the police after conflict is over, while state-perpetrated violence is not. Victims of wartime state predation are, however, more likely to update their priors about the police in response to positive interactions with newly reformed police officers. We also show that abuses committed by police officers in the post-conflict period are negatively correlated with citizens’ perceptions of the police, potentially counteracting the positive effects of security sector reform. We corroborate our quantitative findings with detailed qualitative observations of interactions between civilians and police officers in the field.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhong-Jie Li ◽  
Hai-Yang Zhang ◽  
Li-Li Ren ◽  
Qing-Bin Lu ◽  
Xiang Ren ◽  
...  

AbstractNationwide prospective surveillance of all-age patients with acute respiratory infections was conducted in China between 2009‒2019. Here we report the etiological and epidemiological features of the 231,107 eligible patients enrolled in this analysis. Children <5 years old and school-age children have the highest viral positivity rate (46.9%) and bacterial positivity rate (30.9%). Influenza virus, respiratory syncytial virus and human rhinovirus are the three leading viral pathogens with proportions of 28.5%, 16.8% and 16.7%, and Streptococcus pneumoniae, Mycoplasma pneumoniae and Klebsiella pneumoniae are the three leading bacterial pathogens (29.9%, 18.6% and 15.8%). Negative interactions between viruses and positive interactions between viral and bacterial pathogens are common. A Join-Point analysis reveals the age-specific positivity rate and how this varied for individual pathogens. These data indicate that differential priorities for diagnosis, prevention and control should be highlighted in terms of acute respiratory tract infection patients’ demography, geographic locations and season of illness in China.


2021 ◽  
Vol 13 (5) ◽  
pp. 2587
Author(s):  
Åsta Birkeland ◽  
Liv Torunn Grindheim

Social and cultural sustainability is outlined as creating surroundings that include and stimulate positive interactions, such as promoting a sense of community and a feeling of belonging to a community, by being safe and attached to the local area. Artefacts chosen in early childhood education (ECE) institutions are integrated parts of the culture in which the ECE institutions are embedded; artefacts, thus, are understood as serving belonging and cultural sustainability. The study examined what insight into cultural sustainability could be surfaced in conflicting perspectives about military artefacts in ECE. Focus group interviews were conducted with Chinese and Norwegian graduate students and ECE researchers, during which photographs of a Chinese kindergarten where military artefacts and toys were highly represented. Conflicting perspectives on military artefacts among the participant surfaced how belonging are closely intertwined with protection and where to belong: locally, nationally or internationally. The skeptical approach to military artefacts is challenged by awareness of different ways to promote national pride and entanglement among generations. The findings indicate a need for more research on conditions for belonging and the normative complexities of artefacts in cultural sustainability.


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