scholarly journals Complex interactions among stressors evolve over time to drive shifts from short turfs to macroalgae on tropical reefs

Ecosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Caitlin R. Fong ◽  
Camille J. Gaynus ◽  
Robert C. Carpenter
Keyword(s):  
Complex Interactions ◽  
Tropical Reefs ◽  
Over Time

A Transparent and Decentralized Model of Perception and Action for Intelligent Virtual Agents

2014 ◽  
Vol 23 (04) ◽  
pp. 1460020 ◽  
Author(s):  
George Anastassakis ◽  
Themis Panayiotopoulos
Keyword(s):  
Knowledge Representation ◽  
Virtual Environment ◽  
Virtual World ◽  
Perception And Action ◽  
Virtual Agents ◽  
Virtual Agent ◽  
Complex Interactions ◽  
Intelligent Virtual Agents ◽  
Decentralized Model ◽  
Over Time

Intelligent virtual agent behaviour is a crucial element of any virtual environment application as it essentially brings the environment to life, introduces believability and realism and enables complex interactions and evolution over time. However, the development of mechanisms for virtual agent perception and action is neither a trivial nor a straight-forward task. In this paper we present a model of perception and action for intelligent virtual agents that meets specific requirements and can as such be systematically implemented, can seamlessly and transparently integrate with knowledge representation and intelligent reasoning mechanisms, is highly independent of virtual world implementation specifics, and enables virtual agent portability and reuse.

Factors Influencing Ethnic Disparities in Outcomes after Deceased Donor Kidney Transplantation

2021 ◽  
Author(s):  
Jasmin Divers ◽  
Sumit Mohan ◽  
William M. Brown ◽  
Stephen O. Pastan ◽  
Ajay K. Israni ◽  
...  
Keyword(s):  
Risk Index ◽  
Graft Function ◽  
Ethnic Disparities ◽  
Deceased Donor ◽  
Allograft Survival ◽  
Complex Interactions ◽  
Hazard Ratios ◽  
Deceased Donor Kidney ◽  
Cox Proportional Hazard Models ◽  
Over Time

Abstract Background: African American (AA) recipients of deceased-donor (DD) kidney transplants (KT) have shorter allograft survival than recipients of other ethnic groups. Reasons for this disparity encompass complex interactions between donors and recipients characteristics. Methods: Outcomes from 3,872 AA and 19,719 European American (EA) DDs who had one kidney transplanted in an AA recipient and one in an EA recipient were analyzed. Four donor/recipient pair groups (DRP) were studied, AA/AA, AA/EA, EA/AA, and EA/EA. Survival random forests and Cox proportional hazard models were fitted to rank and evaluate modifying effects of DRP on variables associated with allograft survival. These analyses sought to identify factors contributing to the observed disparities in transplant outcomes among AA and EA DDKT recipients. Results: Transplant era, discharge serum creatinine, delayed graft function, and DRP were among the top predictors of allograft survival and mortality among DDKT recipients. Interaction effects between DRP with the kidney donor risk index and transplant era showed significant improvement in allograft survival over time in EA recipients. However, AA recipients appeared to have similar or poorer outcomes for DDKT performed after 2010 versus before 2001; allograft survival hazard ratios (95% CI) were 1.15 (0.74, 1.76) and 1.07 (0.8, 1.45) for AA/AA and EA/AA, compared to 0.62 (0.54, 0.71) and 0.5 (0.41, 0.62) for EA/EA and AA/EA DRP, respectively. Recipient mortality improved over time among all DRP, except unemployed AA/AAs. Relative to DDKT performed pre-2001, employed AA/AAs had HR=0.37 (0.2, 0.69) versus 0.59 (0.31, 1.11) for unemployed AA/AA after 2010. Conclusion: Relative to DDKT performed before 2001, similar or worse overall DCAS was observed among AA/AAs, while EA/EAs experienced considerable improvement regardless of employment status, KDRI, and EPTS. AA recipients of an AA DDKT, especially if unemployed, had worse allograft survival and mortality and did not appear to benefit from advances in care over the past 20 years.

The Special Case of Anesthesia

2019 ◽  
pp. 49-56
Author(s):  
Robert L. Wears ◽  
Kathleen M. Sutcliffe
Keyword(s):  
Medical Specialty ◽  
Clinical Safety ◽  
Complex Interactions ◽  
State Of Affairs ◽  
Special Case ◽  
Over Time

Anesthesia became the only medical specialty to undertake systematic and dramatic improvements in safety over time. Evidence suggests that this process began through the fortuitous engagement of engineers in anesthesia work, supported by respected leaders in the field. The goal was not simply to solve a problem. The aims were too deeply understand the nature of the technology, the work, and the complex interactions that take place in work as carried out. Oddly, healthcare more generally failed to emulate these efforts. This state of affairs may be attributed to the substantive influence of non-clinical safety scientists in anesthesia, and also to differences in widely accepted methodological and investigative research approaches.

scholarly journals ADDRESSING THE THEORETICAL GAPS IN ELDER FAMILY FINANCIAL EXPLOITATION

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S384-S384
Author(s):  
Megan Gilligan ◽  
Axton Betz-Hamilton ◽  
Ashton Chapman
Keyword(s):  
Family Communication ◽  
Original Model ◽  
Factors Associated ◽  
The Past ◽  
Complex Interactions ◽  
Financial Exploitation ◽  
Theoretical Perspectives ◽  
Bioecological Theory ◽  
Person Characteristics ◽  
Over Time

Abstract A systematic review of elder family financial exploitation (EFFE) literature from the past five years reflects limited use or consensus of theoretical perspectives. In this paper, we propose using Bronfenbrenner’s Bioecological Theory to frame the dynamic, interrelated factors associated with EFFE. Bronfenbrenner’s Bioecological Theory, specifically the PPCT model includes Proximal processes, Person characteristics, Contextual systems, and Time. Proximal processes are increasingly complex interactions between individuals (e.g., family communication). Person characteristics include demand (e.g., gender, age), resource (e.g., education), and force (e.g., temperament) characteristics affecting interactions. Contextual levels drawn from Bronfenbrenner’s original model (e.g., micro, meso, exo, and macro) emphasize the effect of interrelated systems on development. T refers to Time, including changes occurring in time (e.g., longitudinal) and over time (e.g., historical). Collectively, the PPCT model provides a framework for understanding the iterative, complex factors linked to EFFE.

The Collective Dynamics of Genocidal Violence in Cambodia, 1975–1979

2014 ◽  
Vol 38 (3-4) ◽  
pp. 411-436 ◽  
Author(s):  
Peter B. Owens
Keyword(s):  
Comparative Analysis ◽  
Collective Action ◽  
Social Factors ◽  
Central State ◽  
Collective Dynamics ◽  
Complex Interactions ◽  
Individual Effects ◽  
Local Patterns ◽  
Historical Accounts ◽  
Over Time

While previous research conceptualizes genocide as an outcome of complex interactions between multiple social factors, the specific ways in which these factors interact and combine with each other, and how their individual effects may be mediated through such interaction, remain to be empirically specified. Using historical accounts given by survivors of the Cambodian genocide, and drawing from insights in the collective action literature, this study presents a configurational and comparative analysis of the collective dynamics of genocidal violence. The analysis focuses on how changing local patterns of relational and cognitive collective mechanisms created distinctly local patterns of violence, affecting both levels of victimization and the targeting of different groups over time. While the expansion and consolidation of central state power accounts for a generalized increase in violence, official framing practices mediated how groups became targeted. These findings confirm and extend the insights of other meso-level studies of genocide, and demonstrate the utility of comparative configurational methods for further inquiry.

Intragroup Subgroup Attitude Clustering, External Intervention, and Intergroup Interaction Patterns: Toward a Dynamical Model of Protracted Intergroup Conflict

2005 ◽  
Author(s):  
Peter Coleman ◽  
Adam Schneider ◽  
Douglass Adams ◽  
Catherine Everett ◽  
Timothy Gameros ◽  
...  
Keyword(s):  
Complex Dynamics ◽  
Dynamical Model ◽  
Intergroup Conflict ◽  
Interaction Patterns ◽  
International Intervention ◽  
Complex Interactions ◽  
Traditional Research ◽  
Multiple Variables ◽  
Using Data ◽  
Over Time

Scholars and practitioners working with protracted conflicts in polarized communities have long recognized the complex dynamics between intragroup disputes and intergroup relations in these settings. In fact, the multitude of factors interacting within and between groups in these conflicts, and their tendency to change over time, largely contributes to their intractable natures. Unfortunately, the ability of scholars to conduct research on such dynamic phenomena has been largely constrained by the atomistic, linear approach of traditional research models and methods. However, recent advances in dynamical systems theory have provided a new set of tools for developing computer simulations that allow us to model the dynamic patterns emerging from complex interactions of multiple variables over time. This paper presents one such model: a dynamical model of protracted intergroup conflict. Using data collected from Israeli and Palestinian communities during the current Intifada, we modeled the dynamic relations between conflict escalation and international intervention on intragroup subgroup attitude clustering and patterns of intergroup interactions. Next steps and refinements for the model are discussed.

scholarly journals Dynamic Functional Brain Reconfiguration During Sustained Pain

2021 ◽  
Author(s):  
Jae-Joong Lee ◽  
Sungwoo Lee ◽  
Dong Hee Lee ◽  
Choong-Wan Woo
Keyword(s):  
Early Stage ◽  
Dynamic Network ◽  
Brain Network ◽  
Dynamic Changes ◽  
Pain Experience ◽  
Functional Brain ◽  
Complex Interactions ◽  
Functional Brain Network ◽  
Functional Brain Networks ◽  
Over Time

Pain is constructed through complex interactions among multiple brain systems, but it remains unclear how functional brain network representations are dynamically reconfigured over time while experiencing pain. Here, we investigated the dynamic changes in the functional brain networks during 20-min capsaicin-induced sustained orofacial pain. In the early stage, the orofacial areas of the primary somatomotor cortex were separated from the other primary somatomotor cortices and integrated with subcortical and frontoparietal regions, constituting a brain-wide pain supersystem. As pain decreased over time, the subcortical and frontoparietal regions were separated from this pain supersystem and connected to multiple cerebellar regions. Machine-learning models based on these dynamic network features showed significant predictions of changes in pain experience across two independent datasets (n = 48 and 74). This study provides new insights into how multiple brain systems dynamically interact to construct and modulate pain experience, potentially advancing our mechanistic understanding of chronic pain.

scholarly journals Employment status at transplant influences ethnic disparities in outcomes after deceased donor kidney transplantation

2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Jasmin Divers ◽  
Sumit Mohan ◽  
W. Mark Brown ◽  
Stephen O. Pastan ◽  
Ajay K. Israni ◽  
...  
Keyword(s):  
Employment Status ◽  
Risk Index ◽  
Graft Function ◽  
Ethnic Disparities ◽  
Deceased Donor ◽  
Allograft Survival ◽  
Complex Interactions ◽  
Hazard Ratios ◽  
Cox Proportional Hazard Models ◽  
Over Time

Abstract Background African American (AA) recipients of deceased-donor (DD) kidney transplants (KT) have shorter allograft survival than recipients of other ethnic groups. Reasons for this disparity encompass complex interactions between donors and recipients characteristics. Methods Outcomes from 3872 AA and 19,719 European American (EA) DDs who had one kidney transplanted in an AA recipient and one in an EA recipient were analyzed. Four donor/recipient pair groups (DRP) were studied, AA/AA, AA/EA, EA/AA, and EA/EA. Survival random forests and Cox proportional hazard models were fitted to rank and evaluate modifying effects of DRP on variables associated with allograft survival. These analyses sought to identify factors contributing to the observed disparities in transplant outcomes among AA and EA DDKT recipients. Results Transplant era, discharge serum creatinine, delayed graft function, and DRP were among the top predictors of allograft survival and mortality among DDKT recipients. Interaction effects between DRP with the kidney donor risk index and transplant era showed significant improvement in allograft survival over time in EA recipients. However, AA recipients appeared to have similar or poorer outcomes for DDKT performed after 2010 versus before 2001; allograft survival hazard ratios (95% CI) were 1.15 (0.74, 1.76) and 1.07 (0.8, 1.45) for AA/AA and EA/AA, compared to 0.62 (0.54, 0.71) and 0.5 (0.41, 0.62) for EA/EA and AA/EA DRP, respectively. Recipient mortality improved over time among all DRP, except unemployed AA/AAs. Relative to DDKT performed pre-2001, employed AA/AAs had HR = 0.37 (0.2, 0.69) versus 0.59 (0.31, 1.11) for unemployed AA/AA after 2010. Conclusion Relative to DDKT performed before 2001, similar or worse overall DCAS was observed among AA/AAs, while EA/EAs experienced considerable improvement regardless of employment status, KDRI, and EPTS. AA recipients of an AA DDKT, especially if unemployed, had worse allograft survival and mortality and did not appear to benefit from advances in care over the past 20 years.

Interactions among Precolonial Foragers, Herders, and Farmers in Southern Africa

2017 ◽  
Author(s):  
James R. Denbow
Keyword(s):  
Southern Africa ◽  
New Technologies ◽  
Central Africa ◽  
Sub Saharan Africa ◽  
Genetic Admixture ◽  
Complex Interactions ◽  
Kalahari Desert ◽  
Geographic Context ◽  
Sub Saharan ◽  
Over Time

Present data indicate that the domestication of wild cattle indigenous to the northern Sahara took place approximately eight to nine thousand years ago. This was followed around seven thousand years ago by the domestication of sorghum and millet in the Sahel and Nile regions of the southern Sahara. Other processes of domestication took place on the margins of the tropical forest in central Africa and in the highlands of Ethiopia. As these new technologies expanded southward, there was a moving frontier of interaction between food producers and autochthonous foragers. In some instances these new technologies may have diffused through preexisting networks that linked indigenous foragers. But in most cases it occurred through migration, as populations expanded to exploit the new technological, ecological, and economic advantages these new adaptations allowed. This did not take place in an empty land, however, and in each case complex interactions and negotiations between incoming farmers and indigenous foragers took place for access to resources and rights to settlement. While the details of this interaction varied along with differences in cultural and geographic context, it transformed the linguistic, genetic, and cultural makeup of sub-Saharan Africa after 5000 bce. In some cases, indigenous foragers and their languages disappeared entirely through assimilation or conflict. In others, a longer-lasting frontier was established through which foragers and farmers continued to interact into historic times. Their cultures, languages, beliefs, and worldviews did not remain static and unchanging, however, but were also transformed as new—often hybrid—societies were born. The history and nature of contact varied widely from place to place. In the northern and eastern Kalahari Desert of southern Africa, the data, as presently discerend through archaeological, linguistic, and genetic lenses, support a model of widespread genetic admixture, with flexible associations between culture, subsistence, and language over time.

An LFG approach to Icelandic reciprocal constructions

2021 ◽  
pp. 103-122
Author(s):  
Peter Hurst ◽  
Rachel Nordlinger
Keyword(s):  
Historical Development ◽  
Complex Interactions ◽  
Construction Type ◽  
The Relationship ◽  
Over Time

Reciprocal constructions in Icelandic involve complex interactions of gender, number, and case. Icelandic prescriptive grammars describe a single construction type, but actual Icelandic usage reveals there to be a number of variations on this construction. In this chapter Hurst and Nordlinger present these variant construction types, based on the results of a survey undertaken by over 500 Icelandic speakers. They discuss the different morphosyntactic properties of these reciprocal constructions and show how they can be given a straightforward account in LFG. They argue that our LFG account not only provides a natural analysis of the different individual constructions, but also of the relationship between them, potentially reflecting stages of historical development in the Icelandic reciprocal construction over time.

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