106 research outputs found
Local biases drive, but do not determine, the perception of illusory trajectories
When a dot moves horizontally across a set of tilted lines of alternating orientations, the dot appears to be moving up and down along its trajectory. This perceptual phenomenon, known as the slalom illusion, reveals a mismatch between the veridical motion signals and the subjective percept of the motion trajectory, which has not been comprehensively explained. In the present study, we investigated the empirical boundaries of the slalom illusion using psychophysical methods. The phenomenon was found to occur both under conditions of smooth pursuit eye movements and constant fixation, and to be consistently amplified by intermittently occluding the dot trajectory. When the motion direction of the dot was not constant, however, the stimulus display did not elicit the expected illusory percept. These findings confirm that a local bias towards perpendicularity at the intersection points between the dot trajectory and the tilted lines cause the illusion, but also highlight that higher-level cortical processes are involved in interpreting and amplifying the biased local motion signals into a global illusion of trajectory perception
Local biases drive, but do not determine, the perception of illusory trajectories
When a dot moves horizontally across a set of tilted lines of alternating orientations, the dot appears to be moving up and down along its trajectory. This perceptual phenomenon, known as the slalom illusion, reveals a mismatch between the veridical motion signals and the subjective percept of the motion trajectory, which has not been comprehensively explained. In the present study, we investigated the empirical boundaries of the slalom illusion using psychophysical methods. The phenomenon was found to occur both under conditions of smooth pursuit eye movements and constant fixation, and to be consistently amplified by intermittently occluding the dot trajectory. When the motion direction of the dot was not constant, however, the stimulus display did not elicit the expected illusory percept. These findings confirm that a local bias towards perpendicularity at the intersection points between the dot trajectory and the tilted lines cause the illusion, but also highlight that higher-level cortical processes are involved in interpreting and amplifying the biased local motion signals into a global illusion of trajectory perception
Theoretical Analysis of Competing Conformational Transitions in Superhelical DNA
We develop a statistical mechanical model to analyze the competitive behavior of transitions to multiple alternate conformations in a negatively supercoiled DNA molecule of kilobase length and specified base sequence. Since DNA superhelicity topologically couples together the transition behaviors of all base pairs, a unified model is required to analyze all the transitions to which the DNA sequence is susceptible. Here we present a first model of this type. Our numerical approach generalizes the strategy of previously developed algorithms, which studied superhelical transitions to a single alternate conformation. We apply our multi-state model to study the competition between strand separation and B-Z transitions in superhelical DNA. We show this competition to be highly sensitive to temperature and to the imposed level of supercoiling. Comparison of our results with experimental data shows that, when the energetics appropriate to the experimental conditions are used, the competition between these two transitions is accurately captured by our algorithm. We analyze the superhelical competition between B-Z transitions and denaturation around the c-myc oncogene, where both transitions are known to occur when this gene is transcribing. We apply our model to explore the correlation between stress-induced transitions and transcriptional activity in various organisms. In higher eukaryotes we find a strong enhancement of Z-forming regions immediately 5′ to their transcription start sites (TSS), and a depletion of strand separating sites in a broad region around the TSS. The opposite patterns occur around transcript end locations. We also show that susceptibility to each type of transition is different in eukaryotes and prokaryotes. By analyzing a set of untranscribed pseudogenes we show that the Z-susceptibility just downstream of the TSS is not preserved, suggesting it may be under selection pressure
The role of inflammation in epilepsy.
Epilepsy is the third most common chronic brain disorder, and is characterized by an enduring predisposition to generate seizures. Despite progress in pharmacological and surgical treatments of epilepsy, relatively little is known about the processes leading to the generation of individual seizures, and about the mechanisms whereby a healthy brain is rendered epileptic. These gaps in our knowledge hamper the development of better preventive treatments and cures for the approximately 30% of epilepsy cases that prove resistant to current therapies. Here, we focus on the rapidly growing body of evidence that supports the involvement of inflammatory mediators-released by brain cells and peripheral immune cells-in both the origin of individual seizures and the epileptogenic process. We first describe aspects of brain inflammation and immunity, before exploring the evidence from clinical and experimental studies for a relationship between inflammation and epilepsy. Subsequently, we discuss how seizures cause inflammation, and whether such inflammation, in turn, influences the occurrence and severity of seizures, and seizure-related neuronal death. Further insight into the complex role of inflammation in the generation and exacerbation of epilepsy should yield new molecular targets for the design of antiepileptic drugs, which might not only inhibit the symptoms of this disorder, but also prevent or abrogate disease pathogenesis
Liver-derived human mesenchymal stem cells: a novel therapeutic source for liver diseases
Healthcare providers' perspectives on parental health literacy and child health outcomes among Southeast Asian American immigrants and refugees
Lowhealth literacy has emerged as an important area of research because of its close linkwith health disparities.
In this study, we used a qualitative approach to investigate healthcare providers' perspectives on the health literacy
of immigrant and refugee parents and its association with children's health. Sixteen health and mental
health professionals serving immigrant and refugee parents and children in various clinical settingswere recruited
through a purposive sampling method and interviewed. Six broad themes were identified: (1) multi-dimensional
components of parental health literacy; (2) parent characteristics and native country experiences; (3) host
systems and their interactions impact on parental health literacy; (4) diverse aspects of help-seeking; (5) culture-
based parental help-seeking; and (6) child health outcomes. Within these larger themes, the complexity
of parental health literacy and its various effects on children's health outcomes among immigrant and refugee
parents were evident. Future research includes more population-based quantitative studies of parental health literacy
and culturally relevant clinical approaches among immigrant and refugee parents
Health Literacy and Associated Factors Among Hmong American Immigrants: Addressing the Health Disparities
Hmong Americans face a disproportionate
health burden ranging from the high prevalence of diabetes
to depressive disorders. Little research attention has
been paid toward exploring contributing factors to this
disparity. As such, the present study seeks to fill the gap
in the literature by examining the health literacy levels in
Hmong Americans and its associated factors. The present
study employed Andersen’s behavioral model of health service
as the theoretical framework. A cross-sectional survey
research design was used and information was gathered
from 168 Hmong American immigrants. Participants were
recruited using a purposive sampling strategy. A multiple
regression analysis was conducted to identify the factors
linked to health literacy. Approximately half of the participants
had low health literacy and reported that they did not
understand health information well. Health literacy levels
were found to differ significantly based on the number of
years participants have lived in the U.S., their social or
religious group attendance, health status, and whether they
had difficulties with activities of daily living. Our exploratory
findings could be used prompt more research to help
inform the development of interventions aiming to improve
health literacy levels and addres
Governance analysis of Nha Trang Bay and Cu Lao Cham Marine Protected Areas, Vietnam
Nha Trang Bay and Cu Lao Cham Marine Protected Areas (MPAs) were established as the first two MPAs in Vietnam to protect the most diverse coral reefs against the impacts of unsustainable resource use. Emerging in a context of increasing decentralisation, the two MPAs have strongly relied on economic incentives, notably funding from donors and NGOs, to encourage behaviour changes towards achieving conservation objectives. Since donor funding ended, economic incentives used in governing the two MPAs have shifted the focus to income generated from MPA user fees. Consequently, the increasing influence of market forces, through mass tourism and incoming fishing pressures, has led to vested interests between provincial/city governments with tourism operators/developers and between local and non-local fishers. This paper stresses that without interventions from the central government or even international actors, the current MPA governance framework and incentives are insufficient to address the growing conflicts between biodiversity conservation and economic development. To improve MPA governance, strengthening legal incentives and stimulating political will from the central government are of the utmost importance. Also, given that social inequity issues are undermining local acceptance and support for MPAs, it is essential to empower local communities in decision-making over their resources by using property rights and promoting small-scale community-based development, while ensuring that such rights and development adhere to MPA conservation objectives. Moreover, tourism operators/developers need to be involved in governing MPAs in such a way that could contribute towards sustainable resource use and social equity for local communities
A Governance analysis of Con Dao National Park, Vietnam
This paper examines the governance of Con Dao National Park (CDNP), through applying the marine protected area governance (MPAG) analysis framework. CDNP was one of the first protected areas in Vietnam for which biodiversity conservation was recognised as being of international importance. It is emerging in a context of increasing economic liberalisation and delegation of decision-making power to province/district-level governments, yet under the tight control of Vietnam's Communist Party. Accordingly, the governance approach that CDNP has adopted is state-led with increasing decentralisation of responsibilities to local governments, with a focus on terrestrial protected area components. Like other protected areas in Vietnam, the governance of CDNP, especially of conservation activities, has significantly benefited from international donor and NGO funding, along with technical support. Key challenges in governing CDNP include a lack of capacity for enforcement under an unclear legal framework, lack of transparency, accountability and fairness, limited coordination among local government agencies, limited community participation, harmful linkages between certain user groups and local authorities, a lack of conditions attached to property/use rights, and weak leadership. With remarkable achievements in socio-economic development over the past three decades, Vietnam arguably has sufficient capacity to adopt more effective and realistic solutions to address such challenges. However, as many of the potential solutions are contradictory to Vietnam's political direction, improving MPA governance will significantly depend on whether the Communist Party's leaders have sufficient political will to put forth conservation initiatives
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