2,233 research outputs found
Search Strategies Used by Older Adults in a Virtual Reality Place Learning Task
Purpose of the study: Older adults often have problems finding their way in novel environments such as senior living residences and hospitals. The purpose of this study was to examine the types of self-reported search strategies and cues that older adults use to find their way in a virtual maze
Design and Methods: Healthy, independently living older adults (n = 129) aged 55â96 were tested in a virtual maze task over a period of 3 days in which they had to repeatedly find their way to a specified goal. They were interviewed about their strategies on days 1 and 3. Content analysis was used to identify the strategies and cues described by the participants in order to find their way. Strategies and cues used were compared among groups.
Results: The participants reported the use of multiple spatial and non-spatial strategies, and some of the strategies differed among age groups and over time. The oldest age group was less likely to use strategies such as triangulation and distance strategies. All participants used visual landmarks to find their way, but the use of geometric cues (corners) was used less by the older participants.
Implications: These findings add to the theoretical understanding of how older adults find their way in complex environments. The understanding of how wayfinding changes with age is essential in order to design more supportive environments
Secondary structural characterization of oligonucleotide strands using electrospray ionization mass spectrometry
Differences in charge state distributions of hairpin versus linear strands of oligonucleotides are analyzed using electrospray ionization mass spectrometry (ESI-MS) in the negative ion detection mode. It is observed that the linear structures show lower charge state distribution than the hairpin strands of the same composition. The concentration of ammonium acetate and the cone voltage are major factors that cause the shift of the negative ions in the charge states. The ESI data presented here are supported by UV spectra of strands acquired at 260 nm wavelength in aqueous ammonium acetate solution. We will show that the strands that demonstrate a higher charge state distribution in the gas phase also have a higher melting temperature in solution
All for one, though not one for all: team players in normal tissue radiobiology
PurposeAs part of the special issue on 'Women in Science', this review offers a perspective on past and ongoing work in the field of normal (non-cancer) tissue radiation biology, highlighting the work of many of the leading contributors to this field of research. We discuss some of the hypotheses that have guided investigations, with a focus on some of the critical organs considered dose-limiting with respect to radiation therapy, and speculate on where the field needs to go in the future.ConclusionsThe scope of work that makes up normal tissue radiation biology has and continues to play a pivotal role in the radiation sciences, ensuring the most effective application of radiation in imaging and therapy, as well as contributing to radiation protection efforts. However, despite the proven historical value of preclinical findings, recent decades have seen clinical practice move ahead with altered fractionation scheduling based on empirical observations, with little to no (or even negative) supporting scientific data. Given our current appreciation of the complexity of normal tissue radiation responses and their temporal variability, with tissue- and/or organ-specific mechanisms that include intra-, inter- and extracellular messaging, as well as contributions from systemic compartments, such as the immune system, the need to maintain a positive therapeutic ratio has never been more urgent. Importantly, mitigation and treatment strategies, whether for the clinic, emergency use following accidental or deliberate releases, or reducing occupational risk, will likely require multi-targeted approaches that involve both local and systemic intervention. From our personal perspective as five 'Women in Science', we would like to acknowledge and applaud the role that many female scientists have played in this field. We stand on the shoulders of those who have gone before, some of whom are fellow contributors to this special issue
A single and rapid calcium wave at egg activation in Drosophila.
Activation is an essential process that accompanies fertilisation in all animals and heralds major cellular changes, most notably, resumption of the cell cycle. While activation involves wave-like oscillations in intracellular Ca(2+) concentration in mammals, ascidians and polychaete worms and a single Ca(2+) peak in fish and frogs, in insects, such as Drosophila, to date, it has not been shown what changes in intracellular Ca(2+) levels occur. Here, we utilise ratiometric imaging of Ca(2+) indicator dyes and genetically encoded Ca(2+) indicator proteins to identify and characterise a single, rapid, transient wave of Ca(2+) in the Drosophila egg at activation. Using genetic tools, physical manipulation and pharmacological treatments we demonstrate that the propagation of the Ca(2+) wave requires an intact actin cytoskeleton and an increase in intracellular Ca(2+) can be uncoupled from egg swelling, but not from progression of the cell cycle. We further show that mechanical pressure alone is not sufficient to initiate a Ca(2+) wave. We also find that processing bodies, sites of mRNA decay and translational regulation, become dispersed following the Ca(2+) transient. Based on this data we propose the following model for egg activation in Drosophila: exposure to lateral oviduct fluid initiates an increase in intracellular Ca(2+) at the egg posterior via osmotic swelling, possibly through mechano-sensitive Ca(2+) channels; a single Ca(2+) wave then propagates in an actin dependent manner; this Ca(2+) wave co-ordinates key developmental events including resumption of the cell cycle and initiation of translation of mRNAs such as bicoid.This work was supported by the University of Cambridge, ISSF to T.T.W. [grant number 097814]; and Wellcome Trust Senior Research Fellowship to I.D. [grant number 096144].This is the final version of the article. It first appeared from the Company of Biologists via http://dx.doi.org/10.1242/bio.20141129
An Evaluation of MacArthur's Window of Opportunity: Preserving Affordable Rental Housing Initiative
In this report, we describe the seven strategies by which the MacArthur Foundation sought ambitious changes in the preservation of affordable rental housing. In brief, these strategies were to* support a cadre of large nonprofit owners of affordable rental housing to both preserve rental housing and act as spokespersons for preservation* increase capital for preservation by investing in special-purpose vehicles, such as preservation-themed loan funds* invest in regional interagency partnerships to retain affordable rental housing* develop business practices, tools, and research for or about preservation* provide loans and grants directly to state and local government agencies that themselves fund preservation transactions* promote low-income tenants' rights to remain in and advocate for affordable rental housing* improve the funding, regulatory, and legislative context for preservation through the foundation's combined investments in nonprofit owners, networks of nonprofit owners, special-purpose vehicles, state and local government agencies, and advocates
The Impacts of Flood, Drought, and Turbidites on Organic Carbon Burial Over the Past 2,000Â years in the Santa Barbara Basin, California
Climate conditions and instantaneous depositional events can influence the relative contribution of sediments from terrestrial and marine environments and ultimately the quantity and composition of carbon buried in the sediment record. Here, we analyze the elemental, isotopic, and organic geochemical composition of marine sediments to identify terrestrial and marine sources in sediment horizons associated with droughts, turbidites, and floods in the Santa Barbara Basin (SBB), California, during the last 2,000ĂÂ years. Stable isotopes (ĂÂŽ13C and ĂÂŽ15N) indicate that more terrestrial organic carbon (OC) was deposited during floods relative to background sediment, while bulk C to nitrogen (C/N) ratios remained relatively constant (~10). Long- chain n- alkanes (C27, C29, C31, and C33), characteristic of terrestrial OC, dominated all types of sediment deposition but were 4 times more abundant in flood layers. Marine algae (C15, C17, and C19) and macrophytes (C21 and C23) were also 2 times higher in flood versus background sediments. Turbidites contained twice the terrestrial n- alkanes relative to background sediment. Conversely, drought intervals were only distinguishable from background sediment by their higher proportion of marine algal n- alkanes. Combined, our data indicate that 15% of the total OC buried in SBB over the past 2,000ĂÂ years was deposited during 11 flood events where the sediment was mostly terrestrially derived, and another 12% of deep sediment OC burial was derived from shelf remobilization during six turbidite events. Relative to twentieth century river runoff, our data suggest that floods result in considerable terrestrial OC burial on the continental margins of California.Key PointsTerrestrial organic carbon is the dominant source of carbon to the SBB with deposition significantly increasing during flood eventsEpisodic flood and turbidite remobilization events were responsible for over 25% of the OC buried in the SBB over the past 2,000ĂÂ yearsDrought sedimentation had significantly lower sedimentation rates and had an n- alkane composition consistent with increased marine inputsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156217/4/palo20901-sup-0002-2020PA003849-fs01.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156217/3/palo20901_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156217/2/palo20901.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156217/1/palo20901-sup-0003-2020PA003849-fs02.pd
Feasibility and acceptability of home delivery of water for dental caries control in latinx children â âsediento por una sonrisa,â thirsty for a smile : single-arm feasibility study
Background: Outcomes of surgical treatments under general anesthesia for early childhood caries of young children from low-income groups are poor requiring retreatment within 2 years. Dietary sugar is an ideal intervention target given that it is the most prominent risk factor for dental caries and there is increasing evidence of successful interventions to reduce its intake. Our aim is to investigate the feasibility and acceptability of the Thirsty for a Smile intervention, designed to promote consumption of water in lieu of sugar sweetened beverages, among children who underwent surgery for early childhood caries and their caregivers, mostly from Latino heritage. Methods: A single-arm feasibility study was conducted in a dental practice from a community health center in eastern Washington State. Bottled water was delivered to the participantsâ homes and caregivers received patientcentered counseling for setting goals to increase childrenâs water intake and reduce sugar sweetened beverages consumption. We assessed the feasibility and acceptability of the intervention and study procedures through participation rates, interviews and a questionnaire completed by the caregivers. Data was analyzed and themes and descriptive statistics presented. Results: Twenty-two dyads of caregivers and their children between 2 and 9 years old who recently had surgical treatment for early childhood dental caries were enrolled. All study assessments were completed by more than 90% of participants, except for the final 24-h dietary recall (73%). Dietary counseling, both in person and brief telephone calls, was highly acceptable to the caregivers, and they also reported their children enjoyed and used the water bottles. On a scale from 1 to 10, the average rating for the helpfulness of the dietary counseling component for changing childâs drinking habits was 9.62 and for the water delivery component, 8.86. Conclusions: This study tested the feasibility of conducting a trial in a dental practice setting, and the acceptability among caregivers of young children who underwent surgery for early childhood caries. It demonstrated that the Thirsty for a Smile intervention and study processes were feasible and acceptable. The study provides useful information for implementation of a two-arm randomized controlled trial in this setting and may also benefit other researchers attempting to test similar interventions
A Validated Method for Identifying Unplanned Pediatric Readmission
Objective
To validate the accuracy of pre-encounter hospital designation as a novel way to identify unplanned pediatric readmissions and describe the most common diagnoses for unplanned readmissions among children.
Study design
We examined all hospital discharges from 2 tertiary care children's hospitals excluding deaths, normal newborn discharges, transfers to other institutions, and discharges to hospice. We performed blinded medical record review on 641 randomly selected readmissions to validate the pre-encounter planned/unplanned hospital designation. We identified the most common discharge diagnoses associated with subsequent 30-day unplanned readmissions.
Results
Among 166â994 discharges (hospital A: n = 55â383; hospital B: n = 111â611), the 30-day unplanned readmission rate was 10.3% (hospital A) and 8.7% (hospital B). The hospital designation of âunplannedâ was correct in 98% (hospital A) and 96% (hospital B) of readmissions; the designation of âplannedâ was correct in 86% (hospital A) and 85% (hospital B) of readmissions. The most common discharge diagnoses for which unplanned 30-day readmissions occurred were oncologic conditions (up to 38%) and nonhypertensive congestive heart failure (about 25%), across both institutions.
Conclusions
Unplanned readmission rates for pediatrics, using a validated, accurate, pre-encounter designation of âunplanned,â are higher than previously estimated. For some pediatric conditions, unplanned readmission rates are as high as readmission rates reported for adult conditions. Anticipating unplanned readmissions for high-frequency diagnostic groups may help focus efforts to reduce the burden of readmission for families and facilities. Using timing of hospital registration in administrative records is an accurate, widely available, real-time way to distinguish unplanned vs planned pediatric readmissions
Exposure to Prenatal Maternal Distress and Infant White Matter Neurodevelopment
The prenatal period represents a critical time for brain growth and development. These rapid neurological advances render the fetus susceptible to various influences with life-long implications for mental health. Maternal distress signals are a dominant early life influence, contributing to birth outcomes and risk for offspring psychopathology. This prospective longitudinal study evaluated the association between prenatal maternal distress and infant white matter microstructure. Participants included a racially and socioeconomically diverse sample of 85 motherâinfant dyads. Prenatal distress was assessed at 17 and 29 weeksâ gestational age (GA). Infant structural data were collected via diffusion tensor imaging (DTI) at 42â45 weeksâ postconceptional age. Findings demonstrated that higher prenatal maternal distress at 29 weeksâ GA was associated with increased fractional anisotropy, b = .283, t(64) = 2.319, p = .024, and with increased axial diffusivity, b = .254, t(64) = 2.067, p = .043, within the right anterior cingulate white matter tract. No other significant associations were found with prenatal distress exposure and tract fractional anisotropy or axial diffusivity at 29 weeksâ GA, or earlier in gestation
Associations between cytokines, endocrine stress response, and gastrointestinal symptoms in autism spectrum disorder
PosterAutism spectrum disorder (ASD) is characterized by impairments in social communication and abnormal repetitive behavior patterns. Recent studies have shown a strong association between ASD and gastrointestinal (GI) symptomatology. Some individuals with ASD show altered reactivity to stress, as well as altered immune markers, particularly stress responsive cytokines including TNF-alpha and IL-6. To assess potential relationships between GI symptoms and stress response, we examined whether GI symptoms are associated with increases in stress-associated endocrine markers and cytokines in ASD. We also conducted exploratory analyses the examine the relationship between IL-6, TNF-alpha, cortisol, and intelligence, as well as the effects of the presence or absence of co-occurring medical conditions on the relationship between IL-6, TNF-alpha, cortisol, and GI symptoms. Given the aforementioned findings, we expected to find positive relationships between GI symptoms and biomarkers of stress, including cortisol levels, IL-6, and TNF-alpha
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