2,751 research outputs found
Extreme pCO2 Variability in a Macrotidal Eelgrass Meadow Mediated by Tidal and Diurnal Cycles
It has been suggested that photosynthetic activity of macrophytes in coastal areas can decrease pCO2 and may provide areas of refuge for organisms sensitive to ocean acidification. To assess the effect of a large eel grass meadow on water chemistry, discreet samples were collected hourly over several 24 hour cycles in Padilla Bay, WA. Calculated pCO2 ranged from less than 100 ppm to greater than 700 ppm, often over the course of only a few hours. Aragonite saturation, DIC and pH were also highly variable. These data, weather station data and in-situ sensors(Padilla Bay National Estuarine Research Reserve) were used to develop a model that estimates pCO2 for the summer season. Tidal height and photosynthetically active radiation were the most significant predictors of pH and pCO2, with Salinity and DO. Model estimates suggest that an even wider range of pCO2 values are common in this estuary, especially in the early summer. Data from a mooring in 20 meters of water over a kilometer from the intertidal eel grass environment, provide some hints of the spatial extent of influence
Performance in Non-Face-to-Face Collaborative Information Environments
Using technology to obtain and process information requires training not only in human-computer interaction but also in human-human-computer (collaborative) interaction. Warfighters must not only develop their own situational awareness (SA), they must understand each others’ SA (Pew, 1995). This common ground is what each collaboration participant assumes about the others to ensure effective interactions (Ross, 2003; Wellons, 1993). Communication is key. Collaborators must coordinate and share information. Collaboration influences military operations at all levels. Technical interoperability is not enough to produce the synchronization required
Training Collaboration in a Network-Assisted Environment
Technology enabled non-face-to-face collaboration has the potential to enhance information sharing and shared situational awareness (SSA) by providing near real-time information to a wide audience. Collaborators require an awareness of what critical information should be shared to develop this SSA. Previous research suggested that participants, while reporting that they shared relevant information, in actuality did not. To explore this issue, the previous research was repeated with the addition of having half of the participants exposed to a short training video on how to collaborate. Participants who received training on how to collaborate located significantly more SCUDs during each of the five turns of the two games played. Similarly, participants who received collaboration training scored higher on shared situational awareness during every turn played. Overall, those receiving the training on collaboration shared information more often with their partners and these information exchanges were longer than those who had not received the training. As technology advances, there is an increased need to understand how humans collaborate at a distance. Findings from this research advance our knowledge of how to enhance non-face-to-face collaboration. SCUDHunt, an on-line game developed by Thoughtlink Inc., was selected for this research on collaboration because it provides a simplified model of the interplay of shared awareness and collaboration, while permitting independent manipulation of variables thought to affect them. SCUDHunt requires participants to do the following: (1) collaborate from distributed locations, and (2) share unique information from their intelligence assets for optimal game performance. The goal of the game is simple: locate three SCUD missile launchers on a map. The game requires geographically dispersed players to collaborate while executing digital tasks to achieve a shared goal
Anemia, Apnea of Prematurity, and Blood Transfusions
Objective To compare the frequency and severity of apneic events in very low birth weight (VLBW) infants before and after blood transfusions using continuous electronic waveform analysis.
Study design We continuously collected waveform, heart rate, and oxygen saturation data from patients in all 45 neonatal intensive care unit beds at the University of Virginia for 120 weeks. Central apneas were detected using continuous computer processing of chest impedance, electrocardiographic, and oximetry signals. Apnea was defined as respiratory pauses of \u3e 10, \u3e 20, and \u3e 30 seconds when accompanied by bradycardia ( \u3c 100 beats per minute) and hypoxemia ( \u3c 80% oxyhemoglobin saturation as detected by pulse oximetry). Times of packed red blood cell transfusions were determined from bedside charts. Two cohorts were analyzed. In the transfusion cohort, waveforms were analyzed for 3 days before and after the transfusion for all VLBW infants who received a blood transfusion while also breathing spontaneously. Mean apnea rates for the previous 12 hours were quantified and differences for 12 hours before and after transfusion were compared. In the hematocrit cohort, 1453 hematocrit values from all VLBW infants admitted and breathing spontaneously during the time period were retrieved, and the association of hematocrit and apnea in the next 12 hours was tested using logistic regression.
Results Sixty-seven infants had 110 blood transfusions during times when complete monitoring data were available. Transfusion was associated with fewer computer-detected apneic events (P \u3c .01). Probability of future apnea occurring within 12 hours increased with decreasing hematocrit values (P \u3c .001).
Conclusions Blood transfusions are associated with decreased apnea in VLBW infants, and apneas are less frequent at higher hematocrits. (J Pediatr 2012;161:417-21)
Emotion Regulation and Positive Affect in the Context of Salivary Alpha-Amylase Response to Pain in Children with Cancer: Physiology, Self-Report, and Behavior
Children with cancer are repeatedly exposed to aversive stimuli including painful procedures. Therefore, emotional regulation techniques may prove useful during such experiences and contribute to pain resilience. This study aimed to determine whether three different emotional regulation strategies (distraction, reappraisal and reassurance) impacted physiological, self- reported and behavioral pain responses in pediatric patients with cancer ages 6 to 18 years (N = 73). The cold pressor task (CPT), an experimental task in which pain is induced by having participants place their hand in cold water, was used to examine pain responses. Patients placed their hand in 7 degree Celsius water for up to 4 minutes. Saliva samples were collected 15 minutes before, immediately after, and then 15 minutes after the CPT. Saliva samples were assayed for alpha amylase, a proxy for sympathetic nervous system activation. Self-reported pain severity was measured upon hand removal. Pain tolerance was assessed by length of time participants kept their hand in the water. Children in the reassurance condition exhibited salivary alpha amylase levels that continued to rise post completion of the CPT as compared to children in the distraction (Beta = -1.68, SE = 0.73, z = -2.30, p = .021, 95% CI [-3.10, -0.25]) and reappraisal (Beta = -1.24, SE = 0.72, z = -1.73, p = .084, 95% CI [-2.65, 0.17]) conditions. However, when self-reported pain and behavior were examined, no differences in pain severity (Wald Chi-squared (2) = 2.47, p = .292), or pain tolerance (Wald Chi-squared (2) = 1.38, p = 0.502) among the emotional regulation strategies were observed. Thus, significant findings were present for physiological markers of distress, but not for self-reported and behavioral measures. These findings suggest that in terms of physiological measures, specific emotional regulation strategies, such as distraction and reappraisal, may be more beneficial in reducing stress responses to painful medical procedures in pediatric patients with cancer as compared to reassurance. These results also demonstrate the importance of examining physiological outcomes in addition to self-report and behavioral outcomes
Grizzly Bear Scavenging of Carrion on the Northern Yellowstone Winter Range (1997-2012)
The Northern Yellowstone Winter Range (NYWR) in northwestern Wyoming and southwestern Montana is an important winter migratory destination for ungulates. The NYWR is within the Greater Yellowstone Ecosystem (GYE), a landscape characterized by a complex ecological system of predators, scavengers, and ungulates. Grizzly bears (Ursus arctos) are dominant members of the scavenging community throughout the spring. However, little is known about factors associated with grizzly bear use of carcasses. Of particular interest to managers is how habitat and anthropogenic factors are associated with carcass use. Such information, for example, may be useful to manage spring recreation in important bear foraging areas to reduce conflict and support conservation efforts. We used logistic regression to analyze spring survey data from 23 transects located in Yellowstone National Park and the Gallatin National Forest during 1997–2012, to identify factors associated with grizzly bear scavenging of winter- or predator-killed ungulates. Multi-model inference was used to evaluate relative support for a set of a priori candidate models containing environmental and temporal correlates. Our preliminary findings showed support for models with distance to forest edge, road density, and elevation. Results indicated negative relationships between these factors and probability of carcass use. Our results suggest that spatial heterogeneity in landscape-level habitat characteristics and human activity affect grizzly bear use of a valuable spring food source
Perceived Neighborhood Cohesion Buffers COVID-19 Impacts on Mental Health in a United States Sample
Objective This study examined whether perceived neighborhood cohesion (the extent to which neighbors trust and count on one another) buffers against the mental health effects of the 2020 COVID-19 pandemic. Methods The XXX University National COVID-19 and Mental Health Study surveyed US adults (N = 3965; M age = 39 years), measuring depressive symptoms, staying home more during than before the 2020 pandemic, and perceived neighborhood cohesion. Results A series of linear regressions indicated that perceiving one\u27s neighborhood as more cohesive was not only associated with fewer depressive symptoms, but also attenuated the relationship between spending more time at home during the pandemic and depressive symptoms. These relationships persisted even after taking into account several individual-level sociodemographic characteristics as well as multiple contextual features, i.e., median household income, population density, and racial/ethnic diversity of the zip codes in which participants resided. Conclusions Neighborhood cohesion may be leveraged to mitigate pandemic impacts on depressive symptoms
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