1,116 research outputs found
Investigating the Urban Heat Island Effect with a Collaborative Inquiry Project
Modification of the earth\u27s surface through urbanization can have a dramatic impact on local climate. A phenomenon known as the Urban Heat Island (UHI) effect, which is a measure of the near-surface air temperature contrast between urbanized and adjoining rural areas, can be evaluated with readily available instruments. Students in an undergraduate general education science course study this phenomenon in the Portland, Oregon area through a collaborative research project. This inquiry project includes background content and literature review, preliminary studies, development of research questions, experimental design and implementation, data analysis and report writing. This project successfully enables students to collaboratively generate a data set that is amenable to sophisticated and interesting analysis and provides an opportunity to study a phenomenon in their local environment
Evaluation of the socially evaluated cold-pressor group test (SECPT-G) in the general population
Background
In stress research, economic instruments for introducing acute stress responses are needed. In this study, we investigated whether the socially evaluated cold-pressor group test (SECPT-G) induces salivary alpha-amylase (sAA) and/or cortisol responses in the general population and whether this is associated with anthropometric, experimental, and lifestyle factors.
Methods
A sample of 91 participants from the general population was recruited. Salivary cortisol and sAA levels were assessed prior to (t0), immediately after (t1), and 10 min after the SECPT-G (t2).
Results
A robust cortisol increase was found immediately after the SECPT-G, which further increased between t1 and t2. This was independent of most of the control variables. However, men showed a trend toward higher cortisol increases than women (p = 0.005). No sAA responses were found at all. However, sAA levels were dependent on measurement time point with highest levels between 9 pm and 9:30 pm. Participants who immersed their hands into the ice water for the maximally allowed time of 3 min showed higher sAA levels at all time points than participants who removed their hands from the water earlier.
Conclusions
We conclude that the SECPT-G is a good means of an acute stress test when cortisol—but not necessarily sAA—responses are intended
Preliminary Development of Two Predictive Models for DNR Patients in Intensive Care
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98260/1/j.1547-5069.1991.tb00658.x.pd
Smells Like Grandparents:Consumers’ Barriers and Motivations to Second-hand Shopping
Consumers’ perspectives on the reuse of products are crucial to understand for supporting and achieving a circular consumption and economy. While second-hand products are still a niche phenomenon (Wilts et al., 2021), second-hand markets validate the consumers’ willingness and desire to reuse products (Gregson & Crewe, 2003). To accommodate the call for knowledge on consumerbehavior regarding the circular economy, this study investigates consumers’ motivations and barriers to shopping in second-hand markets. The research includes 20 semi-structured interviews with a diverse set of informants to ensure rich data (Kvale & Brinkmann, 2015). With the departure in existingknowledge about barriers and motivations to second-hand shopping from literature, the authors have, based on analysis of the interviews, identified, and categorized seven additional barriers and five motivations, which have not yet been described in the literature. The motivations concern aspects suchas social-, quality-, and design aspects, whereas the barriers mostly relate to the shopping experience and the social aspects. Thereby this study builds on prior studies and extends the theoretical understanding of the different aspects of second-hand shopping, that can either enhance or worsen theexperience.<br/
EVALUATION OF SILHOUETTE-BASED MARKERLESS TRACKING FOR KINEMATICS IN SPORT
The purpose of this study was to evaluate markerless, silhouette-based tracking for different applications in sports science. Data of segment center of gravity locations, joint center locations as well as joint angles were taken into account. To quantify the accuracy of silhouette-based in comparison to marker-based tracking, all mentioned parameters were compared with the correlation coefficient and standard deviation of the differences for three classes of movements: specific joint movements, complex movements, and highly dynamic movements (with racquet). Very strong correlations result for the segment center of gravity locations, the joint center locations as well as for joint angles in the sagittal plane except the elbow joints. Joint angle accuracy impairs in the transversal and the frontal plane with an increasing complexity and speed in the movement patterns. To obtain accurate joint angles separated into the three body planes, however, we recommend to enhance the tracking of segment rotations should be stabilized by additional information (e.g. marker or IMU)
Influence of repair proteins and chromatin modifiers on mobility of DNA double-strand breaks induced by heavy ion irradiation
Ionizing radiation induces DNA double strand breaks (DSBs) in cell nuclei which represent the most dangerous type of DNA lesions. Through error prone repair mechanisms they can lead to the formation of chromosome rearrangements, favoring genomic instability and the development of cancer. Movement of DSBs and surrounding chromatin domains is expected to influence DSB repair and promote the formation of chromosomal translocations. Addressing this expectation, DSB mobility was analyzed after heavy ion irradiation. To gain insight into influences of chromatin organization and repair related factors on the dynamic behavior of DSB sites, knockdown or inhibition of repair proteins and chromatin modifying proteins was used. Occurring changes in irradiation induced foci (IRIF) mobility were examined either by immunofluorescent analysis of fixed samples or by live cell microscopy
Time course of the physiological stress response to an acute stressor and its associations with the primacy and recency effect of the serial position curve
Whether stress affects memory depends on which stress pathway becomes activated and which specific memory system is involved. The activation of the sympathetic nervous system (SNS), leads to a release of catecholamines. The activation of the hypothalamic-pituitary-adrenal (HPA) axis, leads to a release of glucocorticoids. In thus study, it was investigated whether SNS and/or HPA axis activation are associated with long-term memory (LTM) and/or working memory (WM) performance in humans. Thirty-three participants underwent the socially evaluated cold-pressor test. Salivary alpha-amylase (sAA) was used as a marker for the activation of the SNS and cortisol as marker for HPA axis activation. Memory was assessed by means of word lists with 15 words each. The primacy effect (i.e., the correctly recalled words from the beginning of the lists) of the serial position curve was considered as indicator for LTM. The recency effect (i.e., the correctly recalled words from the end of the lists) were used as estimator for WM performance. In sAA responders, the recency effect and, therefore, WM performance increased immediately after the stressor. This was not found in sAA non-responders. In cortisol responders, the primacy effect and, thus, LTM performance decreased 20 minutes after the stressor. No change in LTM performance was found in cortisol non-responders. Our study supports the assumptions that 1) SNS activation is associated with WM processes via stimulation of the prefrontal cortex, and 2) HPA axis activation is associated with LTM processes through interactions with the hippocampus
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