1,687 research outputs found
The chronology of Anglo-Saxon style pottery in radiocarbon dates:Improving the typo-chronology
In the fourth and fifth centuries AD, the Anglo‐Saxon style was introduced in north‐western Europe. To what extent immigrants contributed to this process for each region is still debated. How and when the Anglo‐Saxon style spread is essential in this debate. Handmade pottery is the most common find category, but so far it can only be dated globally. An earlier and a later style have been postulated and the introduction of this pottery is seemingly not simultaneous in every region. Hitherto this could not be supported by the radiocarbon dates. The present study shows that, with the help of Bayesian modelling, it is possible to substantiate these patterns, which is of utmost importance for understanding migration patterns, contacts and exchange along the southern North Sea coastal regions during this period
Potentiation of C1 esterase inhibitor by StcE, a metalloprotease secreted by escherichia coli O157:H7
The complement system is an essential component of host defense against pathogens. Previous research in our laboratory identified StcE, a metalloprotease secreted by Escherichia coli O157:H7 that cleaves the serpin C1 esterase inhibitor (C1-INH), a major regulator of the classical complement cascade. Analyses of StcE-treated C1-INH activity revealed that surprisingly, StcE enhanced the ability of C1-INH to inhibit the classical complement-mediated lysis of sheep erythrocytes. StcE directly interacts with both cells and C1-INH, thereby binding C1-INH to the cell surface. This suggests that the augmented activity of StcE-treated C1-INH is due to the increased concentration of C1-INH at the sites of potential lytic complex formation. Indeed, removal of StcE abolishes the ability of C1-INH to bind erythrocyte surfaces, whereas the proteolysis of C1-INH is unnecessary to potentiate its inhibitory activity. Physical analyses showed that StcE interacts with C1-INH within its aminoterminal domain, allowing the unaffected serpin domain to interact with its targets. In addition, StcE-treated C1-INH provides significantly increased serum resistance to E. coli K-12 over native C1-INH. These data suggest that by recruiting C1-INH to cell surfaces, StcE may protect both E. coli O157:H7 and the host cells to which the bacterium adheres from complement-mediated lysis and potentially damaging inflammatory events
Examining the Impact of a University-driven Exercise Programming Event on End-of-semester Stress in Students
International Journal of Exercise Science 10(5): 754-763, 2017. Stress levels in university students peak during the final exam period. An inverse association exists between Physical Activity (PA) and poor mental health. UNLV has created Fitness4Finals (F4F), an event novel in its approach to academic stress reduction by incorporating both physical activity and mental relaxation. To our knowledge, a university-driven programming event aimed at reducing physiological and psychological stress among students approaching final exams had never been studied. Therefore, the aims of this research were to 1) examine the influence of F4F on physiological stress and perceived psychological stress (PPS) and 2) to examine the relationship between physiological stress and PPS. Fifteen full-time university students were recruited to participate in their choice of one of two groups: F4F or control (NonF4F). Pre-F4F and post-F4F measures of physiological stress, measured by salivary cortisol, and perceived psychological stress, measured by survey were collected. The F4F event was held the week prior to final examinations. Participants in the F4F group engaged in one F4F activity per day for the duration of the 3-day event. Results of the repeated measures MANOVA indicated nonsignificant interaction (p = .864) between F4F participation, physiological stress and PPS. PPS and cortisol were not correlated at the onset of the study (r = -0.18, p = 0.48) or at the last sampling period (r = 0.097, p = 0.73). Preemptive elevated levels of PA in the F4F group may have influenced results. Qualitative data indicates a unanimous perceived reduction in stress from F4F participation. While the physiological measures of stress in the present study were not significantly different, the perceived stress reduction reported by F4F participants is influential. Further investigation with improvements in timing and measurement tools is warranted
The effectiveness of the Dutch Meaningful Roles program in children : a study protocol for a cluster randomized controlled study
Background: A positive, prosocial classroom climate is associated with improved social competence and academic achievement, as well as with decreased internalizing problems and antisocial behavior in children. It is expected that motivation to behave prosocially is needed to achieve a prosocial climate in the classroom, and that such motivation can be enhanced through three components of self-determination theory (SDT): competence, relatedness, and autonomy. The goal of this protocol is to describe the design of a study aiming to evaluate the effectiveness of a classroom-based program based on SDT components promoting a prosocial classroom climate. Methods: A cluster randomized controlled trial (RCT) will be conducted to examine the effectiveness of the classroom-based program Meaningful Roles, aiming to improve prosocial classroom climate through increasing children’s intrinsic prosocial motivation, stimulated by increasing social autonomy, social competence, and social relatedness. A multi-informant (i.e., children, teachers, and school leaders) and multi-method (i.e., questionnaires and focus groups) approach will be used to assess primary outcomes (i.e., prosocial behavior, intrinsic (prosocial) motivation, social autonomy, social competence, and social relatedness) and secondary outcomes (i.e., school wellbeing, social position, bullying, victimization, and civic skills), as well as moderators (i.e., working elements, child, teacher, school, and program characteristics, and program integrity). Discussion: The current study will provide information on the effectiveness of a classroom-based program promoting a prosocial classroom climate. It is of crucial importance that the school environment can provide a positive, prosocial classroom climate in which children feel safe and can achieve optimal social and academic competence and wellbeing. Trial registration: ClinicalTrials (NCT05891067)
Cues of intraguild predators affect the distribution of intraguild prey
Theory on intraguild (IG) predation predicts that coexistence of IG-predators and IG-prey is only possible for a limited set of parameter values, suggesting that IG-predation would not be common in nature. This is in conflict with the observation that IG-predation occurs in many natural systems. One possible explanation for this difference might be antipredator behaviour of the IG-prey, resulting in decreased strength of IG-predation. We studied the distribution of an IG-prey, the predatory mite Neoseiulus cucumeris (Acari: Phytoseiidae), in response to cues of its IG-predator, the predatory mite Iphiseius degenerans. Shortly after release, the majority of IG-prey was found on the patch without cues of IG-predators, suggesting that they can rapidly assess predation risk. IG-prey also avoided patches where conspecific juveniles had been killed by IG-predators. Because it is well known that antipredator behaviour in prey is affected by the diet of the predator, we also tested whether IG-prey change their distribution in response to the food of the IG-predators (pollen or conspecific juveniles), but found no evidence for this. The IG-prey laid fewer eggs on patches with cues of IG-predators than on patches without cues. Hence, IG-prey changed their distribution and oviposition in response to cues of IG-predators. This might weaken the strength of IG-predation, possibly providing more opportunities for IG-prey and IG-predators to co-exist
Enhancing Production Efficiency and Farm Profitability Through Innovative Extension Programming
Cooperative Extension strives to provide agricultural producers with non-formal educational opportunities designed to positively impact agriculture (NIFA, 2021). Therefore, a team of Extension professionals at the University of Nebraska – Lincoln developed and facilitate an ongoing professional development program designed to enhance the engagement of agricultural producers in farm management, especially in the areas of input use efficiency and profitability. Andragogy was used as the framework to help ensure the Testing Agricultural Performance Solutions (TAPS) program provided agricultural producers with non-formal education that aligned with andragogical principles. Knowles (1980) refers to andragogy as the “art and science of helping adults learn” (p. 45) and his assumptions of andragogy include: 1) Learner’s need to know, 2) Self-Concept of the learner, 3) Prior experience of the learner, 4) Readiness to learn, 5) Orientation to learning, and 6) Motivation to learn (Knowles, 1998, as cited in Knowles et al., 2015, p. 6). The TAPS program uses the assumptions of andragogy (Knowles, 1998, as cited in Knowles et al., 2015) to provide a common platform for experiential and peer-to-peer learning that includes the involvement of university researchers, extension specialists, and industry personnel
For better or worse:Governing healthcare organisations in times of financial distress
Due to processes of financialisation, financial parties increasingly penetrate the healthcare domain and determine under which conditions care is delivered. Their influence becomes especially visible when healthcare organisations face financial distress. By zooming-in on two of such cases, we come to know more about the considerations, motives and actions of financial parties in healthcare. In this research, we were able to examine the social dynamics between healthcare executives, banks and health insurers involved in a Dutch hospital and mental healthcare organisation on the verge of bankruptcy. Informed by interviews, document analysis and translation theory, we reconstructed the motives and strategies of executives, banks and health insurers and show how they play a crucial role in decision-making processes surrounding the survival or downfall of healthcare organisations. While parties are bound by legislation and company procedures, the outcome of financial distress can still be influenced. Much depends on how executives are perceived by financial stakeholders and how they deal with threats of destabilisation of the network. We further draw attention to the consequences of financialisation processes on the practices of healthcare organisations in financial distress
Changes in PM2.5 Peat Combustion Source Profiles with Atmospheric Aging in an Oxidation Flow Reactor
Smoke from laboratory chamber burning of peat fuels from Russia, Siberia, the USA (Alaska and Florida), and Malaysia representing boreal, temperate, subtropical, and tropical regions was sampled before and after passing through a potential-aerosol-mass oxidation flow reactor (PAM-OFR) to simulate intermediately aged (∼2 d) and well-aged (∼7 d) source profiles. Species abundances in PM2.5 between aged and fresh profiles varied by several orders of magnitude with two distinguishable clusters, centered around 0.1 % for reactive and ionic species and centered around 10 % for carbon. Organic carbon (OC) accounted for 58 %–85 % of PM2.5 mass in fresh profiles with low elemental carbon (EC) abundances (0.67 %–4.4 %). OC abundances decreased by 20 %–33 % for well-aged profiles, with reductions of 3 %–14 % for the volatile OC fractions (e.g., OC1 and OC2, thermally evolved at 140 and 280 ∘C). Ratios of organic matter (OM) to OC abundances increased by 12 %–19 % from intermediately aged to well-aged smoke. Ratios of ammonia (NH3) to PM2.5 decreased after intermediate aging. Well-aged NH+4 and NO−3 abundances increased to 7 %–8 % of PM2.5 mass, associated with decreases in NH3, low-temperature OC, and levoglucosan abundances for Siberia, Alaska, and Everglades (Florida) peats. Elevated levoglucosan was found for Russian peats, accounting for 35 %–39 % and 20 %–25 % of PM2.5 mass for fresh and aged profiles, respectively. The water-soluble organic carbon (WSOC) fractions of PM2.5 were over 2-fold higher in fresh Russian peat (37.0±2.7 %) than in Malaysian (14.6±0.9 %) peat. While Russian peat OC emissions were largely water-soluble, Malaysian peat emissions were mostly water-insoluble, with WSOC ∕ OC ratios of 0.59–0.71 and 0.18–0.40, respectively. This study shows significant differences between fresh and aged peat combustion profiles among the four biomes that can be used to establish speciated emission inventories for atmospheric modeling and receptor model source apportionment. A sufficient aging time (∼7 d) is needed to allow gas-to-particle partitioning of semi-volatilized species, gas-phase oxidation, and particle volatilization to achieve representative source profiles for regional-scale source apportionment
Health care reform and financial crisis in the Netherlands:consequences for the financial arena of health care organizations
Over the past decade, many health care systems across the Global North have implemented elements of market mechanisms while also dealing with the consequences of the financial crisis. Although effects of these two developments have been researched separately, their combined impact on the governance of health care organizations has received less attention. The aim of this study is to understand how health care reforms and the financial crisis together shaped new roles and interactions within health care. The Netherlands – where dynamics between health care organizations and their financial stakeholders (i.e., banks and health insurers) were particularly impacted – provides an illustrative case. Through semi-structured interviews, additional document analysis and insights from institutional change theory, we show how banks intensified relationship management, increased demands on loan applications and shifted financial risks onto health care organizations, while health insurers tightened up their monitoring and accountability practices towards health care organizations. In return, health care organizations were urged to rearrange their operations and become more risk-minded. They became increasingly dependent on banks and health insurers for their existence. Moreover, with this study, we show how institutional arenas come about through both the long-term efforts of institutional agents and unpredictable implications of economic and societal crises.<br/
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