Displaying a boundary in graphic and symbolic “wait” displays: Duration estimates and users’ preferences

Two experiments assessed the effect of displaying a boundary on duration estimates and preference ratings for dynamic displays that were shown while users waited for the system's response. Displays were either symbolic (changing numbers) or graphic (increasing rectangles) and could contain a boundary that indicated when the interval was expected to be over. Duration estimates were similar for symbolic and graphic displays and for displays with and without a boundary. However, when the displays were encountered successively, participants assessed the graphic displays as having shorter durations than the symbolic displays. Faster rates of change in both types of displays led to increased duration estimates. Although displaying a boundary did not affect duration estimates, participants preferred displays in which a boundary was shown and preferred the graphic displays over the symbolic displays. Hence, bounded graphic displays are recommended as “wait” displays for computerized applications.     

ENROUTE: An Entropy Aware Routing Scheme for Information-Centric Networks (ICN)

With the exponential growth of end users and web data, the internet is undergoing the change of paradigm from a user-centric model to a content-centric one, popularly known as information-centric networks (ICN). Current ICN research evolves around three key-issues namely (i) content request searching, (ii) content routing, and (iii) in-network caching scheme to deliver the requested content to the end user. This would improve the user experience to obtain requested content because it lowers the download delay and provides higher throughput. Existing researches have mainly focused on on-path congestion or expected delivery time of a content to determine the optimized path towards custodian. However, it ignores the cumulative effect of the link-state parameters and the state of the cache, and consequently it leads to degrade the delay performance. In order to overcome this shortfall, we consider both the congestion of a link and the state of on-path caches to determine the best possible routes. We introduce a generic term entropy to quantify the effects of link congestion and state of on-path caches. Thereafter, we develop a novel entropy dependent algorithm namely ENROUTE for searching of content request triggered by any user, routing of this content, and caching for the delivery this requested content to the user. The entropy value of an intra-domain node indicates how many popular contents are already cached in the node, which, in turn, signifies the degree of enrichment of that node with the popular contents. On the other hand, the entropy for a link indicates how much the link is congested with the traversal of contents. In order to have reduced delay, we enhance the entropy of caches in nodes, and also use path with low entropy for downloading contents. We evaluate the performance of our proposed ENROUTE algorithm against state-of-the-art schemes for various network parameters and observe an improvement of 29–52% in delay, 12–39% in hit rate, and 4–39% in throughput.

     

How do clinicians reconcile conditions and medications? The cognitive context of medication reconciliation

Medication omissions and dosing failures are frequent during transitions in patient care. Medication reconciliation (MR) requires bridging discrepancies in a patient’s medical history as a setting for care changes. MR has been identified as vulnerable to failure, and a clinician’s cognition during MR remains poorly described in the literature. We sought to explore cognition in MR tasks. Specifically, we sought to explore how clinicians make sense of conditions and medications. We observed 24 anesthesia providers performing a card-sorting task to sort conditions and medications for a fictional patient. We analyzed the spatial properties of the data using statistical methods. Most of the participants (58%) arranged the medications along a straight line (p < 0.001). They sorted medications by organ systems (Friedman’s χ ²(54) = 325.7, p < 0.001). These arrangements described the clinical correspondence between each two medications (Wilcoxon W = 192.0, p < 0.001). A cluster analysis showed that the subjects matched conditions and medications related to the same organ system together (Wilcoxon W = 1917.0, p < 0.001). We conclude that the clinicians commonly arranged the information into two groups (conditions and medications) and assigned an internal order within these groups, according to organ systems. They also matched between conditions and medications according to similar criteria. These findings were also supported by verbal protocol analysis. The findings strengthen the argument that organ-based information is pivotal to a clinician’s cognition during MR. Understanding the strategies and heuristics, clinicians employ through the MR process may help to develop practices to promote patient safety.     

Making sense of diseases in medication reconciliation

Patients are most at risk during transitions in care across settings and providers. The communication and reconciliation of an accurate medication list throughout the care continuum are essential in the reduction in transition-related adverse drug events. Most current research focuses on the outcomes of reconciliation interventions, yet not on the clinician’s perspective. We aimed to explore clinicians’ cognitive processes and heuristics of making sense of patients’ disease histories. We used the affinity diagram method to simulate real-life medication reconciliation with 24 clinicians. The participants were given paper cards with diseases and medications representing a real case from an anesthesiology department. The task was to sort the cards in a set that made sense to the clinician. The experiment was video-recorded, and the data were analyzed using a quantitative spatial analysis technique. Levene’s test for equality of variance showed that 79% of the 24 participants arranged the diseases along a straight line (p < 0.001). With only few exceptions, the diseases were arranged along the line in a fixed order, from cardiac conditions to depression (Friedman’s χ²(44) = 291.9, p < 0.001). We learn from this study that although clinicians employ a variety of coping strategies while reconciling patients’ medical histories, there are common reconciliation strategies. Understanding heuristics and the mental models clinicians have for the reconciliation process may help to develop and implement methods and tools to promote safety research and practice.     

Priority-based content processing with Q-routing in information-centric networking (ICN)

With exponential increase in the number of users and available data, service providers are facing hard times to satisfy and improve end user experience. Researchers have come up with the idea of exploiting increasing number of routers in a network, and it leads to the development of information-centric networking (ICN). Efficient usage of the in-network caches and content forwarding methodology are the key issues in an ICN architecture. ICN reduces average hop count and correspondingly average content download delay because the intra-domain routers in ICN have storage capacity and they can act as temporary content provider. In this paper, we address the content management issue in a cache with finite storage capability and propose an efficient content management policy that changes a router to a self-sustained cache. We propose a novel methodology to process content packets in the buffer of a cache and correspondingly reduce the propagation delay through a cache. We simulate our proposed algorithm over real-life network environment and evaluate the performance of different user experience metrics, e.g. average latency, throughput, goodput, and link load. Simulation results suggest that our proposed model outperforms the existing state-of-the-art on-path caching strategies.     

Study of thermal comfort in courtyards in a hot arid climate

The outdoor thermal comfort in an enclosed courtyard has been studied numerically by the three dimensional prognostic microclimate model, Envi-met 3.1. The effect of wind, and shading by different means – galleries, horizontal shading or trees – has been examined. The effect of wind is evaluated by allowing cross-ventilation through openings at 3 and 5 m height above ground level, designed according to the prevalent wind direction. The study was conducted for the hours 11–17 LT during June assuming average climate conditions. The thermal comfort is evaluated by the Predicted Mean Vote (PMV) index.During hot summer days, outdoor comfort is mainly dependent on solar radiation; hence, shading is the best means to improve comfort, while the contribution of wind under all configurations studied was limited and much smaller than the shade contribution.The amount of shade is mainly determined by the courtyard orientation. Inspection of empty enclosed courtyards has shown that an elongated E–W rectangular courtyard has the least shade, and therefore it is the most uncomfortable.When the courtyard is ventilated by openings, hot air and radiation penetrate through them increasing the air temperature and the radiation temperature in the courtyard relative to the conditions obtained in a closed courtyard. Higher openings are less comfortable to stay under, and further decrease the comfort in the courtyard. The addition of trees or/and galleries to the closed courtyard significantly improves the outdoor comfort. Under the assumption of constant building temperature of 25°, the addition of galleries is the most efficient shading strategy.Quantitative results exhibiting these trends are presented for specific configurations and orientations of ventilated and/or shaded courtyards.     

A two-step strategy for structure-activity relationship studies of N-methylated aβ42 C-terminal fragments as aβ42 toxicity inhibitors

Neurotoxic Aβ42 oligomers are believed to be the main cause of Alzheimer's disease. Previously, we found that the C-terminal fragments (CTFs), Aβ(30-42) and Aβ(31-42) were the most potent inhibitors of Aβ42 oligomerization and toxicity in a series of Aβ(x-42) peptides (x=28-39). Therefore, we chose these peptides as leads for further development. These CTFs are short (12-13 amino acids) hydrophobic peptides with limited aqueous solubility. Our first attempt to attach hydrophilic groups to the N?terminus resulted in toxic peptides. Therefore, we next incorporated N-methyl amino acids, which are known to increase the solubility of such peptides by disrupting the β-sheet formation. Focusing on Aβ(31-42), we used a two-step N-methyl amino acid substitution strategy to study the structural factors controlling inhibition of Aβ42-induced toxicity. First, each residue was substituted by N-Me-alanine (N-Me-A). In the next step, in positions where substitution produced a significant effect, we restored the original side chain. This strategy allowed exploring the role of both side chain structure and N-Me substitution in inhibitory activity. We found that the introduction of an N-Me amino acid was an effective way to increase both the aqueous solubility and the inhibitory activity of Aβ(31-42). In particular, N-Me amino acid substitution at position 9 or 11 increased the inhibitory activity relative to the parent peptide. The data suggest that inhibition of Aβ42 toxicity by short peptides is highly structure-specific, providing a basis for the design of new peptidomimetic inhibitors with improved activity, physicochemical properties, and metabolic stability.     

Modulating self-assembly of amyloidogenic proteins as a therapeutic approach for neurodegenerative diseases: strategies and mechanisms

Abnormal protein assembly causes multiple devastating disorders in the central nervous system (CNS), such as Alzheimer's, Parkinson's, Huntington's, and prion diseases. Due to the now extended human lifespan, these diseases have been increasing in prevalence, resulting in major public health problems and the associated financial difficulties worldwide. The wayward proteins that lead to disease self-associate into neurotoxic oligomers and go on to form fibrillar polymers through multiple pathways. Thus, a range of possible targets for pharmacotherapeutic intervention exists along these pathways. Many compounds have shown different levels of effectiveness in inhibiting aberrant self-assembly, dissociating existing aggregates, protecting cells against neurotoxic insults, and in some cases ameliorating disease symptoms in vivo, yet achieving efficient, disease-modifying therapy in humans remains a major unattained goal. To a large degree, this is because the mechanisms of action for these drugs are essentially unknown. For successful design of new effective drugs, it is crucial to elucidate the mechanistic details of their action, including the actual target(s) along the protein aggregation pathways, how the compounds modulate these pathways, and their effect at the cellular, tissue, organ, and organism level. Here, the current knowledge of major mechanisms by which some of the more extensively explored drug candidates work are discussed. In particular, we focus on three prominent strategies: 1)?stabilizing the native fold of amyloidogenic proteins, 2)?accelerating the aggregation pathways towards the fibrillar endpoint thereby reducing accumulation of toxic oligomers, and 3)?modulating the assembly process towards nontoxic oligomers/aggregates. The merit of each strategy is assessed, and the key points to consider when analyzing the efficacy of possible drug candidates and their mechanism of action are discussed.     

Meta-heuristic optimization algorithms for comparative analysis of uniform and non-uniform elliptical array antenna for enhanced gain

In this article, the synthesis of a non-uniform elliptical array antenna (EAA) is presented applying three relatively new, well-performing meta-heuristic optimization algorithms; quantum particle swarm optimization (QPSO), symbiotic organism search (SOS), and moth fly optimization (MFO) algorithms. The design objective allows simultaneous minimization of side lobes and maximization of gain by finding the best optimal combination of angular locuses of the antennas in the array structure. The proposed technique is efficient enough to resolve the underlying multi-objective problems at two principle planes of radiation and adaptable enough to the effective implementation of additional design constraints which make this design suitable for practical high-frequency applications as well as long-distance communication. The iterative accomplishment of the three algorithms is compared depending on the radiation parameters as well as statistical parameters. The outcomes are validated by performing a t test on the obtained data sets.     

Nurses’ reactions to alarms in a neonatal intensive care unit

Neonatal intensive care units (NICUs), like other intensive care units, are intended to provide immediate responses to any change in the patients condition. Patient-monitoring alarms and alarms from other medical equipment are very common in these units, and most alarms have no clinical significance. This study addresses the question of how alarms affect nurses actions by measuring the occurrence of alarms from different causes in a NICU, recording the nurses reactions, and analyzing the relationship between the alarms and the actions. The results show that nurses often do not respond directly to alarms, but, rather, use them as additional sources of information in their ongoing flow of actions. The probabilities for their responding to an alarm depend on the causes of the alarm, its duration, and the characteristics of the patient. These findings support the view that experienced nurses dynamically adjust their activities according to the information they receive from alarm systems and other sources, and that they combine their reactive actions with the periodic performance of routine tasks.