\u3cem\u3eChlamydomonas\u3c/em\u3e mutants display reversible deficiencies in flagellar beating and axonemal assembly

Axonemal complexes in flagella are largely prepackaged in the cell body. As such, one mutation often results in the absence of the co-assembled components and permanent motility deficiencies. For example, a Chlamydomonas mutant defective in RSP4 in the radial spoke (RS), which is critical for bend propagation, has paralyzed flagella that also lack the paralogue RSP6 and three additional RS proteins. Intriguingly, recent studies showed that several mutant strains contain a mixed population of swimmers and paralyzed cells despite their identical genetic background. Here we report a cause underlying these variations. Two new mutants lacking RSP6 swim processively and other components appear normally assembled in early log phase indicating that, unlike RSP4, this paralogue is dispensable. However, swimmers cannot maintain the typical helical trajectory and reactivated cell models tend to spin. Interestingly the motile fraction and the spokehead content dwindle during stationary phase. These results suggest that (1) intact RS is critical for maintaining the rhythm of oscillatory beating and thus the helical trajectory; (2) assembly of the axonemal complex with subtle defects is less efficient and the inefficiency is accentuated in compromised conditions, leading to reversible dyskinesia. Consistently, several organisms only possess one RSP4/6 gene. Gene duplication in Chlamydomonas enhances RS assembly to maintain optimal motility in various environments

There’s a standard for that: Aligning academic aspirations, professional standards, and ALA accreditation

The Syracuse University library and information science (LIS) program has committed to a new focus on INformation Justice, Equity, and Community EngagemenT (INJECT) that will guide a redesign of our program and redefine our commitment to our students, our coursework, and our impact on the information profession and broader community. While INJECT concepts form the bedrock of our new curriculum, our program is committed to being responsive to library professional standards as well as the ALA Standards for Accreditation of Master’s Programs in Library and Information Studies. Professional standards produced by library associations including ALA, IFLA, ACRL, SLA, RUSA, and YALSA reflect the needs of the library profession and impact the knowledge, skills, abilities, and dispositions librarians need to learn. In designing professional curriculum, LIS faculty must respond to and design for existing standards and competency lists in order to create a program that correlates with the ideals held by various library organizations. At the same time, LIS programs must demonstrate alignment with ALA Standards for Accreditation. So, how do the various competency lists compare to accreditation standards? How do the competencies and standards support INJECT topics, including critical librarianship, social justice, and equity and where do they fall short? This poster reveals an analysis and alignment of professional standards, accreditation standards, and our aspirations to better represent information justice, equity, and community engagement in LIS. This work can enable faculty to transform LIS curricula and create a resilient future for our programs, our student, and the broader LIS profession

Modeling Land and Hold Short Operations: Balancing Safety and Arrival Rate

Many airports conduct simultaneous operations on intersecting runways to increase the rate of takeoffs and landings. This requires landing aircraft to hold short of the intersecting runway, which incurs a safety risk of runway incursions in the process. A Monte Carlo simulation was conducted to analyze the traffic load at maximum operational capacity at Charlotte-Douglas International Airport in order to analyze the fleet types and the rate of those landing aircraft unable to stop short of the intersecting runway. The researchers used the actual and four alternative compositions of the subject airline’s aircraft arrivals, interspersed among other airport traffic, to assess how such changes affect the rate of runway incursions, the rate of operations at the airport, and the mean number of passengers the subject airline can land per hour. The simulation revealed that runway length up to the hold short point was the biggest determinant of aircraft being unable to hold short. The total airport rate of operations decreased when heavy wake turbulence category aircraft were introduced. Despite heavy wake turbulence category aircraft carrying more passengers individually, the decreased operations rate also led to fewer passengers per hour that the subject airline could carry

Design and Development of an Amplitude Leveling Subsystem for FM Radars

To better understand contributions of large ice sheets to sea level rise, remote sensing radars are used to measure relevant characteristics. The Center for Remote Sensing of Ice Sheets (CReSIS) at the University of Kansas has been developing ultra wideband radars to measure the surface elevation of polar ice sheets, near-surface internal layers in polar firn, and thickness of snow cover on sea ice. There is a need for an amplitude leveling subsystem for these radars to achieve constant transmit power since amplitude distortions degrade range sidelobe performance of these radars. A closed-loop amplitude leveling subsystem for frequency-modulated radars is designed, constructed and tested. This system uses a coupler and power detector to sample transmit power and feedback a control voltage to a variable-gain amplifier that controls the amplitude of the transmit signal. The closed-loop system is able to decrease amplitude variation to ±0.72 dB. Results are presented, and sources of error are analyzed for this system. Measurements of required control voltage versus frequency are presented for an open-loop system that does not use the coupler or power detector. These two systems are compared, and recommendations are given for future work

Dimeric heat shock protein 40 binds radial spokes for generating coupled power strokes and recovery strokes of 9 + 2 flagella

T-shape radial spokes regulate flagellar beating. However, the precise function and molecular mechanism of these spokes remain unclear. Interestingly, Chlamydomonas reinhardtii flagella lacking a dimeric heat shock protein (HSP) 40 at the spokehead–spokestalk juncture appear normal in length and composition but twitch actively while cells jiggle without procession, resembling a central pair (CP) mutant. HSP40− cells begin swimming upon electroporation with recombinant HSP40. Surprisingly, the rescue doesn't require the signature DnaJ domain. Furthermore, the His-Pro-Asp tripeptide that is essential for stimulating HSP70 adenosine triphosphatase diverges in candidate orthologues, including human DnaJB13. Video microscopy reveals hesitance in bend initiation and propagation as well as irregular stalling and stroke switching despite fairly normal waveform. The in vivo evidence suggests that the evolutionarily conserved HSP40 specifically transforms multiple spoke proteins into stable conformation capable of mechanically coupling the CP with dynein motors. This enables 9 + 2 cilia and flagella to bend and switch to generate alternate power strokes and recovery strokes

A temporal framework of large wildfire suppression in practice, a qualitative descriptive study

Suppression activities on large wildfires are complicated. Existing suppression literature does not take into account this complexity which leaves existing suppression models and measures of resource productivity incomplete. A qualitative descriptive analysis was performed on the suppression activities described in operational documents of 10 large wildfires in Victoria, Australia. A five-stage classification system summarises suppression in the everyday terms ofwildfire management. Suppression can be heterogeneous across different sectors with different stages occurring across sectors on the same day. The stages and the underlying 20 suppression tasks identified provide a fundamental description of how suppression resources are being used on largewildfires. We estimate that at least 57% of resource use on our sample of 10 large wildfires falls outside of current suppression modelling and productivity research

A Mixed Method Approach for Evaluating and Improving the Design of Learning in Puzzle Games

Despite the acknowledgment that learning is a necessary part of all gameplay, the area of Games User Research lacks an established evidence based method through which designers and researchers can understand, assess, and improve how commercial games teach players game-specific skills and information. In this paper, we propose a mixed method procedure that draws together both quantitative and experiential approaches to examine the extent to which players are supported in learning about the game world and mechanics. We demonstrate the method through presenting a case study of the game Portal involving 14 participants, who differed in terms of their gaming expertise. By comparing optimum solutions to puzzles against observed player performance, we illustrate how the method can indicate particular problems with how learning is structured within a game. We argue that the method can highlight where major breakdowns occur and yield design insights that can improve the player experience with puzzle games

Using the Traditional Ex Vivo Whole Blood Model to Discriminate Bacteria by Their Inducible Host Responses

Whole blood models are rapid and versatile for determining immune responses to inflammatory and infectious stimuli, but they have not been used for bacterial discrimination. Staphylococcus aureus, S. epidermidis and Escherichia coli are the most common causes of invasive disease, and rapid testing strategies utilising host responses remain elusive. Currently, immune responses can only discriminate between bacterial ‘domains’ (fungi, bacteria and viruses), and very few studies can use immune responses to discriminate bacteria at the species and strain level. Here, whole blood was used to investigate the relationship between host responses and bacterial strains. Results confirmed unique temporal profiles for the 10 parameters studied: IL-6, MIP-1α, MIP-3α, IL-10, resistin, phagocytosis, S100A8, S100A8/A9, C5a and TF3. Pairwise analysis confirmed that IL-6, resistin, phagocytosis, C5a and S100A8/A9 could be used in a discrimination scheme to identify to the strain level. Linear discriminant analysis (LDA) confirmed that (i) IL-6, MIP-3α and TF3 could predict genera with 95% accuracy; (ii) IL-6, phagocytosis, resistin and TF3 could predict species at 90% accuracy and (iii) phagocytosis, S100A8 and IL-10 predicted strain at 40% accuracy. These data are important because they confirm the proof of concept that host biomarker panels could be used to identify bacterial pathogens