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The kinetoplast DNA (kDNA) is the archetype of a two-dimensional Olympic network, composed of thousands of DNA minicircles and found in the mitochondrion of certain parasites. The evolution, replication and self-assembly of this structure are fascinating open questions in biology that can also inform us how to realise synthetic Olympic networks in vitro. To obtain a deeper understanding of the structure and assembly of kDNA networks, we sequenced the Crithidia fasciculata kDNA genome and performed high-resolution Atomic Force Microscopy (AFM) and analysis of kDNA networks that had been partially digested by selected restriction enzymes. We discovered that these topological perturbations lead to networks with significantly different geometrical features and morphologies with respect to the unperturbed kDNA, and that these changes are strongly dependent on the class of DNA circles targeted by the restriction enzymes. Specifically, cleaving maxicircles leads to a dramatic reduction in network size once adsorbed onto the surface, whilst cleaving both maxicircles and a minor class of minicircles yields non-circular and deformed structures. We argue that our results are a consequence of a precise positioning of the maxicircles at the boundary of the network, and we discuss our findings in the context of kDNA biogenesis, design of artificial Olympic networks and detection of in vivo perturbations.

Within the framework of the first phase of MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) project, called MINERVA, IJCLab was in charge of a fully equipped Spoke cryomodule prototype development, tested at 2K. It integrates two superconducting single spoke cavities, the RF power couplers and the Cold Tuning Systems associated. On the control side, a MTCA.4-based Low Level Radio Frequency (LLRF) system prototype and the Software/EPICS developments has been realized by IJCLab and the SCK CEN in collaboration with the company IOxOS Technologies. The final version of the global system and the results of the tests at 2K will show with some perspectives., Comment: Poster pr\'esent\'e au LLRF Workshop 2023 (LLRF2023, arXiv : 2310.03199)

Halide perovskite nanocrystals (NCs) have emerged as a promising material for applications ranging from light-emitting diodes (LEDs) to solar cells and photodetectors. Still, several issues impede the realization of the nanocrystals' full potential, most notably their susceptibility to degradation from environmental stress. This work demonstrates highly stable perovskite nanocrystals (NCs) with quantum yields as high as 95 % by exploiting a ligand-assisted copolymer nanoreactor-based synthesis. The organic ligands thereby serve a dual function by enhancing the uptake of precursors and passivating the NCs. The polymer micelles and ligands thus form a double protection system, shielding the encapsulated NCs from water-, heat- and UV-light-induced degradation. We demonstrate the optoelectronic integrability by incorporating the perovskite NCs as spectrally pure downconverters on top of a deep-blue-emitting organic LED. These results establish a way of stabilizing perovskite NCs for optoelectronics while retaining their excellent optical properties.

Halide perovskite nanocrystals (NCs) have shown impressive advances, exhibiting optical properties that outpace conventional semiconductor NCs, such as near-unity quantum yields and ultrafast radiative decay rates. Nevertheless, the NCs suffer even more from stability problems at ambient conditions and due to moisture than their bulk counterparts. Herein, we report a strategy of employing polymer micelles as nanoreactors for the synthesis of methylammonium lead trihalide perovskite NCs. Encapsulated by this polymer shell, the NCs display strong stability against water degradation and halide ion migration. Thin films comprising these NCs exhibit a more than 15-fold increase in lifespan in comparison to unprotected NCs in ambient conditions and even survive over 75 days of complete immersion in water. Furthermore, the NCs, which exhibit quantum yields of up to 63% and tunability of the emission wavelength throughout the visible range, show no signs of halide ion exchange. Additionally, heterostructures of MAPI and MAPBr NC layers exhibit efficient F\"orster resonance energy transfer (FRET), revealing a strategy for optoelectronic integration., Comment: This document is the unedited Author version of a Submitted Work that was subsequently accepted for publication in Nano Letters, copyright American Chemical Society after peer review. To access the final edited and published work see http://pubs.acs.org/articlesonrequest/AOR-W59yZfkIX7sG6Xuvp8NE

Recent magnetic tweezers experiments have reported systematic deviations of the twist response of double-stranded DNA from the predictions of the twistable worm-like chain model. Here we show, by means of analytical results and computer simulations, that these discrepancies can be resolved if a coupling between twist and bend is introduced. We obtain an estimate of 40 $\pm$ 10 nm for the twist-bend coupling constant. Our simulations are in good agreement with high-resolution, magnetic-tweezers torque data. Although the existence of twist-bend coupling was predicted long ago (Marko and Siggia, Macromolecules 27, 981 (1994)), its effects on the mechanical properties of DNA have been so far largely unexplored. We expect that this coupling plays an important role in several aspects of DNA statics and dynamics., Comment: 6 pages, 3 figures, Supplemental Material included

This study focused on administrator perceptions of technology issues in higher education and the effects of technology on their work. This analysis is based on a study that used an instrument developed for the study with 34 questions with open-ended response items. The survey was sent to a stratified random sample of community college administrators across 14 position codes, and 910 usable surveys were received (54% response rate). The study aimed to report trends and patterns in the data. Thus the data reported is mainly descriptive. Administrators described an increasing number of conferences, workshops, and professional development workshops on the incorporation of technology, but the most pressing issues and challenges were not always clear. What responses did make apparent is that the rapid changes as a result of technology demand more systematic approaches to faculty development, staff training, and technological compatibility and upgrades, as well as student support services. Data show many different administrative perspectives, making clear the need for additional research. (Contains 2 tables and 36 references.) (SLD)

This research brief examines administrator perspectives on institutional mission and priorities, while taking note of regional differences in perspectives. In addition, this brief presents other dimensions of the institutional context such as the factors that keep administrators engaged and satisfied in their positions. Given the challenges and opportunities facing community colleges, it is particularly important to understand administrative priorities, as well as factors that affect administrators' satisfaction levels. Research findings include: (1) Administrators indicated that academic transfer, workforce preparation, and lifelong learning remain the mission of community colleges, with an increased emphasis on workforce development and technology usage forecasted for the future; (2) Administrators advocated a more comprehensive mission based on changing constituent needs and a more focused mission because of future funding challenges, reflecting the continuing conflict in institutional priorities; (3) Administrators rated the following external issues as very high in importance at their institutions: state financial support for programs and teaching, linkages with business and industry, and meeting community needs; (4) The most pressing internal issues, according to administrators, were student retention, creation of new program delivery systems, and student recruitment and marketing; and (5) A majority of surveyed administrators indicated that technology support for instructional and administrative processes was of very high importance at their institutions. (Contains 3 tables and 6 figures.)

With about four-fifths of incumbent community college presidents planning to retire within 10 years (Weisman and Vaughan 2002), leadership development is now an essential focus for community colleges. Successful colleges of the future will be the ones that today are cultivating new generations of leaders at all administrative levels. Community colleges must consider not only the presidency but the range of career positions including administrators, faculty, and staff. This research brief presents the results of a 2000 survey of community college senior administrators; the study examined career paths and backgrounds as well as the mechanisms administrators used to upgrade their skills and acquire additional knowledge and training. (Contains 14 figures.)

This research report examines community college administrators' perspectives on institutional missions and priorities, while taking note of regional differences in their views. The brief also examines factors that keep administrators engaged and satisfied in their positions. The research reported here comes from a national survey that used a stratified random sample of 1,700 community college administrators across 14 position codes, drawn from the American Association of Community Colleges (AACC) data bank. Data collection efforts yielded a 54% usable survey response rate. The instrument consisted of 34 open-ended, closed-ended, and Likert-scale questions. The report is divided into the following categories: (1) important external issues facing community colleges; (2) important internal issues facing community colleges; (3) important technology issues facing community colleges; (4) what keeps administrators in their positions; (5) administrators' satisfaction levels with aspects of their institutions; (6) administrators' satisfaction levels with the quality of support for women's and minority issues; and (7) administrators' satisfaction levels with aspects of their careers. Some of the findings regarding internal issues include: 54% of administrators rated student retention as very important, and 51% rated creation of new program delivery systems as very important. Only 22% considered faculty compensation to be very important, while 15% considered collective bargaining to be very important. (NB)

This research brief presents the results of a year 2000 survey of community college senior administrators. The study examines career paths and backgrounds, as well as the mechanisms administrators used to upgrade their skills and acquire additional knowledge and training. Results indicate that: (1) the most likely previous position of community college presidents was provost (37%), followed by president of another community college (25%) and senior academic affairs/instruction officer (15%); (2) 22% of presidents were promoted to the presidency from within their institution, and 66% came from other community colleges; (3) women were underrepresented in certain administrative positions, most notably the offices of president (only 27% women) and occupational or vocational education officer (29% women); (4) 84% of administrators were White, 6% African American, 4% Hispanic, and 1% Asian or Native American; and (5) 41% had a Master's as their highest-earned degree, 18% an Ed.D., and 19% a Ph.D. This brief concludes that the path to the presidency is changing. Much work remains to be done in generating candidate pools for senior positions, in equipping younger generations of administrators with the skills and experiences that will help them win promotion, and in ensuring equity in promotion into the most senior positions. (EMH)

Landing delays are currently a problem at major air carrier airports and many forecasters agree that airport congestion will get worse by the end of the century. It is anticipated that some types of delays can be reduced by an efficient optimal runway exist system allowing increased approach volumes necessary at congested airports. A computerized Probabilistic Runway Turnoff Model which locates exits and defines path geometry for a selected maximum occupancy time appropriate for each TERPS aircraft category is defined. The model includes an algorithm for lateral ride comfort limits.

The effect of localized structural damping on the excitability of higher order normal modes of the large space telescope was investigated. A preprocessor computer program was developed to incorporate Voigt structural joint damping models in a NASTRAN finite-element dynamic model. A postprocessor computer program was developed to select critical modes for low-frequency attitude control problems and for higher frequency fine-stabilization problems. The mode selection is accomplished by ranking the flexible modes based on coefficients for rate gyro, position gyro, and optical sensors, and on image-plane motions due to sinusoidal or random power spectral density force and torque inputs.