DNA metabolic processes such as DNA replication, recombination, and repair are fundamentally important for the maintenance of genome integrity and cell viability. Although a large number of proteins involved in these pathways have been extensively studied, many proteins still remain to be identified. In this study, we isolated DNA-binding proteins from Saccharomyces cerevisiae using DNA-cellulose columns. By analyzing the proteins using mass spectrometry, an uncharacterized protein, Cmr1/YDL156W, was identified. Cmr1 showed sequence homology to human Damaged-DNA binding protein 2 in its C-terminal WD40 repeats. Consistent with this finding, the purified recombinant Cmr1 protein was found to be intrinsically associated with DNA-binding activity and exhibited higher affinity to UV-damaged DNA substrates. Chromatin isolation experiments revealed that Cmr1 localized in both the chromatin and supernatant fractions, and the level of Cmr1 in the chromatin fraction increased when yeast cells were irradiated with UV. These results suggest that Cmr1 may be involved in DNA-damage responses in yeast.

Since the mid-2000 s, longitudinal tinning has been applied to concrete pavements of expressways to improve the comfort and safety of road vehicle users. However, in certain longitudinal tinning sections, lateral vibrations occur during driving, which poses a safety hazard. This paper analyzes the cause behind this problem and proposes a longitudinal texturing specification that can minimize lateral vibration. To perform this analysis, the accelerations of driving vehicles and the degree of lateral vibration transmitted to panels in the vehicles were evaluated for each longitudinal texture applied in South Korea. Structural analysis was also conducted for the lateral force and moment according to the tire tread profile and longitudinal texturing specifications using the finite element method. In addition, field investigation, indoor drivability evaluation, and field application were performed to evaluate the optimal longitudinal texturing specification. The results indicate that the texture designated as 2 × 3 × 19 mm is the optimal longitudinal texture on hardened concrete pavement. However, because this specification is difficult to apply to fresh concrete, 3 × 3 × 16 mm is proposed as the optimal longitudinal texture owing to its excellent performance in the panel survey and in structural analysis.

Eukaryotic genomes contain many duplicated genes closely located with each other, such as the hexose transporter (HXT) genes in Saccharomyces cerevisiae. They can potentially recombine via single-strand annealing (SSA) pathway. SSA between highly divergent sequences generates heteroduplex DNA intermediates with many mismatches, which can be corrected by mismatch repair (MMR), resulting in recombinant sequences with a single junction point. In this report, we demonstrate that SSA between HXT1 and HXT4 genes in MMR-deficient yeast cells produces recombinant genes with multiple-junctions resulting from alternating HXT1 and HXT4 tracts. The mutations in MMR genes had differential effects on SSA frequencies; msh6Δ mutation significantly stimulated SSA events, whereas msh2Δ and msh3Δ slightly suppressed it. We set up an assay that can identify a pair of recombinant genes derived from a single heteroduplex DNA. As a result, the recombinant genes with multiple-junctions were found to accompany genes with single-junctions. Based on the results presented here, a model was proposed to generate multiple-junctions in SSA pathway involving an alternative short-patch repair system.

Blowup refers to concrete pavement distress resulting from compressive failure at joints or cracks when excessive concrete expansion occurs, compressive forces are generated, and the horizontal movement of the pavement is constrained. Blowup occurs because of many reasons including heatwaves caused by abnormal climatic conditions, improper installation spacing between expansion joints, pavement expansion due to an alkali-aggregate reaction, concrete pavement aging, and contraction joint failure. In the summer of 2018, the Korean peninsula experienced the worst heatwave ever recorded, and hence, the possibility of blowup increased. Consequently, the Korea Expressway Corporation established a draft policy for installing pressure relief joints (PRJs) to prevent blowup. In this draft, three installation classes were specified for installing PRJs on in-service roads, and the installation priority for each class was set such that the limited budget could be used efficiently. In addition, the draft presented specific guidelines for installing each class of PRJs and suggested PRJ cross sections that could ensure structural stability. However, the draft lacks systematic research on the causes of blowup and the development of countermeasures and does not provide an engineering basis for the suggested technological solutions to prevent blowup. Therefore, this study aimed to reexamine and complement the suitability of the existing PRJ installation standards through field studies, laboratory experiments, and analytical techniques.

The preventive maintenance (PM) of asphalt pavements reduces life-cycle costs and minimizes resource consumption compared with reactive rehabilitation, yet its cost-effectiveness is highly sensitive to application timing. This study develops a data-driven framework for determining optimal PM timing on Korean expressways by integrating network-level pavement management system (PMS) deterioration modeling with life-cycle cost analysis (LCCA). Using 10-year PMS time-series data from approximately 2200 asphalt pavement sections (2012–2021), a nonlinear regression of the Highway Pavement Condition Index (HPCI) yielded an exponential deterioration model with exponent β = 1.87 (R² = 0.996), confirming accelerating deterioration beyond a critical service age. The HPCI inflection coincides with the Grade-2 boundary (3.5–4.0), where surface distress growth—dominated by linear cracking (91.3% of total SD)—also peaks. A LCCA across 44 scenarios demonstrated that PM applied immediately before this acceleration onset minimizes the 40-year net present value (NPV; discount rate 4.5%). The optimal first PM application time was estimated at 10.8 years (≈56% of the 19.3-year average service life), reducing the 40-year NPV by up to 7 million KRW per section relative to the milling and overlay baseline (up to 16 million KRW in absolute NPV terms for concrete overlay sections). These findings provide a quantitative, reproducible basis for PM timing decisions applicable to the approximately 4000 km of expressway pavement managed by Korea Expressway Corporation.