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Objectives Between July 2, 2021, and September 20, 2022, a Mycobacterium bovis outbreak occurred among exhibition animals at a zoo in the Republic of Korea. This study was conducted to assess the likelihood of M. bovis transmission to human contacts through a contact investigation and to implement preventive treatment for latent tuberculosis infection (LTBI). Methods In this descriptive study, the Korea Disease Control and Prevention Agency conducted a contact investigation, which included interviews, interferon-gamma release assay (IGRA) tests, and chest X-rays. Contacts underwent IGRA testing on 2 occasions: initial testing of 29 contacts (15 in the first cluster of infection and 14 in the second cluster) and follow-up testing of the 15 contacts in the first cluster. Results The study included 29 participants, 18 of whom were male (62.1%) and 11 female (37.9%). The mean participant age was 37.3 years (standard deviation, 9.6 years). In the initial IGRA tests, 6 of the 29 participants tested positive, indicating a prevalence of 20.7%. Following prolonged exposure, 1 additional positive case was detected in follow-up testing, raising the prevalence of LTBI to 24.1%. None of the contacts had active tuberculosis. Among the 7 individuals with positive results, 2 (28.6%) underwent treatment for LTBI. Conclusion This study faced challenges in confirming the transmission of M. bovis infection from infected animals to humans in the Republic of Korea. Nevertheless, adopting a One Health approach necessitates the implementation of surveillance systems and infection control protocols, particularly for occupational groups at high risk of exposure.

BackgroundThe Government of South Korea launched a national preemptive latent tuberculosis infection (LTBI) screening program in 2016, including more than 1. 6 million population in congregate settings. The objective of this study was to analyze LTBI prevalence and its risk factors in each setting. Additionally, the proportion of LTBI pool covered by the current national LTBI strategy was investigated.MethodsDatabase for results of interferon gamma release assay (IGRA), X-ray, and baseline demographic information was linked with National Health Information Database, national tuberculosis (TB) surveillance database, and national contact investigation database. Participants were categorized into three groups: Group A, workers of postpartum care centers, social welfare facilities and educational institutions; Group B, first year students in high school and out-of-school youths; and Group C, inmates of correctional facilities. Relative risks of LTBI by sex, age, place of living, income level, and comorbidities were calculated.ResultsA total of 444,394 participants in Group A, 272,224 participants in Group B, and 11,511 participants in Group C who participated in the national LTBI screening program between 2017 and 2018 were included, with LTBI prevalence of 20.7, 2.0, and 33.2%, respectively. Age was the single most important risk factor in Group A and Group C. Low-income level was another risk factor commonly identified in all groups. Among participants with positive IGRA results, 2.7, 4.4, and 3.3% in Groups A, B and C, respectively, had past TB exposure history since 2013. Current LTBI guideline targeting high or moderate TB risk disease covered 6.5, 0.6, and 1.1% of participants with positive IGRA results in Groups A, B and C, respectively.ConclusionOnly a small proportion of participants with positive IGRA results could be covered by the current LTBI strategy. Expansion of LTBI strategy by identifying further high-TB risk group in the general population is required.

Database forensics is becoming more important for investigators with the increased use of the information system. Although various database forensic methods such as log analysis and investigation model development have been studied, among the database forensic methods, recovering deleted data is a key technique in database investigation for DB tampering and anti-forensics. Previous studies mainly focused on transaction or journal log to recover deleted data, but if logs are set to be deleted periodically or logs containing critical evidence are overwritten by new logs, the log-based recovery method can not be used practically. For this reason, an engine-based recovery method that analyzes data file at a raw level has been also introduced. There is research to recover small-sized databases such as SQLite and EDB, but there is no prior work describing the structure of data file and technology to recover deleted data of large databases used by enterprises or large organizations. In this context, we investigate Microsoft SQL Server (MSSQL), which is one of the most used large databases. Our method focuses on a storage engine of MSSQL. Through analyzing the storage engine, we identify the internal structure of MSSQL data files and the storage mechanism. Based on these findings, a method to recover tables and records is presented by empirical examination. It is compatible with various versions of MSSQL because it accesses data at the raw level. Our proposed method is verified by a comparative experiment with forensic tools implemented to recover deleted MSSQL data. The experimental results show that our method recovers all deleted records from the unallocated area. It recovers all data types including multimedia data, called Large Objects (LOB) in the database field. To contribute digital forensic community, we also provide the source code of the implementation; it facilitates the knowledge sharing of database forensics.

Objectives: Between July 2, 2021, and September 20, 2022, a Mycobacterium bovis outbreak occurred among exhibition animals at a zoo in the Republic of Korea. This study was conducted to assess the likelihood of M. bovis transmission to human contacts through a contact investigation and to implement preventive treatment for latent tuberculosis infection (LTBI). Methods: In this descriptive study, the Korea Disease Control and Prevention Agency conducted a contact investigation, which included interviews, interferon-gamma release assay (IGRA) tests, and chest X-rays. Contacts underwent IGRA testing on 2 occasions: initial testing of 29 contacts (15 in the first cluster of infection and 14 in the second cluster) and follow-up testing of the 15 contacts in the first cluster. Results: The study included 29 participants, 18 of whom were male (62.1%) and 11 female (37.9%). The mean participant age was 37.3 years (standard deviation, 9.6 years). In the initial IGRA tests, 6 of the 29 participants tested positive, indicating a prevalence of 20.7%. Following prolonged exposure, 1 additional positive case was detected in follow-up testing, raising the prevalence of LTBI to 24.1%. None of the contacts had active tuberculosis. Among the 7 individuals with positive results, 2 (28.6%) underwent treatment for LTBI. Conclusion: This study faced challenges in confirming the transmission of M. bovis infection from infected animals to humans in the Republic of Korea. Nevertheless, adopting a One Health approach necessitates the implementation of surveillance systems and infection control protocols, particularly for occupational groups at high risk of exposure. [ABSTRACT FROM AUTHOR]

Feedback control for self-triggering frequency modulation is proposed for an integrated buck-boost DC-DC converter in an AMOLED display. The goal is to reduce the ripple noise and transient time during the switching process. The converter uses two control modes: switching frequency modulation (SFM) mode for light load current and pulse width modulation (PWM) mode for heavy load current, which result in high power efficiency over a wide range of load current. The mode is automatically changed according to the load current and triggering pulse. A ring-type voltage controlled oscillator (VCO) is applied to obtain a proper operating frequency in the feedback control circuit by the load-dependent current source. The set and reset pulses are used to limit the switching-on time in the sensing signals with less transient time. The converter was fabricated with 0.35-µm BCD (BIPOLAR-CMOS-DMOS) process technology. An experiment shows that the maximum power efficiency is 90% over a wide current range of 10 - 150 mA. Compared to a conventional converter, the proposed converter shows significantly less ripple noise and transient time. [ABSTRACT FROM AUTHOR]

This paper studies variance risk premiums in the Treasury market. We first develop a theory to price variance swaps and show that the realized variance can be perfectly replicated by a static position in Treasury futures options and a dynamic position in the underlying. Pricing and hedging is robust even in the underlying jumps. Using a large options panel data set on Treasury futures with different tenors, we report the following findings: First, the term structure of implied variances is downward sloping across maturities and increases in tenors. Moreover, the slope of the term structure is strongly linked to economic activity. Second, returns to the Treasury variance swap are negative and economically large. Shorting a variance swap produces an annualized Sharpe ratio of almost two and the associated returns cannot be explained by standard risk factors. Finally, the returns remain highly statistically significant even when accounting for transaction costs and margin requirements. [ABSTRACT FROM AUTHOR]

Objective : The purpose of this study was to evaluate long-term follow-up radiologic/clinical outcomes of patients who underwent anterior cervical discectomy and inter-body fusion (ACDF) with stand-alone cages (SAC) in a single academic institution. Methods : Total 99 patients who underwent ACDF with SAC between February 2004 and December 2012 were evaluated retrospectively. A total of 131 segments were enrolled in this study. Basic demographic information, radiographic [segmental subsidence rate, fusion rate, C2–7 global angle, and segmental angle changes)/clinical outcomes (by Odom's criteria and visual analog score (VAS)] and complications were evaluated to determine the long-term outcomes. Results : The majority were males (55 vs. 44) with average age of 53.2. Mean follow-up period was 62.9 months. The segmental subsidence rate was 53.4% and fusion rate was 73.3%. In the subsidence group, anterior intervertebral height (AIH) had more tendency of subsiding than middle or posterior intervertebral height (p=0.01). The segmental angle led kyphotic change related to the subsidence of the AIH. Adjacent segmental disease was occurred in 18 (18.2%) patients. Total 6 (6%) reoperations were performed at the index level. There was no statistical significance between clinical and radiological outcomes. But, overall long-term clinical outcome by Odom's criteria was unsatisfactory (64.64%). The neck and arm VAS score were increased by over time. Conclusion : Long-term outcomes of ACDF with SAC group were acceptable but not satisfactory. For optimal decision making, more additional comparative long-term outcome data is needed between ACDF with SAC and ACDF with plating. [ABSTRACT FROM AUTHOR]

In this paper, a test generation algorithm STAR for sequential circuits based on Boolean function manipulation is presented. Based on the product machine traversal (PMT) method, which generates test patterns using breadth-first search of state-pairs and an implicit state enumeration method of a product machine of fault-free and faulty machines, STAR algorithm attempts to improve the computational efficiency by introducing a mixture of breadth-first/depth-first traversal based on the sequential depth, improvement on the image computation, and the computation of fault-difference functions by the symbolic single-fault propagation method. The results of the experiments on ISCAS 89 benchmark circuits show threefold improvement on the computational time over the simple PMT method. [ABSTRACT FROM AUTHOR]