Advances in Understanding the “Perfect Monsoon-influenced Typhoon”: Summary from International Conference on Typhoon Morakot (2009)

Cheng-Shang Lee,Chun-Chieh Wu,Tai-Chi Chen Wang,Russell L. Elsberry 한국기상학회 2011 Asia-Pacific Journal of Atmospheric Sciences Vol.47 No.3

Typhoon Morakot (2009) produced 2855 mm of rain and was the deadliest typhoon to impact Taiwan with 619 deaths and 76missing persons, including a landslide that wiped out an entire village. While Morakot did not exceed the heaviest 24-h rain record,the combination of heavy rain and long duration that led to the record accumulation is attributed to the southwest summer monsoon influence on the typhoon. Thus, a special combination of factors was involved in the Morakot disaster: (i) Strong southwesterly monsoon winds; (ii) Convergence between the typhoon circulation and monsoon flow to form an east-west oriented convective band over the Taiwan Strait that was quasi-stationary and long-lasting; (iii) A typhoon in a specific location relative to the Central Mountain Range and moving slowly; and (iv) Steep topography that provided rapid lifting of the moist air stream. The contributions of each of these four factors in leading to the Morakot disaster are reviewed primarily based on new research presented at the International Conference on Typhoon Morakot (2009). Historical data sets, new Doppler radar observations, and numerical modeling have advanced the understanding of the special conditions of monsoon-influenced typhoons such as Morakot. This research is also leading to modifications of existing and development of new forecasting tools. Gaps in scientific understanding, limits to the predictability, and requirements for advanced forecast guidance tools are described that are challenges to improved warnings of these extreme precipitation and flooding events in monsoon-influenced typhoons.

Mitochondrial PARP1 regulates NAD+-dependent poly ADP-ribosylation of mitochondrial nucleoids

Lee Jong-Hyuk,Hussain Mansoor,Kim Edward W.,Cheng Shang-Jung,Leung Anthony K. L.,Fakouri Nima Borhan,Croteau Deborah L.,Bohr Vilhelm A. 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

PARPs play fundamental roles in multiple DNA damage recognition and repair pathways. Persistent nuclear PARP activation causes cellular NAD+ depletion and exacerbates cellular aging. However, very little is known about mitochondrial PARP (mtPARP) and poly ADP-ribosylation (PARylation). The existence of mtPARP is controversial, and the biological roles of mtPARP-induced mitochondrial PARylation are unclear. Here, we demonstrate the presence of PARP1 and PARylation in purified mitochondria. The addition of the PARP1 substrate NAD+ to isolated mitochondria induced PARylation, which was suppressed by treatment with the inhibitor olaparib. Mitochondrial PARylation was also evaluated by enzymatic labeling of terminal ADP-ribose (ELTA). To further confirm the presence of mtPARP1, we evaluated mitochondrial nucleoid PARylation by ADP ribose-chromatin affinity purification (ADPr-ChAP) and PARP1 chromatin immunoprecipitation (ChIP). We observed that NAD+ stimulated PARylation and TFAM occupancy on the mtDNA regulatory region D-loop, inducing mtDNA transcription. These findings suggest that PARP1 is integrally involved in mitochondrial PARylation and that NAD+-dependent mtPARP1 activity contributes to mtDNA transcriptional regulation.

Elevated plasma YKL-40 level is found in the dogs with cancer and is related to poor prognosis

Kai-Chung Cheng,Jih-Jong Lee,Shang-Lin Wang,Chun-Yu Lin,Ching-Tien Tseng,Chen-Si Lin,Albert Taiching Liao 대한수의학회 2019 Journal of Veterinary Science Vol.20 No.5

YKL-40, a secreted glycoprotein, may serve as an autoantigen, which mediates multipleinflammatory diseases and cancers. A high YKL-40 serum level is correlated with metastasisand poor survival in a variety of human cancers. However, the role of YKL-40 in dogs is stillunder evaluation. Herein, we examined the associations between plasma YKL-40 level andYKL-40 autoantibody (YAA) titers with malignancy and prognosis in canine cancer. Plasmalevels of YKL-40 in healthy dogs (n = 20) and in dogs (n = 82) with cancer were evaluatedusing enzyme-linked immunosorbent assay. Our results indicated that plasma YKL-40 levelswere significantly higher (p < 0.01) in dogs with cancer than in healthy dogs. A significantdecrease in the YAA titers was detected in the dogs with cancer when compared with thoseof the healthy dogs (p < 0.05), although the change was not correlated with the YKL-40levels. Among the dogs with cancer, plasma YKL-40 levels in the dogs that later relapsed orhad metastasis were significantly higher than in the dogs with no signs of relapse (p < 0.01)or metastasis (p <0.05). The relapse and metastasis rates were significantly higher in thehigh YKL-40 group (> 180 pg/mL) than in the low YKL-40 group (< 180 pg/mL). The resultsimply that plasma YKL-40 levels might have the potential to be developed as a marker ofmalignancy progression and prognosis in canine cancers.

Degree-degree Correlated Low-density Parity-check Codes and Their Extensions

Hsiao-Wen Yu,Cheng-En Lee,Ruhui Zhang,Cheng-Shang Chang,Duan-Shin Lee 한국통신학회 2024 Journal of communications and networks Vol.26 No.4

Most existing work on analyzing the performance of a random ensemble of low-density parity-check (LDPC) codes assumes that the degree distributions of the two ends of a randomly selected edge are independent. In this paper, we go one step further by considering ensembles of LDPC codes with degree-degree correlations. We propose two methods to construct such an ensemble of degree-degree correlated LDPC codes and derive a system of density evolution equations for these codes over a binary erasure channel (BEC). By conducting extensive numerical experiments, we demonstrate how the degree-degree correlation affects the performance of LDPC codes. Our numerical results suggest that LDPC codes with negative degree-degree correlation could enhance the maximum tolerable erasure probability. Moreover, increasing the negative degree-degree correlation could facilitate better unequal error protection (UEP) design. In the final part of our extension efforts, we extend degree-degree correlated LDPC codes to multi-edge type LDPC codes and leverage these to construct convolutional LDPC codes.

Synoptic Controls of Outer Mesoscale Convective Systems with High Impact Rainfall in Western North Pacific Tropical Cyclones

Buo-Fu Chen,Russell L. Elsberry,Cheng-Shang Lee 한국기상학회 2016 Asia-Pacific Journal of Atmospheric Sciences Vol.52 No.1

The generality of our conceptual model of Outer Mesoscale Convective System (OMCS) formation in western North Pacific Tropical Cyclones (TCs) that was based on a case study of Typhoon Fengshen (2008) is examined with a data base of 80 OMCSs during 1999-2009. Formations of 41 “Intersection type (Itype)” OMCSs are similar to our conceptual model in that the key feature is an elongated moisture band in the northerly TC circulation that interacts with the southwest monsoon flow. Two subtypes of these I-type OMCSs are defined based on different formation locations relative to the TC center, and relative to the monsoon flow, that lead to either outward or more cyclonic propagation of the OMCSs. Twenty-five “Upstream type (U-type)” OMCSs form in a similar moisture band, but upstream of the intersection of the outer TC circulation with the monsoon flow. Another 12 “Monsoon type (Mtype)” OMCSs are different from our conceptual model as the formation locations are within the monsoon flow south to the confluence region of TC northerly circulation with the monsoon flow. In all of these OMCSs, the monsoon flow is an important contributor to their climatology and synoptic environment. Expanded conceptual models of where the threat of heavy rainfall associated with the four types of OMCSs may be expected are provided based on different OMCS formation locations relative to the TC center and different propagation vectors in a storm-relative coordinate system.

Risk of Hepatitis B Virus (HBV) Reactivation in HBsAg-Negative, Anti-HBc-Negative Patients Receiving Rituximab for Autoimmune Diseases in HBV Endemic Areas

Lan Ting-Yuan,Lin Yen-Chun,Tseng Tai-Chung,Yang Hung-Chih,Kao Jui-Hung,Cheng Chiao-Feng,Lee Tai-Ju,Huang Shang-Chin,Lu Cheng-Hsun,Li Ko-Jen,Hsieh Song-Chou 거트앤리버 소화기연관학회협의회 2023 Gut and Liver Vol.17 No.2

Background/Aims: Rituximab is known to be associated with high hepatitis B virus (HBV) reactivation rate in patients with resolved HBV infection and hematologic malignancy. However, data regarding HBV reactivation (HBVr) in rheumatic patients receiving rituximab is limited. To assess the HBVr rate in hepatitis B surface antigen (HBsAg)-negative patients receiving rituximab for autoimmune diseases in a large real-world cohort. Methods: From March 2006 to December 2019, 900 patients with negative HBsAg receiving at least one cycle of rituximab for autoimmune diseases in a tertiary medical center in Taiwan were retrospectively reviewed. Clinical outcome and factors associated with HBVr were analyzed. Results: After a median follow-up period of 3.3 years, 21 patients developed HBVr, among whom 17 patients were positive for hepatitis B core antibody (anti-HBc) and four were negative. Thirteen patients had clinical hepatitis flare, while eight patients had HBsAg seroreversion without hepatitis. Old age, anti-HBc positivity, undetectable serum hepatitis B surface antibody level at rituximab initiation and a higher average rituximab dose were associated with a higher HBVr rate. There was no significant difference in the HBVr risk between rheumatoid arthritis and other autoimmune diseases. Among anti-HBc-negative patients, subjects without HBV vaccination at birth had an increased risk of HBVr (4/368, 1.1%) compared with those who received vaccination (0/126, 0%). Conclusions: In HBV endemic areas where occult HBV is prevalent, anti-HBc-negative patients, may still be at risk for HBVr after rituximab exposure. HBVr may still be considered in HBsAgnegative patients developing abnormal liver function after rituximab exposure, even in patients with negative anti-HBc.