Keynote Speech

David Griffith 한국마케팅과학회 2008 한국마케팅과학회 학술대회 발표 논문집 Vol.- No.-

Marketing in the Dynamic World

David Griffith,Sang Hoon Kim,Feifei Liu,jong Ho Lee,Tony C,Garrett,Stefan Bodenberg,Allan Afuah,Jina Kang,Claus Ebster,Udo Wagner,Barbara Geider 한국마케팅과학회 2008 한국마케팅과학회 학술대회 발표 논문집 Vol.- No.-

Defining the Normal Trends of Serum Creatine Kinase Levels Following Spinal Surgery

Matthew Griffith,Kenneth Aaron Shaw,Michael Baird,Patrick Rushford,Victoria Shaw,Aaron Roberts,David M. Gloystein 대한척추외과학회 2019 Asian Spine Journal Vol.13 No.3

Study Design: Prospective, prognostic study, level II evidence. Purpose: To define the normal change in the creatine kinase (CK) levels in patients undergoing prone or supine lumbar or cervical spine surgery and to determine if positioning influences the postoperative changes in the CK levels. Overview of Literature: Spine surgery is one of the most commonly performed and fastest growing areas of surgery in the United States. Thus, the various possible complications need to be understood, and risk factors for these complications need to be mitigated. One of the rare complications, reported in the literature as small case series and case reports, is rhabdomyolysis, diagnosed by high CK levels. Thus far, very few studies have examined the rise in CK levels following spine surgery, and to our knowledge, none has assessed the potential association of surgical positioning and the rise in CK levels. Methods: We retrospectively analyzed 94 patients. We obtained their preoperative CK levels, and re-assessed their CK levels at postoperative day (POD) 1, 2, and 3, as well as at their 2-week follow-up. The data were analyzed with respect to the spine level and positioning to determine if positioning had any effect on the postoperative rise in the CK level. Results: Total 94 consecutive patients were enrolled in this study. The average preoperative CK level was 179.64, and the average CK level was 847.04 on POD 1. Prone positioning showed a greater rise in the CK levels following surgery than the supine positioning. In a similar manner, lumbar procedures led to a larger rise in the CK levels than cervical surgery. Prone/lumbar surgery showed the largest increase among all groups. Finally, revision surgery and instrumentation both increased the postoperative CK levels. Conclusions: This study demonstrated that positioning can affect the postoperative CK level rise, with patients undergoing prone/lumbar surgery showing the greatest rise in the postoperative CK levels. This rise, however, may be related to paraspinal muscle damage, rather than the positioning itself.

A whole child approach to student success

Sean Slade,David Griffith 한국교육개발원 2013 KEDI Journal of Educational Policy Vol.10 No.-

A whole child approach to education is one which focuses attention on the social, emotional, mental, physical as well as cognitive development of students. At its core such an approach views the purpose of schooling as developing future citizens and providing the basis for each child to fulfill their potential. In 2007 ASCD (formerly the Association for Curriculum Development and Supervision) outlined a whole child approach to education as its core mission. It developed 5 tenets based upon child development theory, which underpins the approach and states that each child in each school and in each community deserves to be healthy, safe, engaged, supported and challenged. This framework has been used as the scaffold in the development of a range of school improvement processes that ensures that the approach is integrated and systemized into the processes and policies of the school, district, and community. The framework does not seek to divorce itself from academic development but it does seek to expand what constitutes academic development in the 21st century and aims to refocus attention on all attributes required for educational and societal success.

A New Call Admission Control Scheme for Heterogeneous Wireless Networks

Duk Kyung Kim,Griffith, David,Golmie, Nada IEEE 2010 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.9 No.10

<P>Call Admission Control (CAC) between heterogeneous networks, such as an integrated 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) network and a Wireless Local Area Network (WLAN), plays an important role to utilize the system resources in a more efficient way. In this paper, we propose that the preference to the WLAN is determined based on the traffic load in the WLAN and the location of the cellular users. Our analysis relies on a previous study that divides the 3G cellular coverage area into zones based on the amount of resources that are required to support a connection to a mobile user. Using this model, we derive new call blocking and handoff failure probabilities as well as new call and handoff attempt failure probabilities. Through simulations, we investigate proper preference settings by changing the WLAN load in a 3 ring-based sector with a WLAN hotspot.</P>

Rapid Increase in Marrow Fat Content and Decrease in Marrow Perfusion in Lumbar Vertebra Following Bilateral Oophorectomy: An MR Imaging-Based Prospective Longitudinal Study

Yi-Xiáng J Wáng,James F Griffith,Min Deng,David KW Yeung,Jing Yuan 대한영상의학회 2015 Korean Journal of Radiology Vol.16 No.1

Bilateral oophorectomy leads to reduced bone mineral density (BMD), and reduced BMD is associated with increased marrow fat and reduced marrow perfusion. Purpose of this study was to investigate how soon these changes occur following surgical oophorectomy. Six patients who underwent hysterectomy and bilateral salpingo-oophorectomy were studied. At baseline, mean patient age was 49.5 years (range: 45–54 years). Third lumbar vertebral body BMD measurement using quantitative CT, marrow fat fraction (FF) using MR spectroscopy and marrow perfusion using dynamic contrast enhanced MRI were conducted immediately prior to surgery and at 3, 9, and 21 months after surgery. Reduced BMD, increased marrow FF, and reduced marrow perfusion occurred synchronously post-oophorectomy. There was a sharp decrease of 12.5 ± 7.2% in BMD (n = 6), a sharp increase of 92.2 ± 46.3% (n = 6) in FF, a sharp decrease of 23.6 ± 3.9% in maximum contrast enhancement (n = 5), and of 45.4 ± 7.7% for enhancement slope (n = 5) during the initial 3 months post surgery. BMD and marrow perfusion continued to decrease, and marrow FF continued to increase at a slower rate during the following 18 months. Friedman test showed a significant trend for these changes (p < 0.05). Bilateral oophorectomy leads to a rapid decrease in lumbar BMD, an increase in marrow fat content, and a decrease in marrow blood perfusion.

Acıbadem University, Atakent Hospital, Istanbul, Turkey

Kenneth Aaron Shaw,Matthew S. Griffith,Edward T. Mottern,David M. Gloystein,John G. Devine 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.1

Cervical corpectomy is a viable technique for the treatment of multilevel cervical spine pathology. Despite multiple advances in both surgical technique and implant technology, the rate of construct subsidence can range from 6% for single-level procedures to 71% for multilevel procedures. In this technical note, we describe a novel technique, the bump-stop technique, for cervical corpectomy. The technique positions the superior and inferior screw holes such that the vertebral bodies bisect them. This allows for fixation in the dense cortical bone of the endplate while providing a buttress to corpectomy cage subsidence. We then discuss a retrospective case review of 24 consecutive patients, who were treated using this approach, demonstrating a lower than previously reported cage subsidence rate.

Centralized Cooperative Directional Spectrum Sensing for Cognitive Radio Networks

Na, Woongsoo,Yoon, Jongha,Cho, Sungrae,Griffith, David,Golmie, Nada IEEE 2018 IEEE transactions on mobile computing Vol.17 No.6

<P>Most previous spectrum sensing techniques use omni-directional antennas. Unlike omni-directional antennas, the use of directional antennas for spectrum sensing is a promising technique that can realize fine-grained sensing for the primary user (PU) with a longer sensing range. In this paper, we propose a centralized cooperative directional sensing technique for cognitive radio networks. We assume that one secondary coordinator called the fusion center (FC), gathers sensing results from secondary nodes. Using the reported information, the FC optimizes the sensing period, sensing power, and sensing beams per secondary node. For optimization, we use a modified gradient descent method with numerical methods to solve the nonlinear optimization problem. The simulation results show that our directional spectrum sensing technique is well suited for the existing cognitive radio environment. The optimal scheme shows proposed here better performance in all simulation factors than the non-optimized scheme.</P>

A study on characterization and feature of XCO2 from g-b TCCON FTS and Satellites on the basis of aircraft in-situ measurements

Samuel Takele Kenea,Tae-Young Goo,Young-Suk Oh,Gawon Kim,Jong-Ho Lee,David W. T. Griffith,Voltaire A. Velazco,Shuji Kawakami,Isamu Morino,Dave Pollard,Martine de Maziere,Jae-Sang Rhee 한국기상학회 2017 한국기상학회 학술대회 논문집 Vol.2017 No.5

Genome-wide identification and functional prediction of silicon (Si) transporters in poplar (Populus trichocarpa)

Hassan Md Mahmudul,Martin Samir,Feng Kai,Yates Timothy B.,Yuan Guoliang,Martin Madhavi Z.,Martin Stanton,Muchero Wellington,Griffiths Natalie A.,Weston David J.,Yang Xiaohan 한국식물생명공학회 2023 Plant biotechnology reports Vol.17 No.2

Silicon (Si) enhances plant tolerance to various biotic and abiotic stressors such as salinity, drought, and heat. In addition, Si can be biomineralized within plants to form organic carbon-containing phytoliths that can have ecosystem-level consequences by contributing to long-term carbon sequestration. Si is taken up and transported in plants via different transporter proteins such as influx transporters (e.g., Lsi1, Lsi6) and efflux transporters (e.g., Lsi2). Additionally, the imported Si can be deposited in plant leaves via silicification process using the Siliplant 1 (e.g., Slp1) protein. Functional homologs of these proteins have been reported in different food crops. Here, we performed a genome-wide analysis to identify different Si transporters and Slp1 homologs in the bioenergy crop poplar (Populus trichocarpa Torr. and A. Gray ex W. Hook). We identified one channel-type Si influx transporter (PtLsi1; Potri.017G083300), one Si efflux transporter (PtLsi2; Potri.012G144000) and two proteins like Slp1 (PtSlp1a; Potri.004G168600 and PtSlp1b; Potri.009G129900) in the P. trichocarpa genome. We found a unique sequence (KPKPPVFKPPPVPI) in PtSlp1a which is repeated six times. Repeated presence of this sequence in PtSlp1a indicates that this protein might be important for silicification processes in P. trichocarpa. The mutation profiles of different Si transporters in a P. trichocarpa genome-wide association study population identified significant and impactful mutations in Potri.004G168600 and Potri.009G129900. Using a publically accessible database (http://bar.utoronto.ca/eplant_poplar/), digital expression analysis of the putative Si transporters in P. trichocarpa found low to moderate expression in the anticipated tissues, such as roots and leaves. Subcellular localization analysis found that PtLsi1/PtLsi2 are localized in the plasma membrane, whereas PtSlp1a/PtSlp1b are found in the extracellular spaces. Protein–Protein interaction analysis of PtLsi1/PtLsi2 identified Delta-1-pyrroline-5-carboxylate synthase (P5CS) as one of the main interacting partners of PtLsi2, which plays a key role in proline biosynthesis. Proline is a well-known participant in biotic and abiotic stress tolerance in plants. These findings will reinforce future efforts to modify Si accumulation for enhancing plant stress tolerance and carbon sequestration in poplar.