Interpreting Soil Tests for Turfgrass

Nick E. Christians 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

The Impact of Stress on Addiction

( Nick E. Goeders ) 한국응용약물학회 2004 학술대회 Vol.2004 No.2

Development of Roundup Ready Bentgrass for the Control of Poa annua

Nick E. Christians(닉 크리스챤스),Jeong-Ho Lee(이정호) 한국잡초학회·한국잔디학회 2006 Weed & Turfgrass Science Vol.20 No.1

애뉴얼 블루그래스는 골프장에서 방제하기가 대단히 어려운 잡초이다. 방제가 어려운 이유로는 애뉴얼 블루그래스의 경우 불량환경에서도 왕성하게 종자생산을 할 수 있는 특성과 또한 낮은 예초환경에서도 적응력이 있기 때문이다. 하지만 무엇보다도 유전적으로 다양성이 있기 때문에 골프장의 잔디에 비해 우점할 수 있는 것이다. 일반적으로 애뉴얼 블루그래스는 일년생 한지형 잔디로, 생육형은 주형이다. 하지만 포복경이 있어 다년생의 특성을 갖는 생태형이 다른 애뉴얼 블루그래스도 있다. 골프장에서 애뉴얼 블루그래스 방제를 위해 화학적 방법과 재배적 방법에 관한 수많은 연구가 지난 85년간 진행되었다. 연구결과 일부 종류의 애뉴얼 블루그래스방제에 성공적인 결과도 있지만, 모든 종류의 애뉴얼 블루그래스 방제에 성공적인 방법은 아직 없는 실정이다. 이 모든 방제 방법들 중에 Roundup ready creeping bentgrass의 사용은 다양한 종류의 새포아풀을 방제 할 수 있다. Roundup readgy bentgrass는 Roundup에 내성이 있어 약해 피해 없이 생존이 가능하다. 따라서 골프장에서 이 새로운 기술을 활용하면 새포아풀이 없는 그린, 티, 훼어웨이를 유지할 수 있다. Annual bluegrass(Poa annua L.) is a problem weed that is very difficult to control on golf courses. There are some reasons that make Poa annua such a difficult weed to be controled. One of these reasons is this plant's ability to reproduce its seed even under stressful conditions. Another reason is its adaptation to low mowing heights. Above all things, the greatest competitive advantage of Poa annua is its genetic diversity. Generally, Poa annua is a bunch type and annual type cool-season grass, but some types act as weak perennials and have stolons. There has been much research on controlling annual bluegrass in golf course turf with chemical and cultural techniques. This research has been conducted for more than 85 years. There has been some progress in controlling some types of Poa annua, but these methods have not been successful on every biotype. Among all of the techniques, Roundup ready creeping bentgrass has the most promise of controlling the diverse types of Poa annua. Roundup ready bentgrass is capable of tolerating the effects of Roundup(glyphosate) while it kills other plants including Poa annua. By using this new technology, we can make Poa annua free greens, tees, and fairways.

Bentgrass 생육에 미치는 Polymer Coated Urea의 효과 ( Growth Response of Bentgrass To Polymer Coated Urea )

주영규,이재필,Nick E. Christans 한국잡초학회·한국잔디학회 1997 Weed & Turfgrass Science Vol.11 No.2

Reconciling the shadow of a subduction signature with rift geochemistry and tectonic environment in Eastern Marie Byrd Land, Antarctica

LeMasurier, Wesley E.,Choi, Sung Hi,Hart, Stanley R.,Mukasa, Sam,Rogers, Nick Elsevier 2016 Lithos Vol.260 No.-

<P><B>Abstract</B></P> <P>Basalt-trachyte volcanoes in the Marie Byrd Land (MBL) Cenozoic province lie along the Amundsen Sea coast on the north flank of the West Antarctic rift. Basalts here are characterized by OIB-like geochemistry, restricted ranges of <SUP>87</SUP>Sr/<SUP>86</SUP>Sr (0.702535–0.703284) and <SUP>143</SUP>Nd/<SUP>144</SUP>Nd (0.512839–0.513008) and a wide range of <SUP>206</SUP>Pb/<SUP>204</SUP>Pb (19.357–20.934).</P> <P>Basalts at three MBL volcanoes display two anomalies compared with the above and with all other basalts in West Antarctica. They include <SUP>143</SUP>Nd/<SUP>144</SUP>Nd (0.512778–0.512789) values at Mt. Takahe and Mt. Siple that are 2σ lower than other West Antarctic basalts, and Ba/Nb, Ba/La, and Ba/Th values at Mt. Murphy and Mt. Takahe that are 3–8 times higher than normal OIB. Isotope and trace element data do not support crustal and lithospheric mantle contamination, or the presence of residual mantle amphibole or phlogopite as explanations of these anomalies.</P> <P>The apparent coincidence of these anomalies with the site of a pre-Cenozoic convergence zone along the Gondwanaland margin suggests a subduction influence. Major episodes of subduction and granitic plutonism took place in MBL during the Devonian, Permian, and Late Cretaceous. Relicts in the source region, of components from these subducted slabs, provide a credible explanation for the uncoupling of Ba from other large ion lithophile elements (LILE), for its erratic distribution, and for the anomalously low <SUP>143</SUP>Nd/<SUP>144</SUP>Nd at Mt. Takahe.</P> <P>The last episode of subduction ended ~85Ma, and was followed by continental break-up, rifting and lithospheric attenuation that produced the West Antarctic rift as we know it today. Thus, the enigmatic geochemical signatures in these three volcanoes seem to have been preserved roughly 61–85m.y. after subduction ended. New calculations of source melting depth and a new determination of lithospheric thickness suggest that the source of the anomalies resides in a fossil mélange diapir that rose from the Cretaceous subducting slab, became attached to the base of the lithosphere at 80–100km depth, and remained there during the subsequent plate motion and source remobilization history of this region.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Three MBL volcanoes display Ba and Nd isotope anomalies unique to West Antarctica. </LI> <LI> Neither lithospheric contamination, nor mantle amphibole explains the anomalies. </LI> <LI> Residual subduction component contamination provides the best explanation. </LI> <LI> Subduction ended ~85Ma followed by formation of the West Antarctic rift. </LI> <LI> The anomaly source is a fossil mantle diapir attached to the base of the lithosphere. </LI> </UL> </P>

Development of Roundup Ready Bentgrass for the Control of Poa annua

닉크리스챤스,이정호,Christians, Nick E.,Lee, Jeong-Ho Turfgrass Society of Korea 2006 한국잔디학회지 Vol.20 No.1

애뉴얼 블루그래스는 골프장에서 방제하기가 대단히 어려운 잡초이다. 방제가 어려운 이유로는 애뉴얼 블루그래스의 경우 불량환경에서도 왕성하게 종자생산을 할 수 있는 특성과 또한 낮은 예초환경에서도 적응력이 있기 때문이다. 하지만 무엇보다도 유전적으로 다양성이 있기 때문에 골프장의 잔디에 비해 우점할 수 있는 것이다. 일반적으로 애뉴얼 블루그래스는 일년생 한지형 잔디로, 생육형은 주형이다. 하지만 포복경이 있어 다년생의 특성을 갖는 생태형이 다른 애뉴얼 블루그래스도 있다. 골프장에서 애뉴얼 블루그래스 방제를 위해 화학적 방법과 재배적 방법에 관한 수많은 연구가 지난 85년간 진행되었다. 연구결과 일부 종류의 애뉴얼 블루그래스 방제에 성공적인 결과도 있지만, 모든 종류의 애뉴얼 블루그래스 방제에 성공적인 방법은 아직 없는 실정이다. 이 모든 방제 방법들 중에 Roundup ready creeping bentgrass의 사용은 다양한 종류의 새포아풀을 방제 할 수 있다. Roundup readgy bentgrass는 Roundup에 내성이 있어 약해 피해 없이 생존이 가능하다. 따라서 골프장에서 이 새로운 기술을 활용하면 새포아풀이 없는 그린, 티, 훼어웨이를 유지할 수 있다. Annual bluegrass(Poa annua L.) is a problem weed that is very difficult to control on golf courses. There are some reasons that make Poa annua such a difficult weed to be controled. One of these reasons is this plant's ability to reproduce its seed even under stressful conditions. Another reason is its adaptation to low mowing heights. Above all things, the greatest competitive advantage of Poa annua is its genetic diversity. Generally, Poa annua is a bunch type and annual type cool-season grass, but some types act as weak perennials and have stolons. There has been much research on controlling annual bluegrass in golf course turf with chemical and cultural techniques. This research has been conducted for more than 85 years. There has been some progress in controlling some types of Poa annua, but these methods have not been successful on every biotype. Among all of the techniques, Roundup ready creeping bentgrass has the most promise of controlling the diverse types of Poa annua. Roundup ready bentgrass is capable of tolerating the effects of Roundup(glyphosate) while it kills other plants including Poa annua. By using this new technology, we can make Poa annua free greens, tees, and fairways.

옥수수 ( Zea mays L. )와 소나무 ( Pinus densiflora L. ) 추출물의 생물학적 활성 ( Biological Activity of Extracts from Zea mays L. and Pinus densiflora L. )

주영규,Soul Chun,Nick E. Christians 한국잡초학회·한국잔디학회 1998 Weed & Turfgrass Science Vol.12 No.4

Evaluation of Various Slow-release Nitrogen Sources for Growth and Establishment of Poa pratensis L. on Sand-based Systems

이상국,David D. Minner,Nick E. Christians 한국잔디학회 2010 Weed & Turfgrass Science Vol.24 No.2

Nitrogen (N) is one of the most important nutrients among 17 essential nutrients for maintaining turfgrass color and quality. The slow release fertilizers were initially developed to provide a more consistent release of nitrogen over a longer period and are often used to decrease leaching potential from sandy soils. The goal of this study is to determine if various slow release N sources affect the rate at which turfgrass establishes. Six nitrogen sources were evaluated; Nitroform (38-0-0), Nutralene (40-0-0), Organiform (30-0-0), Sulfur coated urea (SCU, 37-0-0), urea (46-0-0), and Milorganite (6-0-0). The root zone media was seeded and sodded with ‘Limousine’ Kentucky bluegrass (Poa pratensis L.). Sodded pots produced 182 to 518 g more clipping dry weight than seeded pots. Among seeded pots,Milorganite produced greater amount of root dry weight than any other N sources. Because the period of turfgrass growth is different between sodded and seeded plots, there were differences on clipping yield and root growth. Overall,high N rate had turf color greater than acceptable color of 6 among seeded pots throughout the study. However, low N rate didn’t produce acceptable turf color throughout the study. Based on the result of this study, Milorganite would be recommended for new establishment of Kentucky bluegrass than urea with less clipping yield which can lead to reduce labor.

Evaluationof Phosphorus Rateand Mixing Depthonthe Growthand Establishment of Kentucky bluegrass(Poapratensis L.) in Sand-Based Systems

이상국,David D. Minner,Nick E, Christians,Henry G. Taber 한국잔디학회 2009 Weed & Turfgrass Science Vol.23 No.2

Phosphorus (P) is one of the essential elements of the phospholipids that are involved in the formation of plant cell membranes. Phosphorus is highly immobile in soils and is often a limiting nutrient for plant growth. Phosphorus mobility and availability varies with several factors such as application frequency, placement in the soil, and the amount of irrigation or precipitation. This study was conducted to evaluate the effect of P applications at level of 0, 146, and 293 kg․ha-1 at four mixing depths (0, 7.6, 15.2, and 22.9 cm )on the growth and establishment of Kentucky bluegrass (Poapratensis L.) in a sand-based system.Grass clipping samples were collectedevery two weeks, dried, and weighed. Total root dry weight, root organic matter, and tissue content of P were measured at the end of the study. Leachate was collected weekly and analyzed for total P concentration. No difference was found between application of P to the surface and to the 7.6 cm mixing depth. However, surface application with 146 and 293 kg P․ha-1 produced 8-10% and 16-20% more P in tissue than subsurface applications, respectively Phosphorus (P) is one of the essential elements of the phospholipids that are involved in the formation of plant cell membranes. Phosphorus is highly immobile in soils and is often a limiting nutrient for plant growth. Phosphorus mobility and availability varies with several factors such as application frequency, placement in the soil, and the amount of irrigation or precipitation. This study was conducted to evaluate the effect of P applications at level of 0, 146, and 293 kg․ha-1 at four mixing depths (0, 7.6, 15.2, and 22.9 cm )on the growth and establishment of Kentucky bluegrass (Poapratensis L.) in a sand-based system.Grass clipping samples were collectedevery two weeks, dried, and weighed. Total root dry weight, root organic matter, and tissue content of P were measured at the end of the study. Leachate was collected weekly and analyzed for total P concentration. No difference was found between application of P to the surface and to the 7.6 cm mixing depth. However, surface application with 146 and 293 kg P․ha-1 produced 8-10% and 16-20% more P in tissue than subsurface applications, respectively

Total knee arthroplasty in patients with severe obesity: outcomes of standard keeled tibial components versus stemmed universal base plates

( Katherine L. Elcock ),( Deborah J. Macdonald ),( Nick D. Clement ),( Chloe E. H. Scott ) 대한슬관절학회 2023 대한슬관절학회지 Vol.35 No.-

Background Patients with severe obesity [body mass index (BMI) ≥ 40 kg/m²] potentially overload the tibial component after total knee arthroplasty (TKA), risking tibial subsidence. Using a cemented single-radius cruciate-retaining TKA design, this study compared the outcomes of two tibial baseplate geometries in patients with BMI ≥ 40 kg/m²: standard keeled (SK) or universal base plate (UBP), which incorporates a stem. Methods This was a retrospective, single-centre cohort study with minimum 2 years follow-up of 111 TKA patients with BMI ≥ 40 kg/m²: mean age 62.2 ± 8.0 (44-87) years, mean BMI 44.3 ± 4.6 (40-65.7) kg/m² and 82 (73.9%) females. Perioperative complications, reoperations, alignment and patient-reported outcomes (PROMS): EQ-5D, Oxford Knee Score (OKS), Visual Analogue Scale (VAS) pain score and satisfaction were collected preoperatively, and at 1 year and final follow-up postoperatively. Results Mean follow-up was 4.9 years. SK tibial baseplates were performed in 57 and UBP in 54. There were no significant differences in baseline patient characteristics, post-operative alignment, post-operative PROMs, reoperations or revisions between the groups. Three early failures requiring revision occurred: two septic failures in the UBP group and one early tibial loosening in the SK group. Five-year Kaplan-Meier survival for the endpoint mechanical tibial failure was SK 98.1 [94.4-100 95% confidence interval (CI)] and UBP 100% (p = 0.391). Overall varus alignment of the limb (p = 0.005) or the tibial component (p = 0.031) was significantly associated with revision and return to theatre. Conclusions At early to mid-term follow-up, no significant differences in outcomes were found between standard and UBP tibial components in patients with BMI ≥ 40 kg/m². Varus alignment of either tibial component or the limb was associated with revision and return to theatre.