Planaire optische versterkers

Langs een glasfiber kan in de vorm van optische pulsjes verschrikkelijk veel informatie worden verzonden: de fiber heeft een zeer hoge transmissiecapaciteit. Wanneer echter voor het schakelen van de informatiestroom, of voor het regenereren van de pulsjes, de informatiestroom naar het elektrische domein omgezet moet worden en vice versa, geeft dit een enorme verlaging van deze capaciteit. Door drie Nederlandse groepen, wordt gedeeltelijk onder de paraplu van het IOP onderzoek gedaan aan een speciale klasse van planaire versterkers: nl die waarin de versterking berust op eigenschappen van zeldzame aard ionen zoals het Erbium-ion. En over dit onderzoek gaat dit artikel

Evaluation of spelt germplasm for polyphenol oxidase activity and aluminium resistance

Kidney transplantation is the best treatment option for patients with end-stage renal failure. At present, approximately 800 Dutch patients are registered on the active waiting list of Eurotransplant. The waiting time in the Netherlands for a kidney from a deceased donor is on average between 3 and 4years. During this period, patients are fully dependent on dialysis, which replaces only partly the renal function, whereas the quality of life is limited. Mortality among patients on the waiting list is high. In order to increase the number of kidney donors, several initiatives have been undertaken by the Dutch Kidney Foundation including national calls for donor registration and providing information on organ donation and kidney transplantation. The aim of the national PROCARE consortium is to develop improved matching algorithms that will lead to a prolonged survival of transplanted donor kidneys and a reduced HLA immunization. The latter will positively affect the waiting time for a retransplantation. The present algorithm for allocation is among others based on matching for HLA antigens, which were originally defined by antibodies using serological typing techniques. However, several studies suggest that this algorithm needs adaptation and that other immune parameters which are currently not included may assist in improving graft survival rates. We will employ a multicenter-based evaluation on 5429 patients transplanted between 1995 and 2005 in the Netherlands. The association between key clinical endpoints and selected laboratory defined parameters will be examined, including Luminex-defined HLA antibody specificities, T and B cell epitopes recognized on the mismatched HLA antigens, non-HLA antibodies, and also polymorphisms in complement and Fc receptors functionally associated with effector functions of anti-graft antibodies. From these data, key parameters determining the success of kidney transplantation will be identified which will lead to the identification of additional parameters to be included in future matching algorithms aiming to extend survival of transplanted kidneys and to diminish HLA immunization. Computer simulation studies will reveal the number of patients having a direct benefit from improved matching, the effect on shortening of the waiting list, and the decrease in waiting time

PIRCHE-II is related to graft failure after kidney transplantation

Individual HLA mismatches may differentially impact graft survival after kidney transplantation. Therefore, there is a need for a reliable tool to define permissible HLA mismatches in kidney transplantation. We previously demonstrated that donor-derived Predicted Indirectly ReCognizable HLA Epitopes presented by recipient HLA class II (PIRCHE-II) play a role in de novo donor-specific HLA antibodies formation after kidney transplantation. In the present Dutch multi-center study, we evaluated the possible association between PIRCHE-II and kidney graft failure in 2,918 donor-recipient couples that were transplanted between 1995 and 2005. For these donors-recipients couples, PIRCHE-II numbers were related to graft survival in univariate and multivariable analyses. Adjusted for confounders, the natural logarithm of PIRCHE-II was associated with a higher risk for graft failure [hazard ratio (HR): 1.13, 95% CI: 1.04-1.23, p = 0.003]. When analyzing a subgroup of patients who had their first transplantation, the HR of graft failure for ln(PIRCHE-II) was higher compared with the overall cohort (HR: 1.22, 95% CI: 1.10-1.34, p < 0.001). PIRCHE-II demonstrated both early and late effects on graft failure in this subgroup. These data suggest that the PIRCHE-II may impact graft survival after kidney transplantation. Inclusion of PIRCHE-II in donor-selection criteria may eventually lead to an improved kidney graft survival

Eigenvalue asymptotics for weighted Laplace equations on rough Riemannian manifolds with boundary

Our topological setting is a smooth compact manifold of dimension two or higher with smooth boundary. Although this underlying topological structure is smooth, the Riemannian metric tensor is only assumed to be bounded and measurable. This is known as a rough Riemannian manifold. For a large class of boundary conditions we demonstrate a Weyl law for the asymptotics of the eigenvalues of the Laplacian associated to a rough metric. Moreover, we obtain eigenvalue asymptotics for weighted Laplace equations associated to a rough metric. Of particular novelty is that the weight function is not assumed to be of fixed sign, and thus the eigenvalues may be both positive and negative. Key ingredients in the proofs were demonstrated by Birman and Solomjak nearly fifty years ago in their seminal work on eigenvalue asymptotics. In addition to determining the eigenvalue asymptotics in the rough Riemannian manifold setting for weighted Laplace equations, we also wish to promote their achievements which may have further applications to modern problems

T-cell epitopes shared between immunizing HLA and donor HLA associate with graft failure after kidney transplantation

CD4(+) T-helper cells play an important role in alloimmune reactions following transplantation by stimulating humoral as well as cellular responses, which might lead to failure of the allograft. CD4(+) memory T-helper cells from a previous immunizing event can potentially be reactivated by exposure to HLA mismatches that share T-cell epitopes with the initial immunizing HLA. Consequently, reactivity of CD4(+) memory T-helper cells toward T-cell epitopes that are shared between immunizing HLA and donor HLA could increase the risk of alloimmunity following transplantation, thus affecting transplant outcome. In this study, the amount of T-cell epitopes shared between immunizing and donor HLA was used as a surrogate marker to evaluate the effect of donor-reactive CD4(+) memory T-helper cells on the 10-year risk of death-censored kidney graft failure in 190 donor/recipient combinations using the PIRCHE-II algorithm. The T-cell epitopes of the initial theoretical immunizing HLA and the donor HLA were estimated and the number of shared PIRCHE-II epitopes was calculated. We show that the natural logarithm-transformed PIRCHE-II overlap score, or Shared T-cell EPitopes (STEP) score, significantly associates with the 10-year risk of death-censored kidney graft failure, suggesting that the presence of pre-transplant donor-reactive CD4(+) memory T-helper cells might be a strong indicator for the risk of graft failure following kidney transplantation.Nephrolog

Allocation to highly sensitized patients based on acceptable mismatches results in low rejection rates comparable to nonsensitized patients

Whereas regular allocation avoids unacceptable mismatches on the donor organ, allocation to highly sensitized patients within the Eurotransplant Acceptable Mismatch (AM) program is based on the patient\'s HLA phenotype plus acceptable antigens. These are HLA antigens to which the patient never made antibodies, as determined by extensive laboratory testing. AM patients have superior long-term graft survival compared with highly sensitized patients in regular allocation. Here, we questioned whether the AM program also results in lower rejection rates. From the PROCARE cohort, consisting of all Dutch kidney transplants in 1995-2005, we selected deceased donor single transplants with a minimum of 1 HLA mismatch and determined the cumulative 6-month rejection incidence for patients in AM or regular allocation. Additionally, we determined the effect of minimal matching criteria of 1 HLA-B plus 1 HLA-DR, or 2 HLA-DR antigens on rejection incidence. AM patients showed significantly lower rejection rates than highly immunized patients in regular allocation, comparable to nonsensitized patients, independent of other risk factors for rejection. In contrast to highly sensitized patients in regular allocation, minimal matching criteria did not affect rejection rates in AM patients. Allocation based on acceptable antigens leads to relatively low-risk transplants for highly sensitized patients with rejection rates similar to those of nonimmunized individuals

Allocation to highly sensitized patients based on acceptable mismatches results in low rejection rates comparable to nonsensitized patients

Whereas regular allocation avoids unacceptable mismatches on the donor organ, allocation to highly sensitized patients within the Eurotransplant Acceptable Mismatch (AM) program is based on the patient's HLA phenotype plus acceptable antigens. These are HLA antigens to which the patient never made antibodies, as determined by extensive laboratory testing. AM patients have superior long-term graft survival compared with highly sensitized patients in regular allocation. Here, we questioned whether the AM program also results in lower rejection rates. From the PROCARE cohort, consisting of all Dutch kidney transplants in 1995-2005, we selected deceased donor single transplants with a minimum of 1 HLA mismatch and determined the cumulative 6-month rejection incidence for patients in AM or regular allocation. Additionally, we determined the effect of minimal matching criteria of 1 HLA-B plus 1 HLA-DR, or 2 HLA-DR antigens on rejection incidence. AM patients showed significantly lower rejection rates than highly immunized patients in regular allocation, comparable to nonsensitized patients, independent of other risk factors for rejection. In contrast to highly sensitized patients in regular allocation, minimal matching criteria did not affect rejection rates in AM patients. Allocation based on acceptable antigens leads to relatively low-risk transplants for highly sensitized patients with rejection rates similar to those of nonimmunized individuals

Population Density, Spatial Distribution and Damage Evolution of Neochetina eichhorniae Warner and N. bruchi Hustache on Eichhornia crassipes (Mart.) Solms - Laubach

於台南縣德元埤田間選定慈善宮 (TK)、新鳳橋 (SF) 及四號池(FP) 等三試驗區釋放象鼻蟲防治布袋蓮，TK及SF試驗區分別於1996/12/08及1997/01/06 ~ 07各釋放一次象鼻蟲，於FP則於1997/05/24釋放一次及1998/01/09 ~ 03/04釋放六次共釋放七次。德元埤於1997年7月及2000年7月進行放水、清池及燒毀乾枯布袋蓮之管理措施，造成三試驗區布內袋蓮族群減少或完全清除，其中釋放於慈善宮試驗區之象鼻蟲仍能於布袋蓮殘株存活達4年以上並隨布袋蓮再次繁殖及增殖族群，證實象鼻蟲在該試驗區已建立其族群，並且放水及清除部分布袋蓮不會造成族群之滅絕。 田間象鼻蟲成蟲於布袋蓮葉片上取食造成之食痕密度與成蟲密度及幼蟲密度之相關係數低，但食痕密度對隧道密度、蟲孔密度及象鼻蟲族群之總密度 (成蟲、幼蟲、隧道及蟲孔) 相關係數則高。經回歸分析以連續20母株及其分生株與側芽為一取樣單位下，獲得 (象鼻蟲族群之總密度 = 85.95 + 0.0404食痕密度 (R2 = 0.903, p = 0.0001)。因此田間象鼻蟲族群之總密度得以由食痕密度評估之。不同取樣單位下象鼻蟲成蟲、幼蟲及食痕均傾向聚集分布，但隧道隨取樣單位不同而傾向聚集或隨機分布，蟲孔隨取樣單位不同而傾向聚集或均勻分布。 三試驗區象鼻蟲密度以慈善宮試驗區最高 (每0.25平方公尺3.37隻成蟲及5.21隻成蟲)，四號池次之 (每0.25平方公尺0.52隻成蟲4.38隻幼蟲)，新鳳橋近於0 (每0.25平方公尺0.01隻成蟲，但幼蟲、隧道及蟲孔密度均為0)。該三試驗區中象鼻蟲族群密度較高之慈善宮試驗區，於布袋蓮植株上成蟲取食之食痕密度與幼蟲造成之隧道及蟲孔密度顯著較高，每株布袋蓮無性繁殖之分生株及側芽密度顯著較低，顯示於較高族群密度下象鼻蟲成蟲對布袋蓮直接嚙食造成之食痕及幼蟲取食葉柄內組織造成隧道與蟲孔，顯著減少布袋蓮分生株及側芽密度，抑制布袋蓮新生之分生株及側芽之無性繁殖，降低布袋蓮生長勢。總之，利用食痕密度評估象鼻蟲之總密度檢定結果，可簡化今後田間之取樣技術及方法。象鼻蟲族群為害布袋蓮族群造成高密度之食痕、隧道及蟲孔密度，顯著降低布袋蓮之生長勢。This research selected three experimental areas (TK, SF, FP)among Der-Yuan irrigation lake in Tainan county to observe the effects of releasing weevils into these areas as biocontrol agent of waterhyacinth. Weevils were released only once into TK and SF area on 12/08/1996 and on 01/06/1997 separately, so were weevils only once into FP area on 05/24/1997 and six times (about once a week) from 01/09 to 03/04/1998. However, these three areas were so badly destroyed by farm irrigative unplug and burning waterhyacinth in July of 1997and of 2000 that the waterhyacinth populations were either eliminated or dwindled in these areas. Nevertheless, we found the weevils in TK area still had successfully survived for 4 years and established its population with the increase of waterhyacinth. It indicates that weevils wouldn't be exterminated by irrigative unplugging and had established its own population. Through this research we find the density of scars has low correlation coefficient with the density of adults as well as with that of larvae. But the correlation coefficients between scar density and young larvae canal density, matural larvae tunnel density, and the total density of weevils (including adults, larvae, canals and tunnels) are high. So using 20 plants (including runners and lateral buds), we can find the relationship below by regression analyses: total density of weevils = 85.95 + 0.0404 * scar density (R2 = 0.903, p = 0.001). This equation can help us to measure the total density of weevils population by scar density. By different methods of sample unit, the amounts of adults, larvae and scars tend to be aggregation distribution, and the canals tend to be aggregation or random distribution, and tunnels to be aggregation or uniform distribution. The density of weevils area is highest(3.37 adults, 5.21 larvae / 0.25 m2)in TK, second in FP(0.52 adults, 4.38 larvae / 0.25 m2), and near zero in SF(0.01 adults, 0 larvae, 0 canal and 0 tunnels / 0.25m2). Among three high weevil population density tested areas, the scar density of adults, canal density and tunnel density of larvae are significantly higher, and the density of runner as well as of lateral bud are significantly lower in the areas. It shows that the direct nibble scars of adults, the tunnels, and the tunnel of larvae decrease the densities of runner as well as of lateral bud, therefore suppress the growth of waterhyacinth. In conclusion, using the scar density to evaluate the total densities of weevils can simplify the techniques and methods of sampling. The weevil population damaging waterhyacinth population caused the high scar density, canals and tunnels density and lowered the growth of weevils.目錄 中文摘要……………………………………………………………i 英文摘要…………………………………………………………iii 誌謝…………………………………………………………………v 目錄……………………………………………………………… vi 表目錄…………………………………………………………… ix 圖目錄…………………………………………………………… xi 1. 前言1 2. 往昔研究3 2.1.布袋蓮之經濟重要性3 2.2.利用該二種象鼻蟲生物防治布袋蓮之實例4 2.3.布袋蓮之植株型態、生長及葉片之衰亡5 2.4.布袋蓮族群之增殖6 2.5.象鼻蟲之寄主範圍7 2.6.象鼻蟲之生活史8 2.7.象鼻蟲之生活習性9 2.8.象鼻蟲之取食行為、取食量及偏好性10 2.9.布袋蓮品質對象鼻蟲取食行為、遷移型及性別比例之影響10 2.10.象鼻蟲對布袋蓮總葉片數、葉片品質及葉面積的影響11 2.11.象鼻蟲對布袋蓮族群分生株數、幼株數之影響13 2.12.國外象鼻蟲田間調查13 2.13.布袋蓮象鼻蟲成蟲與布袋蓮葉面食痕數之關係15 3.材料及分析方法17 3.1.象鼻蟲之取得17 3.2.象鼻蟲釋放蟲源之繁殖17 3.3.田間釋放象鼻蟲18 3.4.田間調查及取樣方法20 3.4.1.釋放象鼻蟲半年內之調查與取樣20 3.4.2.釋放象鼻蟲第二年之調查與取樣20 3.4.3.釋放象鼻蟲第三~四年之調查與取樣22 3.5.資料分析方法22 3.5.1.各均值顯著性分析：22 3.5.2.食痕密度與象鼻蟲族群平均密度值之相關性分析23 3.5.3.食痕密度與象鼻蟲族群平均密度值之相關性分析23 3.5.4.食痕數、成蟲、幼蟲、隧道及蟲孔之空間分布型分析23 4.結果與討論26 4.1.象鼻蟲在田間之立足26 4.2.象鼻蟲族群密度與食痕密度關係31 4.3.象鼻蟲族群之空間分布34 4.4.象鼻蟲族群對布袋蓮族群之損害評估35 5.結論36 5.1.象鼻蟲族群之立足36 5.2.象鼻蟲族群平均密度與食痕密度之相關40 5.3.食痕密度評估象鼻蟲族群平均密度之線性迴歸分析42 5.4.象鼻蟲族群對布袋蓮族群之損害評估43 6.參考文獻4