Vascular complications of diabetes: natural history and corresponding risks of dementia in a national cohort of adults with diabetes.

AIMS: This study aimed to determine the trajectory of diabetic vascular diseases and to investigate the association between vascular diseases and dementia. METHODS: We included adults aged ≥ 50 years with newly diagnosed type 2 diabetes (n = 173,118) from 2001 to 2005 who were followed-up until December 31, 2013 in the Taiwan's National Health Insurance Research Database. Multivariable Cox regression models were constructed to estimate hazard ratios (HRs) and confidence limits (CLs) for all-cause dementia in relation to the number, types, and occurrence patterns of vascular disease. RESULTS: Within 1 year of diabetes diagnosis, 26.3% of adults developed their first vascular disease. During the 1,864,279 person-years of follow-up, 17,426 adults had all-cause dementia, corresponding to an incidence of 97.9 cases/10,000 person-years in 127,718 adults with at least one vascular disease and 67.5 cases/10,000 person-years in 45,400 adults without vascular diseases. Across all age groups, adults who subsequently developed a vascular disease in two one-year windows since diabetes diagnosis had the highest incidence of all-cause dementia. In comparison with adults without vascular diseases, HR for all-cause dementia was 1.99 (CL: 1.92-2.07) for those with one vascular disease only; 2.04 (CL: 1.98-2.13) for two or more vascular diseases; 3.56 (CL: 3.44-3.70) for stroke only; and 2.06 (CL: 1.99-2.14) for neuropathy alone. Similar associations were also observed with a smaller magnitude for adults with nephropathy, retinopathy, cardiovascular disease, or peripheral arterial disease. CONCLUSIONS: Patients with diabetes-related complications, particularly stroke and neuropathy, and those with rapidly developed vascular diseases appeared to have a high risk of dementia.

Lasiodiplodia theobromae as a Causal Agent of Kumquat Dieback in Taiwan.

Kumquat (Fortunella margarita (Lour.) Swingle) is an important citrus fruit crop of Iland County in northeastern Taiwan. Fruit produced in this area are mainly for making preserves, which is a well-known product in Taiwan. Decline of kumquat was first noticed in 1990. Since 1995, it has become an important problem affecting ≈80% of kumquat orchards. The problem was especially serious after the passage of a typhoon. Some orchards were abandoned due to death of many declining trees. Initial symptoms were yellowing and browning of leaves on some branches of affected trees. Abscission of leaves and fruits occurred, subsequently resulting in the appearance of dieback of affected branches. Disease symptoms could progress to other branches of the same tree, gummosis on the trunk, and eventually death of the tree. Previously, Phytophthora citrophthora (Smith & Smith) Leonian was reported to be a causal organism of kumquat decline (1). Recently, isolations from declining kumquat trees in several orchards failed to recover P. citrophthora and instead we isolated Lasiodiplodia theobromae (Pat.) Griffon & Maubl. (syn. Botryodiplodia theobromae Pat.) from tissue taken from the margin of discolored bark and wood on symptomatic branches. The fungus produced grayish black colonies on V8 agar and black ostiolate pycnidia (125 to 650 µm in diameter) with ovoid to elongate conidia (20 to 32 × 12 to 16 µm) on autoclaved whole wheat grains that were placed on V8 agar. Young conidia were hyaline and nonseptate, whereas mature conidia were brown, one septate, and striate. Pathogenicity tests were carried out on healthy kumquat trees located at the Taiwan Agricultural Research Institute experimental farm. Three isolates of L. theobromae were cultured on wheat-oat medium. Colonized grains (≈5 g) were held against a wound made by lightly scrapping a branch (5 to 7 mm in diameter) 200 to 250 cm above the ground by wrapping a sheet of clear plastic around the branch (2). Eighteen branches were used for each isolate, and the same number of branches similarly inoculated with sterile grains as a control. Healthy branches inoculated with L. theobromae showed disease symptoms similar to those observed on naturally infected plants. Discoloration of leaves on inoculated branches occurred within 1 week. Subsequently, all the leaves fell and infected branches died. The numbers of inoculated branches killed by the three isolates of L. theobromae tested were 18, 9, and 14 after 1 month. All control branches remained disease free. L. theobromae was reisolated from symptomatic tissues, completing Koch's postulates. The same isolates were used to inoculate trunks of kumquat trees with the method described above. Six trunks were inoculated with each isolate, and the same number of trunks similarly inoculated with sterile grains was used as the control. Gummosis on inoculated trunks occurred in 1 week. The numbers of inoculated trunks showing gummosis induced by the three isolates of L. theobromae tested were 6, 5, and 6 after 1 month. L. theobromae was reisolated from symptomatic tissue. All control trunks remained free of gummosis. Our results show that in addition to P. citrophthora, L. theobromae can also cause a dieback on kumquat. To our knowledge, this is the first report of disease caused by L. theobromae on kumquat or on any species in the Rutaceae family in Taiwan. References: (1) P. J. Ann et al. Plant Pathol. Bull. (Taiwan) 6:198, 1997. (2) W. H. Ko et al. Plant Pathol. 35:254, 1986.

Development, Evaluation, and Application of a Primary Aerosol Model.

The Segmented-Plume Primary Aerosol Model (SPPAM) has been developed over the past several years. The earlier model development goals were simply to generalize the widely used Industrial Source Complex Short-Term (ISCST) model to simulate plume transport and dispersion under light wind conditions and to handle a large number of roadway or line sources. The goals have been expanded to include development of improved algorithm for effective plume transport velocity, more accurate and efficient line and area source dispersion algorithms, and recently, a more realistic and computationally efficient algorithm for plume depletion due to particle dry deposition. A performance evaluation of the SPPAM has been carried out using the 1983 PNL dual tracer experimental data. The results show the model predictions to be in good agreement with observations in both plume advection-dispersion and particulate matter (PM) depletion by dry deposition. For PM2.5 impact analysis, the SPPAM has been applied to the Rubidoux area of California. Emission sources included in the modeling analysis are: paved road dust, diesel vehicular exhaust, gasoline vehicular exhaust, and tire wear particles from a large number of roadways in Rubidoux and surrounding areas. For the selected modeling periods, the predicted primary PM2.5 to primary PM10 concentration ratios for the Rubidoux sampling station are in the range of 0.39-0.46. The organic fractions of the primary PM2.5 impacts are estimated to be at least 34-41%. Detailed modeling results indicate that the relatively high organic fractions are primarily due to the proximity of heavily traveled roadways north of the sampling station. The predictions are influenced by a number of factors; principal among them are the receptor locations relative to major roadways, the volume and composition of traffic on these roadways, and the prevailing meteorological conditions.