Quantitative assessment of the effects of human activities on phytoplankton communities in lakes and reservoirs.

Global algal blooms have been severely threatening safety of drinking water and development of socio-economy. Effective prevention and accurate control of algal blooms require a quantitative assessment of the influence of human activities and identification of priority areas. However, previous studies on the quantitative assessment of the effects of human activities on algal communities are lacking, severely hindering the effective and precise control of algal blooms. This paper proposes a quantitative assessment model to evaluate the impact intensity of human activities on phytoplankton. Applications showed that the proliferation of phytoplankton were more limited by nutrients such as total phosphorus and ammonia where waters are less influenced by human activities, yet were less limited by these nutrients where there are highly intensive human activities. The density of phytoplankton in waters increased with an increase in human activity intensity, particularly in concentrated agricultural areas, which are priority areas for the prevention and control of algal blooms. The methodologies can clearly identify key areas for algal bloom prevention and control and can provide scientific evidence for water and nutrient management throughout the world, reducing the risk of algal blooms and ensuring aquatic ecosystem health and potable water safety.

[The comparison of neurobehavioral changes and impaired locations between the mouse model of manganism and Parkinson's disease].

Objective: To investigate the effect of manganese chloride (MnCl(2)) or 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) on the neurobehavioral and histopathology in C57BL/6 mice and provide evidence for the diagnosis, treatment and prevention of manganism. Methods: Adult male C57BL/6 mice were treated with MnCl(2) and MPTP respectively by intraperitoneal injection at the doses of 5, 10, 20mg Mn/kg and 30mg MPTP/kg. Controls were injected equivalent normal saline. All animals were administrated 5 times a week for 4 consecutive weeks and sacrificed after behavior tests on the fifth week. Balance ability, anxiety and depression level and cognitive function were tested respectively by vertical pole test, open field locomotion test and Morris swim task. The neuron pathological changes of striatum and substantia nigra were examined through HE-staining pathological section by using optical microscope. Results: Compared with the control group, the high dose of MnCl(2) reduced body weight obviously (P<0.01) . The results of vertical pole test showed that MnCl(2) and MPTP lengthened the pole-climbing time and turnaround time. Open field locomotion test showed that movement distance, stand-up time and central field time were decreased after the exposure of MnCl(2) or MPTP. In the Morris swim task, the escape latency time increased and the target quadrant activity time decreased significantly after the injection of MPTP as well as high-dose MnCl(2), comparing with controls (P<0.05) . Moreover, the escape latency time of high dose MnCl(2) prolonged prominently comparing with MPTP grou (P<0.05) . The results of histopathology showed that acidophilic changes elevated in MnCl(2) and MPTP group, comparing with controls. Furthermore, in striatum the oxyphil cells number increased in MnCl(2) high-dose group comparing with MPTP group (P<0.01) . On the contrary, there were more oxyphil cells in MPTP group comparing with MnCl(2) groups in substantia nigra (P<0.01) . Conclusion: Both manganese and MPTP can induce the impairment of dopaminergic neural system, but the symptons and injured location of manganism are inconsistent with PD models induced by MPTP.

Clinical and microbiological characteristics of infections caused by various Nocardia species in Taiwan: a multicenter study from 1998 to 2010.

This multicenter study in Taiwan investigated the clinical presentations of various Nocardia species infections based on 16S rRNA sequence analysis. Patients with nocardiosis in four large medical centers from 1998 to 2010 were included. A total of 100 preserved nonduplicate isolates causing human infection were identified as Nocardia species. Sequencing analysis of 16S rRNA confirmed that 35 of 36 N. asteroides isolates identified by conventional tests were non-asteroides Nocardia species, and that two of 50 N. brasiliensis isolates had also been initially misidentified. N. brasiliensis (50%) was the most common pathogen, followed by N. cyriacigeorgica (18%). In addition, several rare pathogens were identified, including N. asiatica, N. rhamnosiphila, N. abscessus, N. transvalensis, N. elegans, and N. carnea. Primary cutaneous infection was the most common presentation, noted in 55 (55%) patients, while pulmonary infection presented in 26 (26%) patients. The crude mortality rate was 6.7% (6/89), and was lowest for primary cutaneous infection (2.2%) and highest for disseminated disease and pulmonary infection (16.7%). In conclusion, N. brasiliensis and N. cyriacigeorgica were the most common pathogens causing nocardiosis in Taiwan. Molecular methods for identifying Nocardia to the species level are mandatory for better understanding the epidemiology and clinical characteristics of patients with nocardiosis.

[Effects of composite blood-activating decoction on adhesive function of bone marrow stroma cells in radiation injured mice].

OBJECTIVE: To evaluate the effect of commonly used "blood activating and stasis-removing" Chinese herbal drugs on adhesive function of bone marrow stroma cells in acute radiation injured mice. METHODS: After irradiation by 8 Gy 60Co gamma-ray, each mouse was intraperitoneally injected immediately with 0.2 ml 100% composite blood-activating decoction (CBAD) twice a day for 6 days. On the 7th day, the femura were taken and the bone karyocyte (BMC) suspension was made. According to long term bone marrow culture procedure, on the 12th day, the fibroblastic colony forming units were counted, and on the 28th day, the adhesion of culture stroma cells to normal murine BMC was observed. RESULTS: The adhesion of culture stroma cells to normal murine BMC was 67.8 +/- 17.2% in normal group, while in CBAD group, it was 55.8 +/- 10.5%. The difference was insignificant (P > 0.05). In the control group, the value was 47.7 +/- 13.6%, which was significantly lower than that in normal group (P < 0.02). CONCLUSION: The commonly used "blood-activating and stasis-removing" Chinese herbal drugs can enhance the adhesive function of bone marrow stroma cells in acute radiation injured mice.