Cascading effects of seed-stem-individual spatial patterns along a grazing gradient.

Studying the seed trait-stem trait-individual spatial pattern system is helpful for understanding the developmental direction of plant dynamics and populations under grazing disturbance as well as the antagonistic relationship between animals and plants, but few systematic analyses of this spatial pattern system have been carried out. Kobresia humilis is the dominant species in alpine grasslands. We studied K. humilis seed traits and their relationship with K. humilis reproductive individuals, the relationship between reproductive and vegetative stems, and the weights and spatial patterns of reproductive and nonreproductive individuals under four grazing treatments: no grazing (control), light grazing, moderate grazing and heavy grazing. We explored the relationship among seed size and seed number with reproductive stems and vegetative stems along the grazing gradient and assessed the spatial pattern changes between reproductive and nonreproductive individuals. The results showed the following: (1) Seed size increased with increasing grazing intensity, and the coefficient of variation for seed size and seed number in the heavy grazing treatment was greater than 0.6. (2) The structural equation model showed that grazing treatment had a positive effect on seed number, seed size and reproductive stem number and a negative effect on reproductive stem weight. (3) Grazing treatment did not affect the resource allocation to reproductive stems and vegetative stems per unit length of reproductive K. humilis individuals. (4) Compared with the number of reproductive individuals in the no grazing treatment, the number in the heavy grazing treatment decreased significantly, and the negative correlation between reproductive individuals and nonreproductive individuals changed from a full-scale negative correlation to a small-scale negative correlation and a large-scale positive correlation. Our study showed that grazing could activate and change the resource allocation pattern of dominant species in a grassland and have significant positive effects on reproductive stem number, reproductive stem weight, seed number and seed size. Along a grazing intensity gradient, with the increase in distance between reproductive and nonreproductive individuals, the transformation of intraspecific relationships from a negative correlation to a positive correlation is an ecological strategy conducive to population survival.

Significance of DC-LAMP and DC-SIGN expression in psoriasis vulgaris lesions.

OBJECTIVE: To detect and compare the expression levels of two dendritic cell proteins, namely Dendritic Cell Lysosome-Associated Membrane Protein (DC-LAMP) and Dendritic Cell-Specific ICAM-3 Grabbing Non-integrin (DC-SIGN) in psoriasis vulgaris lesions and normal skin tissues. METHODS: We used Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and immunohistochemical analysis to detect the expression of DC-LAMP and DC-SIGN in 33 samples representing plaque lesions of psoriasis vulgaris and 11 normal skin samples from healthy volunteers. RESULTS: RT-PCR The expression levels of DC-LAMP and DC-SIGN were higher in samples of psoriasis vulgaris lesions than in that of normal skin, based on RT-PCR results.Whereas DC-LAMP staining was mostly cytoplasmic in keratinocytes of basal and spinous epidermis and dermal dendritic cells, DC-SIGN staining was both cytoplasmic and nuclear in keratinocytes of spinous epidermis and dermal dendritic cells. The expression levels of DC-LAMP and DC-SIGN proteins were significantly higher in psoriasis vulgaris lesions when compared with normal skin tissues (P<0.01). Furthermore, we found a positive correlation between high DC-LAMP and high DC-SIGN expression levels in psoriasis vulgaris lesions (P<0.05, r=0.368). CONCLUSION: Compared with normal tissues, the levels of DC-LAMP and DC-SIGN were higher in psoriasis vulgaris lesions. Both DC-LAMP and DC-SIGN proteins may be involved in the pathogenesis of psoriasis vulgaris. The high expression of DC-LAMP may be associated with the altered differentiation of keratynocytes in psoriasis.

Pandemic influenza A (H1N1) virus infection factors among healthcare workers - a case-control study / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore factors related to pandemic influenza A (H1N1) virus infection among healthcare workers.</p><p><b>METHODS</b>H1N1 influenza confirmed cases of health workers in hospital of Beijing from Aug 30th 2009 to Jan 31st 2010 were included. A 1:4 matched case-control study was conducted with 54 healthcare workers who were infected by influenza A(H1N1) virus and 216 matched controls who were not infected. Face-to-face interview with questionnaires was used to collect information of work and family aspects of the study participants. Conditional logistic regression was used to analyze the H1N1 infection factors.</p><p><b>RESULTS</b>The age was 29.6 ± 7.4 years old and male subjects accounted for 17.4% (47/270). There were 5.6% (3/54) and 34.4% (74/216) of the cases get the influenza A (H1N1) vaccine immunization separately in the case group and control group. Among 18.5% (10/54) and 40.1% (88/216) of the cases and controls used high protection level masks during the epidemic. Besides, 33 (61.1%)and 161 (74.5%) cases lengthening the time of mask wearing separately. There were 13 (24.1%) and 85 (39.4%) cases using disposable tissue to clean hands in the case group and control group, 24 (44.4%) and 46 (21.3%) cases feel they were much easier to get infected in respiratory disease than others based on experience in the case and control group. Univariate analysis showed that factors such as using disposable tissue to clean hands (OR = 0.15, 95%CI = 0.04 - 0.57), lengthening the time of mask wearing (OR = 0.43, 95%CI = 0.20 - 0.92), using high protection level masks (OR = 0.26, 95%CI = 0.11 - 0.58), getting influenza A (H1N1) vaccine immunization (OR = 0.04, 95%CI = 0.01 - 0.32), much easier to get infected in respiratory disease than others based on experience (OR = 2.85, 95%CI = 1.44 - 5.62), were all associated with influenza A (H1N1) infection. Results of multivariate logistic regression analysis showed that variables such as history of influenza A (H1N1) virus immunization (OR = 0.18, 95%CI = 0.06 - 0.51), using high protection level masks (OR = 0.05, 95%CI = 0.01 - 0.35), much easier to get infected in respiratory disease than others based on experience (OR = 3.69, 95%CI = 1.58 - 8.63) were all correlated to influenza A (H1N1) infection.</p><p><b>CONCLUSIONS</b>Factors such as history of influenza A (H1N1) vaccine immunization, using high protection level masks and improving respiratory health can protect healthcare workers from infection of influenza A (H1N1).</p>

Estimation on the real number of novel influenza A (H1N1) cases, Beijing, 2009 / 中华流行病学杂志

Objective To estimate the real number of novel influenza A(H1N1 ) infection in Beijing, 2009. Methods A multiplier model (Impact 2009 v 1.0 software) based on Monte Carlo approach was used to estimate the real number of novel influenza A (H1N1 ) based on the number of influenza-like illness (ILI) cases, novel influenza A(H1N1 ) positive rate among ILI cases and rate on clinical visit of ILIs in secondary and tertiary hospitals. Results There were 1.80 million (90%CI: 1.46-2.30) estimated novel influenza A (H1N1) cases in 2009 in Beijing with the rate of infection as 11.0%. One reported case would represent 167 real infections. The highest age groups of infection were 0-4 years and 5-14 years, being 32.5% and 33.3%, respectively. Conclusion Laboratory-confirmed infections with novel influenza A (H1N1 ) only represented a fraction of the total cases in a population, suggesting that it was imperative to estimate the real number of novel influenza A (H1N1) infection.

The growth of Salvia miltiorrhiza seedling and root system following transplantation / 中国中药杂志

<p><b>OBJECTIVE</b>To study the relationship between plant growth and accumulation of active ingredients in Salvia miltiorrhiza.</p><p><b>METHOD</b>Transplants of S. miltiorrhiza were sampled at 20 day intervals. At each stage, the growth of seedling and root system was recorded and the contents of tanshinone II (A) and salvia acid were measured.</p><p><b>RESULT AND CONCLUSION</b>This study showed that the rapid growth stage of the root system lags behind that of the seedling system, but the growing period of root system lasts longer. The quantitative change of roots reveals a double "S" curve; two rapid growth stages emerge during 30 - 70 days and 140 - 200 days after the seedlings were transplanted. The content of salvia acid reaches the highest level during 140 - 180 days, whereas the content of tanshinone peaks during 100 - 120 days.</p>

Study on configuration fabric and germinative conditions of Salvia miltiorrhizy seeds / 中国中药杂志

<p><b>OBJECTIVE</b>To provide theoretic warrant and technical reference for Salvia miltiorrhizr standardization planting, by carrying out various systemic studies such as observation of seeds configuration fabric, idiosyncrasy of water absorption and groping germinating conditions.</p><p><b>METHOD</b>In the study of configuration fabric, seeds were observed and taken photos by scanning electronic microscope, and heft method was used for measuring changes of water absorption velocity and dehydration velocity. Seeds germination conditions were probed into under the national test regulations for crop seeds and related prescription from international standards.</p><p><b>RESULT</b>(1) There was a layer of slime about 10-20 microm thickness covering epicarp of Danshen seeds. The slime formed as diamond meshwork (reseau) and the weight of it was 8%-10% of total seeds weight. (2) The speed of water absorption of seeds was extremely rapid. The weight of seeds could increase above 10 times as original while the dehydration velocity was quite low. (3) The optimal temperature for the seeds germination is around 25 degrees C, and the germination rate of the new seeds gained yearly was above 75%, but the rate would decrease sharply as years went by. It was also found that the seeds germination power and exponent of vigor were quite high under the temperature transformation between 23 degrees C, 28 degrees C. Such treatments as pre-cool, PEG treatment and infusing with GA3 could increase the rate of seeds germination capacity obviously.</p>