Distribution and suitable habitats of ticks in the Yangtze River Delta urban agglomeration / 中国血吸虫病防治杂志

Objective To investigate the current distribution of ticks and predict the suitable habitats of ticks in the Yangtze River Delta urban agglomeration in 2017, so as to provide insights into tick control and management of tick-borne diseases in these areas. Methods All publications pertaining to tick and pathogen distribution in the Yangtze River Delta urban agglomeration were retrieved, and the geographical location of tick distribution was extracted. The effects of 19 climatic factors on the distribution of ticks were examined using the jackknife method, including the mean temperature of the wettest quarter, precipitation of the coldest quarter, mean temperature of the driest quarter, maximum temperature of the warmest month, precipitation of the driest month, minimal temperature of the coldest month, annual precipitation, mean daily temperature range, precipitation seasonality, annual temperature range, temperature seasonality, annual mean temperature, mean temperature of the warmest quarter, precipitation of the wettest quarter, isothermality, mean temperature of the coldest quarter, precipitation of the wettest month, precipitation of the driest quarter and precipitation of the warmest quarter. The distribution of ticks was analyzed in 2020 using the maximum entropy (MaxEnt) model, and the potential suitable habitats of ticks were predicted in 2070 using the MaxEnt model based on climatic data. Results A total of 380 Chinese and English literatures were retrieved, and 148 tick distribution sites were extracted, with 135 sites included in the subsequent analysis. There were 7 genera (Haemaphysalis, Rhipicephalus, Ixodes, Dermacentor, Boophilus, Hyalomma and Amblyomma) and 27 species of ticks detected in the Yangtze River Delta urban agglomeration. The climatic factors affecting the distribution of ticks in the Yangtze River Delta urban agglomeration mainly included the mean temperature of the wettest quarter and the precipitation of the coldest quarter, with 26.1% and 23.6% contributions to tick distributions. The high-, medium- and low-suitable habitats of ticks were 20 337.08, 40 017.38 km2 and 74 931.43 km2 in the Yangtze River Delta urban agglomeration in 2020, respectively. The climate changes led to south expansion of the suitable habitats of ticks in the Yangtze River Delta urban agglomeration in 2070, and the total areas of suitable habitats of ticks was predicted to increase by 18 100 km2. In addition, the high-, medium- and low-suitable habitats of ticks were predicted to increase to 24 317.84, 45 283.02 km2 and 83 766.38 km2 in the Yangtze River Delta urban agglomeration in 2070, respectively. Conclusions Multiple tick species are widespread in the Yangtze River Delta urban agglomeration, and the future climate changes may lead to expansion of tick distribution in these areas.

Correlations between content of linarin in Chrysanthemum indicum and climatic factors in habitats / 中国中药杂志

Chrysanthemi Indici Flos(CIF), the capitulum of Chrysanthemum indicum, is widely used in proprietary Chinese medicine and daily chemical products. At present, CIF is mainly produced from wild resources and rarely cultivated. This study aims to reveal the correlations between linarin content in CIF and climatic factors in different habitats, and provide a theoretical basis for suitable zoning and rational production of medicinal materials. The content of linarin in CIF was determined by HPLC. Grey relational analysis and Pearson correlation analysis were carried out for linarin content with climatic factors. The results showed that the content of linarin in CIF was significantly different among different habitats. The grey relational degrees of climatic factors with linarin content was in an order of average annual precipitation>annual average sunshine hours>annual average temperature>longitude>annual frost-free period>latitude>altitude. Longitude, annual average temperature and average annual precipitation had significantly positive correlations with the content of linarin in CIF, whereas latitude and altitude showed negative correlations with it. The annual frost-free period and annual average sunshine hours had no significant correlation with the content of linarin in CIF. The content of linarin in CIF varied significantly in different habitats. High longitude, low latitude, low altitude, high annual average temperature and high annual average precipitation could be used as indicators for the habitats of high-quality Ch. indicum. This study provides a reference for selecting suitable producing areas of Ch. indicum and establishing artificial cultivation system.

Response of volatiles of Artemisiae Argyi Folium to climatic factors / 中国中药杂志

Combined headspace solid-phase microextraction with gas chromatography-mass spectrometry (HS-SPME-GC-MS), this paper studied the volatiles of Artemisiae Argyi Folium that respectively collected from Kongdong, Huanglong, Ankang, Qichun and Tongbai，and then explored the influence of climatic factors on the main components of the volatiles. The results showed that 54, 52, 57, 47 and 55 compounds were respectively identified from the leaves from five regions, mainly consist of monoterpenes, sesquiterpenoids and their oxygen-containing derivatives, a few aldehydes, alkanes and benzenes. It is different that the volatiles of Artemisiae Argyi Folium that collected in different habitats, neither composition nor content. There are total 18 kinds of compounds that exist in all five leaves. Eucalyptol, camphor, terpinen-4-ol, eugenol and caryophyllene could be considered to be the main conponents because of their efficacy or toxicity and relatively high content. Grey correlation analysis shows that the annual lowest temperature and annual sunshine duration have a great influence on the content of eucalyptol and camphor; the effect of annual precipitation and annual accumulated temperature on the content of terpinen-4-ol and caryophyllene was relatively significant; while the annual sunshine duration and the annual highest temperature are the main influencing factors for eugenol. The research suggests that long-day and extreme temperature may be more conductive to the accumulation of volatiles. According to the laws of effect of climatic factors on volatiles, we can optimize the cultivation conditions and select suitable locality to improve the quality of Artemisiae Argyi Folium.

Relationship between Spontaneous Cerebral Hemorrhage and Climatic Factor

The author investigated whether there were clear seasonal variations in the incidence of both spontaneous intracerebral hemorrhages(SICH) and subarachnoid hemorrhage(SSAH), and which climatic factor affected on the occurrence rate. From January 1988 to December 1994, 787 patients with SICHs and 556 patients with SSAHs were admitted to our hospital. The author compared the occurrence rate of spontaneous cerebral hemorrhages and the meteorological data on each date, such as daily temperatures(average, maximu, and minimum), temperature change(intradiurnal and daily), precipitation, average wind speed, average relative humidity, duration of sunshine, mean sea level barometric pressure, daily barometric pressure difference and wind-chilling effect. There was a clear seasonal variation in the occurrence rate of SICHs. It was high in early spring(February, March, and April) and early winter(October and December)(P<0.05). In SSAHs, there was no statistically significant differences in the occurrence rate, however. Daily temperatures(average, maximum, and minimum) and mean sea-level barometric pressure were the important climatic factors influencing the occurrence rate of SICHs(P<0.05). The lower daily temperatures(average, maximum, and minimum ), and the higher mean sea-level barometric pressure, the more SICHs occurred. In SSAHs, daily average temperature and intradiurnal temperature affected on the occurrence rate(P<0.05), however, there was no climatic factors with a statistically significant correlation. These results suggested that SSAHs differed from SICHs in its pathogenic mechanism. In any events, the dry(high barometric pressure) and cold(low temperature) weather might be a risk factor for the hypertensive patients. To reduce or prevent SICHs, such a hypertensive patient should not go out in dry and cold weather.