Pollination Biology of the Endangered Herbal Medicines Dendrobium chrysotoxum(Orchidaceae)

Pollination biology studies of the endangered herbal medicines Dendrobium chrysotoxum were conducted in natural pollination conditions using flower observation,pollinator observation and artificial pollination experiments.Populations of D.chrysotoxum with fragrance and nectar were pollinated by Ctenoplectra davidi Valhalla(Hymenoptera:Apidae)species.The floral structure of D.chrysotoxum adapted precisely to its pollinators.Flowers had a low capsule setting(0.17%)under natural conditions.However,compared to open pollination,artificial pollination experiments showed a significant increase in capsule setting,and D.chrysotoxum was cross-compatible and self-compatible,but there was pollinator limitation also.This study will provide important information for the preservation of this endangered species.

Aberrant dynamic functional connectivity of thalamocortical circuitry in major depressive disorder

Thalamocortical circuitry has a substantial impact on emotion and cognition.Previous studies have demonstrated alterations in thalamocortical functional connectivity(FC),characterized by region-dependent hypo-or hyper-connectivity,among individuals with major depressive disorder(MDD).However,the dynamical reconfiguration of the thalamocortical system over time and potential abnormalities in dynamic thalamocortical connectivity associated with MDD remain unclear.Hence,we analyzed dynamic FC(dFC)between ten thalamic subregions and seven cortical subnetworks from resting-state functional magnetic resonance images of 48 patients with MDD and 57 healthy controls(HCs)to investigate time-varying changes in thalamocortical FC in patients with MDD.Moreover,dynamic laterality analysis was conducted to examine the changes in functional lateralization of the thalamocortical system over time.Correlations between the dynamic measures of thalamocortical FC and clinical assessment were also calculated.We identified four dynamic states of thalamocortical circuitry wherein patients with MDD exhibited decreased fractional time and reduced transitions within a negative connectivity state that showed strong correlations with primary cortical networks,compared with the HCs.In addition,MDD patients also exhibited increased fluctuations in functional laterality in the thalamocortical system across the scan duration.The thalamo-subnetwork analysis unveiled abnormal dFC variability involving higher-order cortical networks in the MDD cohort.Significant correlations were found between increased dFC variability with dorsal attention and default mode networks and the severity of symptoms.Our study comprehensively investigated the pattern of alteration of the thalamocortical dFC in MDD patients.The heterogeneous alterations of dFC between the thalamus and both primary and higher-order cortical networks may help characterize the deficits of sensory and cognitive processing in MDD.

Erratum to:Aberrant dynamic functional connectivity of thalamocortical circuitry in major depressive disorder

The article(Zheng et al.,2024)unfortunately contained a mistake:in Table 3,four"I"elements in the last"LF in thalamus"column are mistaken.The four arrows should be"↑"in the following correctversion of Table3.

Seroprevalence of Toxoplasma gondii infection among patients with hand, foot and mouth disease in Henan, China: a hospital-based study

Background:The prevalence of infection with Toxoplasma gondii(T.gondii)in humans has been increasing in China due to the growing number of cats in the country.Hand,foot and mouth disease(HFMD)is a serious public health issue in China and still one of the leading causes of child mortality.However,little is known about the epidemiology of T.gondii infection among HFMD patients.Methods:A case–control study of 281 HFMD patients from the First People’s Hospital of Pingdingshan in Pingdingshan city,Henan province,central China,and 222 controls from Pingdingshan city was conducted.Anti-T.gondii antibodies were serologically detected using the enzyme-linked immunosorbent assay.Results:We found that the overall anti-T.gondii immunoglobulin G(IgG)antibody prevalence among HFMD patients was 12.46%,which was significantly higher than that in clinically healthy children(1.80%).The highest T.gondii seroprevalence was detected in critical cases(22.58%),followed by severe cases(11.50%),and the lowest was detected in mild cases(8.33%).Conclusion:The present study is the first survey of T.gondii seroprevalence among HFMD patients in China;12.46%were defined as seropositive.It is imperative that improved integrated measures are taken to prevent and control T.gondii infection among HFMD patients.

Comparison of surface water chemistry and weathering effects of two lake basins in the Changtang Nature Reserve,China

The geochemistry of natural waters in the Changtang Nature Reserve,northern Tibet,can help us understand the geology of catchments,and provide additional insight in surface processes that influence water chemistry such as rock weathering on the Qinghai–Tibet Plateau.However,severe natural conditions are responsible for a lack of scientific data for this area.This study represents the first investigation of the chemical composition of surface waters and weathering effects in two lake basins in the reserve（Lake Dogaicoring Qiangco and Lake Longwei Co）.The results indicate that total dissolved solids（TDS）in the two lakes are significantly higher than in other gauged lakes on the Qinghai–Tibet Plateau,reaching 20–40 g/L,and that TDS of the tectonic lake（Lake Dogaicoring Qiangco）is significantly higher than that of the barrier lake（Lake Longwei Co）.Na＋and Cl-are the dominant ions in the lake waters as well as in the glacier-fed lake inflows,with chemical compositions mainly affected by halite weathering.In contrast,ion contents of inflowing rivers fed by nearby runoff are lower and concentrations of dominant ions are not significant.Evaporite,silicate,and carbonate weathering has relatively equal effects on these rivers.Due to their limited scope,small streams near the lakes are less affected by carbonate than by silicate weathering.

Effects of Land Use Changes Across Different Urbanization Periods on Summer Rainfall in the Pearl River Delta Core Area

The Pearl River Delta(PRD)is one of the three urban agglomerations in China that have experienced rapid development.For this study,a core area of the PRD was identified,comprising the highly urbanized areas of Guangzhou,Foshan,Zhongshan,Zhuhai,Shenzhen,and Dongguan Cities.The expansion of these urban areas was tracked across three time periods—the year population urbanization rate exceeded 70%(2000),18 years before(1982),and 18 years after(2018).This study used the Weather Research and Forecasting(WRF)model to explore summer rainfall changes across different urbanization periods in the PRD core area.The results show that urban land expansion mainly occurred in the post urbanization period.Rainfall changes acros s different urbanization periods were roughly consistent with previously observed spatial and temporal changes accompanying urban expansion in the PRD core area.Extreme rainfall mainly increased in the post urbanization period,shifting rainstorm center towards the PRD core area.Further causal analysis revealed that land use changes affected rainfall by altering thermodynamics and water vapor transfer.The urban expansion changed the surface energy balance,resulting in increased surface heating and heat island effects.The heat island effects thickened the planetary boundary layer and increased vertical wind speeds,which initiated dry island effects,thereby causing more water vapor transportation to the atmosphere.Consequently,rainstorms and extreme rainfall events have become concentrated in urban areas.