Multivariate analysis of leaf shape patterns in Asian species of the Uvaria group (Annonaceae)

Multivariate analysis of leaf radian measurements was used to investigate variation in leaf shape among 34 Asian species of the Uvaria group, a large palaeotropical group of climbing Annonaceae characterized by imbricate petals and stellate hairs. Raw data were normalized by conversion into 15 ratio characters and using the log₁₀ transformation. All species surveyed showed a unique leaf-shape 'bauplan'. The ratio character with the greatest discriminating power in both the Principal Components Analysis and Discriminant Analysis (DA) results was a measure of the shape of the leaf base. Ratio characters with the highest factor loadings for principal components 1 and 2 clearly separated the sampled taxa when plotted against one another and provided support for the retention of several taxa as distinct species or varieties. Classification of cases into taxa using DA yielded a correct classification rate of only 52% for the ratio-transformed data; however, division of taxa in the dataset into smaller subgroups defined by discrete morphological characters significantly increased the accuracy of case identification to between 67 and 100% of cases correctly classified, depending on the group. Case identification using DA on log₁₀-transformed data was higher than for the ratio values in the entire dataset (61.7%) and the larger subgroups. However, the rate of correct case assignment was lower in the smaller groups than for the ratio data.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 143 , 231–242.     

Review of Indian species of Monoceromyia Shannon (Diptera: Syrphidae) with description of two new species

Flower fly species of the genus Monoceromyia Shannon (Diptera: Syrphidae) in India are reviewed and two new species, M. flavoscutata Sankararaman, Anooj and Mengual, sp. nov. and M. nigra Sankararaman, Anooj and Mengual, sp. nov., are described from Tamil Nadu and Arunachal Pradesh (India), respectively. A new synonym is proposed: M. multipunctata (Hull, 1941) is synonymised under M. polistoides (Brunetti, 1923). Moreover, lectotypes are designated for Ceria patricia Brunetti, 1923 and Ceria tredecimpunctata Brunetti, 1923. An identification key to the Indian Monoceromyia species is also provided.     

The functional roles of m6A modification in T lymphocyte responses and autoimmune diseases

RNA N6-methyladenosine (m⁶A) modification is abundant in eukaryotes, bacteria and archaea. It is an RNA modification mainly existing in messenger RNA (mRNAs) and has a significant effect on the metabolism and function of mRNAs. m⁶A modification is controlled by three types of proteins, namely methyltransferase as the “writers”, demethylase as the “erasers”, and specific m⁶A recognized protein (YTHDF1–3) as the “readers”. Recent studies have shown that m⁶A modification plays an important role in cancer, viral infection and autoimmune diseases. In this review, we will elaborate on the m⁶A modifications in the homeostasis and differentiation of T cells. Then we will further summarize the effects of m⁶A modification on the T cell responses and T cell-mediated autoimmune diseases. This will advance T cell epigenetics research and provide potential biomarkers and therapeutic targets for autoimmune diseases.     

Probability of lung cancer in a population excluded from screening due to low PLCOM2012 risk

BackgroundSeveral randomized trials demonstrated have reduced lung cancer mortality with screening using computed tomography. However, there remains debate about the optimal approach for determining screening eligibility, and no evidence yet exists reporting lung cancer rates in those excluded from screening due to too low of a personalized risk.MethodsThis study was based on the Alberta Lung Cancer Screening Study, which received 1737 applicants and enrolled 850 based on the NLST criteria or a PLCO_M2012 risk ≥ 1.5%. We excluded 887 applicants who were interested in screening but deemed ineligible. We report lung cancer rates in the screened and unscreened cohorts.ResultsWe observed 30 and 8 lung cancers in the screened and unscreened groups, respectively. Only 1 of 8 lung cancers were among those considered too low risk (0.14%), while the remaining 7 were among those excluded for other reasons, including symptoms requiring more immediate workup. No NLST eligible but PLCO risk < 1.5% screened individual had a lung cancer detected as part of the study, so that of all applicants contacting the program with risk estimates less than 1.5%, only 1/857 (0.12%) developed lung cancer.ConclusionOur findings indicate that a risk-based approach for screening eligibility is unlikely to miss many lung cancers.     

MS-based technologies for untargeted single-cell proteomics

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福建省安溪县土地利用时空演变规律及其关键驱动因素

以福建省安溪县为研究边界,选取了1999—2019年该县及所属乡镇的耕地、林地、草地、园地、水域、建设用地和未利用地等7个土地利用类型作为物种变量,与其相关性较大的社会经济指标为环境变量,采用典范对应分析和空间自相关等方法进行分析,以明确安溪县和所属乡镇的土地利用时空演变特征及其关键驱动因素。研究结果表明:安溪县1999—2019年间土地利用类型变化总体上呈"三减四增"态势,并在全局空间分布格局上呈明显的聚焦状态。全县耕地、草地和水域面积分别减少36.82%、22.91%和8.18%,而林地、园地(主要是茶园)、建设用地和未利用地面积则分别增加了10.37%、56.39%、206.08%和90.14%。就林地面积而言,近10年来安溪县24个乡镇中有1/3的乡镇林地呈下降趋势。其中,祥华、大坪、虎邱、参内、福田和城厢6个乡镇林地面积减少明显。研究表明:在县域水平上,主要土地利用类型变化,除了受地理因素的制约外,主要受社会经济指标和宏观政策的驱动因素调控。排位最大的前3个因素分别是社会消费品零售总额、地区生产总值和茶叶产量。在镇域水平上,不同乡镇由于地理条件,特别是城镇化水平和经济发展状况...     

Higher blood selenium level is associated with lower risk of hyperhomocysteinemia in the elderly

Background and aimsEarlier studies have reported inconsistent association between selenium (Se) and homocysteine (Hcy) levels, while no evidence could be found from Chinese population. To fill this gap, we investigated the association between blood Se and hyperhomocysteinemia (HHcy) of rural elderly population in China.MethodsA cross-sectional study on 1823 participants aged 65 and older from four Chinese rural counties was carried out in this study. Whole blood Se and serum Hcy concentrations were measured in fasting blood samples. Analysis of covariance and restricted cubic spline models were used to examine the association between Se and Hcy levels. Logistic regression models were used to evaluate the risk of prevalent HHcy among four Se quartile groups after adjusting for covariates.ResultsFor this sample, the mean blood Se concentration was 156.34 (74.65) μg/L and the mean serum Hcy concentration was 17.25 (8.42) μmol/L. A significant non-linear relationship was found between blood Se and serum Hcy, the association was inverse when blood Se was less than 97.404 μg/L and greater than 156.919 μg/L. Participants in the top three blood Se quartile groups had significantly lower risk of prevalent HHcy compared with the lowest quartile group. When defined as Hcy> 10 μmol/L, the odds ratios and 95% confidence interval of HHcy were 0.600 (0.390, 0.924), 0.616 (0.398, 0.951) and 0.479 (0.314, 0.732) for Q2, Q3, and Q4 Se quartile groups compared with the Q1 group, respectively. When defined as Hcy≥ 15 μmol/L, the odds ratios and 95% confidence interval of HHcy were 0.833 (0.633, 1.098) and 0.827 (0.626, 1.092), 0.647 (0.489, 0.857) for Q2, Q3, and Q4 Se quartile groups compared with Q1 group.ConclusionsOur findings suggest that higher blood Se level could be a protective factor for HHcy in the elderly.     

Stochastic matrix models for conservation and management: a comparative review of methods

Stochastic matrix models are frequently used by conservation biologists to measure the viability of species and to explore various management actions. Models are typically parameterized using two or more sets of estimated transition rates between age/size/stage classes. While standard methods exist for analyzing a single set of transition rates, a variety of methods have been employed to analyze multiple sets of transition rates. We review applications of stochastic matrix models to problems in conservation and use simulation studies to compare the performance of different analytic methods currently in use. We find that model conclusions are likely to be robust to the choice of parametric distribution used to model vital rate fluctuations over time. However, conclusions can be highly sensitive to the within-year correlation structure among vital rates, and therefore we suggest using analytical methods that provide a means of conducting a sensitivity analysis with respect to correlation parameters. Our simulation results also suggest that the precision of population viability estimates can be improved by using matrix models that incorporate environmental covariates in conjunction with experiments to estimate transition rates under a range of environmental conditions.