Random Forest characterization of upland vegetation and management burning from aerial imagery

Aim The upland moorlands of Great Britain form distinctive landscapes of international conservation importance, comprising mosaics of heathland, acid grassland, blanket bog and bracken. Much of this landscape is managed by rotational burning to create gamebird habitat and there is concern over whether this is driving long‐term changes in upland vegetation communities. However, the inaccessibility and scale of uplands means that monitoring changes in vegetation and burning practices is difficult. We aim to overcome this problem by developing methods to classify aerial imagery into high‐resolution maps of dominant vegetation cover, including the distribution of burns on managed grouse moors. Location  Peak District National Park, England, UK. Methods Colour and infrared aerial photographs were classified into seven dominant land‐cover classes using the Random Forest ensemble machine learning algorithm. In addition, heather (Calluna vulgaris) was further differentiated into growth phases, including sites that were newly burnt. We then analysed the distributions of the vegetation classes and managed burning using detrended correspondence analysis. Results Classification accuracy was c. 95% and produced a 5‐m resolution map for 514 km² of moorland. Cover classes were highly aggregated and strong nonlinear effects of elevation and slope and weaker effects of aspect and bedrock type were evident in structuring moorland vegetation communities. The classification revealed the spatial distribution of managed burning and suggested that relatively steep areas may be disproportionately burnt. Main conclusions Random Forest classification of aerial imagery is an efficient method for producing high‐resolution maps of upland vegetation. These may be used to monitor long‐term changes in vegetation and management burning and infer species–environment relationships and can therefore provide an important tool for effective conservation at the landscape scale.     

齐墩果酸对APP/PS-1双转基因AD小鼠的神经保护作用研究

摘要 目的：研究齐墩果酸（Oleanolic Acid，OA）对APP/PS-1双转基因阿尔茨海默病（Alzheimer''s disease，AD）小鼠模型神经保护作用及机制。方法：选取6月龄APP/PS-1雄性小鼠21只，随机分为模型组（0.5% CMC-Na）、阳性组（多奈哌齐组，0.7 mg?kg^-1）、齐墩果酸组（10 mg?kg^-1）每组7只，6月龄同背景SPF级C57BL/6小鼠7只为对照组。灌胃8周之后通过Morris水迷宫实验观察小鼠学习记忆能力的改变，HE染色观察神经元细胞形态，ELISA检测血清中Aβ1-42含量；免疫组化检测Aβ_1-42、APP、Iba1蛋白表达情况；Western blot检测APP、Iba1蛋白表达水平。结果：（1）对照组，模型组，阳性组及齐墩果酸组进入有效区域次数分别为7.00±2.09，1.00±0.89，3.67±1.97，4.33±2.50，与模型组相比，对照组，阳性组，齐墩果酸组均有统计学意义（P<0.05）；（2）血清Aβ_1-42含量按上述顺序依次为4.98±0.25，2.50±0.66，4.63±0.73，4.36±0.97，与模型组相比，对照组，阳性组，齐墩果酸组均有统计学意义（P<0.05）；（3）免疫组化结果显示与模型组相比，对照组，阳性组，齐墩果酸组Aβ_1-42、APP、Iba1蛋白阳性细胞数减少；（4）WB结果：对照组，模型组，阳性组，齐墩果酸组APP蛋白相对表达量分别为0.52±0.17，1.38±0.35，0.89±0.25，0.93±0.27；这四组的IBA1蛋白相对表达量分别为0.98±0.34，1.79±0.74，1.06±0.61，0.88±0.49，与模型组相比，野生对照组，阳性组，齐墩果酸组APP、IBA1蛋白相对含量有统计学意义（P<0.05）。结论：齐墩果酸组可以改善APP/PS-1模型小鼠记忆力及认知功能，降低海马神经元的损伤，并通过下调Aβ_1-42、APP、Iba1蛋白的表达水平来发挥保护神经作用。     

Chloroplast nucleoids are highly dynamic in ploidy,number, and structure during angiosperm leaf development

Chloroplast nucleoids are large, compact nucleoprotein structures containing multiple copies of the plastid genome. Studies on structural and quantitative changes of plastid DNA (ptDNA) during leaf development are scarce and have produced controversial data. We have systematically investigated nucleoid dynamics and ptDNA quantities in the mesophyll of Arabidopsis, tobacco, sugar beet, and maize from the early post‐meristematic stage until necrosis. DNA of individual nucleoids was quantified by DAPI‐based supersensitive epifluorescence microscopy. Nucleoids occurred in scattered, stacked, or ring‐shaped arrangements and in recurring patterns during leaf development that was remarkably similar between the species studied. Nucleoids per organelle varied from a few in meristematic plastids to >30 in mature chloroplasts (corresponding to about 20–750 nucleoids per cell). Nucleoid ploidies ranged from haploid to >20‐fold even within individual organelles, with average values between 2.6‐fold and 6.7‐fold and little changes during leaf development. DNA quantities per organelle increased gradually from about a dozen plastome copies in tiny plastids of apex cells to 70–130 copies in chloroplasts of about 7 μm diameter in mature mesophyll tissue, and from about 80 plastome copies in meristematic cells to 2600–3300 copies in mature diploid mesophyll cells without conspicuous decline during leaf development. Pulsed‐field electrophoresis, restriction of high‐molecular‐weight DNA from chloroplasts and gerontoplasts, and CsCl equilibrium centrifugation of single‐stranded and double‐stranded ptDNA revealed no noticeable fragmentation of the organelle DNA during leaf development, implying that plastid genomes in mesophyll tissues are remarkably stable until senescence.     

Association of TNF-α polymorphisms (−857, −863 and −1031), TNF-α serum level and lipid profile with acne vulgaris

BackgroundAcne is an inflammatory condition principally affected by genetic and dietary factors. Investigation into functional polymorphisms of TNF-α gene and their association with acne vulgaris will be helpful in exploring genetic influence on skin immune mediated inflammatory events. In the present study, we analyzed association of TNF-α gene polymorphisms, its expression levels and lipid profiles in a large cohort of acne patients and controls.MethodsWe used PCR-RFLP to study association of TNF-α polymorphisms at −857C/T, −863C/A and −1031 T/C sites with acne vulgaris. Lipid profiles were measured using enzymatic end-point method. The serum levels of TNF-α and apolipoprotein a were measured using ELISA. NIH, LDlink was used to investigate patterns of linkage disequilibrium across south Asian reference genome (Punjabi from Lahore Pakistan).ResultsWe found that TNF-α −863 polymorphism is strongly associated with acne in overall population as well as in gender and severity based groups of acne patients. Polymorphisms at −863 and −1031 position were in linkage disequilibrium. Importantly, TNF-α serum level was significantly increased in acne patients with severe disease symptoms. Furthermore, levels of total cholesterol (TC) and triglycerides (TG) were significantly increased, whereas high density lipoprotein cholesterol (HDL-C) level was significantly decreased in acne patients. The levels of apolipoprotein a varied widely in studied populations and no significant difference was found in the analyzed groups.ConclusionIn conclusion, we found that TNF-α expression increases in acne patients affected by TNF-α polymorphisms, and that the lipid profile is specifically disrupted in acne patients.     

The Genetic Basis of the Interaction Between Pyrimidine 5′ Nucleotidase I Deficiency and Hemoglobin E

We have previously described a family in which the interaction between pyrimidine 5′ nucleotidase I (P5N‐I) deficiency and hemoglobin E resulted in severe haemolytic anaemia. In this study we explored the genetic basis of the severe clinical phenotype and look for evidence of the interaction between these conditions. A P5N‐I gene mutation (IVS8 + 1–2delGT) was found in the family, confirming that the severe phenotype results from the interaction between two genetic diseases.