Maxillary sinus floor augmentation: a review of current evidence on anatomical factors and a decision tree

Maxillary sinus floor augmentation using lateral window and crestal technique is considered as predictable methods to increase the residual bone height;however,this surgery is commonly complicated by Schneiderian membrane perforation,which is closely related to anatomical factors.This article aimed to assess anatomical factors on successful augmentation procedures.After review of the current evidence on sinus augmentation techniques,anatomical factors related to the stretching potential of Schneiderian membrane were assessed and a decision tree for the rational choice of surgical approaches was proposed.Schneiderian membrane perforation might occur when local tension exceeds its stretching potential,which is closely related to anatomical variations of the maxillary sinus.Choice of a surgical approach and clinical outcomes are influenced by the stretching potential of Schneiderian membrane.In addition to the residual bone height,clinicians should also consider the stretching potential affected by the membrane health condition,the contours of the maxillary sinus,and the presence of antral septa when evaluating the choice of surgical approaches and clinical outcomes.

Identification and fine mapping of quantitative trait loci for the number of vascular bundle in maize stem

Studies that investigated the genetic basis of source and sink related traits have been widely conducted.However, the vascular system that links source and sink received much less attention. When maize was domesticated from its wild ancestor, teosinte, the external morphology has changed dramatically; however, less is known for the internal anatomy changes. In this study, using a large maize-teosinte experimental population, we performed a high-resolution quantitative trait locus（QTL） mapping for the number of vascular bundle in the uppermost internode of maize stem.The results showed that vascular bundle number is dominated by a large number of small-effect QTLs, in which a total of 16 QTLs that jointly accounts for 52.2% of phenotypic variation were detected, with no single QTL explaining more than 6% of variation. Different from QTLs for typical domestication traits, QTLs for vascular bundle number might not be under directional selection following domestication.Using Near Isogenic Lines（NILs） developed from heterogeneous inbred family（HIF）, we further validated the effect of one QTL qVb9-2 on chromosome 9 and fine mapped the QTL to a 1.8-Mb physical region. This study provides important insights for the genetic architecture of vascular bundle number in maize stem and sets basis for cloning of qVb9-2.

Genome-wide Analysis of Transcriptional Variability in a Large Maize-Teosinte Population

Gene expression regulation plays an important role in controlling plant phenotypes and adaptation. Here, we report a comprehensive assessment of gene expression variation through the transcriptome analyses of a large maize-teosinte experimental population. Genome-wide mapping identified 25 660 expression quantitative trait loci （eQTL） for 17 311 genes, capturing an unprecedented range of expression variation. We found that local eQTL were more frequently mapped to adjacent genes, displaying a mode of expression piggybacking, which consequently created co-regulated gene clusters. Genes within the co-regulated gene clusters tend to have relevant functions and shared chromatin modifications. Distant eQTL formed 125 significant distant eQTL hotspots with their targets significantly enriched in specific functional cate- gories. By integrating different sources of information, we identified putative trans- regulators for a variety of metabolic pathways. We demonstrated that the bHLH transcription factor R1 and hexokinase HEX9 might act as crucial regulators for flavonoid biosynthesis and glycolysis, respectively. Moreover, we showed that domestication or improvement has significantly affected global gene expression, with many genes targeted by selection. Of particular interest, the Bx genes for benzoxazinoid biosynthesis may have undergone coordinated cis-regulatory divergence between maize and teosinte, and a transposon insertion that inactivates Bx12 was under strong selection as maize spread into temperate environments with a distinct herbivore community.

Glossy15 Plays an Important Role in the Divergence of the Vegetative Transition between Maize and Its Progenitor, Teosinte

Dear Editor,The timing of developmental transitions is important for plant growth and environmental adaptation. All plants undergo a series of developmental transitions during their life cycles, and each of these phases is characterized by unique morphological and physiological attributes （Baurle and Dean, 2006）. In maize, the vegetative transition from juvenile-to-adult vegetative development occurs in a coordinated manner and is marked by the production of leaves that differ in a suite of morphological and physiological traits, many of which contribute to fitness and crop productivity （Moose and Sisco, 1994）. Significant advances have been made in understanding the molecular mechanisms regulating the juvenile-to-adult vegetative transition.

Peatland area change in the southern Altay Mountains over the last twenty years based on GIS and RS analysis

Analyses results of total peatland area changes in the southern AItay Mountain region over the past 20 years are discussed in this paper. These analyses were based on remote sensing （RS） and geographical information system （GIS） studies. Possible control methods are evaluated by comparing these results to other regional records and climate data. The area of the peatland zones was calculated by overlaying a peatland layer of Landsat TM （Thematic Map） image constructed by using supervised classification with a layer of slope based on a digital elevation model （DEM）. The results show that slope layer is crucial to improving the accuracy of peatland extracted from TM images. The peatland area of the Altay Mountains increased from 931.5km^2 in 1990 to 977.7 km^2 in 2010. This trend is consistent with the climate change in this region, due in part to increasing temperatures and precipitation, suggesting possible climate controls on peatland expansion. The increase in the peatland area in the Altay Mountains over the last 20 years has been influenced by the westerlies. Alternatively, changes in the largest highland peatland area of the Zoige Basin, located in the eastern Tibetan Plateau have been influenced by the intensity of the Asian summer monsoons. In addition to increased temperatures, decreased precipitation in the Zoige Basin and increased precipitation in the Altay Mountains, due to varied patterns of atmospheric circulation, are the probable causes for driving the change differences in these two peatland areas.