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Mingjia Zhu

and 5 more

 Dimorphic flowers growing on a single individual plant play a critical role in extreme adaption and reproductive assurance in plants and have high ecological and evolutionary significance. However, the omics bases underlying such a differentiation and maintenance remain largely unknown. We aimed to investigate this through genomic, transcriptome and metabolomic analyses of dimorphic flowers in an alpine biennial, Sinoswertia tetraptera (Gentianaceae).  A high-quality chromosome-level genome sequence (903 Mb) was first assembled for S. tetraptera with 31,359 protein-coding genes annotated. Two rounds of recent independent whole-genome duplication (WGD) were revealed. More than 10% of the novel genes from the recent species-specific WGD were found to be differentially expressed in the two types of flowers, and this may have helped contribute to the origin of this innovative trait.  Other contrasting gene expression between flowers included that related to flower development and color, hormones, and iridoid biosynthesis. Metabolomic analyses similarly suggested differential concentrations of both hormones and iridoids in the two types of flowers. The interactions between multiple genes may together lead to contrasting morphology and open versus closed pollination of the dimorphic flowers in this species.  A total of 56 candidate genes were identified from the known iridoid biosynthesis-related pathways. Two hub genes were found to play an essential role in transferring intermediate products between leaves and flowers during iridoid biosynthesis.

Arthur Calegario

and 5 more

In the world, the most significant change in the ecosystems structure is the conversion from natural land surface into cultivated systems. In 2018, 26.8% of the Brazilian territory was occupied by agricultural activities, from which 73% is pasture. Considering that the management adopted in Brazilian pastures is incipient and leads to degradation, there is a need to characterize the state of the pastures to diagnose the intensity of this use on the soil. However, the diagnosis of large areas using satellites with more detailed resolution is limited by cloud coverage and low temporal resolution. In this sense, the present work aims to diagnose the intensity of land use by pastures (ILUP) in large areas based on the mosaic of images from Landsat 8 (LS8), Landsat 7 (LS7), Sentinel-2 (S2), and MODIS. The methodology consists of harmonizing the NDVI from LS7 and S2 satellites with LS8. For MODIS, the harmonization was carried out based on ILUP obtained previously from NDVI LS8. The methodology was applied at the Doce river basin (DRB). The combination of different sensors allowed to overcome the cloud coverage limitation. DRB has 61.3% of its area occupied by pastures and 78.2% of them have some degree of degradation. ILUP was dependent on DRB’s pedological and climatic characteristics. This dependence is enhanced due to pasture management in the basin, mainly characterized by continuous grazing, which commonly leads to overgrazing scenarios. The areas with great rainfall seasonality and associated with Acrisols/Cambisols are the most susceptible to degradation.

Jingwu Bu

and 4 more

The Yunnan-Guizhou Plateau (YGP) is characterized by the distinctive isolated habitat of limestone Karst Islands and features the Wumeng Mountains (Mts), which divide the YGP into the two Plateaus of Yunnan and Guizhou. This study aims to assess the effects of past geographic and environmental isolation and climate fluctuation on the flora distribution in the YGP. To this effect, we analyzed the phylogeographical pattern and genetic structure for Myrica nana, a vulnerable species endemic to the YGP, based on chloroplast and nuclear ribosomal DNA sequence. The results suggest that the genetic and haplotype network structures are divided into at least two groups—cpDNA haplotype H2 (or nrDNA haplotypes h1, h2, and the native haplotype) mainly distributed to the east of the Wumeng Mts, and cpDNA haplotype H1 and haplotypes H3–H10 (or nrDNA haplotype h3) distributed to the west of the Wumeng Mts. A deep genetic split was noted within the two groups to reach 25 steps, especially for the cpDNA fragment variation. The east–west divergence reveals the existence of a natural geographical isolation boundary in the form of the Wumeng Mts, which divides the YGP into the Yunnan and Guizhou Plateaus. Therefore, there existed at least two glacial refugia during the Quaternary glacial period, along with a genetic diversity center, and at least two large geographic protection units for the vulnerable species of M. nana, distributed throughout the eastern and western sides of the Wumeng Mts. This study not only clarifies that the phylogeographical pattern and genetic structure for M. nana can be attributed to geographic and environmental isolation and climate fluctuation, but it also proposes an effective strategy to protect vulnerable species and the important wild flora of the YGP.

Sandeep Sainathan

and 1 more

Objectives: Innominate artery compression syndrome (IAS) is caused by an anterior compression of the trachea by an abnormally originating innominate artery. One option to relieve such a compression is an anterior aortopexy (AA). In this paper we describe our technique of an AA via a partial upper median sternotomy. Methods: A retrospective review of a prospectively maintained database of patients with IAS (July 2017 to November 2020) treated with AA via a partial upper median sternotomy at University teaching hospitals in the US was done. Results: Nine consecutive patients underwent AA for IAS during the study period. The median age was 9 months (IQR 3- 16.5). The male to female ratio was 1.25. All patients had > 70% compression by flexible bronchoscopy. 2 patients had previous surgeries. The follow-up was a median of 6 (IQR 4- 8.5) months. The indications for the operation were: reflex apnea (4/9 patients), recurrent intubation (4/9 patients), and severe stridor (1/9). IAS was a technical success (defined as ≤ 20 % residual stenosis) in 78 % (7/9) of the patients. Complete symptom resolution after an AA was seen in 71% (5/7) of the patients. 2 patients had an unsuccessful AA, requiring a tracheal resection and an innominate artery reimplantation, respectively. Conclusion: An upper partial sternotomy approach provides a very versatile approach to an AA for IAS. Besides facilitating an adequate AA, it provides options for direct tracheal surgery or an innominate artery reimplantation in case an optimal result is not obtained by an AA.

Rowland Burdon

and 1 more

Plant phenology is manifested in the seasonal timing of vegetative and reproductive processes, but also has ontogenetic aspects. The adaptive basis of seasonal phenology has been considered mainly in terms of climatic drivers. However, some biotic factors as likely evolutionary influences on plants’ phenology appear to have been under-researched. Several specific cases of putative biotic factors driving plant phenology are outlined, involving both herbivores and pathogens. These illustrate the diversity of likely interactions rather than any systematic coverage or review. Emphasis is on woody perennials, in which phenology is often most multi-faceted and complicated by the ontogenetic aspect. The complete seasonal leaf fall that characterises deciduous plants may be a very important defence against some pathogens. Whether biotic influences drive acquisition or long-term persistence of deciduousness is considered. In one case; of leaf rusts in poplars, countervailing influences of the rusts and climate suggest persistence. Often, however, biotic and environmental influences likely reinforce each other. The timing and duration of shoot flushing may in at least some cases contribute to defences against herbivores, largely through brief periods of ‘predator satiation’ when plant tissues have highest food value. Wide re-examination of plant phenology, accommodating the roles of biotic factors and their interplays with environments as additional adaptive drivers, is advocated, towards developing and applying hypotheses that are observationally or experimentally testable.

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