Drivers of herbivore damage on tree seedlings at Powdermill Nature Reserve, PA, USA

Herbivores can cause major damage and affect survival of tree seedlings. The factors that cause variation in herbivore damage rates among individual plants are not well known. Most prior studies have focused on single factors that affect herbivore damage rates on plants. The purpose of this study is to test which variables affect herbivore damage rates on tree seedlings. Specifically, I was interested in testing whether abiotic variables, such as elevation and moisture levels (as measured by distance from stream), and biotic variables (such as the density of conspecifics and plant species diversity), influence herbivore damage rates. I took data from thirty-seven 20×20 meter plots at Powdermill Nature Reserve (PNR) in southwestern Pennsylvania (40°09’S, 79°16’W). I took photos of tree seedling leaves and quantified percent herbivore damage in the photos using Image J software for 296 tree seedlings of 22 species. I ran Spearman rank correlations and a generalized linear regression model to test for effects of distance from stream, elevation, seedling diversity and conspecific neighbor density on percent herbivore damage. I found large variation in herbivore damage rates among species (0.373-10.8%) and among individuals (0-40.6%). The herbivore damage rate was particularly high for American basswood(Tilia americana) seedlings. From the multiple linear regression model, I found the biotic factors had significant, but minimal effects on herbivore damage rate, while the abiotic variables had no significant effects on herbivore damage rate. In related biotic factors, height had a positive relationship with herbivore damage and species richness had a negative relationship with herbivore damage. My results suggest that herbivore damage is not influenced by abiotic factors such as elevation and moisture level. It shows that biotic factors can affect the relationship between herbivores and tree seedlings, although the effects were small. This study helps eliminate some of the potential abiotic factors that could affect herbivore damage rates, and also indicates that further studies are needed to determine what other abiotic elements can drive variation in herbivore damage rates.Liza ComitaNo embargoAcademic Major: Biolog

Neutral beam current drive in a tokamak

Neutral beam current drive (NBCD) on the EAST tokamak is studied by using Monte-Carlo simulation. The electron shielding effect to the fast ion current is taken into account by using a fitting formula applicable to general tokamak equilibria and arbitrary collisionality regime. The net currents driven by the beam are off-axis although the fast ion currents are on-axis. This is found to be due to the electron shielding effect being strong near the magnetic axis. We also investigate the dependence of NBCD efficiency on the plasma density. The results indicate that the NBCD efficiency decreases with the increase in plasma density. A simple semi-analytic estimation of the dependence of NBCD efficiency on the density is proposed and is in reasonable agreement with the results directly obtained in the simulations

Spatial Heterogeneity of Soil and Vegetation Characteristics and Soil-Vegetation Relationships along an Ecotone in Southern Mu Us Sandy Land, China

Spatial pattern analysis is an essential component of spatial heterogeneity studies on soil properties and vegetation characteristics. It was conducted in several studies for both soil and vegetation characteristics (Strand et al., 2007; Dick and Gilliam, 2007; Zuo et al., 2010). This study aims to examine the changes in the spatial heterogeneity of soil properties at different soil layers, the spatial heterogeneity of soil and vegetation characteristics along an ecotone, and soil-vegetation relationships along the ecotone in a critical area of desertification

Aligning Sub-national Climate Actions for the new post-Paris Climate Regime

The rise of sub-national actors in global climate governance underscores the need for clear alignment between these efforts and their national counterparts. As these sub-national climate actions are filling gaps in mitigation, adaptation, and financing, among other functions, a critical question is how these efforts complement or overlap with national climate pledges. This consideration is particularly important in the context of the Paris Agreement’s mandate for fiveyear review cycles, where national governments will be asked to demonstrate progress towards climate mitigation goals and increase their ambition. In this paper, we argue that alignment – both vertically between multiple jurisdictions and horizontally with external networks and actors – is critical to clarifying climate actions between multiple levels of actors and to maximizing mitigation potential. We use nine case studies to demonstrate the varying degrees and modes of vertical integration between subnational and national climate actors. We find that the case studies embody different styles of vertical alignment, and exhibit significant variation in the degree and direction of vertical alignment within each of these modes. We also find that many case studies rely on horizontally- aligned international networks and coalitions to fill gaps in financial resources or technical support. As a proof of concept, we demonstrate that an additional 1 gigaton carbon dioxide equivalent (CO2e) in 2020 can be achieved in these nine case studies through stronger alignment that makes it possible to scale sub-national climate actions to the national level. These findings suggest there may be a missed opportunity to realize greater mitigation potential by fostering stronger vertical alignment, and enhancing coordination between horizontal networks of climate action and national governments

A Novel Projection Distortion Correction Method on Patient's Body Surface

In this paper, the projection distortion correction method of patient's body surface is studied. First, the applicability of four typical projection image distortion correction methods to different surfaces were compared. Secondly, Based on the correction method based on quadratic surface fitting, and a correction method based on point cloud mapping was designed, which uses structured light to extract the point cloud information on the surface of the projection screen for coordinate transformation. Combined with the depth information, it solves the distortion problem of complex surface projection images, expands the surface applicability of the correction method, and improves the correction accuracy and real-time performance. The projection distortion correction of different types of surfaces is realized by simulation, and the correction effect of the two methods is compared. The correction time is shortened from 67s to 7s by the correction method based on point cloud mapping. Finally, organ simulation experiment was used to verify the intraoperative feasibility, and the virtual "perspective" display effect was presented as a whole

Desertification Reversal Promotes the Complexity of Plant Community by Increasing Plant Species Diversity of Each Plant Functional Type

Desertification reversal is globally significant for the sustainable development of land resources. However, the mechanisms of desertification reversal at the level of plant community are still unclear. We hypothesized that desertification reversal has clear effects on plant community composition, plant functional types (PFTs), and other vegetation characteristics, including plant diversity and biomass, and their changes in the early stages of reversal are more dramatic than in later stages. We investigated the vegetation of four to five different stages of desertification reversal at each of seven large study sites in southwestern Mu Us Sandy Land, China. The results show that the dominant species in very severe desertification areas were replaced by perennial grasses in potential desertification areas. The importance values of annual forbs and perennial sub-shrubs decreased dramatically (from 42.59 and 32.98 to 22.13 and 5.54, respectively), whereas those of perennial grasses and perennial forbs increased prominently (from 13.26 and 2.71 to 53.94 and 11.79, respectively) with the reversal of desertification. Desertification reversal increased the complexity of plant community composition by increasing plant species in each PFT, and C3 plants replaced C4 plants to become the dominant PFT with reversal. Plant species richness and species diversity rose overall, and aboveground plant biomass significantly (p < 0.05) increased with the reversal of desertification. Most vegetation characteristics changed more strikingly in the early stages of desertification reversal than in later stages. Our results indicate that the type and composition of the plant community were dramatically affected by desertification reversal. Anthropogenic measures are more applicable to being employed in early stages than in later stages, and Amaranthaceae C4 plants are suggested to be planted in mobile dunes for the acceleration of desertification reversal. This study is useful for designing strategies of land management and ecological restoration in arid and semiarid regions

Identifying tumor antigens and immune subtypes of gastrointestinal MALT lymphoma for immunotherapy development

MALT lymphoma is an extranodal B-cell lymphoma of the marginal zone of mucosa-associated lymphoid tissue (MALT), caused by malignant transformation of B-cells in the marginal zone. In this work, we aim to explore the potential relationship between MALT lymphoma and DLBCL. Vaccines derived from messenger ribonucleic acid (mRNA) may provide satisfactory results. Despite being a promising treatment option, immunotherapy isn’t widely used in treating renal cell carcinoma, as only a few patients respond to the treatment. The Cancer Genome Atlas (TCGA) analysis revealed gene expression profiles and clinical information. Antigen-presenting cells infiltrated the immune system using TIMER tool (http://timer.cistrome.org/). GDSC (Genomics of Drug Sensitivity in Cancer) data were used to estimate drug sensitivity. Immune-related genes were associated with a better prognosis in MALT lymphoma patients and higher levels of antigen-presenting cells. There is a significant relationship between these immune subtypes and immunological checkpoints, immunogenic cell death regulators, and prognostic variables for MALT lymphoma patients. In this study, we provide a theoretical foundation for the development of mRNA vaccines and suggest that KLHL14 could potentially be used as antigens to develop mRNA vaccines for MALT lymphoma

The dual-frequency zero-backward scattering realized in a hybrid metallo-dielectric nanoantenna

In this paper, we propose a hybrid metallo-dielectric core-shell nanorod for the Kerker-type effect at two different frequencies. The effect arises from the interference of the scattering waves of the nanorod, which are generated by the magnetic dipole moment (MD) of the high-index hollow particle and the electric dipole moment (ED) induced in both metallic and dielectric particles. Interestingly, we find that such kind of unidirectional radiation properties, (i.e., zero back scattering occurring at dual frequencies) can be sustained with a single nanorod, which usually being equivalent to a local electric dipole source. The effect of substrate is also considered to investigate the typical experimental realization for the dual-frequency unidirectionalities of the nanoantenna. Furthermore, the unidirectionality can be further improved by the design of one-dimensional array of the hybrid nanoantenna. Our results could provide an additional degree of freedom for light scattering manipulation, and widen the versatile applications in nanoantennas, optical sensor, light emitters, as well as photovoltaic devices

Development of Magnetically Levitated Rotary Table for Repetitive Trajectory Tracking

The magnetic levitation system has been considered as a promising actuator in micromachining areas of study. In order to improve the tracking performance and disturbance rejection of the magnetically levitated rotary table, an iterative learning PID control strategy with disturbance compensation is proposed. The estimated disturbance compensates for the control signals to enhance the active disturbance rejection ability. The iterative learning control is used as a feed-forward unit to further reduce the trajectory tracking error. The convergence and stability of the iterative learning PID with disturbance compensation are analysed. A series of comparative experiments are carried out on the in-house, custom-made, magnetically levitated rotary table, and the experimental results highlight the superiority of the proposed control strategy. The iterative learning PID with disturbance compensation enables the magnetically levitated rotary table to realize good tracking performance with complex external disturbance. The proposed control strategy strengthens the applicability of magnetically levitated systems in the mechanism manufacturing area