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Remnant populations of Betula papyrifera Marshall have persisted in the Great Plains after the Wisconsin Glaciation along the Niobrara River Valley, Nebraska. Population health has declined in recent years, which has been hypothesized to be due to climate change. We used dendrochronological techniques to assess the response of B. papyrifera to microclimate (1950-2014) and the normalized difference vegetation index (NDVI) derived from satellite imagery (Landsat 5 TM (1985-2011) and MODIS (2000-2014)) as a proxy for population health. Growing-season streamflow and precipitation were positively correlated with raw and standardized tree-ring widths and basal area increment increase. Increasing winter and spring temperatures were unfavorable for tree growth, while increasing summer temperatures were favorable in the absence of drought. The strongest predictor for standardized tree rings was the Palmer Drought Severity Index, suggesting that B. papyrifera is highly responsive to a combination of temperature and water availability. The NDVI from the vegetation community was positively correlated with standardized tree-ring growth, indicating the potential of these techniques to be used as a proxy for ex situ monitoring of B. papyrifera. These results aid in forecasting the dynamics of the species in the face of climate variability and change in both remnant populations and across its current distribution in northern latitudes of North America. Key words: paper birch, tree rings, riparian, MODIS, Landsat, NDVI, water, temperature, Nebraska Sandhills. Des populations reliques de Betula papyrifera Marshall ont persiste dans les grandes plaines apres la glaciation du Wisconsin le long de la vallee de la riviere Niobrara, au Nebraska. L'etat de sante des populations s'est deteriore au cours des recentes annees, vraisemblablement a cause des changements climatiques. Nous avons utilise les techniques dendrochronologiques pour evaluer la reaction de B. papyrifera au microclimat (1950-2014), ainsi que l'indice de vegetation NDVI derive de l'imagerie satellitaire (Landsat 5 TM (1985-2011) et MODIS (2000-2014)) en tant que substitut refletant l'etat de sante des populations. La precipitation et l'ecoulement fluvial durant la saison se croissance etaient positivement correles avec l'augmentation de l'accroissement de la surface terriere et la largeur brute et standardisee des cernes annuels. L'augmentation des temperatures hivernales et printanieres etait defavorable pour la croissance des arbres tandis que l'augmentation des temperatures estivales etait favorable en l'absence de secheresse. Le meilleur predicteur pour les cernes annuels standardises etait l'indice de severite de la secheresse de Palmer, ce qui indique que B. papyrifera est tres sensible aune combinaison de temperature et de disponibilite de l'eau. L'indice NDVI de la communaute vegetale etait positivement correle a la croissance des cernes annuels standardises, ce qui indique que ces techniques peuvent etre utilisees comme substitut pour le suivi ex situ de B. papyrifera. Ces resultats vont aider a predire la dynamique de cette espece face aux changements climatiques tant dans les populations reliques que partout dans son aire de repartition actuelle sous les latitudes septentrionales de l'Amerique du Nord. [Traduit par la Redaction] Mots-cles: bouleau blanc, cernes annuels, riverain, MODIS, Landsat, indice de vegetation NDVI, eau, temperature, dunes du Nebraska., 1. Introduction Paper birch (Betula papyrifera Marshall) is a widely distributed deciduous tree species across continental North America. It grows in the boreal forest from Newfoundland in eastern Canada all [...]

Changes in climate, land use and management have led to an increase in woody species encroachment into grasslands, threatening key ecosystem services and resilience. This study uses dendroecological techniques to investigate acclimation strategies of two native woody species, Juniperusimgimanaaad Finns ponderosa, to spatial and temporal variability in precipitation and stand density in Nebraska (NE). Two locations in Eastern NE and one in Western NE, were selected and tree cores for ring-width measurements were collected. Stable Isotope ratios of carbon were analysed to investigate water use efficiency (WUE), and stable isotope ratios of oxygen were used to understand stomatal conductance and control. Our results showed trees in dense stands exhibited less intra-specific variability in response to climate and narrower tree rings than sparse open stands, with P'. ponderosa being more responsive to density and climate variability than J. virginiana. Populations in the drier Sandhills grasslands of Western NE were more dependent on intra- and inter-annual precipitation and generally more impacted by drought events than those in the East. Eastern NE trees were less limited by drought and displayed lower WUE relative to Western location, even though temperatures were slightly higher, but this was compensated for by the overall higher precipitation levels in the East. Generally, above average winter temperatures were positively correlated with ring widths, while temperature extremes dining the growing season were negatively correlated. Although years of extreme drought events were risible in the tree-ring width patterns for both species independent of stand density and location, it seems that once the trees are established and have access to soil moisture, the current climate variability and extremes in NE do not limit or cause a permanent decline in growth of either species., INTRODUCTION Changes in climate, land use, and anthropogenic management, such as fire regime and livestock grazing, have contributed to an increase in woody species encroachment into grassland and savanna ecosystems [...]

Abstract Changes in climate, land use and management have led to an increase in woody species encroachment into grasslands, threatening key ecosystem services and resilience. This study uses dendroecological techniques to investigate acclimation strategies of two native woody species, Juniperus virginiana and Pinus ponderosa, to spatial and temporal variability in precipitation and stand density in Nebraska (NE). Two locations in Eastern NE and one in Western NE, were selected and tree cores for ring-width measurements were collected. Stable Isotope ratios of carbon were analysed to investigate water use efficiency (WUE), and stable isotope ratios of oxygen were used to understand stomatal conductance and control. Our results showed trees in dense stands exhibited less intra-specific variability in response to climate and narrower tree rings than sparse open stands, with P. ponderosa being more responsive to density and climate variability than J. virginiana. Populations in the drier Sandhills grasslands of Western NE were more dependent on intra- and inter-annual precipitation and generally more impacted by drought events than those in the East. Eastern NE trees were less limited by drought and displayed lower WUE relative to Western location, even though temperatures were slightly higher, but this was compensated for by the overall higher precipitation levels in the East. Generally, above average winter temperatures were positively correlated with ring widths, while temperature extremes during the growing season were negatively correlated. Although years of extreme drought events were visible in the tree-ring width patterns for both species independent of stand density and location, it seems that once the trees are established and have access to soil moisture, the current climate variability and extremes in NE do not limit or cause a permanent decline in growth of either species. [ABSTRACT FROM AUTHOR]

The primary aim of this study was to assess the clinical and radiological results after hemi-hamate resurfacing arthroplasty in patients with acute or chronic unstable fractures of the base of the middle phalanx and to describe technical features that can facilitate the surgical procedure. Hemi-hamate arthroplasties were done in 19 patients (mean age 39 years) with an isolated fracture at the base of the middle phalanx that involved more than 40% of the articular surface. We assessed ten chronic cases (treated >6 weeks after fracture) and nine acute ones (<6 weeks) at a mean of 24 months. Pain scores, QuickDASH scores, grip strengths, range of motion and radiological findings were recorded at follow-up. At follow-up, the mean active flexion at the proximal interphalangeal joint was to 83° with a mean fixed flexion of 17° (active range of motion 66°). The mean active distal interphalangeal motion was 41°. The mean visual analogue scale score was 1.1. The mean QuickDASH score was 11. The mean pinch strength was 82% of the opposite side. Radiographs revealed one partial graft lysis.Level of evidence: IV [ABSTRACT FROM AUTHOR]

The treatment of ulnar nerve compression at the elbow remains controversial. No single technique has yet proven its superiority. We describe a technique combining the advantages of the mini-invasive approach with those of transposition. We present the results of 30 patients, of mean age 52 years, who underwent anterior subcutaneous transposition of the ulnar nerve using a mini-invasive approach with a follow-up of more than six months. The incision measures 3 cm. The results were evaluated by measuring pain intensity, quick disabilities of the arm shoulder and hand (DASH), grip strength and pinch, and McGowan score, pre- and post-operatively. All parameters were improved post-operative. The mean pain score went from 5.5 to 4, the quick DASH from 48 to 38, mean grip strength from 28 to 31 kg, and mean pinch strength from 4.7 to 6.4 kg. The McGowan score was also improved; pre-operatively, there were 16 patients at stage III, seven patients stage II, seven patients stage I, and post-operatively there was one patient stage III, three patients stage II, 16 patients stage I, and 10 patients stage 0. Analysis of our series shows that a 3 cm incision without endoscopy allows subcutanous transposition, with results at least as good as those with other techniques. The advantages of our technique are that it is easy, has a limited approach, preserves blood supply, allows placement of the nerve in a favourable environment, and decreases nerve stretching during elbow flexion. [ABSTRACT FROM PUBLISHER]

Changes in climate, land management and fire regime have contributed to woody species expansion into grasslands and savannas worldwide. In the USA, Pinus ponderosa P.&C. Lawson and Juniperus virginiana L. are expanding into semiarid grasslands of Nebraska and other regions of the Great Plains. We examined P. ponderosa and J. virginiana seedling response to soil water content, one of the most important limiting factors in semiarid grasslands, to provide insight into their success in the region. Photosynthesis, stomatal conductance, maximum photochemical efficiency of PSII, maximum carboxylation velocity, maximum rate of electron transport, stomatal limitation to photosynthesis, water potential, root-to-shoot ratio, and needle nitrogen content were followed under gradual soil water depletion for 40 days. J. virginiana maintained lower Ls, higher A, gs, and initial Fv/Fm, and displayed a more gradual decline in Vcmax and Jmax with increasing water deficit compared to P. ponderosa. J. virginiana also invested more in roots relative to shoots compared to P. ponderosa. Fv/Fm showed high PSII resistance to dehydration in both species. Photoinhibition was observed at ∼30% of field capacity. Soil water content was a better predictor of A and gs than Ψ, indicating that there are other growth factors controlling physiological processes under increased water stress. The two species followed different strategies to succeed in semiarid grasslands. P. ponderosa seedlings behaved like a drought-avoidant species with strong stomatal control, while J. virginiana was more of a drought-tolerant species, maintaining physiological activity at lower soil water content. Differences between the studied species and the ecological implications are discussed. [ABSTRACT FROM AUTHOR]

Background: Autofluorescence-based imaging has the potential to non-destructively characterize the biochemical and physiological properties of plants regulated by genotypes using optical properties of the tissue. A comparative study of stress tolerant and stress susceptible genotypes of Brassica rapa with respect to newly introduced stress-based phenotypes using machine learning techniques will contribute to the significant advancement of autofluorescence-based plant phenotyping research., Methods: Autofluorescence spectral images have been used to design a stress detection classifier with two classes, stressed and non-stressed, using machine learning algorithms. The benchmark dataset consisted of time-series image sequences from three Brassica rapa genotypes ( CC , R500 , and VT ), extreme in their morphological and physiological traits captured at the high-throughput plant phenotyping facility at the University of Nebraska-Lincoln, USA. We developed a set of machine learning-based classification models to detect the percentage of stressed tissue derived from plant images and identified the best classifier. From the analysis of the autofluorescence images, two novel stress-based image phenotypes were computed to determine the temporal variation in stressed tissue under progressive drought across different genotypes, i.e., the average percentage stress and the moving average percentage stress., Results: The study demonstrated that both the computed phenotypes consistently discriminated against stressed versus non-stressed tissue, with oilseed type ( R500 ) being less prone to drought stress relative to the other two Brassica rapa genotypes ( CC and VT )., Conclusion: Autofluorescence signals from the 365/400 nm excitation/emission combination were able to segregate genotypic variation during a progressive drought treatment under a controlled greenhouse environment, allowing for the exploration of other meaningful phenotypes using autofluorescence image sequences with significance in the context of plant science., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Das Choudhury, Guadagno, Bashyam, Mazis, Ewers, Samal and Awada.)

Fall-planted cover crop (CC) within a continuous corn (Zea mays L.) system offers potential agroecosystem benefits, including mitigating the impacts of increased temperature and variability in precipitation patterns. A long-term simulation using the Decision Support System for Agrotechnology Transfer model was made to assess the effects of cereal rye (Secale cereale L.) on no-till continuous corn yield and soil properties under historical (1991-2020) and projected climate (2041-2070) in eastern Nebraska. Local weather data during the historical period were used, while climate change projections were based on the Canadian Earth System Model 2 dynamically downscaled using the Canadian Centre for Climate Modelling and Analysis Regional Climate Model 4 under two representative concentration pathways (RCP), namely, RCP4.5 and RCP8.5. Simulations results indicated that CC impacts on corn yield were nonsignificant under historical and climate change conditions. Climate change created favorable conditions for CC growth, resulting in an increase in biomass. CC reduced N leaching under climate change scenarios compared to an average reduction of 60% (7 kg ha - 1 ) during the historical period. CC resulted in a 6% (27 mm) reduction in total water in soil profile (140 cm) and 22% (27 mm) reduction in plant available water compared to no cover crop during historical period. CC reduced cumulative seasonal surface runoff/soil evaporation and increased the rate of soil organic carbon buildup. This research provides valuable information on how changes in climate can impact the performance of cereal rye CC in continuous corn production and should be scaled to wider locations and CC species., (© 2023 The Authors. Journal of Environmental Quality published by Wiley Periodicals LLC on behalf of American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

The paper introduces two novel algorithms for predicting and propagating drought stress in plants using image sequences captured by cameras in two modalities, i.e., visible light and hyperspectral. The first algorithm, VisStressPredict, computes a time series of holistic phenotypes, e.g., height, biomass, and size, by analyzing image sequences captured by a visible light camera at discrete time intervals and then adapts dynamic time warping (DTW), a technique for measuring similarity between temporal sequences for dynamic phenotypic analysis, to predict the onset of drought stress. The second algorithm, HyperStressPropagateNet, leverages a deep neural network for temporal stress propagation using hyperspectral imagery. It uses a convolutional neural network to classify the reflectance spectra at individual pixels as either stressed or unstressed to determine the temporal propagation of stress in the plant. A very high correlation between the soil water content, and the percentage of the plant under stress as computed by HyperStressPropagateNet on a given day demonstrates its efficacy. Although VisStressPredict and HyperStressPropagateNet fundamentally differ in their goals and hence in the input image sequences and underlying approaches, the onset of stress as predicted by stress factor curves computed by VisStressPredict correlates extremely well with the day of appearance of stress pixels in the plants as computed by HyperStressPropagateNet. The two algorithms are evaluated on a dataset of image sequences of cotton plants captured in a high throughput plant phenotyping platform. The algorithms may be generalized to any plant species to study the effect of abiotic stresses on sustainable agriculture practices., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Das Choudhury, Saha, Samal, Mazis and Awada.)

The emergence timing of a plant, i.e., the time at which the plant is first visible from the surface of the soil, is an important phenotypic event and is an indicator of the successful establishment and growth of a plant. The paper introduces a novel deep-learning based model called EmergeNet with a customized loss function that adapts to plant growth for coleoptile (a rigid plant tissue that encloses the first leaves of a seedling) emergence timing detection. It can also track its growth from a time-lapse sequence of images with cluttered backgrounds and extreme variations in illumination. EmergeNet is a novel ensemble segmentation model that integrates three different but promising networks, namely, SEResNet, InceptionV3, and VGG19, in the encoder part of its base model, which is the UNet model. EmergeNet can correctly detect the coleoptile at its first emergence when it is tiny and therefore barely visible on the soil surface. The performance of EmergeNet is evaluated using a benchmark dataset called the University of Nebraska-Lincoln Maize Emergence Dataset (UNL-MED). It contains top-view time-lapse images of maize coleoptiles starting before the occurrence of their emergence and continuing until they are about one inch tall. EmergeNet detects the emergence timing with 100% accuracy compared with human-annotated ground-truth. Furthermore, it significantly outperforms UNet by generating very high-quality segmented masks of the coleoptiles in both natural light and dark environmental conditions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed a potential conflict of interest., (Copyright © 2023 Das, Das Choudhury, Das, Samal and Awada.)

High-throughput plant phenotyping (HTPP) has become an emerging technique to study plant traits due to its fast, labor-saving, accurate and non-destructive nature. It has wide applications in plant breeding and crop management. However, the resulting massive image data has raised a challenge associated with efficient plant traits prediction and anomaly detection. In this paper, we propose a two-step image-based online detection framework for monitoring and quick change detection of the individual plant leaf area via real-time imaging data. Our proposed method is able to achieve a smaller detection delay compared with some baseline methods under some predefined false alarm rate constraint. Moreover, it does not need to store all past image information and can be implemented in real time. The efficiency of the proposed framework is validated by a real data analysis., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2022 Informa UK Limited, trading as Taylor & Francis Group.)

Estrogen is a steroid hormone that induces skeletal growth and affects endochondral ossification of the long tubular bone growth plate during the growth period. However, the effects of estrogen on endochondral ossification of the mandibular condylar cartilage are unclear. In this study, ovariectomized Wistar/ST rats were used to investigate the longitudinal effects of estrogen on mandibular growth. The rats were administered different doses of estrogen. Longitudinal micro-computed tomographic scanning, histological staining and ELISA on plasma growth hormone were performed to examine the effects of estrogen on mandibular growth. The results showed that mandibular growth was suppressed throughout the growth period by estrogen in a dose-dependent manner. In addition, long-term administration of a high dose of estrogen to the rats resulted in significant increase in growth hormone throughout the growth period, significant circularization of cell nuclei in the proliferative layer, intensely staining cartilage matrix in the subchondral bone, and significant suppression of estrogen receptor (ER) alpha and beta expression in the mandibular cartilage. However, regardless of estrogen concentration, in the posterior part of the mandibular cartilage, ER expression extended to both the hypertrophic and proliferative layers. These results indicate that estrogen suppresses mandibular growth throughout the growth period. Additionally, it influences endochondral ossification via its effect on ERs., Competing Interests: Declarations of competing interest The authors declare that they have no competing interests., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Our understanding of the physiological responses of rice inflorescence (panicle) to environmental stresses is limited by the challenge of accurately determining panicle photosynthetic parameters and their impact on grain yield. This is primarily due to the lack of a suitable gas exchange methodology for panicles and non-destructive methods to accurately determine panicle surface area., Results: To address these challenges, we have developed a custom panicle gas exchange cylinder compatible with the LiCor 6800 Infra-red Gas Analyzer. Accurate surface area measurements were determined using 3D panicle imaging to normalize the panicle-level photosynthetic measurements. We observed differential responses in both panicle and flag leaf for two temperate Japonica rice genotypes (accessions TEJ-1 and TEJ-2) exposed to heat stress during early grain filling. There was a notable divergence in the relative photosynthetic contribution of flag leaf and panicles for the heat-tolerant genotype (TEJ-2) compared to the sensitive genotype (TEJ-1)., Conclusion: The novelty of this method is the non-destructive and accurate determination of panicle area and photosynthetic parameters, enabling researchers to monitor temporal changes in panicle physiology during the reproductive development. The method is useful for panicle-level measurements under diverse environmental stresses and is sensitive enough to evaluate genotypic variation for panicle physiology and architecture in cereals with compact inflorescences., (© 2022. The Author(s).)

Idiopathic mandibular condylar resorption (ICR) is a pathological condition characterized by idiopathic resorption of the mandibular condyle, resulting in a decrease in the size and height of the mandibular condyle. The purpose of this study was to characterize the maxillofacial morphology of ICR patients. Subjects were selected from patients that attended our orthodontic clinic between 1991 and 2019. Twenty-five patients were diagnosed with ICR by magnetic resonance imaging; however, growing patients were excluded. In total, 18 patients were finally selected. The control group comprised 18 healthy volunteers. Lateral and frontal cephalograms were also used. The ICR group had significantly more severe skeletal class II malocclusions than the control group, mainly due to retrusion of the mandible. In the ICR group, there was a tendency for a skeletal open bite due to a significantly larger clockwise rotation of the mandible than in the control group. There was no significant difference between the two groups in the inclination of the upper and lower central incisors or protrusion of the upper and lower central incisors and first molars. ICR patients have been suggested to exhibit skeletal open bite and maxillary protrusion with changes in maxillofacial morphology due to abnormal resorption of the mandibular condyle.

Tree rings provide an invaluable long-term record for understanding how climate and other drivers shape tree growth and forest productivity. However, conventional tree-ring analysis methods were not designed to simultaneously test effects of climate, tree size, and other drivers on individual growth. This has limited the potential to test ecologically relevant hypotheses on tree growth sensitivity to environmental drivers and their interactions with tree size. Here, we develop and apply a new method to simultaneously model nonlinear effects of primary climate drivers, reconstructed tree diameter at breast height (DBH), and calendar year in generalized least squares models that account for the temporal autocorrelation inherent to each individual tree's growth. We analyze data from 3811 trees representing 40 species at 10 globally distributed sites, showing that precipitation, temperature, DBH, and calendar year have additively, and often interactively, influenced annual growth over the past 120 years. Growth responses were predominantly positive to precipitation (usually over ≥3-month seasonal windows) and negative to temperature (usually maximum temperature, over ≤3-month seasonal windows), with concave-down responses in 63% of relationships. Climate sensitivity commonly varied with DBH (45% of cases tested), with larger trees usually more sensitive. Trends in ring width at small DBH were linked to the light environment under which trees established, but basal area or biomass increments consistently reached maxima at intermediate DBH. Accounting for climate and DBH, growth rate declined over time for 92% of species in secondary or disturbed stands, whereas growth trends were mixed in older forests. These trends were largely attributable to stand dynamics as cohorts and stands age, which remain challenging to disentangle from global change drivers. By providing a parsimonious approach for characterizing multiple interacting drivers of tree growth, our method reveals a more complete picture of the factors influencing growth than has previously been possible., (© 2021 The Authors. Global Change Biology published by John Wiley & Sons Ltd. This article has been contributed to by US Government employees and their work is in the public domain in the USA.)

Water deficit during the early vegetative growth stages of wheat (Triticum) can limit shoot growth and ultimately impact grain productivity. Introducing diversity in wheat cultivars to enhance the range of phenotypic responses to water limitations during vegetative growth can provide potential avenues for mitigating subsequent yield losses. We tested this hypothesis in an elite durum wheat background by introducing a series of introgressions from a wild emmer (Triticum turgidum ssp. dicoccoides) wheat. Wild emmer populations harbor rich phenotypic diversity for drought-adaptive traits. To determine the effect of these introgressions on vegetative growth under water-limited conditions, we used image-based phenotyping to catalog divergent growth responses to water stress ranging from high plasticity to high stability. One of the introgression lines exhibited a significant shift in root-to-shoot ratio in response to water stress. We characterized this shift by combining genetic analysis and root transcriptome profiling to identify candidate genes (including a root-specific kinase) that may be linked to the root-to-shoot carbon reallocation under water stress. Our results highlight the potential of introducing functional diversity into elite durum wheat for enhancing the range of water stress adaptation., (© American Society of Plant Biologists 2021. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Roadside vegetation provides a multitude of ecosystem services, including pollutant remediation, runoff reduction, wildlife habitat, and aesthetic scenery. Establishment of permanent vegetation along paved roads after construction can be challenging, particularly within 1 m of the pavement. Adverse soil conditions could be one of the leading factors limiting roadside vegetation growth. In this study, we assessed soil physical and chemical properties along a transect perpendicular to the road at six microtopographic positions (road edge, shoulder, side slope, ditch, backslope, and field edge) along two highway segments near Beaver Crossing and Sargent, NE. At the Beaver Crossing site, Na concentration was 81 times, exchangeable Na 66 times, and cone index (compaction parameter) six times higher at the road-edge position (closest to the paved road and with sparse vegetation) compared to positions with abundant vegetation (ditch or field edge). At the Sargent site, Na concentration was 111 times, exchangeable Na 213 times, and cone index up to two times higher at the road-edge position compared with ditch or field-edge positions. Likewise, electrical conductivity was higher and macroaggregation and water infiltration were lower at the road edge than at the ditch or field-edge positions. Soil properties improved with increasing distance from the road. Exchangeable Na percentage and cone index at the road-edge position exceeded threshold levels for the growth of sensitive plants. Thus, high Na concentration and increased compaction at the road edge appear to be the leading soil properties limiting vegetation establishment along Nebraska highways., (© 2020 The Authors. Journal of Environmental Quality © 2020 American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.)