Large Amount Of Variation Research Articles

HTS library plate rejuvenation using a DMSO-rich atmosphere

Dry DMSO can rapidly pull water vapor out of the air due to its hygroscopic nature. This is a well-documented problem within drug discovery, particularly within high-throughput screening (HTS). This hydration is caused by atmospheric moisture being absorbed each time a compound library is used. This effect becomes increasingly pronounced when a compound library is used routinely. The result of this hydration is a change to both the total volume of solution and the concentration of sample still in solution. This can result in a large amount of variability in the measured biological activity of a sample depending on the library usage. In this paper, we show the detrimental effects the hydration of sample libraries has on the reproducibility of biological data and present a novel way to remove it from HTS library plates. Our approach involves creating a DMSO-rich environment, created by placing anhydrous DMSO in compound storage pods purged with nitrogen, and incubating library plates in this environment for up to 3 days. Quantification via evaporative light scattering detection (ELSD) showed that removing water greatly increased the molarity of solutions, with a greater effect being seen for compounds with poor solubility. We also demonstrated how this approach can restore the inhibitory activity of stock solutions of compounds (pIC50) of samples containing ∼30 % water from >30 µM to sub-micromolar after moisture removal. This method improves the reliability of tested compounds in HTS by potentially saving pharmaceutical companies hundreds of thousands of dollars in screening campaigns and increasing the quality of data.

What predicts hurricane evacuation decisions? The importance of efficacy beliefs, risk perceptions, and other factors

Risk theories and empirical research indicate that a variety of factors can influence people’s protective decisions for natural hazards. Using data from an online survey that presented coastal U.S. residents with a hypothetical hurricane scenario, this study investigates the relative importance of cognitive risk perceptions, negative affect, efficacy beliefs, and other factors in explaining people’s anticipated evacuation decisions. The analysis finds that multiple factors, including individual and household characteristics, previous experiences, cognitive and affective risk perceptions, and efficacy beliefs, can help predict hurricane evacuation intentions. However, the largest amount of variance in survey participants’ evacuation intentions is explained by their evacuation-related response efficacy (coping appraisals) and their perceived likelihood of getting hurt if they stay home during the storm. Additional analysis explores how risk perceptions and efficacy beliefs interact to influence people’s responses to risk information. Although further investigation in additional situations is needed, these results suggest that persuading people at high risk that evacuating is likely to reduce harm can serve as an important risk communication lever for motivating hurricane evacuation.

Quality of IEPs for Students with Complex Support Needs: Is There Alignment Across IEP Components?

ABSTRACT Educators and families develop individualized education programs (IEPs) to address unique needs of individual students with disabilities. Addressing all student needs is critical to ensuring students receive a free and appropriate public education. To understand how IEP teams address the needs of students with complex support needs, we examined the alignment of IEP goals and supplementary aids and services with the stated needs of 112 elementary students with complex support needs as reported in their present levels of academic achievement and functional performance. We found there was a large amount of variation in alignment, but that 32.76% of stated student needs were not addressed by goals or supplementary aids and services. Neither educational placement nor type of student need was statistically significant in terms of whether a student need was addressed in the IEP. These findings suggest a serious threat to a student’s right to a free and appropriate public education. Implications for practice and research are discussed.

An examination of the criterion-related validity of varying methods of indexing clinically significant change in posttraumatic stress disorder treatment.

Clinicians, patients, and researchers need benchmarks to index individual-level clinically significant change (CSC) to guide decision making and inferences about treatment efficacy. Yet, there is no consensus best practice for determining CSC for posttraumatic stress disorder (PTSD) treatments. We examined criterion-related validity of the most common approach-Jacobson and Truax's (J&T; 1991) procedures for indexing CSC. We generated and compared four methods of calculating the J&T indices of CSC (two sets of sample-specific inputs, putatively norm-referenced benchmarks, and a combination of sample-specific and norm-referenced criteria) with respect to their association with a criterion index of quality of life (QoL). Participants were 91 women Veterans enrolled in a randomized clinical trial for PTSD who completed self-report measures on PTSD symptoms and various domains of QoL and functioning, pre- and posttreatment. For each of the four methods used to calculate CSC, the QoL composite was regressed onto the CSC categories. All methods explained large variance in change in QoL. Across all methods, participants categorized as unchanged had smaller changes in QoL, compared with those who improved or had probable recovery. The norm-referenced benchmarks accounted for the relatively largest amount of variance in QoL, but categorized the fewest patients as having made CSC. The J&T methodology for indexing CSC in PTSD symptoms has criterion-related validity, and a norm-referenced benchmark appears to be the most potent. However, the norm-referenced parameters may be overly specific, potentially leading to an underestimate of improvement. Research is needed to test the generalizability of these results. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Comparison of Regression Analysis and Mathematical Methods for Stature Estimation from the Upper Limb Measurements of the Modern South Indian Population

This study aimed to establish reliable mathematical and regression analysis (RA) methods for estimating stature using upper limb (UL) anthropometric parameters in the modern South Indian (MSI) population. This study was conducted on a sample size (117 men and 97 women) from the MSI population. Dead bodies within 3 hours of death were included in this study, as the study outcome is meant to apply to the dead and dismembered UL parts. Mathematical and linear RA methods were used to derive multiplication factors (MFs) and regression equations (REs) for the estimation of stature from UL measurements (arm length [AL], forearm length, palm length, and middle finger length [MFL]) and assess their prediction accuracy. A statistically significant correlation was found between UL measurements and stature, indicating their potential use for stature estimation. Both genders showed a statistically significant positive relationship between UL measurements and stature. Both MF and RA methods exhibited reasonable goodness of fit, albeit the RA method yielded a closer estimate of the actual stature than the former. The derived RE showed reasonable goodness of fit and precision in both genders, as evidenced by high R2 values and low standard errors. The RA and MF methods slightly over- and under-estimated the actual stature, respectively. The MFL and AL showed the strongest and weakest relationship with the stature. Both methods have practical significance though the precision is higher with RA methods. The MF method is simpler, as it is independent of statistical resources, while the RA method may be more useful in cases where there is a large amount of variation in the data. The outcome of this study has significant implications for the forensic and anthropology fields. The derived RE and MF provide a reliable framework for estimating stature from anthropometric measurements of dismembered UL remnants. This information can be valuable in forensic investigations, unidentified remains cases and archaeological studies.

Individual differences in secondary school students' conceptual knowledge: Latent profile analysis of biology concepts

Extensive research has been conducted on the misconceptions related to photosynthesis and respiration. However, most of these studies have failed to consider the heterogeneity of learners. In this study, latent profile analysis was used to determine the differences in students' understanding of biological concepts. Students' profiles were validated by relating them to their grade level, academic achievement in biology and sophistication of epistemic beliefs. Between the scientific and non-scientific understanding of photosynthesis and respiration, there were different conceptual profiles (prescientific, inaccurate preconceptions, fragmented and synthetic) in this cross-sectional study that helped in understanding the possible, qualitatively different steps between misconceptions and scientific understanding. Higher grade levels, higher biology grades and more sophisticated epistemic beliefs were related to a higher probability of belonging to the subgroups with more scientific conceptual knowledge. Educational relevance and implicationsBetween the scientific and non-scientific understanding of photosynthesis and respiration, there were different conceptual profiles (prescientific, inaccurate preconceptions, fragmented and synthetic) that helped in understanding the steps from misconceptions to scientific understanding. Higher grade levels, higher biology grades and more sophisticated epistemic beliefs were related to a higher probability of belonging to the subgroups with more scientific conceptual knowledge. Teachers should be aware that a large amount of variance may present among students in terms of their level and quality of understanding of central biological topics. Accordingly, teachers should allocate time to understand the students' level and quality of prior knowledge. They should focus on helping learners integrate correct fragments of information into a full, systemic understanding as well as encourage them to critically evaluate and compare their existing conceptions with scientific explanations. To improve the understanding of science, teachers should address the topic of the nature of knowledge, taking into account key aspects of discipline-specific epistemic beliefs. This approach will help students understand the nature, foundation and principles underlying scientific research and the empirical grounds for its acceptance.

Developmental programming of the ovarian reserve in livestock

Mammalian females are born with a finite number of follicles in their ovaries that is referred to as the ovarian reserve. There is a large amount of variation between females in the number of antral follicles that they are born with, but this number is positively correlated to size of the ovarian reserve, has a strong repeatability within a female, and a moderate heritability. Although the heritability is moderate, numerous external factors including health, nutrition, ambient temperature, and litter size influence the size and function of the ovarian reserve throughout life. Depletion of the ovarian reserve contributes to reproductive senescence, and genetic and epigenetic factors can lead to a more rapid decline in follicle numbers in some females than others. The relationship of the size of the ovarian reserve to development of the reproductive tract and fertility is generally positive, although some studies report antagonistic associations of these traits. It seems likely that management decisions and environmental factors that result in epigenetic modifications to the genome throughout life may cause variability in the function of ovarian genes that influence fecundity and fertility, leading to differences in reproductive longevity among females born with ovarian reserves of similar size. This review summarizes our current understanding of factors influencing size of the ovarian reserve in cattle, sheep, and pigs and the relationship of the ovarian reserve to reproductive tract development and fertility. It provides strategies to apply this knowledge to improve diagnostics for better assessment of fertility and reproductive longevity in female livestock.

Analysis of ontogenetic changes in head shape and diet in a catfish with moderately enlarged jaw adductors (Clariallabes melas)

Jaw adductor hypertrophy, or the presence of enlarged jaw-closing muscles, has arisen several times independently in African clariid catfish. Previous work has demonstrated that species characterized by enlarged jaw adductors may have unusual ways of foraging such as terrestrial foraging and prey capture, and often include a large proportion of hard and terrestrial prey in their diet. However, relatively little is known about species of the genus Clariallabes with an intermediate degree of jaw adductor hypertrophy. In the present study we present data on head shape and diet for a range of sizes of specimens of a poorly known species of Clariallabes, C. melas. Our data show that growth patterns in this species and the previously studied 
 C. longicauda are similar in some ways (e.g. positive allometry of the growth of the jaw muscles) but different in others (negative allometry in hyoid width). However, C. melas has a smaller head for its body size in all dimensions. Due to the large number of empty stomachs we encountered, dietary data remain preliminary, but suggest a varied diet including both hard and soft prey. Our data show that a large amount of variation in head shape may exist even among related species and that species with jaw adductor hypertrophy generally show positive allometry in the growth of the jaw adductors and associated structures. Whether jaw muscle hypertrophy is an adaptive trait in clariid catfish awaits further comparative analyses testing for the evolutionary association between jaw adductor hypertrophy and the inclusion of hard prey into the diet.

The noise is the signal: spatio-temporal variability of production and productivity in high elevation meadows in the Sierra Nevada mountain range of North America

There are expectations that increasing temperatures will lead to significant changes in structure and function of montane meadows, including greater water stress on vegetation and lowered vegetation production and productivity. We evaluated spatio-temporal dynamics in production and productivity in meadows within the Sierra Nevada mountain range of North America by: (1) compiling Landsat satellite data for the Normalized Difference Vegetation Index (NDVI) across a 37-year period (1985–2021) for 8,095 meadows >2,500 m elevation; then, (2) used state-space models, changepoint analysis, geographically-weighted regression (GWR), and distance-decay analysis (DDA) to: (a) identify meadows with decreasing, increasing or no trends for NDVI; (b) detect meadows with abrupt changes (changepoints) in NDVI; and (c) evaluate variation along gradients of latitude, longitude, and elevation for eight indices of temporal dynamics in annual production (mean growing season NDVI; MGS) and productivity (rate of spring greenup; RSP). Meadows with no long-term change or evidence of increasing NDVI were 2.6x more frequent as those with decreasing NDVI (72% vs. 28%). Abrupt changes in NDVI were detected in 48% of the meadows; they occurred in every year of the study and with no indication that their frequency had changed over time. The intermixing of meadows with different temporal dynamics was a consistent pattern for monthly NDVI and, especially, the eight annual indices of MGS and RSP. The DDA showed temporal dynamics in pairs of meadow within a few 100 m of each other were often as different as those hundreds of kilometers apart. Our findings point strongly toward a great diversity of temporal dynamics in meadow production and productivity in the SNV. The heterogeneity in spatial patterns indicated that production and productivity of meadow vegetation is being driven by interplay among climatic, physiographic and biotic factors at basin and meadow scales. Thus, when evaluating spatio-temporal dynamics in condition for many high elevation meadow systems, what might often be considered “noise” may provide greater insight than a “signal” embedded within a large amount of variability.

Predicting Mood Based on the Social Context Measured Through the Experience Sampling Method, Digital Phenotyping, and Social Networks

Social interactions are essential for well-being. Therefore, researchers increasingly attempt to capture an individual's social context to predict well-being, including mood. Different tools are used to measure various aspects of the social context. Digital phenotyping is a commonly used technology to assess a person's social behavior objectively. The experience sampling method (ESM) can capture the subjective perception of specific interactions. Lastly, egocentric networks are often used to measure specific relationship characteristics. These different methods capture different aspects of the social context over different time scales that are related to well-being, and combining them may be necessary to improve the prediction of well-being. Yet, they have rarely been combined in previous research. To address this gap, our study investigates the predictive accuracy of mood based on the social context. We collected intensive within-person data from multiple passive and self-report sources over a 28–day period in a student sample (Participants: N = 11, ESM measures: N = 1313). We trained individualized random forest machine learning models, using different predictors included in each model summarized over different time scales. Our findings revealed that even when combining social interactions data using different methods, predictive accuracy of mood remained low. The average coefficient of determination over all participants was 0.06 for positive and negative affect and ranged from − 0.08 to 0.3, indicating a large amount of variance across people. Furthermore, the optimal set of predictors varied across participants; however, predicting mood using all predictors generally yielded the best predictions. While combining different predictors improved predictive accuracy of mood for most participants, our study highlights the need for further work using larger and more diverse samples to enhance the clinical utility of these predictive modeling approaches.

The association between the interviewers’ and the respondents’ political attitudes in a telephone survey

ABSTRACT Interviewer effects in telephone surveys on political topics are likely to occur. The literature has yielded considerable evidence about the impact of basic interviewer characteristics, but research is lacking on how interviewers’ beliefs may shape responses. This study is aimed at assessing the association between the interviewers’ party affiliation and political ideology and the answers provided to the same questions by the respondents, using a large-scale telephone survey conducted in Hungary. The results show that interviewers account for a relatively large amount of variance, especially in the models predicting item-nonresponse. The interviewer’s reluctance to answer these questions strongly predicted missing data on the respondent level. On the other hand, only weak interviewer effects were found regarding the valid, substantive responses. The results demonstrate how, for instance, estimations of nonrespondents’ party preferences in electoral polls may be biased due to interviewer-related errors, and highlight the need for standardized persuasion strategies.

Global yield from aquaculture systems

AbstractAquaculture is expected to expand significantly in the coming decades to meet growing demand. A key variable for understanding the potential benefit of and impact from this growth is efficiency; yet a comprehensive assessment of on‐farm area use and yield is limited. Much like land‐based agriculture, range and variation in yields across space, species, and practice provide insights into area use and production efficiencies. Current estimates of aquaculture yields (production per area per time) aggregate on‐farm and off‐farm land use into one ‘land use’ category; in contrast, we disaggregate this category to provide on‐farm yield estimates and account for water area use. We use a quantitative review of scientific literature to synthesize and compare on‐farm area use and yield patterns across countries, taxa, aquatic systems, data source, and production mode (n = 378). Because recirculating aquaculture systems (RAS) have been touted as a particularly efficient production mode, we also found estimates for RAS from industry (n = 4). Median, mean and range in yields among countries and taxa vary by orders of magnitude, with algal production greatly exceeding that of crustaceans, fishes and molluscs. Yields in marine systems were on average roughly 5× greater than yields in freshwater systems. RAS had particularly high yields but sparse data and estimates from private corporations were approximately 3.7× higher than literature estimates, on average. This comprehensive assessment of global aquaculture yields offers critical insight into the production efficiencies of different aquaculture forms and the large amount of variability, which could help guide aquaculture policy and practice.

A novel fault detection framework integrated with variable importance analysis for quality-related nonlinear process monitoring

Monitoring the quality-related variables is an essential task in industrial processes. However, large amounts of variables and complex relationship between measured and quality variables pose challenges in improving fault detection performance. This paper proposes a novel quality-related fault detection framework based on variable importance analysis for nonlinear process monitoring. In the proposed framework, a new nonlinear variable division index called improved variable importance in the projection (IVIP) is designed to better identify quality-related variables. First, measured variables are divided into quality-related and independent spaces according to their IVIP values. Then, considering different data characteristics, a hybrid detection model combined multivariate exponentially weighted moving average and kernel principal component analysis (MEKPCA) is constructed in these two spaces to monitor abnormal events. To provide an integrated decision, the Bayesian inference strategy is finally utilized to fuse useful information from different spaces. Three case studies, including a simulated numerical system, the Tennessee Eastman process, and a wastewater treatment process, demonstrate that our proposed IVIP-MEKPCA outperforms other comparison methods.

Nest size parameters of Great Tits and Blue Tits: a long-term study

Nest construction behaviour is widespread among bird species. Causes for the occurrence and great variation in nest characteristics between and within populations are still poorly understood. In this study, we present results concerning nest parameters of Great Tits Parus major and Blue Tits Cyanistes caeruleus over a period of 11 breeding seasons (2012–2022) in two structurally and floristically contrasting study areas in central Poland. The nest depth differed significantly between young (yearlings) and older females (≥ 2 years after hatching) in Blue Tits (but not in Great Tits): younger females tended to build deeper nests. The size and mass of the nest were very variable in both tit species. Blue Tits tended to build deeper and heavier nests than Great Tits. The depth of the nest was positively correlated with nest mass in Great and Blue Tits. In Great Tits, the nest mass (but not nest depth) differed between study sites, with nests being heavier in the forest and the nest depth differed between years; in Blue Tits, there was an interaction between year and study site that affected nest depth. The nest mass (but not depth) from the same nestbox tended to be consistently similar within species in Great Tits and Blue Tits. We argue that the large amount of variation in nest parameters between and within populations of both tit species may be a multi-factorial result of female age, breeding area, breeding season, individual predispositions and the size of the nestbox/natural hole.

Statistical shape modeling of mean shape and principal variability of the human talar bone in the Chinese population.

The talar bone plays a crucial role in ankle biomechanics and stability. Understanding the shape variability of the talar bone within specific populations is essential for various clinical applications. In this study, we aimed to investigate the mean shape and principal variability of the human talar bone in the Chinese population using statistical shape modeling (SSM). CT scans of 214 tali were included to create SSM models. Principal component analysis was used to describe shape variation among the male, female, and overall groups. The largest amount of variation among three groups ranges from 17.2%-18.8% of each variation. The first seven principal components (modes) captured 62.4%-67.5% of the cumulative variance. No dominant shape of the talus was found. Male tali generally have a larger size than the female tali, with the exception of the articular surface of the anterior subtalar joint. SSM is an effective method of finding mean shape and principal variability. Considerable variabilities were noticed among these three groups and all principal modes of variation. No dominant talar model was found to represent the majority of tali, regardless the gender. Such information is crucial to improve the current understanding of talar pathologies and their treatment strategies.

The grammar of typically developing Oromo-speaking 3-year-olds

This study investigates the grammatical skills of typically developing Oromo-speaking preschool-age children and lays the foundation for a language assessment tool for Oromo, a Cushitic language spoken in Ethiopia. The current study used a standard picture–based elicitation task that evaluated children’s accuracy in producing grammatical utterances. Language samples were collected from 44 monolingual 3- to 4-year-old Oromo children with typical language development. The percentage of grammatical utterances (PGU) was computed and error types were analyzed. The average level of grammatical accuracy as measured by PGU was 69%, with a large amount of variability. The data for Oromo 3-year-olds showed a variety of infrequent error types. The results of the study provide crucial foundational knowledge on grammatical development in Oromo, which could form the basis of future language assessments and diagnostic materials.

Assessment of COVID-19 RT-PCR Positive Symptomatic Patients With Clinical, Hematological, and Radiological Parameters Among Three Groups: A Comparative Study.

Nearly 70.1 million individuals have been infected by the pandemic viral disease known as coronavirus disease 2019 (COVID-19), which was first discovered in China and is caused by a novel coronavirus known as severe acute respiratory syndrome coronavirus 2(SARS‑CoV‑2). This disease is responsible for the deaths of 6 million people. India ranks third in the total number of cases. The purpose of this study was to classify COVID-19 patients according to several criteria and to determine which clinical, hematological, and radiological indicators were most important in their care. An analytical cross-sectionalstudy was conducted on a total of 70 symptomatic patients who tested positive for COVID-19 reverse transcription polymerase chain reaction(RT-PCR)and were hospitalized at the Saveetha Medical College and Hospital in Chennai, Tamil Nadu, India, for the duration of the study. Comorbidities and oxygen reliance were taken into consideration while classifying patients into one of three categories. Initial symptoms, as well as hematological (interleukin-6 (IL-6),erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), D-dimer, serum ferritin, and total cell counts) and radiographic (X-ray and computed tomography (CT) of the thorax) characteristics, were taken and analyzed among the different groups. According to our research, the symptom of fever was the most common, accounting for 84.3% of all cases. This was followed by breathlessness (55.7%), myalgia (31.4%), dry cough (27.1%), sore throat (24.3%), cough with expectoration (20%), loose stools (12.9%), loss of taste (12.9%), and smell (11.4%). Although there was a large amount of variation in D-dimer, with Category C having the highest values, there was only a minor amount of variation in ESR and CRP. The X-ray and CT scans of the chest showed substantial differences between the groups, with CT findings such as COVID-19 Reporting and Data System(CO-RADS)and CT severity score, consolidation, crazy paving pattern, and vascular dilatation showing a wide range of differences between the groups. To facilitate easier treatment and place more attention on radiological characteristics using D-dimer, treating physicians are required to categorize COVID-19 patients into several groups. Patients who need oxygen support were included in this category.

On the relationship between valence and arousal in samples across the globe.

Affect is involved in many psychological phenomena, but a descriptive structure, long sought, has been elusive. Valence and arousal are fundamental, and a key question-the focus of the present study-is the relationship between them. Valence is sometimes thought to be independent of arousal, but, in some studies (representing too few societies in the world) arousal was found to vary with valence. One common finding is that arousal is lowest at neutral valence and increases with both positive and negative valence: a symmetric V-shaped relationship. In the study reported here of self-reported affect during a remembered moment (N = 8,590), we tested the valence-arousal relationship in 33 societies with 25 different languages. The two most common hypotheses in the literature-independence and a symmetric V-shaped relationship-were not supported. With data of all samples pooled, arousal increased with positive but not negative valence. Valence accounted for between 5% (Finland) and 43% (China Beijing) of the variance in arousal. Although there is evidence for a structural relationship between the two, there is also a large amount of variability in this relation. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Retrospective Analysis of Associated Anomalies in 636 Patients with Operatively Treated Congenital Scoliosis.

Congenital scoliosis is frequently associated with anomalies in multiple organ systems. However, the prevalence and distribution of associated anomalies remain unclear, and there is a large amount of variation in data among different studies. Six hundred and thirty-six Chinese patients who had undergone scoliosis correction surgery at Peking Union Medical College Hospital from January 2012 to July 2019 were recruited, as a part of the Deciphering disorders Involving Scoliosis and COmorbidities (DISCO) study. The medical data for each subject were collected and analyzed. The mean age (and standard deviation) at the time of presentation for scoliosis was 6.4 ± 6.3 years, and the mean Cobb angle of the major curve was 60.8° ± 26.5°. Intraspinal abnormalities were found in 186 (30.3%) of 614 patients, with diastematomyelia being the most common anomaly (59.1%; 110 of 186). The prevalence of intraspinal abnormalities was remarkably higher in patients with failure of segmentation and mixed deformities than in patients with failure of formation (p < 0.001). Patients with intraspinal anomalies showed more severe deformities, including larger Cobb angles of the major curve (p < 0.001). We also demonstrated that cardiac anomalies were associated with remarkably worse pulmonary function, i.e., lower forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF). Additionally, we identified associations among different concomitant malformations. We found that patients with musculoskeletal anomalies of types other than intraspinal and maxillofacial were 9.2 times more likely to have additional maxillofacial anomalies. In our cohort, comorbidities associated with congenital scoliosis occurred at a rate of 55%. To our knowledge, our study is the first to show that patients with congenital scoliosis and cardiac anomalies have reduced pulmonary function, as demonstrated by lower FEV1, FVC, and PEF. Moreover, the potential associations among concomitant anomalies revealed the importance of a comprehensive preoperative evaluation scheme. Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Host Tree and Geography Induce Metabolic Shifts in the Epiphytic Liverwort Radula complanata.

Bryophytes are prolific producers of unique, specialized metabolites that are not found in other plants. As many of these unique natural products are potentially interesting, for example, pharmacological use, variations in the production regarding ecological or environmental conditions have not often been investigated. Here, we investigate metabolic shifts in the epiphytic Radula complanata L. (Dumort) with regard to different environmental conditions and the type of phorophyte (host tree). Plant material was harvested from three different locations in Sweden, Germany, and Canada and subjected to untargeted liquid chromatography high-resolution mass-spectrometry (UPLC/ESI-QTOF-MS) and data-dependent acquisition (DDA-MS). Using multivariate statistics, variable selection methods, in silico compound identification, and compound classification, a large amount of variation (39%) in the metabolite profiles was attributed to the type of host tree and 25% to differences in environmental conditions. We identified 55 compounds to vary significantly depending on the host tree (36 on the family level) and 23 compounds to characterize R. complanata in different environments. Taken together, we found metabolic shifts mainly in primary metabolites that were associated with the drought response to different humidity levels. The metabolic shifts were highly specific to the host tree, including mostly specialized metabolites suggesting high levels of ecological interaction. As R. complanata is a widely distributed generalist species, we found it to flexibly adapt its metabolome according to different conditions. We found metabolic composition to also mirror the constitution of the habitat, which makes it interesting for conservation measures.