Structural neuroimaging findings in younger and older adults with major depressive disorder (MDD) are highly heterogeneous, possibly as a result of methodological limitations, lack of distinction ...between MDD and late-life depression (LLD), or clinical moderators. Using a novel meta-analytic network mapping approach, the authors sought to identify the circuits affected in different clinical subtypes of MDD.
The authors identified all voxel-based and surface-based morphometry studies published through October 2020 that compared younger adults with MDD or older adults with LLD to nonpsychiatric control participants. An activation likelihood estimation (ALE) analysis and a novel coordinate-based network mapping approach were used to identify brain circuits affected in MDD and LLD. Meta-regressions examined the impact of age at onset in older patients with LLD and treatment with antidepressants in younger patients with MDD.
The authors analyzed 145 comparisons from 143 articles, including a total of 14,318 participants (MDD: N=6,362; LLD: N=535; control subjects: N=7,421). Significant ALE results confirmed previous findings implicating the left and right parahippocampus and anterior cingulate in MDD and the anterior cingulate in LLD. In contrast, coordinate-based network mapping showed differences in the frontoparietal, dorsal attention, and visual networks both in MDD and LLD. Meta-regressions showed that late onset was significantly associated with widespread structural abnormalities in LLD, and treatment with antidepressants showed a significant association with abnormalities in the anterior cingulate (Brodmann's area 32) and dorsolateral prefrontal cortex (Brodmann's area 9) in MDD.
These findings help to clarify the shared circuitry of depression across the adult lifespan and highlight some unique circuitry relevant to late-onset depression, which may explain some of the risk for cognitive decline and dementia.
Microcellular polymer foams afford a wide variety of attributes relative to their dense analogues, and efforts remain underway to establish viable routes to generate foams with substantially reduced ...pore cell size and increased pore cell density. Barrier constraints are applied in the present work to achieve diffusion-controlled isothermal foaming of thin polymer films in the presence of supercritical carbon dioxide (scCO2). Poly(methyl methacrylate) (PMMA) films measuring ca. 95−100 μm in thickness are physically constrained between two impenetrable plates so that scCO2 exit diffusion is restricted to the film edges. Results obtained here demonstrate that the pore size can be systematically reduced to less than 100 nm in such systems by applying high saturation scCO2 pressures, relatively low foaming temperatures (near the glass transition temperature of the scCO2-plasticized polymer), and a rapid pressure quench. Classical nucleation theory (CNT) modified to account for the compressible nature of scCO2 is used to describe pore cell growth as a function of foaming temperature and scCO2 saturation pressure. Incorporation of a gradient model based on the Sanchez−Lacombe equation of state to account for PMMA−CO2 interfacial tension in conjunction with the CNT yields accurate predictions of foam cell densities as a function of relevant system parameters.
We tested how variation at a gene of adaptive importance, MHC class I (UBA), in a wild, endemic Salmo trutta population compared to that in both a previously studied non-native S. trutta population ...and a co-habiting Salmo salar population (a sister species). High allelic diversity is observed and allelic divergence is much higher than that noted previously for co-habiting S. salar. Recombination was found to be important to population-level divergence. The α1 and α2 domains of UBA demonstrate ancient lineages but novel lineages are also identified at both domains in this work. We also find examples of recombination between UBA and the non-classical locus, ULA. Evidence for strong diversifying selection was found at a discrete suite of S. trutta UBA amino acid sites. The pattern was found to contrast with that found in re-analysed UBA data from an artificially stocked S. trutta population.
PurposeThis paper investigates developing a learning-to-learn capability as a critical success factor for sustainable lean transformation.Design/methodology/approachThis research design is guided by ...our research question: how can suppliers learn to learn as part of a buyer-led collaborative lean transformation? The authors adopt action learning research to generate actionable knowledge from a lean supplier development initiative over a three-year period.FindingsDrawing on emergent insights from the initiative, the authors find that developing a learning-to-learn capability is a core and critical success factor for lean transformation. The authors also find that network action learning has a significant enabling role in buyer-led collaborative lean transformations.Originality/valueThe authors contribute to lean theory and practice by making the distinction between learning about and implementing lean best practices and adopting a learning-to-learn perspective to build organisational capabilities, consistent with lean thinking and practice. Further, the authors contribute to methodology, adopting action learning research to explore learning-to-learn as a critical success factor for sustainable lean transformation.
Genomic conflicts may play a central role in the evolution of reproductive barriers. Theory predicts that early-onset hybrid inviability may stem from conflict between parents for resource allocation ...to offspring. Here, we describe M. decorus: a group of cryptic species within the M. guttatus species complex that are largely reproductively isolated by hybrid seed inviability (HSI). HSI between M. guttatus and M. decorus is common and strong, but populations of M. decorus vary in the magnitude and directionality of HSI with M. guttatus. Patterns of HSI between M. guttatus and M. decorus, as well as within M. decorus, conform to the predictions of parental conflict: first, reciprocal F1s exhibit size differences and parent-of-origin-specific endosperm defects; second, the extent of asymmetry between reciprocal F1 seed size is correlated with asymmetry in HSI; and third, inferred differences in the extent of conflict predict the extent of HSI between populations. We also find that HSI is rapidly evolving, as populations that exhibit the most HSI are each others’ closest relative. Lastly, although all populations appear largely outcrossing, we find that the differences in the inferred strength of conflict scale positively with π, suggesting that demographic or life history factors other than transitions to self-fertilization may influence the rate of parental-conflict-driven evolution. Overall, these patterns suggest the rapid evolution of parent-of-origin-specific resource allocation alleles coincident with HSI within and between M. guttatus and M. decorus. Parental conflict may therefore be an important evolutionary driver of reproductive isolation.
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•Mimulus decorus is a cryptic species complex within the M. guttatus species complex•M. decorus is reproductively isolated from M. guttatus by hybrid seed inviability•Patterns of hybrid seed inviability conform to the predictions of parental conflict•Differences in conflict between species scale with genome-wide diversity
Genomic conflict may play a central role in speciation. Coughlan et al. find that parental conflict may play a role in the evolution of hybrid seed inviability between Mimulus guttatus and a newly discovered species complex M. decorus. Differences in conflict between these lineages may stem from demographic or life history differences.
Objective
Methotrexate has shown efficacy for the treatment of several diseases, especially rheumatoid arthritis (RA). Methotrexate has also been implicated as a causative agent in interstitial lung ...disease. Patients with RA may develop pulmonary manifestations of their disease and are at increased risk of respiratory infection. The aim of this study was to evaluate the relative risk (RR) of pulmonary disease among patients with RA treated with methotrexate.
Methods
We searched the PubMed and Cochrane databases (publication dates January 1, 1990 to February 1, 2013) for double‐blind, randomized, controlled trials of methotrexate versus placebo or active comparator agents in adults with RA. Studies with <100 subjects or with a duration of <24 weeks were excluded. Two investigators independently searched both databases, and all of the investigators reviewed the selected studies. We compared differences in the RR using the Mantel‐Haenszel random‐effects method.
Results
A total of 22 studies with 8,584 participants met the inclusion criteria. Heterogeneity across studies was not significant (I2 = 3%), allowing combination of the trial results. Methotrexate was associated with an increased risk of all adverse respiratory events (RR 1.10, 95% confidence interval 95% CI 1.02−1.19) and respiratory infection (RR 1.11, 95% CI 1.02−1.21). Patients treated with methotrexate were not at increased risk of death due to lung disease (RR 1.53, 95% CI 0.46−5.01) or noninfectious respiratory events (RR 1.02, 95% CI 0.65−1.60). A subgroup analysis of studies in which pneumonitis was described revealed an increased risk associated with methotrexate (RR 7.81, 95% CI 1.76−34.72).
Conclusion
Our study demonstrated a small but significant increase in the risk of lung disease in patients with RA treated with methotrexate compared with other disease‐modifying antirheumatic drugs and biologic agents.
Objective To evaluate the relative risk of pulmonary disease among patients with psoriasis, psoriatic arthritis, and inflammatory bowel disease treated with methotrexate.Data sources PubMed, Cochrane ...central register of controlled trials, and Embase to 9 January 2014.Study selection Double blind randomised controlled trials of methotrexate versus placebo or active comparator agents in adults with psoriatic arthritis, psoriasis, or inflammatory bowel disease. Studies with fewer than 50 participants or of less than 12 weeks’ duration were excluded.Data synthesis Two investigators independently searched both databases. All authors reviewed selected studies. We compared relative risk differences using the Mantel-Haenszel random effects method to assess total respiratory adverse events, infectious respiratory adverse events, non-infectious respiratory adverse events, interstitial lung disease, and death.Results Seven studies met our inclusion criteria, six with placebo as the comparator. Heterogeneity across the studies was not significant (I2=0%), allowing combination of trial results. 504 respiratory adverse events were documented in 1630 participants. Methotrexate was not associated with an increased risk of adverse respiratory events (relative risk 1.03, 95% confidence interval 0.90 to 1.17), respiratory infections (1.02, 0.88 to 1.19), or non-infectious respiratory events (1.07, 0.58 to 1.96). No pulmonary deaths occurred.Conclusions Findings suggested that there was no increased risk of lung disease in methotrexate treated patients with non-malignant inflammatory diseases. Given the limitations of the study, however, we cannot exclude a small but clinically important risk.
Chromosomal inversions can play an important role in adaptation, but the mechanism of their action in many natural populations remains unclear. An inversion could suppress recombination between ...locally beneficial alleles, thereby preventing maladaptive reshuffling with less‐fit, migrant alleles. The recombination suppression hypothesis has gained much theoretical support but empirical tests are lacking. Here, we evaluated the evolutionary history and phenotypic effects of a chromosomal inversion which differentiates annual and perennial forms of Mimulus guttatus. We found that perennials likely possess the derived orientation of the inversion. In addition, this perennial orientation occurs in a second perennial species, M. decorus, where it is strongly associated with life history differences between co‐occurring M. decorus and annual M. guttatus. One prediction of the recombination suppression hypothesis is that loci contributing to local adaptation will predate the inversion. To test whether the loci influencing perenniality pre‐date this inversion, we mapped QTLs for life history traits that differ between annual M. guttatus and a more distantly related, collinear perennial species, M. tilingii. Consistent with the recombination suppression hypothesis, we found that this region is associated with life history in the absence of the inversion, and this association can be broken into at least two QTLs. However, the absolute phenotypic effect of the LG8 inversion region on life history is weaker in M. tilingii than in perennials which possess the inversion. Thus, while we find support for the recombination suppression hypothesis, the contribution of this inversion to life history divergence in this group is likely complex.
Summary
Aquatic birds can facilitate the dispersal of plants, animals, microbes and fungi. Here, we review existing literature on bird‐mediated external (ectozoochorous; synonyms epizoochorous, ...exozoochorous) dispersal to determine the importance of birds as mobile links between aquatic environments, and to evaluate ectozoochory as a mechanism of dispersal for aquatic organisms and their propagules (collectively referred to as dispersal units). Bird‐mediated ectozoochory occurs when dispersal units stick to feathers, feet and bills, become enmeshed within plumage or encapsulated within mud coating the soft parts of vector birds.
The importance of waterbird‐mediated ectozoochorous dispersal relates to the topical problems of increasing anthropogenic habitat fragmentation, climate change and the associated alterations in species distributions and biological invasions. Nevertheless, some aspects of the bird‐mediated ectozoochorous dispersal remain understudied, and poorly understood.
This review identifies two areas where further research is required. Firstly, the quantitative contribution of bird‐mediated ectozoochory to overall dispersal remains unclear. Secondly, greater consideration of all the requirements necessary for successful waterbird‐mediated ectozoochorous dispersal is needed. In particular, the impact of factors which influence attachment and detachment of dispersal units (e.g. dispersal unit densities, preening behaviour and the role of encapsulating mud) needs further examination. Moreover, few investigators have taken the step of examining viability of found dispersal units, and fewer still have examined tolerances of dispersal units to the ‘in‐flight’ conditions experienced during transport, in order to determine probability of survival of external dispersal.
Evidence presented in this review indicates that bird‐mediated ectozoochorous transport of aquatic dispersal units is a frequent process, at least at a local scale, and therefore needs to be considered in the context of connectivity and gene flow between isolated aquatic environments.
Ecological divergence is a fundamental source of phenotypic diversity between closely related species, yet the genetic architecture of most ecologically relevant traits is poorly understood. ...Differences in elevation can impose substantial divergent selection on both complex, correlated suites of traits (such as life-history), as well as novel adaptations. We use the
species complex to assess if the divergence in elevation is accompanied by trait divergence in a group of closely related perennials and determine the genetic architecture of this divergence. We find that divergence in elevation is associated with differences in life-history, as well as a unique trait, the production of rhizomes. The divergence between two perennials is largely explained by few mid-to-large effect quantitative trait loci (QTLs). However, the presence of QTLs with correlated, but opposing effects on multiple traits leads to some hybrids with transgressive trait combinations. Lastly, we find that the genetic architecture of the ability to produce rhizomes changes through development, wherein most hybrids produce rhizomes, but only later in development. Our results suggest that elevational differences may shape life-history divergence between perennials, but aspects of the genetic architecture of divergence may have implications for hybrid fitness in nature.
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