Fatigue-related feedback from calf muscles impairs knee extensor voluntary activation

INTRODUCTION: Fatigue-related group III/IV muscle afferent firing from agonist, antagonist or distal muscles impairs the ability to drive the elbow flexors maximally, that is, reduces voluntary activation. In the lower limb, the effect of feedback from distal muscles on the proximal knee extensors is unknown. Here, we test whether maintained group III/IV afferent feedback from the plantarflexor muscles reduces voluntary activation of the knee extensors. METHODS: On 2 d, voluntary activation of the knee extensors during maximal voluntary contractions (MVCs) was assessed in 12 participants before and after a 3-min fatiguing task of the plantarflexors. On 1 d, an inflatable cuff around the calf occluded blood flow for 2 min immediately postexercise (cuff day). The other day had no occlusion (no-cuff day). Supramaximal stimulation of the femoral nerve elicited superimposed twitches during MVC of the knee extensors and resting twitches 2 to 3 s after relaxation. Pain (0-10 point scale) was reported throughout. RESULTS: In the 2 min after the 3-min fatiguing plantarflexor task, voluntary activation was 5.3% (SD, 7%) lower on the cuff day than on the no-cuff day (P = 0.045), and MVC force was reduced by 13% (SD, 16%) (P = 0.021). The resting twitch was similar on both days (P = 0.98). Pain rated 4.9 points higher with the cuff inflated (P = 0.001). CONCLUSIONS: Maintained group III/IV afferent feedback from the fatigued plantarflexor muscles reduced maximal force and voluntary activation of the unfatigued knee extensors, suggesting that afferents from the calf act centrally to inhibit the ability to drive the motoneurones of the knee extensors

Topical, geospatial, and temporal diffusion of the 2015 North American Menopause Society position statement on nonhormonal management of vasomotor symptoms

OBJECTIVE: We sought to depict the topical, geospatial, and temporal diffusion of the 2015 North American Menopause Society position statement on the nonhormonal management of menopause-associated vasomotor symptoms released on September 21, 2015, and its associated press release from September 23, 2015. METHODS: Three data sources were used: online news articles, National Public Radio, and Twitter. For topical diffusion, we compared keywords and their frequencies among the position statement, press release, and online news articles. We also created a network figure depicting relationships across key content categories or nodes. For geospatial diffusion within the United States, we compared locations of the 109 National Public Radio (NPR) stations covering the statement to 775 NPR stations not covering the statement. For temporal diffusion, we normalized and segmented Twitter data into periods before and after the press release (September 12, 2015 to September 22, 2015 vs September 23, 2015 to October 3, 2015) and conducted a burst analysis to identify changes in tweets from before to after. RESULTS: Topical information diffused across sources was similar with the exception of the more scientific terms "vasomotor symptoms" or "vms" versus the more colloquial term "hot flashes." Online news articles indicated media coverage of the statement was mainly concentrated in the United States. NPR station data showed similar proportions of stations airing the story across the four census regions (Northeast, Midwest, south, west; P = 0.649). Release of the statement coincided with bursts in the menopause conversation on Twitter. CONCLUSIONS: The findings of this study may be useful for directing the development and dissemination of future North American Menopause Society position statements and/or press releases

Sexual selection and the evolution of condition-dependence: an experimental test at two resource levels

Stronger condition-dependence in sexually selected traits is well-documented, but how this relationship is established remains unknown. Moreover, resource availability can shape responses to sexual selection, but resource effects on the relationship between sexual selection and condition-dependence are also unknown. In this study, we directly test the hypotheses that sexual selection drives the evolution of stronger-condition-dependence and that resource availability affects the outcome, by evolving fruit flies (Drosophila melanogaster) under relatively strong or weak sexual selection (through varied sex ratios) and at resource-poor or resource-rich adult diets. We then experimentally manipulated condition via developmental diet and assessed condition-dependence in adult morphology, behavior, and reproduction. We observed stronger condition-dependence in female size in male-biased populations and in female ovariole production in resource-limited populations. However, we found no evidence that male condition-dependence increased in response to sexual selection, or that responses depended on resource levels. These results offer no support for the hypotheses that sexual selection increases male condition-dependence or that sexual selection's influence on condition-dependence is influenced by resource availability. Our study is, to our knowledge, the first experimental test of these hypotheses. If the results we report are general, then sexual selection's influence on the evolution of condition-dependence may be less important than predicted

Potential ecological impacts of climate intervention by reflecting sunlight to cool Earth

As the effects of anthropogenic climate change become more severe, several approaches for deliberate climate intervention to reduce or stabilize Earth’s surface temperature have been proposed. Solar radiation modification (SRM) is one potential approach to partially counteract anthropogenic warming by reflecting a small proportion of the incoming solar radiation to increase Earth’s albedo. While climate science research has focused on the predicted climate effects of SRM, almost no studies have investigated the impacts that SRM would have on ecological systems. The impacts and risks posed by SRM would vary by implementation scenario, anthropogenic climate effects, geographic region, and by ecosystem, community, population, and organism. Complex interactions among Earth’s climate system and living systems would further affect SRM impacts and risks. We focus here on stratospheric aerosol intervention (SAI), a well-studied and relatively feasible SRM scheme that is likely to have a large impact on Earth’s surface temperature. We outline current gaps in knowledge about both helpful and harmful predicted effects of SAI on ecological systems. Desired ecological outcomes might also inform development of future SAI implementation scenarios. In addition to filling these knowledge gaps, increased collaboration between ecologists and climate scientists would identify a common set of SAI research goals and improve the communication about potential SAI impacts and risks with the public. Without this collaboration, forecasts of SAI impacts will overlook potential effects on biodiversity and ecosystem services for humanity

Reviews

George MacDonald: Divine Carelessness and Fairytale Levity. Daniel Gabelman. Reviewed by Bonnie Gaarden. The Gender Dance: Ironic Subversion in C.S. Lewis\u27s Cosmic Trilogy. Monika B. Hilder. Preface by Matthew Dickerson. Reviewed by Joe R. Christopher. Sir Gawain and the Green Knight: In a Modern English Version with a Critical Introduction. John Gardner. Reviewed by Perry Neil Harrison. Myths of Light: Eastern Metaphors of the Eternal. Joseph Campbell. Reviewed by Christopher Tuthill. The Riddles of the Hobbit. Adam Roberts. Reviewed by Jon Garrad. The Modern Literary Werewolf: A Critical Study of the Mutable Motif. Brent A. Stypczynski. Reviewed by Sharon L. Bolding. Fairy Tales Reimagined: Essays on New Retellings. Ed. by Susan Redington Bobby. Reviewed by Kazia Estrada. C.S. Lewis\u27s Perelandra: Reshaping the Image of the Cosmos. Ed. Judith Wolfe and Brendan Wolfe. Reviewed by Holly Ordway. The Ideal of Kingship in the Writings of Charles Williams, C.S. Lewis, and J.R.R. Tolkien: Divine Kingship is Reflected in Middle-Earth. Christopher Scarf. Reviewed by Melody Green. The Ring of Words: Tolkien and the Oxford English Dictionary. By Peter Gilliver, Jeremy Marshall, and Edmund Weiner. Reviewed by Mike Foster. Tolkien: The Forest and the City. Ed. Helen Conrad-O\u27Briain and Gerard Hynes. Reviewed by T.S. Miller. Tolkien Studies X. Edited by Michael D.C. Drout, Verlyn Flieger, and David Bratman. Reviewed by Janet Brennan Croft. Seven: An Anglo-American Literary Review 30. Edited by Marjorie Lamp Mead. Reviewed by Janet Brennan Croft

Recovery from Covid-19 critical illness:a secondary analysis of the ISARIC4C CCP-UK cohort study and the RECOVER trial

Background: We aimed to compare the prevalence and severity of fatigue in survivors of Covid-19 versus non-Covid-19 critical illness, and to explore potential associations between baseline characteristics and worse recovery. Methods: We conducted a secondary analysis of two prospectively collected datasets. The population included was 92 patients who received invasive mechanical ventilation (IMV) with Covid-19, and 240 patients who received IMV with non-Covid-19 illness before the pandemic. Follow-up data was collected post-hospital discharge using self-reported questionnaires. The main outcome measures were self-reported fatigue severity and the prevalence of severe fatigue (severity >7/10) 3 to 12-months post-hospital discharge. Results: Covid-19 IMV-patients were significantly younger with less prior comorbidity, and more males, than pre-pandemic IMV-patients. At 3-months, the prevalence (38.9% [7/18] vs. 27.1% [51/188]) and severity (median 5.5/10 vs. 5.0/10) of fatigue was similar between the Covid-19 and pre-pandemic populations respectively. At 6-months, the prevalence (10.3% [3/29] vs. 32.5% [54/166]) and severity (median 2.0/10 vs. 5.7/10) of fatigue was less in the Covid-19 cohort. In the total sample of IMV-patients included (i.e. all Covid-19 and pre- pandemic patients), having Covid-19 was significantly associated with less severe fatigue (severity <7/10) after adjusting for age, sex, and prior comorbidity (adjusted OR 0.35 (95%CI 0.15-0.76, p=0.01). Conclusion: Fatigue may be less severe after Covid-19 than after other critical illness

The politics of the teaching of reading

Historically, political debates have broken out over how to teach reading in primary schools and infant classrooms. These debates and “reading wars” have often resulted from public concerns and media reportage of a fall in reading standards. They also reflect the importance placed on learning to read by parents, teachers, employers, and politicians. Public and media-driven controversies over the teaching of reading have resulted in intense public and professional debates over which specific methods and materials to use with beginning readers and with children who have reading difficulties. Recently, such debates have led to a renewed emphasis on reading proficiency and “standardized” approaches to teaching reading and engaging with literacy. The universal acceptance of the importance of learning to read has also led to vested interests in specific methods, reading programmes, and early literacy assessments amongst professional, business, commercial, and parental lobbying groups. This article traces these debates and the resulting growing support for a quantitative reductionist approach to early-reading programmes

Pathways to care with HIV-associated cryptococcal meningitis in Botswana and Uganda: Findings from a qualitative methods study.

HIV-associated cryptococcal meningitis remains a key driver of AIDS-related mortality. Mortality is twice as high in those who present later to care and with severe symptoms such as confusion. We embedded a qualitative methods study within a randomised controlled trial in Gaborone, Botswana and Kampala, Uganda with the aim of understanding pathways to care. We conducted in-depth interviews with trial participants and surrogate decision makers and analysed data thematically. Between January 2020 and June 2021 we interviewed 58 individuals. Pathways to care were prolonged because headaches were disregarded by participants and healthcare workers as a common occurrence with a broad differential diagnosis of predominantly benign aetiologies. There was also a lack of awareness of cryptococcal meningitis, and it was often after HIV was diagnosed or disclosed that the pathway accelerated, resulting in hospital admission. We outline key recommendations to reduce mortality and argue for the integration of social and behavioural interventions within differentiated service delivery models for advanced HIV disease

Connectivity between the superior colliculus and the amygdala in humans and macaque monkeys:Virtual dissection with probabilistic DTI tractography

It has been suggested that some cortically blind patients can process the emotional valence of visual stimuli via a fast, subcortical pathway from the superior colliculus (SC) that reaches the amygdala via the pulvinar. We provide in vivo evidence for connectivity between the SC and the amygdala via the pulvinar in both humans and rhesus macaques. Probabilistic diffusion tensor imaging tractography revealed a streamlined path that passes dorsolaterally through the pulvinar before arcing rostrally to traverse above the temporal horn of the lateral ventricle and connect to the lateral amygdala. To obviate artifactual connectivity with crossing fibers of the stria terminalis, the stria was also dissected. The putative streamline between the SC and amygdala traverses above the temporal horn dorsal to the stria terminalis and is positioned medial to it in humans and lateral to it in monkeys. The topography of the streamline was examined in relation to lesion anatomy in five patients who had previously participated in behavioral experiments studying the processing of emotionally valenced visual stimuli. The pulvinar lesion interrupted the streamline in two patients who had exhibited contralesional processing deficits and spared the streamline in three patients who had no deficit. Although not definitive, this evidence supports the existence of a subcortical pathway linking the SC with the amygdala in primates. It also provides a necessary bridge between behavioral data obtained in future studies of neurological patients, and any forthcoming evidence from more invasive techniques, such as anatomical tracing studies and electrophysiological investigations only possible in nonhuman species

Durvalumab (MEDI 4736) in combination with extended neoadjuvant regimens in rectal cancer : a study protocol of a randomised phase II trial (PRIME-RT)

Acknowledgements We are grateful to Mr George Davidson and Ms Monica Jeffers for their input with writing the PRIME-RT protocol and patient information sheet. This study is co-sponsored by the University of Glasgow and NHS Greater Glasgow and Clyde. Funding PRIME-RT is funded by Astrazeneca and receives core funding from CRUK Clinical Trials Unit Glasgow for the purposes of trial set-up and data collection. The trial is co-sponsored by the University Of Glasgow and NHS Greater Glasgow and Clyde.Peer reviewedPublisher PD