19683 research outputs found
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Delayed leaf greening involves a major shift in the expression of cytosolic and mitochondrial ribosomes to plastid ribosomes in the highly phosphorus-use-efficient Hakea prostrata (Proteaceae)
No full textBackground and aims: Hakea prostrata (Proteaceae) is a highly phosphorus-use-efficient plant native to southwest Australia. It maintains a high photosynthetic rate at low leaf phosphorus (P) and exhibits delayed leaf greening, a convergent adaptation that increases nutrient-use efficiency. This study aimed to provide broad physiological and gene expression profiles across leaf development, uncovering pathways leading from young leaves as nutrient sinks to mature leaves as low-nutrient, energy-transducing sources. Methods: To explore gene expression underlying delayed greening, we analysed a de novo transcriptome for H. prostrata across five stages of leaf development. Photosynthesis and respiration rates, and foliar pigment, P and nitrogen (N) concentrations were determined, including the division of P into five biochemical fractions. Key results: Transcripts encoding functions associated with leaf structure generally decreased in abundance across leaf development, concomitant with decreases in foliar concentrations of 85% for anthocyanins, 90% for P and 70% for N. The expression of genes associated with photosynthetic function increased during or after leaf expansion, in parallel with increases in photosynthetic pigments and activity, much later in leaf development than in species that do not have delayed greening. As leaves developed, transcript abundance for cytosolic and mitochondrial ribosomal proteins generally declined, whilst transcripts for chloroplast ribosomal proteins increased. Conclusions: There was a much longer temporal separation of leaf cell growth from chloroplast development in H. prostrata than is found in species that lack delayed greening. Transcriptome-guided analysis of leaf development in H. prostrata provided insight into delayed greening as a nutrient-saving strategy in severely phosphorus-impoverished landscapes
Genome-based tools for onchocerciasis elimination: utility of the mitochondrial genome for delineating Onchocerca volvulus transmission zones
No full textNational programs in Africa have expanded their objectives from control of onchocerciasis (river blindness) as a public health problem to elimination of parasite transmission, motivated by the reduction of Onchocerca volvulus infection prevalence in many African meso- and hyperendemic areas due to mass drug administration of ivermectin (MDAi). Given the large, contiguous hypo-, meso-, and hyperendemic areas, sustainable elimination of onchocerciasis in sub-Saharan Africa requires delineation of geographic boundaries for parasite transmission zones, so that programs can consider the risk of parasite re-introduction through vector or human migration from areas with ongoing transmission when making decisions to stop MDAi. We propose that transmission zone boundaries can be delineated by characterising the parasite genetic population structure within and between potential zones. We analysed whole mitochondrial genome sequences of 189 O. volvulus adults to determine the pattern of genetic similarity across three West African countries: Ghana, Mali, and Côte d'Ivoire. Population genetic structure indicates that parasites from villages near the Pru, Daka, and Black Volta rivers in central Ghana belong to one parasite population, indicating that the assumption that river basins constitute individual transmission zones is not supported by the data. Parasites from Mali and Côte d'Ivoire are genetically distinct from those from Ghana. This research provides the basis for developing tools for elimination programs to delineate transmission zones, to estimate the risk of parasite re-introduction via vector or human movement when intervention is stopped in one area while transmission is ongoing in others, to identify the origin of infections detected post-treatment cessation, and to investigate whether persisting prevalence despite ongoing interventions in one area is due to parasites imported from others
The trauma challenge: How teachers experience students with complex trauma
No full textResearch documenting the effects of trauma in early childhood describes the profound and long-term consequences of child abuse and neglect on the developing brain and the subsequent deficits in critical cognitive and social development. While educators have increasingly endeavoured to understand this impact and become more ‘trauma-informed’ in their classrooms, little is understood about the process or what it requires of the teacher. This study explores the experiences of six teachers in regional Victoria, Australia, who sought to apply their neuroscientific understandings in their classrooms, and identifies the many personal and professional challenges they confronted. Critical reflection was employed both to deeply explore their collective experiences and to support them in this complex work. Findings describe the nuanced and interpersonal nature of trauma-informed education and imply the need for critical reflection in teacher practice as an important element in the process
Under the Gun: Percussive Massage Therapy and Physical and Perceptual Recovery in Active Adults
No full textCONTEXT: Handheld percussive massage devices (ie, massage guns) are a relatively new and under-researched recovery tool. These tools are intended to increase range of motion and reduce muscle soreness by delivering targeted vibration to soft tissues. Empirical knowledge about the potential influence of these devices on perceptual recovery and the recovery of performance characteristics after exercise is scarce. OBJECTIVE: To investigate the effect of a 5-minute massage gun application, using a commercially available device, on physical and perceptual recovery after a strenuous bout of lower body exercise. DESIGN: Controlled laboratory study. SETTING: Physiology laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 65 active young adults (age = 21.3 ± 1.4 years; age range = 18-30 years; 34 women: height = 165.8 ± 6.1 cm, mass = 66.0 ± 7.4 kg; 31 men: height = 181.1 ± 6.0 cm, mass = 81.5 ± 11.8 kg). INTERVENTION(S): Participants applied a massage gun on the calf muscles of 1 leg after strenuous exercise (massage gun recovery group) for 5 minutes and used no recovery intervention on the other leg (control group). MAIN OUTCOME MEASURE(S): Ankle range of motion, calf circumference, isometric strength, calf endurance, and perceived muscle soreness measures were collected at baseline and at various points after lower body exercise. RESULTS: No significant group × time interactions were recorded for any of the performance or perceptual measures (P values > .05). Effect sizes were mostly unclear, except for a small increase in perceived muscle soreness in the massage gun recovery group compared with the control group immediately (d = -0.35) and 4 hours (d = -0.48) postrecovery. CONCLUSIONS: Massage guns appeared to have little effect on physical measures when applied for 5 minutes immediately after strenuous calf exercise. Given the small increase in muscle soreness up to 4 hours after their use, caution is recommended when using massage guns immediately after strenuous lower body exercise.</p
Learning from artificial intelligence researchers about international business implications
No full textArtificial intelligence is a dynamic and emerging form of technological innovation that has numerous ramifications for international business managers. The aim of this article is to obtain commentary from researchers about the role artificial intelligence will play in the global arena. This includes asking questions about how it will affect internationalization processes and whether it will lead to more international collaboration. Well-known researchers provide advice on what international business managers should do in terms of staying competitive but also how they can integrate learning from artificial intelligence into their business operations. Lastly, suggestions for future research regarding the interplay between international business and artificial intelligence are provided
Mind the gap! Gender differences in alcohol consumption among Swedish ninth graders 1989–2021
No full textIntroduction: To examine gender differences in drinking habits among Swedish ninth graders over the period 1989–2021. Methods: Annual school surveys with nationally representative samples of ninth-grade students in Sweden covering the period 1989–2021, total sample of 180,538 students. Drinking habits were measured with self-reports of frequency and quantity of use and frequency of heavy episodic drinking. Differences between genders were compared annually and differences were tested using logistic and ordinary least square regression models with cluster robust standard errors. Results: Small gender differences in the prevalence of alcohol use during the first part of the study period were followed by an increasing gap over the past decade with girls being more likely to drink alcohol than boys. Boys consumed larger amounts of alcohol than girls during the first three decades of the studied period but no gender differences were found in later years. Binge drinking was more prevalent among boys during 1989 to 2000 but no systematic gender difference was found during the past 15 years. Discussion and Conclusions: There used to be clear gender differences in drinking habits among ninth graders in Sweden with boys drinking more than girls. This gap has narrowed over the past three decades and among contemporary adolescents, no gender differences are found neither in binge drinking nor volume of drinking and the prevalence of drinking is even higher among girls
Tumor-infiltrating mast cells stimulate ICOS+regulatory T cells through an IL-33 and IL-2 axis to promote gastric cancer progression
No full textIntroduction: In solid tumors, regulatory T cell (Treg) and mast cell perform different roles depending on the microenvironment. Nevertheless, mast cell and Treg-mediated interactions in gastric cancer (GC) are unclear, as are their regulation, function, and clinical significance. Objective: The present study demonstrated the mechanism of tumor-infiltrating mast cells stimulating ICOS+ regulatory T cells via the IL-33/IL-2 axis to promote the growth of gastric cancer. Methods: Analyses of 98 patients with GC were conducted to examine mast cell counts, ICOS+ Tregs, and the levels of IL-33 or IL-2. Isolated ICOS+ Treg and CD8+ T cell were stimulated, cultured and tested for their functional abilities in vitro and in vivo. Results: GC patients exhibited a significantly more production of IL-33 in tumors. Mast cell stimulated by tumor-derived IL-33 exhibited a prolonged lifespan through IL-33 mediated inhibition of apoptosis. Moreover, mast cells stimulated by tumor-derived IL-33 secreted IL-2, which induced Treg expansion. These inducible Tregs displayed an activated immunosuppressive phenotype with positive expression for the inducible T cell co-stimulator (ICOS). In vitro, IL-2 from IL to 33-stimulated mast cells induced increased numbers of ICOS+ Tregs with increased immunosuppressive activity against proliferation and effector function of CD8+ T cell. In vivo, ICOS+ Tregs were treated with anti-IL-2 neutralizing antibody followed by co-injection with CD8+ T cells in GC mouse model, which showed an increased CD8+ T cell infiltration and effector molecules production, meanwhile tumor growth and progression were inhibited. Besides, reduction in GC patient survival was associated with tumor-derived ICOS+ Tregs. Conclusion: Our results highlight a crosstalk between GC-infiltrating mast cells and ICOS+ Tregs and provide a novel mechanism describing ICOS+ Treg expansion and induction by an IL-33/mast cell/IL-2 signaling axis in GC, and also provide functional evidence that the modulation of this immunosuppressive pathway can attenuate GC-mediated immune tolerance
Temporal dynamics in the composition of bird communities along a gradient of farmland restoration
No full textRevegetation plantings are a key activity in farmland restoration and are commonly assumed to support biotic communities that, with time, replicate those of reference habitats. Restoration outcomes, however, can be highly variable and difficult to predict; hence there is value in quantifying restoration success to improve future efforts. We test the expectation that, over time, revegetation will restore bird communities to match those in reference habitats; and assess whether specific planting attributes enhance restoration success. We surveyed birds in 255 sites in south-east Australia, arranged along a restoration gradient encompassing three habitat types: unrestored farmland (paddocks), revegetation plantings (comprising a chronosequence up to 52 years old) and reference habitats (remnant native vegetation). Surveys were undertaken in 2006/2007 and again in 2019, with data used to compare bird assemblages between habitat types. We also determined whether, in the intervening 12 years, bird communities in revegetation had shifted toward reference habitats on the restoration gradient. Our results showed that each habitat contained a unique bird community and that, over time, assemblages in revegetation diverged away from those in unrestored farmland and converged toward those in reference habitats. Two planting attributes influenced this transition: the bird assemblages of revegetation were more likely to have diverged away from those of unrestored farmland (with scattered mature trees) 12 years later if they were located in areas with more surrounding tree cover, and were mostly ungrazed by livestock (compared with grazed plantings). Our results highlight three key ways in which revegetation contributes to farmland restoration: (1) by supporting richer and more diverse bird assemblages than unrestored farmland, (2) by enhancing beta diversity in rural landscapes through the addition of a unique bird community, and (3) by shifting bird assemblages toward those found in reference habitats over time. However, revegetation plantings did not replicate reference habitats by ~40–50 years in our region, and complete convergence may take centuries. These findings have implications for environmental offset programs and mean that effective conservation in farmland environments depends on the retention and protection of natural and seminatural habitats as a parallel management strategy to complement restoration.</p
Phosphate starvation regulates cellulose synthesis to modify root growth
No full textIn the model plant Arabidopsis (Arabidopsis thaliana), the absence of the essential macro-nutrient phosphate reduces primary root growth through decreased cell division and elongation, requiring alterations to the polysaccharide-rich cell wall surrounding the cells. Despite its importance, the regulation of cell wall synthesis in response to low phosphate levels is not well understood. In this study, we show that plants increase cellulose synthesis in roots under limiting phosphate conditions, which leads to changes in the thickness and structure of the cell wall. These changes contribute to the reduced growth of primary roots in low-phosphate conditions. Furthermore, we found that the cellulose synthase complex (CSC) activity at the plasma membrane increases during phosphate deficiency. Moreover, we show that this increase in the activity of the CSC is likely due to alterations in the phosphorylation status of cellulose synthases in low-phosphate conditions. Specifically, phosphorylation of CELLULOSE SYNTHASE 1 (CESA1) at the S688 site decreases in low-phosphate conditions. Phosphomimic versions of CESA1 with an S688E mutation showed significantly reduced cellulose induction and primary root length changes in low-phosphate conditions. Protein structure modeling suggests that the phosphorylation status of S688 in CESA1 could play a role in stabilizing and activating the CSC. This mechanistic understanding of root growth regulation under limiting phosphate conditions provides potential strategies for changing root responses to soil phosphate content
The experiences of a regional Aboriginal community accessing primary health care during times of crisis
No full textIntroduction: The importance of primary health care (PHC) to Aboriginal Australians is widely acknowledged, as is the underservicing of the Aboriginal Australian population. Aboriginal People continue to face significant obstacles when accessing and using health care services. Objective: This study identifies environmental factors (beyond personal and service delivery) that functioned as barriers and enablers to Aboriginal Australians' experiences accessing PHC during crises and recommends approaches during future events. Design: This research utilised a case study approach. Data were collected through in-depth interviews and analysed using thematic analysis. The study was set in Lakes Entrance, a regional Victorian locality with a sizable Aboriginal community, which was affected by bushfires during 2019/2020 and COVID-19 restrictions during 2020-2021. Participants were 18 Aboriginal People over the age of 18 living in the locality during either bushfires or COVID-19. Findings: The barriers identified included the impact on PHC access of priorities other than health, including housing; financial constraints; difficulties with transport; medical bureaucracy and the physical environment of the health care setting, including appointment-making processes; interactions with medical reception staff; and waiting room environments. Enablers identified included the supportive role of the local Aboriginal Community Controlled Health Organisations (ACCHO) and their staff, which was highlighted in participant responses. Discussion: The preference of many Aboriginal people to access PHC via their local ACCHO, rather than mainstream health care services, appears even more salient during crises than in normal times. This research identified that ACCHOs are ideally placed to promote and protect the health of Aboriginal communities during crises. Conclusion: Results may help direct interventions to improve PHC access and experiences for regional Aboriginal communities both during and outside periods of crisis