growth loss
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2022 ◽  
Author(s):  
Minh-Hoang Nguyen ◽  
Thomas E. Jones

The rapidly declining biosphere integrity, representing one of the core planetary boundaries, is alarming. One of the most widely accepted measures to halt the rate of biodiversity loss is to maintain and expand protected areas that are effectively managed. However, it requires substantial finance derived from nature-based tourism, specifically visitors from urban areas. Using the Bayesian Mindsponge Framework (BMF) on 535 Vietnamese urban residents, the current study examined how their biodiversity loss perceptions can affect their willingness to pay for the entrance fee and conservation in protected areas. We found that perceived environmental degradation, loss of economic growth, loss of nature-based recreation opportunity, and loss of knowledge as consequences of biodiversity loss has indirect effects on paying willingness through the mediation of the attitude towards conservation. Especially, the perceived knowledge loss also has a direct positive influence on the willingness to pay for the entrance fee and conservation. In contrast, perceived loss of health is negatively associated with the attitude towards conservation. Based on these findings, we suggest that building an eco-surplus culture among urban residents can be a promising way to generate more finance from nature-based tourism for conservation in protected areas and ease the domestic government’s and international organizations’ funding allocations problems.


2021 ◽  
Author(s):  
Sanjoy Paul ◽  
Paul Bowyer ◽  
Michael John Bromley ◽  
W. Scott Moye-Rowley

The production of a collection of disruption mutant strains corresponding to a large number of transcription factors from the filamentous fungal pathogen Aspergillus fumigatus has permitted rapid identification of transcriptional regulators involved in a range of different processes. Here we characterize a gene designated ffmA (favors fermentative metabolism) as an C2H2-containing transcription factor that is required for azole drug resistance and normal growth. Loss of ffmA caused cells to exhibit significant defects in growth, either under untreated or azole-challenged conditions. Loss of FfmA caused a reduction in expression of the AbcG1 ATP-binding cassette transporter, previousy shown to contribute to azole resistance. Strikingly, overproduction of the AtrR transcription factor gene restored a wild-type growth phenotype to a ffmAD strain. Overexpression of AtrR also suppressed the defect in AbcG1 expression caused by loss of FfmA.  Replacement of the ffmA promoter with a doxycycline-repressible promoter restored near normal growth in the absence of doxycycline. Finally, chromatin immunoprecipitation experiments indicated that FfmA bound to its own promoter as well as to the abcG1 promoter. These data imply that FfmA and AtrR interact both with respect to abcG1 expression and also more broadly to regulate hyphal growth.


2021 ◽  
Vol 15 ◽  
Author(s):  
Keqin Li ◽  
Shuai Shao ◽  
Tongjie Ji ◽  
Min Liu ◽  
Lufeng Wang ◽  
...  

Capicua (Cic), a transcriptional repressor frequently mutated in brain cancer oligodendroglioma, is highly expressed in adult neurons. However, its function in the dendritic growth of neurons in the hippocampus remains poorly understood. Here, we confirmed that Cic was expressed in hippocampal neurons during the main period of dendritogenesis, suggesting that Cic has a function in dendrite growth. Loss-of-function and gain-of function assays indicated that Cic plays a central role in the inhibition of dendritic morphogenesis and dendritic spines in vitro. Further studies showed that overexpression of Cic reduced the expression of Ets in HT22 cells, while in vitro knockdown of Cic in hippocampal neurons significantly elevated the expression of Ets. These results suggest that Cic may negatively control dendrite growth through Ets, which was confirmed by ShRNA knockdown of either Etv4 or Etv5 abolishing the phenotype of Cic knockdown in cultured neurons. Taken together, our results suggest that Cic inhibits dendritic morphogenesis and the growth of dendritic spines through Ets.


Author(s):  
Cathlene Hillier

Parent engagement is often promoted as a remedy for reducing achievement gaps between students from high socio-economic and low socio-economic backgrounds. However, researchers have found mixed results when examining parent engagement and student outcomes. Drawing on a study investigating the effectiveness of summer literacy camps offered by schools in Ontario, I compare the influence of parent engagement on two outcomes: (1) spring snapshot of cumulative learning, and (2) summer literacy growth/loss. In considering summer learning in regression analysis, I aim to investigate the effect of parent engagement without the influence of schools during the academic year. Out of 14 parent engagement measures, I find only three (parents’ aspirations, home resources, discussions of school with children) are positive predictors of spring literacy outcomes and that none predict summer literacy growth/loss. Family socio-economic status remains a powerful predictor of achievement for both outcomes. I interpret my findings within three proposed mechanisms of parent engagement: cultivation ethic, realist reaction, and expressive logic. Keywords: parent engagement, literacy achievement, socio-economic status, inequality, summer learning, summer literacy camp(s)


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jen Nguyen ◽  
Vicente Fernandez ◽  
Sammy Pontrelli ◽  
Uwe Sauer ◽  
Martin Ackermann ◽  
...  

AbstractIt has long been known that bacteria coordinate their physiology with their nutrient environment, yet our current understanding offers little intuition for how bacteria respond to the second-to-minute scale fluctuations in nutrient concentration characteristic of many microbial habitats. To investigate the effects of rapid nutrient fluctuations on bacterial growth, we couple custom microfluidics with single-cell microscopy to quantify the growth rate of E. coli experiencing 30 s to 60 min nutrient fluctuations. Compared to steady environments of equal average concentration, fluctuating environments reduce growth rate by up to 50%. However, measured reductions in growth rate are only 38% of the growth loss predicted from single nutrient shifts. This enhancement derives from the distinct growth response of cells grown in environments that fluctuate rather than shift once. We report an unexpected physiology adapted for growth in nutrient fluctuations and implicate nutrient timescale as a critical environmental parameter beyond nutrient identity and concentration.


2020 ◽  
Author(s):  
Jen Nguyen ◽  
Vicente Fernandez ◽  
Sammy Pontrelli ◽  
Uwe Sauer ◽  
Martin Ackermann ◽  
...  

AbstractIt has been long known that bacteria coordinate their physiology with environmental nutrient, yet our current understanding offers little intuition for how bacteria respond to the second-to-minute scale fluctuations in nutrient concentration characteristic of many microbial habitats. To investigate the effects of rapid nutrient fluctuations on bacterial growth, we coupled custom microfluidics with single-cell microscopy to quantify the growth rate of E. coli experiencing 30 s to 60 min nutrient fluctuations. Compared to steady environments of equal average concentration, fluctuating environments reduced growth rate by up to 50%. However, measured reductions in growth rate were only 38% of the growth loss predicted from single nutrient shifts — an enhancement produced by the distinct growth response of cells grown in environments that fluctuate rather than shift once. We report an unexpected physiology adapted for growth in nutrient fluctuations and implicate nutrient timescale as a critical environmental parameter beyond nutrient concentration and source.


Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 639
Author(s):  
Shah Rukh ◽  
Werner Poschenrieder ◽  
Michael Heym ◽  
Hans Pretzsch

Frequency of drought years is expected to increase through climate warming. Mixed stands have often shown to be more productive than monospecific stands in terms of yield and of resistance against windthrows and bark beetle attacks. Mixture of beech and spruce is of particular interest. However, little is known about its growth reaction to drought. Therefore, we investigated the drought reaction of beech and spruce in mixed vs. monospecific stands along an ecological gradient. In particular, we sought evidence for mixture-related resilience on the individual tree level. Therefore, we quantified the response of tree ring width to drought. Moreover, we attempted to explain the relevance of individual tree response on the stand level by quantifying the stand level loss of volume growth after drought. At the individual tree level, beech was found to be more resilient and resistant in pure vs. mixed stands. Spruce, in contrast, was favored by mixture, and this was especially evident on drier sites. Along the gradient, growth losses at stand level increased in both mixed and pure stands in 2015, with growth gains on the drier sites observed in the same drought year, in accordance with the Stress Gradient Hypothesis. However, the stand level difference of growth loss between mixed and pure stands was not statistically significant. Mitigating mixture effects on the level of the individual tree thus did not become evident on the level of the whole stand.


2020 ◽  
Vol 50 (4) ◽  
pp. 380-389
Author(s):  
Julie Losseau ◽  
Mathieu Jonard ◽  
Caroline Vincke

Since 2013, pedunculate oak (Quercus robur L.) mortality has been observed in the Ardennes region of Belgium. We aimed to understand the current decline by retrospectively (1945–2015) studying radial growth patterns of trees classified by three health statuses (reference, declining, and dying) and by linking them to abiotic and biotic hazard history, which we recorded and quantified. Our results show that oak mortality in the Ardennes is a long-term process, with 1987 as a tipping point for growth trajectories of declining and dying trees. That year was preceded by two growth crises (1976–1981 and 1984–1987), and it falls within the last major episode of oak decline in Belgium. Among hazards, very cold winters and caterpillar outbreaks have significant impacts on growth-pattern differentiation. Apart from 1976, extreme drought is still rare; however, mild spring droughts, especially in the years n − 1 and n − 2, explain some of the growth loss relative to the reference trees. Finally, masting appears to be an important contributing factor for the death of weakened trees. Given the direct and delayed impacts of the extreme drought of 1976 and subsequent water balance impairment due to winter frosts and mild spring droughts, the health of pedunculate oak is giving cause for concern in the context of climate change.


Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 208
Author(s):  
Mary Anne S. Sayer ◽  
Michael C. Tyree ◽  
Eric A. Kuehler ◽  
John K. Jackson ◽  
Dylan N. Dillaway

We hypothesized that physiological and morphological responses to prescribed fire support the post-scorch foliage recovery and growth of young longleaf pine. Two studies conducted in central Louisiana identified three means of foliage regrowth after fire that included an increase in the gas exchange rate of surviving foliage for 3 to 4 months after fire. Saplings also exhibited crown developmental responses to repeated fire that reduced the risk of future crown scorch. Starch reserves were a source of carbon for post-scorch foliage regrowth when fire was applied in the early growing season. However, the annual dynamics of starch accumulation and mobilization restricted its effectiveness for foliage regrowth when fire was applied late in the growing season. As such, post-scorch foliage regrowth became increasingly dependent on photosynthesis as the growing season progressed. Additionally, the loss of foliage by fire late in the growing season interrupted annual starch dynamics and created a starch void between the time of late growing season fire and mid-summer of the next year. The occurrence of drought during both studies revealed barriers to foliage reestablishment and normal stem growth among large saplings. In study 1, spring water deficit at the time of May fire was associated with high crown scorch and poor foliage and stem growth among large saplings. We attribute this lag in stem growth to three factors: little surviving foliage mass, low fascicle gas exchange rates, and poor post-scorch foliage recovery. In study 2, May fire during a short window of favorable burning conditions in the tenth month of a 20-month drought also reduced stem growth among large saplings but this growth loss was not due to poor post-scorch foliage recovery. Application of this information to prescribed fire guidelines will benefit young longleaf pine responses to fire and advance efforts to restore longleaf pine ecosystems.


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