scholarly journals Relationship between the Hormonal Balance and the Regulation of Iron Deficiency Stress Responses in Cucumber

2009 ◽  
Vol 134 (6) ◽  
pp. 589-601 ◽  
Author(s):  
Eva Bacaicoa ◽  
Ángel María Zamarreño ◽  
Diane Leménager ◽  
Roberto Baigorri ◽  
José María García-Mina
Keyword(s):  
Stress Responses ◽  
Time Course ◽  
Activity Levels ◽  
Hormonal Balance ◽  
Time Course Experiment ◽  
Root Responses ◽  
The Relationship ◽  
Cucumber Cultivar ◽  
Indole 3 Acetic Acid ◽  
Over Time

Some studies suggest that iron (Fe) stress root responses are regulated by variations in specific plant hormones. However, this question remains unclear. A time-course experiment dealing with the relationship between the expression of the Fe-stress root responses at transcriptional (CsFRO1, CsIRT1, CsHA1, and CsHA2) and enzymatic levels [root Fe(III)-chelate reductase and plasma membrane H+-ATPase], and the variation of phytohormone concentrations in the shoot and root of Fe-starved plants have been studied in a Fe-efficient cucumber cultivar (Cucumis sativus L. cv. Ashley). The results indicate that the expression over time of the physiological Fe-stress root responses at transcriptional and enzyme activity levels are consistent with significant increases in indole-3-acetic acid root (transient) and shoot (sustained) concentrations. Fe-starvation also caused transient changes in the root concentration of abscisic acid and nitric oxide. Finally, an increase in root ethylene production and a decrease in the root concentration of some cytokinins were observed under Fe starvation, but they were not clearly timely coordinated with the expression of Fe physiological root responses.

Associations Between Change Over Time in Pandemic-Related Stress and Change in Physical Activity

2021 ◽  
pp. 1-8
Author(s):  
Kathryn E. Wilson ◽  
Andrew Corbett ◽  
Andrew Van Horn ◽  
Diego Guevara Beltran ◽  
Jessica D. Ayers ◽  
...  
Keyword(s):  
Physical Activity ◽  
Stress Reduction ◽  
Activity Levels ◽  
Latent Growth ◽  
Linear Change ◽  
Change Over Time ◽  
Trajectories Of Change ◽  
Related Stress ◽  
The Relationship ◽  
Over Time

Background: Physical activity (PA) mitigated psychological distress during the initial weeks of the COVID-19 pandemic, yet not much is known about whether PA had effects on stress in subsequent months. We examined the relationship between change over time in COVID-related stress and self-reported change in PA between March and July 2020. Methods: Latent growth modeling was used to examine trajectories of change in pandemic-related stress and test their association with self-reported changes in PA in an international sample (n = 679). Results: The participants reported a reduction in pandemic-related stress between April and July of 2020. Significant linear (factor mean = −0.22) and quadratic (factor mean = 0.02) changes (Ps < .001) were observed, indicating a deceleration in stress reduction over time. Linear change was related to change in PA such that individuals who became less active during the pandemic reported less stress reduction over time compared with those who maintained or increased their PA during the pandemic. Conclusions: Individuals who experienced the greatest reduction in stress over time during the pandemic were those who maintained their activity levels or became more active. Our study cannot establish a causal relationship between these variables, but the findings are consistent with other work showing that PA reduces stress.

scholarly journals Physical activity trajectories following gynecological cancer: results from a prospective, longitudinal cohort study

2020 ◽  
Vol 30 (11) ◽  
pp. 1784-1790
Author(s):  
Steven Fleming ◽  
Tamara Jones ◽  
Monika Janda ◽  
Dimitrios Vagenas ◽  
Leigh Ward ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Physical Activity ◽  
Endometrial Cancer ◽  
Gynecological Cancer ◽  
Activity Levels ◽  
Physical Activity Levels ◽  
Low Levels ◽  
The Relationship ◽  
Over Time

BackgroundParticipating in physical activity after a diagnosis of cancer is associated with reduced morbidity and improved outcomes. However, declines in, and low levels of, physical activity are well documented in the broader cancer population, but with limited evidence following gynecological cancer.ObjectiveTo describe physical activity levels from before and up to 2 years after gynecological cancer surgery; to explore the relationship between physical activity patterns and quality of life; and to describe characteristics associated with physical activity trajectories post-gynecological cancer.MethodsWomen with gynecological cancer (n=408) participated in a prospective study that assessed physical activity and quality of life pre-surgery (baseline), at 6 weeks, and 3, 6, 9, 12, 15, 18 and 24 months post-surgery. Validated questionnaires were used to assess physical activity (Active Australia Survey) and quality of life outcomes (Functional Assessment of Cancer Therapy-General). Generalized estimating equation modeling, group-based trajectory analysis, and analysis of variance were used to identify physical activity levels over time, to categorize women into physical activity trajectory groups, and to assess the relationship between physical activity levels and quality of life, respectively.ResultsWomen had a mean±SD age of 60±11.4 years at diagnosis, with the majority diagnosed with endometrial cancer (n=235, 58%) or stage I disease (n=241, 59%). Most women (80%) started with and maintained low levels of physical activity (1–10 metabolic equivalent task hours per week), reported no physical activity throughout the follow-up period, or reduced physical activity levels over time. Only 19% of women maintained or doubled physical activity levels, so that by 24 months post-diagnosis they were engaging in sufficient levels of physical activity. Women with endometrial cancer (58% of the sample) were more likely to be overweight or obese and to report low levels of physical activity or none at all. Higher physical activity levels were associated with higher quality of life (p<0.05).ConclusionThe low baseline and surveillance levels of physical activity show that the vast majority of gynecological cancer survivors have the ability to improve their physical activity levels. Integration of physical activity advice and support into standard care could lead to gains in quality of life during gynecological cancer survivorship.

Nutrient-stimulated GLP-2 release and crypt cell proliferation in experimental short bowel syndrome

2005 ◽  
Vol 288 (3) ◽  
pp. G431-G438 ◽  
Author(s):  
G. R. Martin ◽  
L. E. Wallace ◽  
B. Hartmann ◽  
J. J. Holst ◽  
L. Demchyshyn ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Time Course ◽  
Intestinal Adaptation ◽  
Intestinal Resection ◽  
Small Bowel Resection ◽  
Crypt Cell ◽  
Crypt Cell Proliferation ◽  
Proximal Intestine ◽  
The Relationship ◽  
Over Time

Glucagon-like peptide-2 (GLP-2) is an enteroendocrine peptide that is released in response to luminal nutrients and has unique trophic actions in the gastrointestinal tract. These features suggest GLP-2 may be important in controlling intestinal adaptation. We examined the relationship over time of GLP-2 production and adaptation to intestinal resection, the effects of resection-induced malabsorption on GLP-2 production, and the correlation of endogenous serum GLP-2 levels with adaptation as measured by crypt-cell proliferation (CCP). We initially examined the effect of nutrient malabsorption, induced by a 90% resection of the proximal intestine studied on day 4, on the time course and levels of GLP-2 release. Secondly, the degree of malabsorption was varied by performing intestinal transection or 50, 75, or 90% resection of proximal small intestine. Finally, the relationship of GLP-2 levels over time with adaptation to a 90% resection was examined by determining GLP-2 levels on days 7, 14, and 28, and correlating this with intestinal adaptation, as assessed by morphology and CCP rate. A 90% resection significantly increased basal and postprandial GLP-2 levels, with a net increase in nutrient-stimulated exposure over 90 min; GLP-2 exposure (integrated levels vs. time) increased 12.7-fold in resected animals ( P < 0.001). Basal and postprandial GLP-2 levels significantly correlated with the magnitude of intestinal resection ( r2 = 0.71; P < 0.001), CCP ( r2 = 0.48; P < 0.005), and nutrient malabsorption (protein, P < 0.001; fat, P < 0.005). The increase in CCP was maintained to 28 days after small bowel resection and was associated with an ongoing elevation in GLP-2 release. These findings suggest that GLP-2 is important in initiating and maintaining the small intestinal adaptive response to resection.

scholarly journals Has resistance to chlorhexidine increased among clinically-relevant bacteria? A systematic review of time course and subpopulation data

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256336
Author(s):  
Stephen Buxser
Keyword(s):  
Antibiotic Resistance ◽  
Linear Regression ◽  
Time Course ◽  
Clinical Medicine ◽  
Food Service ◽  
Nonlinear Least Squares ◽  
Least Squares Regression ◽  
Microbial Strains ◽  
The Relationship ◽  
Over Time

Chlorhexidine (CHX) was introduced for use as an antimicrobial more than 70 years ago. CHX has been and continues to be used broadly for disinfecting surfaces in medical and food service facilities as well as directly on skin of humans and animals. Considering its widespread use over many decades, questions of resistance to CHX have been raised. Additionally, questions of possible coincident resistance to the biocide and resistance to clinically relevant antibiotics have also been raised. A number of important questions remain, including is there consistent evidence of resistance, what is the degree of resistance, especially among clinically isolated microbial strains, and what is the degree of resistance compared to the typical concentrations of the biocide used? Data for microbial species isolated over the last 70+ years were compiled to construct as complete a picture as practical regarding possible resistance, especially among species in which resistance to commonly used antibiotics has been noted to be increasing. This is a compilation and analysis of individual MIC values for CHX reported in the literature, not a compilation of the conclusions individual authors reached. The data were analyzed using straight-forward and robust statistical procedures to detect changes in susceptibility to CHX over time, i.e. linear regression. Linear regression was supplemented with the use of nonlinear least squares regression analysis to detect the presence of population parameters associated with subpopulations of microbial strains which exhibit increased resistance to CHX. Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii were all found to have an increased resistance to CHX over time with the most profound change detected in A. baumannii. Additionally, subpopulations with log-normal distributions were found consistent with the presence of a baseline subpopulation of susceptible strains and a subpopulation with increased resistance to CHX. However, the CHX-resistant subpopulations did not correlate exactly with antibiotic resistance, so details of the relationship remain to be addressed. Increased resistance over time was not detected for Escherichia coli, Enterobacter faecalis, Staphylococcus aureus, or Candida albicans, although a subpopulation with greater than baseline resistance to CHX was detected among strains of E. faecalis and C. albicans. A difference in susceptibility to CHX was also detected between methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) S. aureus strains. The levels of resistance to CHX detected were all markedly lower than concentrations routinely used in medical and food service applications. Reaching conclusions regarding the relationship between antibiotic and CHX resistance was complicated by the limited overlap between tests of CHX and antibiotic resistance for several species. The results compiled here may serve as a foundation for monitoring changes in resistance to CHX and possible relationships between the use of CHX and resistance to antibiotics commonly used in clinical medicine.

Investment Traits and Intelligence in Adulthood

2013 ◽  
Vol 34 (2) ◽  
pp. 82-89 ◽  
Author(s):  
Sophie von Stumm
Keyword(s):  
Individual Differences ◽  
Personality Traits ◽  
Fluid Intelligence ◽  
Need For Cognition ◽  
Openness To Experience ◽  
Intelligence Tests ◽  
Crystallized Intelligence ◽  
New Knowledge ◽  
The Relationship ◽  
Over Time

Intelligence-as-knowledge in adulthood is influenced by individual differences in intelligence-as-process (i.e., fluid intelligence) and in personality traits that determine when, where, and how people invest their intelligence over time. Here, the relationship between two investment traits (i.e., Openness to Experience and Need for Cognition), intelligence-as-process and intelligence-as-knowledge, as assessed by a battery of crystallized intelligence tests and a new knowledge measure, was examined. The results showed that (1) both investment traits were positively associated with intelligence-as-knowledge; (2) this effect was stronger for Openness to Experience than for Need for Cognition; and (3) associations between investment and intelligence-as-knowledge reduced when adjusting for intelligence-as-process but remained mostly significant.

Power Values and Power Distance Moderate the Relationship Between Workplace Supervisory Power and Job Satisfaction

2020 ◽  
Vol 19 (3) ◽  
pp. 135-141
Author(s):  
Kenneth D. Locke
Keyword(s):  
Job Satisfaction ◽  
Multilevel Modeling ◽  
Power Distance ◽  
European Social Survey ◽  
Social Survey ◽  
The Relationship ◽  
Workplace Power ◽  
Over Time

Abstract. Person–job (or needs–supplies) discrepancy/fit theories posit that job satisfaction depends on work supplying what employees want and thus expect associations between having supervisory power and job satisfaction to be more positive in individuals who value power and in societies that endorse power values and power distance (e.g., respecting/obeying superiors). Using multilevel modeling on 30,683 European Social Survey respondents from 31 countries revealed that overseeing supervisees was positively associated with job satisfaction, and as hypothesized, this association was stronger among individuals with stronger power values and in nations with greater levels of power values or power distance. The results suggest that workplace power can have a meaningful impact on job satisfaction, especially over time in individuals or societies that esteem power.

Emotional Impact Feedback Changes How We Remember Negative Autobiographical Experiences

2010 ◽  
Vol 57 (5) ◽  
pp. 354-359 ◽  
Author(s):  
Melanie K. T. Takarangi ◽  
Deryn Strange
Keyword(s):  
Well Being ◽  
The Other ◽  
Personal Perspective ◽  
Emotional Impact ◽  
Potential Mechanism ◽  
Negative Experiences ◽  
Negative Memory ◽  
The Relationship ◽  
Negative Memories ◽  
Over Time

When people are told that their negative memories are worse than other people’s, do they later remember those events differently? We asked participants to recall a recent negative memory then, 24 h later, we gave some participants feedback about the emotional impact of their event – stating it was more or less negative compared to other people’s experiences. One week later, participants recalled the event again. We predicted that if feedback affected how participants remembered their negative experiences, their ratings of the memory’s characteristics should change over time. That is, when participants are told that their negative event is extremely negative, their memories should be more vivid, recollected strongly, and remembered from a personal perspective, compared to participants in the other conditions. Our results provide support for this hypothesis. We suggest that external feedback might be a potential mechanism in the relationship between negative memories and psychological well-being.

Rethinking social remittances and the migration-development nexus from the perspective of time

2013 ◽  
Vol 10 (1) ◽  
pp. 11-22 ◽  
Author(s):  
Peggy Levitt ◽  
Deepak Lamba-Nieves
Keyword(s):  
Social Influence ◽  
Change Over Time ◽  
Social Remittances ◽  
The Relationship ◽  
Migration And Development ◽  
Over Time

This article explores how the conceptualization, management, and measurement of time affect the migration-development nexus. We focus on how social remittances transform the meaning and worth of time, thereby changing how these ideas and practices are accepted and valued and recalibrating the relationship between migration and development. Our data reveal the need to pay closer attention to how migration’s impacts shift over time in response to its changing significance, rhythms, and horizons. How does migrants’ social influence affect and change the needs, values, and mind-frames of non-migrants? How do the ways in which social remittances are constructed, perceived, and accepted change over time for their senders and receivers?

Changing Places: Rock Art and Holocene Landscapes in the Wadi al-Ajal, South-West Libya

2014 ◽  
Vol 12 (2) ◽  
pp. 165-182 ◽  
Author(s):  
Tertia Barnett ◽  
Maria Guagnin
Keyword(s):  
Spatial Analysis ◽  
Surface Water ◽  
Rock Art ◽  
Human Settlement ◽  
Gis Model ◽  
South West ◽  
Settlement Location ◽  
Central Sahara ◽  
The Relationship ◽  
Over Time

This article examines the relationship between rock art and landscape use by pastoral groups and early settled communities in the central Sahara from around 6000 BC to 1000 AD. During this period the region experienced significant climatic and environmental fluctuations. Using new results from a systematic survey in the Wadi al-Ajal, south-west Libya, our research combines data from over 2000 engraved rock art panels with local archaeological and palaeoenvironmental evidence within a GIS model. Spatial analysis of these data indicates a correspondence between the frequency of rock art sites and human settlement over time. However, while changes in settlement location were guided primarily by the constraints on accessibility imposed by surface water, the distribution of rock art relates to the availability of pasture and patterns of movement through the landscape. Although the reasons for these movements undoubtedly altered over time, natural routes that connected the Wadi al-Ajal and areas to the south continued to be a focus for carvings over several thousand years.

Soil and Stream Water Chemistry During Spring Snowmelt

1992 ◽  
Vol 23 (1) ◽  
pp. 13-26 ◽  
Author(s):  
W. H. Hendershot ◽  
L. Mendes ◽  
H. Lalande ◽  
F. Courchesne ◽  
S. Savoie
Keyword(s):  
Stream Water ◽  
Base Cations ◽  
Stream Chemistry ◽  
Stream Water Chemistry ◽  
The Matrix ◽  
Adsorption Desorption ◽  
The Relationship ◽  
Best Fit ◽  
Spring Snowmelt ◽  
Over Time

In order to determine how water flowpath controls stream chemistry, we studied both soil and stream water during spring snowmelt, 1985. Soil solution concentrations of base cations were relatively constant over time indicating that cation exchange was controlling cation concentrations. Similarly SO4 adsorption-desorption or precipitation-dissolution reactions with the matrix were controlling its concentrations. On the other hand, NO3 appeared to be controlled by uptake by plants or microorganisms or by denitrification since their concentrations in the soil fell abruptly as snowmelt proceeded. Dissolved Al and pH varied vertically in the soil profile and their pattern in the stream indicated clearly the importance of water flowpath on stream chemistry. Although Al increased as pH decreased, the relationship does not appear to be controlled by gibbsite. The best fit of calculated dissolved inorganic Al was obtained using AlOHSO4 with a solubility less than that of pure crystalline jurbanite.

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