A soil physical parameter,
S, is defined. It is equal to the slope of the soil water retention curve at its inflection point. This curve must be plotted as the logarithm (to base e) of the water ...potential against the gravimetric water content (kg kg
−1). The value of
S is indicative of the extent to which the soil porosity is concentrated into a narrow range of pore sizes. In most soils, larger values of
S are consistent with the presence of a better-defined microstructure. Much previous work has shown that this microstructure is responsible for most of the soil physical properties that are necessary for the proper functioning of soil in agriculture and the environment. The use of
S is illustrated with examples of soils with different texture, density (or degree of compaction), and organic matter (OM) content. The effects of
S on root growth in soil are investigated, and
S is shown to be a better indicator of soil rootability than bulk density. It is suggested that
S can be used as an index of soil physical quality that enables different soils and the effects of different management treatments and conditions to be compared directly.
To investigate the mechanisms that maintain differentiated cells, here we inducibly delete the histone demethylase LSD1/KDM1A in adult mice. Loss of LSD1 leads to paralysis, along with widespread ...hippocampus and cortex neurodegeneration, and learning and memory defects. We focus on the hippocampus neuronal cell death, as well as the potential link between LSD1 and human neurodegenerative disease and find that loss of LSD1 induces transcription changes in common neurodegeneration pathways, along with the re-activation of stem cell genes, in the degenerating hippocampus. These data implicate LSD1 in the prevention of neurodegeneration via the inhibition of inappropriate transcription. Surprisingly, we also find that transcriptional changes in the hippocampus are similar to Alzheimer's disease (AD) and frontotemporal dementia (FTD) cases, and LSD1 is specifically mislocalized to pathological protein aggregates in these cases. These data raise the possibility that pathological aggregation could compromise the function of LSD1 in AD and FTD."LSD1 is a histone demethylase that plays many roles during development. Here, the authors provide evidence that loss of LSD1 in adult mice leads to paralysis and neurodegeneration in the hippocampus and cortex and suggest a potential link between LSD1 and human neurodegenerative disease.
Breast cancer is a commonly diagnosed malignancy and the second leading cause of cancer-related death among American women today. The literature suggests that African American Women (AAW) are more ...likely to die from the disease each year compared to their White counterparts. A biological basis for this disparity exists—early age of onset, more advanced stage of the disease, more aggressive histological changes, and worse survival. Even though mechanisms underlying these disparities are poorly understood, recent studies suggest that the poorer breast cancer outcome observed in AAW may, in part, result from underlying molecular factors. The present review was undertaken to investigate if AAW do, in fact, develop a more aggressive form of breast cancer compared to other racial groups based on molecular level differences and social determinants. This review also addresses health policy changes that may be implemented to aid in eliminating this disparity.
Tauopathies are a class of neurodegenerative diseases associated with pathological tau. Despite many advances in our understanding of these diseases, the direct mechanism through which tau ...contributes to neurodegeneration remains poorly understood. Previously, our laboratory implicated the histone demethylase LSD1 in tau-induced neurodegeneration by showing that LSD1 localizes to pathological tau aggregates in Alzheimer’s disease cases, and that it is continuously required for the survival of hippocampal and cortical neurons in mice. Here, we utilize the P301S tauopathy mouse model to demonstrate that pathological tau can exclude LSD1 from the nucleus in neurons. In addition, we show that reducing LSD1 in these mice is sufficient to highly exacerbate tau-mediated neurodegeneration and tau-induced gene expression changes. Finally, we find that overexpressing LSD1 in the hippocampus of tauopathy mice, even after pathology has formed, is sufficient to significantly delay neurodegeneration and counteract tau-induced expression changes. These results suggest that inhibiting LSD1 via sequestration contributes to tau-mediated neurodegeneration. Thus, LSD1 is a promising therapeutic target for tauopathies such as Alzheimer’s disease.
The proper regulation of spermatogenesis is crucial to ensure the continued production of sperm and fertility. Here, we investigated the function of the H3K4me2 demethylase KDM1A/LSD1 during ...spermatogenesis in developing and adult mice. Conditional deletion of Kdm1a in the testis just prior to birth leads to fewer spermatogonia and germ cell loss before 3 weeks of age. These results demonstrate that KDM1A is required for spermatogonial differentiation, as well as germ cell survival, in the developing testis. In addition, inducible deletion of Kdm1a in the adult testis results in the abnormal accumulation of meiotic spermatocytes, as well as apoptosis and progressive germ cell loss. These results demonstrate that KDM1A is also required during adult spermatogenesis. Furthermore, without KDM1A, the stem cell factor OCT4 is ectopically maintained in differentiating germ cells. This requirement for KDM1A is similar to what has been observed in other stem cell populations, suggesting a common function. Taken together, we propose that KDM1A is a key regulator of spermatogenesis and germ cell maintenance in the mouse.
It is shown that, for mineral soils, it is not the total amount of organic carbon (or organic matter) that controls soil physical behaviour but the amount of complexed organic carbon (COC). We assume ...that this complex is formed by the association of unit mass (i.e. 1 g) of organic carbon with
n grams of clay. Analysis of data from two French and two Polish databases shows that, for these soils,
n
=
10. A consequence of this is that in soils with small contents of organic carbon (OC), such as arable soils, COC is proportional to OC. However, in soils with large contents of organic carbon, such as pasture soils, COC is proportional to the clay content. This explains why we find that soil bulk density is significantly correlated with OC in French arable soils but with the clay content in French pasture soils. The use of COC instead of OC enables the arable and pasture soils to be considered on the same scale.
Water retention data were fitted to a double-exponential equation which allows both the matrix and structural porosities to be estimated. It is shown that in soils with low contents of organic carbon, the carbon content is positively correlated with the matrix porosity. In contrast, in soils with high contents of organic carbon, the matrix porosity is constant at its maximum value and the structural porosity is not significantly correlated with either the total organic carbon or the non-complexed organic carbon (NCOC). It is suggested that the complexed organic carbon can be considered as being sequestered. The soil clay content can similarly be partitioned between clay that is complexed with organic carbon and clay that is not complexed. It is shown that non-complexed clay is more easily dispersed in water than clay that is complexed with organic carbon. These findings indicate how improved pedo-transfer functions for the prediction of soil physical properties may be produced. Such functions need to use the values of complexed and non-complexed organic carbon and clay which must be determined by algorithms. The values produced by the algorithms may then be used in the improved pedo-transfer functions.
Introduction:
The amygdala is a limbic region of high value for understanding anxiety and its treatment. Dopamine D2 receptors (D2Rs) and oxytocin receptors (OXTRs) have both been shown to ...participate in modulating anxiety involving effects in the amygdala. The goal is to understand if D2R–OXTR heterocomplexes exist in the central amygdala and if, through enhancing allosteric receptor–receptor interactions, may enhance anxiolytic actions.
Methods:
The methods used involve the shock-probe burying test, the
in situ
proximity ligation assay (PLA), image acquisition and analysis, and the BRET2 assay. Bilateral cannulas were introduced into the amygdala, and the effects of the coadministration of oxytocin and the D2R-like agonist quinpirole into the amygdala were studied.
Results:
The combination treatment enhanced the anxiolytic effects compared to the single treatment. The D2R/D3R antagonist raclopride blocked the effects of the combination treatment of oxytocin and the D2R agonist, although oxytocin is regarded as a distinct modulator of fear-mediating anxiolytic effects.
In situ
PLA results indicate the existence of D2R–OXTR heteroreceptor complexes and/or the co-location of OXTR and D2R within the same cell membrane nanodomains in the central amygdala. With BRET2, evidence is given for the existence of D2R–OXTR heteromers in HEK293 cells upon co-transfection.
Discussion:
The enhanced behavioral effects observed upon co-treatment with OXTR and D2R agonists may reflect the existence of improved positive receptor–receptor interactions in the putative D2R–OXTR heterocomplexes in certain neuronal populations of the basolateral and central amygdala. The D2R–OXTR heterocomplex, especially upon agonist co-activation in the central amygdala, may open a new pharmacological venue for the treatment of anxiety.
Teacher burnout is a mental state resulting from job strain that arises when teachers lack the adequate coping abilities to successfully handle the demands of the teaching profession. When compared ...to other professions, teachers exhibit high levels of exhaustion and cynicism, which are the core dimensions of burnout. Teacher self-efficacy is a well-established predictor of burnout, yet little research has investigated potential psychological predictors of self-efficacy. Reflective functioning is a psychological construct that reflects a cognitive ability to understand and analyze one's own and other peoples' behavior in the context of their mental states. The purpose of this study is to investigate the role that reflective functioning plays in predicting self-efficacy, and in turn, teacher burnout. Forty-six elementary school teachers in the United States participated in a cross-sectional, survey-based research study. Mediation analyses indicate an indirect effect between reflective functioning and teacher burnout, with teacher self-efficacy mediating this relationship. The findings from this study suggest teachers who are more reflective view themselves as more self-efficacious, which collectively prevents the gradual development of burnout. Future studies should further examine the relationships between these variables as it may have important implications for future teacher professional development initiatives.
Pollution reduction from waste management and energy generation is necessary to mitigate climate change and is one of the major challenges of the 21st century. This can be achieved through the ...development of innovative energy recovery technologies from biomass and wastes, such as microwave plasma gasification. An envelope of stable CO2 plasma operation is described, by varying working gas flow rate at applied microwave powers between 1 and 6 kW, whereas H2O plasma operation is possible with flow rate ranging from 20 to 50 g/min and microwave powers between 2.5 and 6 kW. The temperature generated in a large chamber connected to the plasma torch is recorded, reaching up to 850 °C, showing a heterogeneous temperature distribution. In addition, optical emission spectroscopy measurements provide an insight into plasma chemistry and demonstrate the dissociation of CO2 and H2O molecules at extremely high temperatures of up to 6300 °C assuming local thermodynamic equilibrium. The experimental results demonstrate that the microwave plasma torch provides an ideal environment for gasification with high temperature and very chemically reactive species. This study provides valuable information for the design of microwave plasma gasification reactors with great potential for effective solid feedstock conversion into high quality syngas for energy production.
•CO2 and H2O plasma operation in a wide range of operating conditions.•Temperatures up to 850 °C achieved in chamber connected to the plasma torch.•CO2 and H2O found to dissociate along 14 cm of the plasma plume.•Temperatures from 6300 °C to 2300 °C achieved along 14 cm of the plasma plume.
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