Functional groups of the activated carbon play the major role in metals removal from aqueous solutions and, for this reason, different treatments can be used to modify the adsorbent surface improving ...the adsorption capacity for a particular pollutant. In this research, oxidation with nitric acid, heating under an inert atmosphere, and ammonia treatment were applied to modify the activated carbon surface. The modified adsorbents were used for the removal of hexavalent chromium (Cr(VI)) from aqueous solutions at different concentrations (10–500 mg L−1), pH 6, and 25 °C. Adsorption mechanisms of Cr(VI) on the activated carbon were proposed based on the surface chemistry, adsorption/reduction, and desorption experiments. Findings demonstrate that acid functional groups of the activated carbon had an important effect on the hexavalent chromium removal. For instance, a high reduction of Cr(VI) to Cr(III) (50%) was obtained by the oxidized adsorbents, whereas the heat treated adsorbents achieved a low reduction (35%), but the ammonia-treated activated carbon achieved the lowest reduction (20%). The heat-treated adsorbent showed the best Cr(VI) adsorption capacity (48 mg g−1), especially at equilibrium Cr(VI) concentration lower than 200 mg L−1, and the fastest adsorption kinetics among the studied adsorbents. Furthermore, the highest Cr(VI) desorption (90%) was achieved with 0.1 N NaOH-NaCl solutions. In summary, an anionic/reduction coupled adsorption mechanism of Cr(VI) seems to be feasible, and the heat-treated activated carbon is an interesting option for sequestering Cr(VI) species from aqueous effluents.
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•Acid functional groups play the major role in the reduction of Cr(VI) to Cr(III).•Heat-treated adsorbent showed the best Cr(VI) adsorption and desorption capacity.•Basic functional groups enhance the adsorption of Cr(VI) species by electrostatic interactions.•Cr(VI) removal is carried out by anionic/reduction coupled adsorption mechanisms.
Summary
A Bayesian hierarchical approach is presented for the estimation of length‐weight relationships (LWR) in fishes. In particular, estimates are provided for the LWR parameters a and b in ...general as well as by body shape. These priors and existing LWR studies were used to derive species‐specific LWR parameters. In the case of data‐poor species, the analysis includes LWR studies of closely related species with the same body shape. This approach yielded LWR parameter estimates with measures of uncertainty for practically all known 32 000 species of fishes. Provided is a large LWR data set extracted from www.fishbase.org, the source code of the respective analyses, and ready‐to‐use tools for practitioners. This is presented as an example of a self‐learning online database where the addition of new studies improves the species‐specific parameter estimates, and where these parameter estimates inform the analysis of new data.
Although the higher incidence of stress-related psychiatric disorders in females is well documented, its basis is unknown. Here, we show that the receptor for corticotropin-releasing factor (CRF), ...the neuropeptide that orchestrates the stress response, signals and is trafficked differently in female rats in a manner that could result in a greater response and decreased adaptation to stressors. Most cellular responses to CRF in the brain are mediated by CRF receptor (CRFr) association with the GTP-binding protein, G(s). Receptor immunoprecipitation studies revealed enhanced CRFr-G(s) coupling in cortical tissue of unstressed female rats. Previous stressor exposure abolished this sex difference by increasing CRFr-G(s) coupling selectively in males. These molecular results mirrored the effects of sex and stress on sensitivity of locus ceruleus (LC)-norepinephrine neurons to CRF. Differences in CRFr trafficking were also identified that could compromise stress adaptation in females. Specifically, stress-induced CRFr association with beta-arrestin2, an integral step in receptor internalization, occurred only in male rats. Immunoelectron microscopy confirmed that stress elicited CRFr internalization in LC neurons of male rats exclusively, consistent with reported electrophysiological evidence for stress-induced desensitization to CRF in males. Together, these studies identified two aspects of CRFr function, increased cellular signaling and compromised internalization, which render CRF-receptive neurons of females more sensitive to low levels of CRF and less adaptable to high levels of CRF. CRFr dysfunction in females may underlie their increased vulnerability to develop stress-related pathology, particularly that related to increased activity of the LC-norepinephrine system, such as depression or post-traumatic stress disorder.
Amygdalar norepinephrine (NE) plays a key role in regulating neural responses to emotionally arousing stimuli and is involved in memory consolidation of emotionally charged events. ...Corticotropin-releasing factor (CRF) and dynorphin (DYN), two neuropeptides that mediate the physiological and behavioral responses to stress, are abundant in the central nucleus of the amygdala (CeA), and directly innervate brainstem noradrenergic locus coeruleus (LC) neurons. Whether the CRF- and DYN-containing amygdalar neurons receive direct noradrenergic innervation has not yet been elucidated. The present study sought to define cellular substrates underlying noradrenergic modulation of CRF- and DYN-containing neurons in the CeA using immunohistochemistry and electron microscopy. Ultrastructural analysis revealed that NE-labeled axon terminals form synapses with CRF- and DYN-containing neurons in the CeA. Semi-quantitative analysis showed that approximately 31 % of NET-labeled axon terminals targeted CeA neurons that co-expressed DYN and CRF. As a major source of CRF innervation to the LC, it is also not known whether CRF-containing CeA neurons are directly targeted by noradrenergic afferents. To test this, retrograde tract tracing using FluoroGold from the LC was combined with immunocytochemical detection of CRF and NET in the CeA. Our results revealed a population of LC-projecting CRF-containing CeA neurons that are directly innervated by NE afferents. Analysis showed that approximately 34 % of NET-labeled axon terminals targeted LC-projecting CeA neurons that contain CRF. Taken together, these results indicate significant interactions between NE, CRF and DYN in this critical limbic region and reveal direct synaptic interactions of NE with amygdalar CRF that influence the LC-NE arousal system.
Emotion recognition is important for social interaction and communication, yet previous research has identified a cross-cultural emotion recognition deficit: Recognition is less accurate for emotions ...expressed by individuals from a cultural group different than one's own. The current study examined whether social categorization based on race, in the absence of cultural differences, influences emotion recognition in a diverse context. South Asian and White Canadians in the Greater Toronto Area completed an emotion recognition task that required them to identify the seven basic emotional expressions when posed by members of the same two groups, allowing us to tease apart the contributions of culture and social group membership. Contrary to our hypothesis, there was no mutual in-group advantage in emotion recognition: Participants were not more accurate at recognizing emotions posed by their respective racial in-groups. Both groups were more accurate at recognizing expressions when posed by South Asian faces, and White participants were more accurate overall compared to South Asian participants. These results suggest that in a diverse environment, categorization based on race alone does not lead to the creation of social out-groups in a way that negatively impacts emotion recognition.
Stress-related psychiatric disorders are more prevalent in women than men. As hypersecretion of the stress neuromediator, corticotropin-releasing factor (CRF) has been implicated in these disorders, ...sex differences in CRF sensitivity could underlie this disparity. Hyperarousal is a core symptom that is shared by stress-related disorders and this has been attributed to CRF regulation of the locus ceruleus (LC)-norepinephrine arousal system. We recently identified sex differences in CRF(1) receptor (CRF(1)) signaling and trafficking that render LC neurons of female rats more sensitive to CRF and potentially less able to adapt to excess CRF compared with male rats. The present study used a genetic model of CRF overexpression to test the hypothesis that females would be more vulnerable to LC dysregulation by conditions of excess CRF. In both male and female CRF overexpressing (CRF-OE) mice, the LC was more densely innervated by CRF compared with wild-type controls. Despite the equally dense CRF innervation of the LC in male and female CRF-OE mice, LC discharge rates recorded in slices in vitro were selectively elevated in female CRF-OE mice. Immunoelectron microscopy revealed that this sex difference resulted from differential CRF(1) trafficking. In male CRF-OE mice, CRF(1) immunolabeling was prominent in the cytoplasm of LC neurons, indicative of internalization, a process that would protect cells from excessive CRF. However, in female CRF-OE mice, CRF(1) labeling was more prominent on the plasma membrane, suggesting that the compensatory response of internalization was compromised. Together, the findings suggest that the LC-norepinephrine system of females will be particularly affected by conditions resulting in elevated CRF because of differences in receptor trafficking. As excessive LC activation has been implicated in the arousal components of stress-related psychiatric disorders, this may be a cellular mechanism that contributes to the increased incidence of these disorders in females.
International gender equity in soil science Dawson, Lorna; Brevik, Eric C.; Reyes‐Sánchez, Laura B.
European journal of soil science,
September 2021, 2021-09-00, 20210901, Letnik:
72, Številka:
5
Journal Article
Recenzirano
Previous studies have indicated that diversity is a concern in soil science, including how this relates to gender equity. However, gender equity data for soil science are extremely limited, with only ...the USA having a current relatively extensive study published in the scientific literature. Therefore, this study was undertaken to gain a preliminary understanding of gender equity issues in a range of countries worldwide using the gender data of membership of national soil science societies, international conferences and journals. Data for 2020 membership was supplied by 44 soil science societies, providing a broad geographic representation. Thirty‐seven of the 44 societies had more male members than female. Only 32% of the soil science society members were women, although the highest percentage for an individual society was 69% female membership. Regionally, Asia had the lowest female membership at 22%, whereas Africa had the highest at 40%. Only 20% of the national soil science societies who are members of the International Union of Soil Sciences had female presidents, indicating that women are under‐represented in the top leadership roles in our professional societies. Women were under‐represented as keynote speakers at conferences and on many editorial boards. This initial scoping study demonstrates that there is an urgent global need to address gender equity within the soil science profession. However, gender equity extends beyond just the number of women in our profession: it also includes equal access to wages, leadership roles and decision making. We conclude that it is critical that individual countries undertake detailed studies of gender equity so we have a more complete picture of the national and international scale of this issue.
Highlights
There is still gender inequity in soil science
Soil science is a male‐dominated field in most countries worldwide
Gender equity is critical to advancing the discipline of soil science
There is a need for comprehensive national studies of gender equity
Equity includes many issues beyond just equality in numbers of men and women in the profession.
The endogenous opioid peptides, met- or leu-enkephalin, and corticotropin-releasing factor (CRF) regulate noradrenergic neurons in the locus coeruleus (LC) in a convergent manner via projections from ...distinct brain areas. In contrast, the opioid peptide dynorphin (DYN) has been shown to serve as a co-transmitter with CRF in afferents to the LC. To further define anatomical substrates targeting noradrenergic neurons by DYN afferents originating from limbic sources, anterograde tract-tracing of biotinylated dextran amine (BDA) from the central amygdaloid complex was combined with immunocytochemical detection of DYN and tyrosine hydroxylase (TH) in the same section of tissue. Triple labeling immunocytochemistry was combined with electron microscopy in the LC where BDA was identified using an immunoperoxidase marker, and DYN and TH were distinguished by the use of sequential immunogold labeling and silver enhancement to produce different sized gold particles. Results show direct evidence of a monosynaptic pathway linking amygdalar DYN afferents with LC neurons. To determine whether DYN-containing amygdalar LC-projecting neurons colocalize CRF, retrograde tract-tracing using fluorescent latex microspheres injected into the LC was combined with immunocytochemical detection of DYN and CRF in single sections in the central amygdala. Retrogradely labeled neurons from the LC were distributed throughout the rostro-caudal extent of the central nucleus of the amygdala (CeA) as previously described. Cell counts showed that approximately 42% of LC-projecting neurons in the CeA contained both DYN and CRF. Taken with our previous studies showing monosynaptic projections from amygdalar CRF neurons to noradrenergic LC cells, the present study extends this by showing that DYN and CRF are co-transmitters in monosynaptic projections to the LC and are poised to coordinately impact LC neuronal activity.
► The central amygdala is a source of dynorphin (DYN) projections to the locus coeruleus (LC). ► Anterograde tract-tracing revealed that amygdalar afferents to the LC exhibit DYN and form synapses with LC neurons. ► Retrograde tract-tracing revealed that amygdalar afferents to LC contain DYN and CRF, and co-regulate LC neuronal activity.
Owstonia aurora sp. nov. is described on the base of three specimens (69.8-88.0 mm in standard length) collected off East Luzon during the "Aurora 2007" Philippine Expedition. The new species differs ...from its congeners by the following combination of characters: dorsal-fin elements III, 21; anal-fin elements I, 14; gill rakers on first arch 35-38; cheek with 80-86 scales in 7-8 rows; lateral line without branch, not forming loop in front of dorsal-fin, ending below 17th to 22th dorsal-fin soft rays; oblique body scale rows in mid-lateral series 54-58; lower margin of preopercle rounded; prominent black blotch on anterior dorsal-fin membrane, and extend downward to dorsal-fin base, remaining membrane of dorsal, anal, and caudal fins red with white margins and bases, distinct white stripes on mid dorsal and caudal fin membranes; membranes between maxillary and premaxillary with discontinuous black stripes or patches.
Introduction
In March 2020, the coronavirus disease 2019 (COVID-19) pandemic forced medical schools in the Philippines to stop face-to-face learning activities and abruptly shift to an online ...curriculum. This study aimed to identify barriers to online learning from the perspective of medical students in a developing country.
Methods
The authors sent out an electronic survey to medical students in the Philippines from 11 to 24 May 2020. Using a combination of multiple-choice, Likert scale, and open-ended questions, the following data were obtained: demographics, medical school information, access to technological resources, study habits, living conditions, self-assessment of capacity for and perceived barriers to online learning, and proposed interventions. Descriptive statistics were calculated. Responses were compared between student subgroups using nonparametric tests.
Results
Among 3670 medical students, 93% owned a smartphone and 83% had a laptop or desktop computer. To access online resources, 79% had a postpaid internet subscription while 19% used prepaid mobile data. Under prevailing conditions, only 1505 students (41%) considered themselves physically and mentally capable of engaging in online learning. Barriers were classified under five categories: technological, individual, domestic, institutional, and community barriers.
Discussion
Medical students in the Philippines confronted several interrelated barriers as they tried to adapt to online learning. Most frequently encountered were difficulty adjusting learning styles, having to perform responsibilities at home, and poor communication between educators and learners. By implementing student-centered interventions, medical schools and educators play a significant role in addressing these challenges during the COVID-19 pandemic and beyond.
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