357 research outputs found
Estudo morfoanatômico comparativo entre a poaia (Psychotria ipecacuanha (Brot.) Stokes - Rubiaceae) obtida da região Amazônica (habitat original) e proveniente de processo biotecnológico submetida a diferentes tratamentos de interceptação da radiação solar.
A poaia ou ipeca (Psychotria ipecacuanha (Brot.) Stokes.-Rubiaceae) apesar de seu valor farmacológico e sócio-econômico é cada vez menos freqüente no seu habitat. O objetivo deste trabalho foi realizar o estudo comparativo dos aspectos morfoanatômicos entre a espécie originária da Amazônia Brasileira e a obtida in vitro submetidas a diferentes tratamentos de interceptação de radiação solar, visando, desta forma, dar suporte a estudos com fins de preservação, cultivo, validação farmacognóstica/farmacopéica e ampliar o conhecimento biotecnológico desta espécie. A espécie nativa foi obtida de fragmento de mata (fase vegetativa) e empregada para micropropagação através do cultivo in vitro de fragmentos de segmentos internodais sobre meio de cultivo Murashige & Skoog com o regulador de crescimento BAP (2,0 mg/l de meio). Obtiveram-se plântulas que foram transferidas para casa de vegetação por 2 anos sob dois tipos de ambiente e três diferentes tratamentos de interceptação da radiação solar. Foi feito o estudo morfoanatômico, analisado estatisticamente. Verifica-se que as plantas originadas por processo biotecnológico e submetidas aos diferentes tratamentos apresentam morfologia semelhante à planta nativa, no entanto constatou-se um maior número de raízes secundárias, não há diferença significativa entre larguras e comprimentos de folhas, comprimento de raízes, estípulas, peso de raízes e rizomas. Mas, observou-se diferença estatística no comprimento do caule em relação à nativa
Stress and Coping Mechanisms in Gig Work
Advancements in digital technology have given rise to the creation of digital platforms and the growth of gig work. Gig work is a new form of work based on short-term, contract arrangements through the open marketplaces on digital platforms (Valley, 2000). As a result of the contract-based work arrangement, participants in gig work are more entrepreneurial and individualistic. To be considered gig work, the work must meet the following requirements: platform-related; predominantly microtasks, which are menial, monotonous, and tightly bounded; external contributors are classified by the platforms as independent contractors self-employed status and being evaluated digitally (Howcroft, 2019). In the gig work environment, workers enjoy a sense of autonomy in making job decisions on a digital platform (Deng and Joshi, 2016), but they are also being managed through a micro-level task control (Howcroft, 2019). Instead of having overall work being observed, gig workers found each function and task being monitored. The relations of the platforms working as intermediaries from a job provider to a job seeker are more like an automated job manager where some platforms combine automation with humans (Howcroft, 2019, p. 26). The platforms have created and applied algorithms to manage job listings and work processes. This type of management enables the platforms to meticulously track workers in an optimized manner over a large scale (Howcroft, 2019, p. 30). In the gig work environment, this management style pushes workers to become dependent on computer algorithms for work and performance evaluation. In the cases where a worker is underperforming, the platform puts pressure on the worker by intense supervisory pressure and discipline on the basis of remote covert monitoring of their work (Wood, 2019, p. 62). In addition to benefits, this new gig work opportunity has also brought problems that should be addressed. One of the problems that we find necessary to address is gig workers’ stress condition and coping mechanism. Stress can be defined as antecedent conditions within one\u27s job or the organization which require adaptive responses on the part of the employees (Jex & Beehr, 1991, p. 312). Multiple factors can lead to the gig worker being stressed. Lazarus and Folkman (1984, p. 141) defined coping as constantly changing cognitive and behavioral efforts to manage specific external and/or internal demands that are appraised as taxing or exceeding the resources of the person. It is necessary to understand the best coping mechanism to generate insights to inform key stakeholders in the gig economy, including workers, platform companies, and client organizations. This study has the potential to help gig workers manage or develop a coping mechanism that helps reduce their emotional and physical stress. Based on our data analysis, we were able to identify some important characteristics of gig workers. Workers with different levels of participation in crowdwork were found to be associated differently with their financial stress. Financial stress is defined as an individual concern about his/her ability to earn sufficient income to provide for their basic needs. Furthermore, the data analysis shows gig workers cope with stress by using different strategies, including reaching out, escape, or avoidance. Our next step for this study is to consider additional individual background factors such as gender, age, and financial dependence on gig work platforms. In addition to the qualitative data analysis, we will also use quantitative analysis to understand the behaviors of the gig work participants. Our study will contribute to gig work research by understanding the factors leading to gig work stress and offering insights into the coping mechanisms to help gig workers reduce stress
Born to yawn? Understanding yawning as a warning of the rise in cortisol levels: Randomized trial
Background: Yawning consistently poses a conundrum to the medical profession and neuroscientists. Despite neurological evidence such as parakinesia brachialis oscitans in stroke patients and thermo-irregulation in multiple sclerosis patients, there is considerable debate over the reasons for yawning with the mechanisms and hormonal pathways still not fully understood. Cortisol is implicated during yawning and may link many neurological disorders. Evidence was found in support of the Thompson cortisol hypothesis that proposes cortisol levels are elevated during yawning just as they tend to rise during stress and fatigue. Objectives: To investigate whether saliva cortisol levels rise during yawning and, therefore, support the Thompson cortisol hypothesis. Methods: We exposed 20 male and female volunteers aged between 18 and 53 years to conditions that provoked a yawning response in a randomized controlled trial. Saliva samples were collected at the start and again after the yawning response, or at the end of the stimuli presentations if the participant did not yawn. In addition, we collected electromyographic data of the jaw muscles to determine rest and yawning phases of neural activity. Yawning susceptibility scale, Hospital Anxiety and Depression Scale, General Health Questionnaire, and demographic and health details were also collected from each participant. A comprehensive data set allowed comparison between yawners and nonyawners, as well as between rest and yawning phases. Collecting electromyographic data from the yawning phase is novel, and we hope this will provide new information about neuromuscular activity related to cortisol levels. Exclusion criteria included chronic fatigue, diabetes, fibromyalgia, heart conditions, high blood pressure, hormone replacement therapy, multiple sclerosis, and stroke. We compared data between and within participants. Results: In the yawning group, there was a significant difference between saliva cortisol samples (t = -3.071, P = .01). Power and effect size were computed based on repeated-measures t tests for both the yawning and nonyawning groups. There was a medium effect size for the nonyawners group (r = .467) but low power (36%). Results were similar for the yawners group: medium effect size (r = .440) and low power (33%). Conclusions: There was significant evidence in support of the Thompson cortisol hypothesis that suggests cortisol levels are elevated during yawning. A further longitudinal study is planned to test neurological patients. We intend to devise a diagnostic tool based on changes in cortisol levels that may assist in the early diagnosis of neurological disorders based on the data collected. Trial Registration: International Standard Randomized Controlled Trial Number (ISRCTN): 61942768; http://www.controlled-trials.com/ISRCTN61942768/61942768 (Archived by WebCite at http://www.webcitation.org/6A75ZNYvr)
Establishment of Latin America Land Administration Network (LALAN)
Networks of academic and higher education institutions are proven platforms for knowledge sharing and experiences in education exchange. During the International Workshop LALA LADM+, 5-9 November 2018 in Quito Ecuador, organized by Universidad de las Fuerzas Armadas ESPE (ESPE University) Ecuador and Kadaster International together with Faculty ITC University of Twente from the Netherlands, Latin America Land Administration Network - LALAN was established. Representatives from seven countries from Latin American continent, Spain and the Netherlands were present at the workshop. The objective of this network is to: perform activities that can support capacity development and sharing knowledge in both fit-for-purpose and responsible land administration within the Latin America Land Administration Network of education institutions. This paper presents the process of establishment of LALAN, the network’s objective and planned activities for the coming period
Vaccenic acid suppresses intestinal inflammation by increasing anandamide and related N-acylethanolamines in the JCR:LA-cp rat
Vaccenic acid (VA), the predominant ruminantderived trans fat in the food chain, ameliorates hyperlipidemia, yet mechanisms remain elusive. We investigated whether VA could influence tissue endocannabinoids (ECs) by altering the availability of their biosynthetic precursor, arachidonic acid (AA), in membrane phospholipids (PLs). JCR:LA-cp rats were assigned to a control diet with or without VA (1% w/w), cis-9, trans-11 conjugated linoleic acid (CLA) (1% w/w) or VA+CLA (1% + 0.5% w/w) for 8 weeks. VA reduced the EC, 2-arachidonoylglycerol (2-AG), in the liver and visceral adipose tissue (VAT) relative to control diet (P 0.05). Interestingly, VA increased jejunal concentrations of anandamide and those of the noncannabinoid signaling molecules, oleoylethanolamide and palmitoylethanolamide, relative to control diet (P < 0.05). This was consistent with a lower jejunal protein abundance (but not activity) of their degrading enzyme, fatty acid amide hydrolase, as well as the mRNA expression of TNFα and interleukin 1β (P < 0.05). The ability of VA to reduce 2-AG in the liver and VAT provides a potential mechanistic explanation to alleviate ectopic lipid accumulation. The opposing regulation of ECs and other noncannabinoid lipid signaling molecules by VA suggests an activation of benefit via the EC system in the intestine
Carabid beetles of tropical dry forests display traits that cope with a harsh environment
The tropical dry forest (TDF) ecosystem is characterised by strong seasonality exasperated periodically by the El Nino/southern oscillation (ENSO). The environment produced by this event could constrain the survival of small organisms, such as insects. Carabid beetles were collected in a TDF in Armero, Colombia, during wet and dry seasons in both El Nino and non-El Nino periods. A series of traits linked to desiccation resistance were measured to characterise their adaptation to the TDF environment and to investigate changes experienced by carabid beetles during both episodes in quantitative (assemblage) and qualitative (traits) parameters. We found no difference in the presence of traits between El Nino and non-El Nino episodes, but carabid assemblages changed significantly in composition and assemblage structure between these episodes. During both periods, small-sized and nocturnal species dominated the assemblages, but in terms of number of individuals, medium and large-sized, and visual hunter species dominated. Calosoma alternans and Megacephala affinis were the most abundant species with high dispersal capacity. Carabid beetles exhibited morphological traits well-adapted to drought experienced in TDF, including when it is exasperated by ENSO. However, long-term studies can help to elucidate the real effects of ENSO and to confirm the adaptation of carabid beetles to cope with this extreme environment.Peer reviewe
Gonadal Hormones Rapidly Enhance Spatial Memory and Increase Hippocampal Spine Density in Male Rats
17β-estradiol (E(2)) rapidly, within minutes, activates behaviors and cognition by binding to membrane estrogen receptors, activating cell signaling cascades and increasing dendritic spines. In female rodents, E(2) enhances spatial memory within 2–4 hours, and spine density is increased in the CA1 area of the hippocampus within 30–60 minutes. Although chronic gonadal hormone treatments in male rats alter cognition and spines/spine synapses and acute hormone effects occur in hippocampal slices, effects of acute, in vivo hormone administration in males are unknown. Therefore, we assessed rapid effects of E(2) (20 μg/kg) and testosterone (T) (750 μg/kg) on spatial memory using the object placement task and on hippocampal spine density using Golgi impregnation. Orchidectomized rats received hormones immediately after the training trial and were tested for retention 2 hours later. Vehicle-injected orchidectomized males spent equal time exploring objects in the old and new locations, but E(2-) or T-treated subjects spent more time exploring objects at the new location, suggesting enhanced memory. Both hormones also increased spine density in CA1, but not the dentate gyrus, by 20%–40% at 30 minutes and 2 hours after injections. This report is the first, to our knowledge, to show E(2) and T enhancements of memory and spine density within such a short time frame in male rats
The S phase checkpoint promotes the Smc5/6 complex dependent SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε
Replication fork stalling and accumulation of single-stranded DNA trigger the S phase checkpoint, a signalling cascade that, in budding yeast, leads to the activation of the Rad53 kinase. Rad53 is essential in maintaining cell viability, but its targets of regulation are still partially unknown. Here we show that Rad53 drives the hyper-SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε, principally following replication forks stalling induced by nucleotide depletion. Pol2 is the main target of SUMOylation within the replisome and its modification requires the SUMO-ligase Mms21, a subunit of the Smc5/6 complex. Moreover, the Smc5/6 complex co-purifies with Pol ε, independently of other replisome components. Finally, we map Pol2 SUMOylation to a single site within the N-terminal catalytic domain and identify a SUMO-interacting motif at the C-terminus of Pol2. These data suggest that the S phase checkpoint regulate Pol ε during replication stress through Pol2 SUMOylation and SUMO-binding abilit
Land administration in Ecuador; Current situation and opportunities with adoption of fit-for-purpose land administration approach
The aim of this paper is to explore current land administration situation in Ecuador and identify opportunities for fit-for-purpose (FFP) land administration approach that could improve the land administration functions for the country and its citizens. In this paper, initially literature about land administration, guidelines to improve and assessment frameworks for land administration are presented. The FFP land administration basic concept with three frameworks which are: spatial, legal and institutional frameworks are reviewed. In addition, a fieldwork for collecting data about the status of land administration in Ecuador is performed. Results from the fieldwork in Ecuador are observed in reflection of the basic concept of FFP land administration. Here, positive developments and areas for improvement are identified. Finally recommendations based on the outcome of this paper are presented
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