Distinct Aspects Research Articles

A solid camp with flowing soldiers: heterogeneous public engagement with science communication on Twitter

AbstractThe science communication community is constantly evolving. However, limited research has explored the relationship between engagement heterogeneity and fluctuations in science communication. This study aims to address this issue by examining the dissemination of scientific research on Twitter using network analysis. The findings reveal the sensitivity of low-engagement users in two distinct aspects. First, low-engagement users’ dissemination of scientific information is positively associated with the overall trend of scientific communication on social media, suggesting their heightened susceptibility to fluctuations and disengagement compared to other users. Second, low-engagement users show decreased attention to health-related topics during fluctuation periods. In light of these findings, an analytical model is developed to integrate the heterogeneity of information acceptance thresholds and external shocks. The simulation results of the model are consistent with empirical observations, highlighting the heterogeneity of information acceptance thresholds in science communication. This study contributes to the understanding of fluidity as the essence of science communication. As the proverb goes, a solid camp is guarded by ever-changing soldiers. The solid camp stabilizes science communication communities while flowing soldiers enable the influence of science communication to cross communities.

Social integration of unemployed young people and adults with disabilities

The study aims to achieve the objective of special psychopedagogy, which aims at two distinct aspects: improving the quality of life of people with disabilities and their social and professional integration. The central objective of this research is the identification of the social and professional integration of people with disabilities from Constanta county. Furthermore, the models of social and professional integration are observed with the help of three Questionnaires: Questionnaire of assessment of social and professional integration (ISP); Quality of life inventory- QOLI and „Happiness” scale from The 46 AB5C Facetes.

Evaluating probabilistic classifiers: The triptych

Probability forecasts for binary outcomes, often referred to as probabilistic classifiers or confidence scores, are ubiquitous in science and society, and methods for evaluating and comparing them are in great demand. We propose and study a triptych of diagnostic graphics focusing on distinct and complementary aspects of forecast performance: Reliability curves address calibration, receiver operating characteristic (ROC) curves diagnose discrimination ability, and Murphy curves visualize overall predictive performance and value. A Murphy curve shows a forecast’s mean elementary scores, including the widely used misclassification rate, and the area under a Murphy curve equals the mean Brier score. For a calibrated forecast, the reliability curve lies on the diagonal, and for competing calibrated forecasts, the ROC and Murphy curves share the same number of crossing points. We invoke the recently developed CORP (Consistent, Optimally binned, Reproducible, and Pool-Adjacent-Violators (PAV) algorithm-based) approach to craft reliability curves and decompose a mean score into miscalibration (MCB), discrimination (DSC), and uncertainty (UNC) components. Plots of the DSC measure of discrimination ability versus the calibration metric MCB visualize classifier performance across multiple competitors. The proposed tools are illustrated in empirical examples from astrophysics, economics, and social science.

Risk and protective factors of mental health in children in residential care: A nationwide study from Luxembourg

BackgroundChildren who grow up in residential care are at high risk for mental health problems. Existing studies have focused on negative mental health indicators and risk factors. There has been less emphasis on identifying protective factors, particularly those associated with positive mental health outcomes. ObjectiveThis study explores positive and negative dimensions of mental health and their links to risk and protective factors in children who have experienced early adversity and trauma and have been placed in residential care. Participants and settingsChildren aged 11 to 18 (N = 264) were recruited from residential care homes in Luxembourg, a small, high-income European country. MethodsThe children completed self-report questionnaires on mental health, perceived stress, school pressure, and participation. Residential care workers provided information on demographic factors, developmental and care history, and pre-care experiences of early adversity and trauma. ResultsConfirmatory factor analysis indicated that subjective well-being, internalising problems, and externalising problems are separate yet interconnected components of mental health. Multiple Indicators Multiple Causes models showed that individual, contextual, and psychosocial predictors contribute differentially to positive and negative mental health outcomes. ConclusionsUsing a national sample of children in residential care in Luxembourg, this research indicates that subjective well-being, internalising problems, and externalising problems are distinct but related aspects of mental health. ‘Child participation’ and ‘school pressure’ displayed strong links with positive mental health outcomes and may serve as a potential path for improving public health interventions for children in care.

Mouthparts of the crab Goniopsis cruentata (Latreille, 1803) (Decapoda, Brachyura, Grapsidae): morphological variations associated with environment, sex and stage of development

Abstract Individuals and populations can display variations in distinct aspects of their life histories, which could be reflected in their morphological characteristics. This study analyzed the mouthpart morphology of the crab Goniopsis cruentata in relation to environment, sex and stage of development. Our results indicate differences in the number of setae between developmental stages and environments, as well as the interaction between developmental stages and environments. There were no differences in setae types between stages, sexes or environments. There were differences in the shape of the ischium between adults and juveniles, with a more homogeneous ischium in juveniles than adults. We also found differences in food content between developmental stages, as well as an interaction between developmental stages and environment. Our results support an association between diet and morphology of mouthparts in G. cruentata, and that these apparatuses vary according to ontogenetic development and the environmental conditions that species are exposed to. These associations should be considered in studies that use these characteristics to verify morphological responses to environmental variations.

11 Social Determinants of Health in Pediatric Brain Tumor Survivors: Associations between Neighborhood Opportunity and Neurocognitive and Psychological Outcomes

Objective:A growing body of research demonstrates that social determinants of health (SDOH) are important predictors of neurocognitive and psychological outcomes in survivors of pediatric brain tumor (PBT). Existing research has focused primarily on individual level SDOH (e.g., family income, education, insurance status). Thus, more information is needed to understand community level factors which may contribute to health inequities in PBT survivors. This study aimed to examine the effects of specific aspects of neighborhood opportunity on cognitive and emotional/behavioral outcomes among PBT survivors.Participants and Methods:The sample included clinically-referred PBT survivors who completed a neuropsychological evaluation (N=199, Mage=11.63, SD= 4.63, 56.8% male, 71.8% White). Data included an age-appropriate Wechsler Scale and parent-report questionnaires (Behavior Rating Inventory of Executive Function, Child Behavior Checklist). Nationally-normed Child Opportunity Index (COI) scores were extracted for each participant from electronic medical records based on home address using Census tract geocoding. The COI measures neighborhood-level quality of environmental and social conditions that contribute to positive health. It includes three component scores assessing distinct aspects of opportunity, which include educational opportunity (e.g., educational quality, resources, and outcomes), health/environmental opportunity (e.g., access to healthy food, healthcare, and greenspace) and social/economic opportunity (e.g., income, employment, poverty). Stepwise linear regression models were examined to identify significant predictors of cognitive/psychological outcomes associated with PBT; the three COI indices were entered as predictors and retained in the model if they significantly contribute to variance in the outcome.Results:Lower educational opportunity was associated with lower processing speed performance (Wechsler Processing Speed Index: t = 2.47, p = 0.02) and increased parent-reported executive functioning problems (BRIEF GEC: t = -2.25, p = 0.03; BRIEF Working Memory: t = -2.45, p = 0.02) and externalizing problems (CBCL Externalizing: t = -2.19, p = 0.03). Lower social/economic opportunity was associated with lower working memory performance (Wechsler Working Memory Index: t = 2.63, p < 0.01) and increased parent-reported internalizing problems (CBCL Internalizing: t = -2.38, p = 0.02). Health/environmental opportunity did not emerge as a primary predictor of any of the examined cognitive/psychological outcomes. Exploratory analyses examining the impact of age on associations between COI and cognitive/psychological outcomes found a significant moderation effect of age on the relationship between educational opportunity and processing speed (t = 2.35, p = 0.02) such that this association was stronger at older ages. There were no other moderation effects by age.Conclusions:Consistent with a growing body of literature demonstrating the impact of social and environmental contexts to health outcomes, these results show inequities in neurocognitive and psychosocial outcomes in PBT survivors related to neighborhood-level SDOH. Examination of specific neighborhood factors highlight educational and social/economic factors as particularly important contributors to neurocognitive/psychological risk for survivors. The identification of these specific and potentially modifiable risk factors is crucial to inform individual-level problem-prevention following oncological treatment, as well as community-level policy and advocacy efforts.

Incorporation of human iPSC-derived stromal cells creates a pancreatic cancer organoid with heterogeneous cancer-associated fibroblasts

The aggressiveness of pancreatic ductal adenocarcinoma (PDAC) is affected by the tumor microenvironment (TME). In this study, to recapitulate the PDAC TME exvivo, we cocultured patient-derived PDAC cells with mesenchymal and vascular endothelial cells derived from human induced pluripotent stem cells (hiPSCs) to create a fused pancreatic cancer organoid (FPCO) in an air-liquid interface. FPCOs were further induced to resemble two distinct aspects of PDAC tissue. Quiescent FPCOs were drug resistant, likely because the TME consisted of abundant extracellular matrix proteins that were secreted from the various types of cancer-associated fibroblasts (CAFs) derived from hiPSCs. Proliferative FPCOs could re-proliferate after anticancer drug treatment, suggesting that this type of FPCO would be useful for studying PDAC recurrence. Thus, we generated PDAC organoids that recapitulate the heterogeneity of PDAC tissue and are a potential platform for screening anticancer drugs.

Clinical Static Balance Assessment: A Narrative Review of Traditional and IMU-Based Posturography in Older Adults and Individuals with Incomplete Spinal Cord Injury.

Maintaining a stable upright posture is essential for performing activities of daily living, and impaired standing balance may impact an individual's quality of life. Therefore, accurate and sensitive methods for assessing static balance are crucial for identifying balance impairments, understanding the underlying mechanisms of the balance deficiencies, and developing targeted interventions to improve standing balance and prevent falls. This review paper first explores the methods to quantify standing balance. Then, it reviews traditional posturography and recent advancements in using wearable inertial measurement units (IMUs) to assess static balance in two populations: older adults and those with incomplete spinal cord injury (iSCI). The inclusion of these two groups is supported by their large representation among individuals with balance impairments. Also, each group exhibits distinct aspects in balance assessment due to diverse underlying causes associated with aging and neurological impairment. Given the high vulnerability of both demographics to balance impairments and falls, the significance of targeted interventions to improve standing balance and mitigate fall risk becomes apparent. Overall, this review highlights the importance of static balance assessment and the potential of emerging methods and technologies to improve our understanding of postural control in different populations.

57 Financial Literacy in Older Adults: Cognitive, Demographic, and Personality Factors Related to Discrepancies between Objective Financial Knowledge and Subjective Financial Confidence

Objective:Management of finances is one of the earliest domains of daily living to decline in the neurodegenerative disease process, and poorer financial literacy is associated with worse cognition even in healthy, normative aging. However, some studies have demonstrated that cognitively normal older adults demonstrate preserved real-world financial outcomes despite the presence of age-related cognitive decline. One account for this discordance posits that older adults rely on intact financial knowledge to circumvent negative effects of declining fluid cognitive abilities. Also important to real-world financial behavior is insight into one’s level of financial knowledge and expertise (i.e., subjective financial confidence), which in some studies has been shown to have an equal or stronger influence on real-world financial behaviors compared to objective financial knowledge. This study investigated older adults’ financial abilities by identifying groups of individuals with discrepancies between objective financial knowledge and subjective financial confidence and exploring cognitive and non-cognitive (demographic, personality) factors associated with discrepancy group membership.Participants and Methods:Participants were 4,610 older adults (M age 71.18 ± .91) from the Wisconsin Longitudinal Study who answered 12 true-false questions on financial concepts (accuracy) and rated their confidence on each response. Standardized scores of accuracy and confidence were used to classify participants into three discrepancy groups (1) Overconfident (confidence >1 SD above accuracy), (2) Underconfident (accuracy >1 SD above confidence), and (3) Equal (accuracy and confidence within 1 SD). Logistic regression examined factors associated with discrepancy group membership.Results:Higher financial accuracy was moderately correlated with greater confidence (r=.42, p<.001). Approximately 29% of participants had standardized accuracy and confidence scores that differed by one standard deviation or more, with 14% of participants belonging to an “Overconfident” group and 15% to an “Underconfident” group. Lower likelihood of Overconfidence group membership was associated with higher levels of education (OR = .87, 95% CI [.82, .93], p<.001) and better cognitive performance on tests of delayed recall (OR = .90, 95% CI [.84, .97], p=.006) and numerical reasoning (OR = .94, 95% CI [.91, .97], p<.001), while higher extraversion was associated with increased likelihood of Overconfidence (OR = 1.03, 95% CI [1.00, 1.05], p=.04). Lower likelihood of Underconfident group membership was associated with better performance on cognitive tests of delayed recall (OR = .90, 95% CI [.84, .96], p=.002), male sex (OR = .60, 95% CI [.47, .77], p<.001), and lower levels of conscientiousness (OR = .95, 95% CI [.92, .99], p<.001), while better letter fluency performance was associated with increased likelihood of Underconfidence (OR = 1.03, 95% CI [1.00, 1.06], p=.04).Conclusions:Objective financial knowledge and subjective financial confidence are related yet distinct aspects of financial literacy. Discrepancies between financial knowledge and confidence are related to both cognitive and non-cognitive factors, such as personality and differing life experiences associated with educational attainment and sex-related social roles. Results may help clinicians identify profiles of older adults (e.g., high confidence and low knowledge/"Overconfident”) at risk for dysfunctional financial behaviors, including susceptibility to fraud and/or irresponsible financial decision-making.

Sustainable business models and grassroots frugal innovations in developing countries

This research explores the origins and evolution of frugal innovations (FIs) within the grassroots communities of developing countries. It scrutinises how these innovations employ inventive business models that hold promise for sustainable development. The analysis centers on distinct aspects of business models, primarily elucidating the concepts of value proposition, value creation, and value capture. FIs, as this study reveals, possess the transformative ability to convert marginalised and underserved populations at the grassroots level into innovative consumer segments. Through an in-depth exploration of three compelling FI (Technology Hub, Albarka Yoghurt and JK Innovation) case studies, this research significantly contributes to the existing literature concerning FI business models. These cases vividly illustrate how individuals constrained by limited access to education, capital, and resources can ingeniously bring affordable products to market, employing unconventional strategies to fulfil the unmet needs of underserved demographics in developing nations."

Three-way group consensus method based on probabilistic linguistic preference relations with acceptable inconsistency

In the realm of addressing consensus challenges within group decision-making (GDM) that encompass individual preferences, this article presents an innovative approach. This article introduces a three-way group consensus methodology grounded in probabilistic linguistic preference relations (PLPRs) that ensures an acceptable level of inconsistency by applying the three-way decision (TWD) principle. This methodology is referred to as the TWD-GC-AIC approach. The TWD-GC-AIC approach consists of two core components, each dedicated to distinct aspects: ensuring the internal consistency of individual expert preference relations and achieving consensus within the expert group. The first component is dedicated to enhancing the consistency of individual expert preferences. This process commences with the determination of expert weights and the development of a novel aggregation formula. Subsequently, the consistency metric is refined through the incorporation of a newly devised distance formula. Once the predefined consistency threshold is reached, this study seamlessly integrates a planning model with an iterative algorithm. This integration serves a dual purpose: minimizing adjustment costs while retaining as much of the original information provided by the experts as possible. In the consensus-reaching phase, known as the consensus reaching process (CRP) of the expert group, this study employs iterative algorithms that incorporate TWD within the feedback mechanism. This strategic approach aims to comprehensively consider the emotional attitudes of the experts when adjusting the evaluation information, ultimately leading to a more informed and rational final decision outcome. Finally, this paper empirically validates the effectiveness and efficiency of the TWD-GC-AIC method, particularly in scenarios involving probabilistic linguistic term sets (PLTSs). The method is applied to a practical example and rigorously benchmarked against various other consensus methodologies to assess its performance.

Urban Planning Strategies Based on Green and Low-Carbon: A Case Study in Guangzhou City, China

The promotion of urbanization has become a major trend in the development of the new era. It brings cities rapid economic growth but also leads to significant carbon emissions. Cities are crucial in adopting low-carbon development policies and carrying out carbon reduction initiatives since they are large sources of energy use and emissions of greenhouse gases. The building of low-carbon cities has been essential at a time when carbon neutrality and carbon peaking have become the consensus and mission of humanity. Following the theory of low-carbon urban growth theory, the article takes Guangzhou city in China as an example, describes its low-carbon policies in urban planning during different periods, and discusses its low-carbon initiatives and effectiveness. It is known that Guangzhou is now constructing a low-carbon metropolis but has issues with two distinct aspects of transportation and industrial transformation. The urban transportation system needs to be improved, and the industry needs to upgrade and transform. In response to the problems, this article recommends countermeasures to intensify efforts to enhance public transportation and enable the low-carbon transformation of industry in order to promote the green and scientific growth of Guangzhou as a low-carbon city.

Distinct Neural Components of Visually Guided Grasping during Planning and Execution.

Selecting suitable grasps on three-dimensional objects is a challenging visuomotor computation, which involves combining information about an object (e.g., its shape, size, and mass) with information about the actor's body (e.g., the optimal grasp aperture and hand posture for comfortable manipulation). Here, we used functional magnetic resonance imaging to investigate brain networks associated with these distinct aspects during grasp planning and execution. Human participants of either sex viewed and then executed preselected grasps on L-shaped objects made of wood and/or brass. By leveraging a computational approach that accurately predicts human grasp locations, we selected grasp points that disentangled the role of multiple grasp-relevant factors, that is, grasp axis, grasp size, and object mass. Representational Similarity Analysis revealed that grasp axis was encoded along dorsal-stream regions during grasp planning. Grasp size was first encoded in ventral stream areas during grasp planning then in premotor regions during grasp execution. Object mass was encoded in ventral stream and (pre)motor regions only during grasp execution. Premotor regions further encoded visual predictions of grasp comfort, whereas the ventral stream encoded grasp comfort during execution, suggesting its involvement in haptic evaluation. These shifts in neural representations thus capture the sensorimotor transformations that allow humans to grasp objects.SIGNIFICANCE STATEMENT Grasping requires integrating object properties with constraints on hand and arm postures. Using a computational approach that accurately predicts human grasp locations by combining such constraints, we selected grasps on objects that disentangled the relative contributions of object mass, grasp size, and grasp axis during grasp planning and execution in a neuroimaging study. Our findings reveal a greater role of dorsal-stream visuomotor areas during grasp planning, and, surprisingly, increasing ventral stream engagement during execution. We propose that during planning, visuomotor representations initially encode grasp axis and size. Perceptual representations of object material properties become more relevant instead as the hand approaches the object and motor programs are refined with estimates of the grip forces required to successfully lift the object.

Hearing loss, depression, and cognition in younger and older adult CI candidates.

Hearing loss in old age is associated with cognitive decline and with depression. Our study aimed to investigate the relationship between hearing loss, cognitive decline, and secondary depressive symptoms in a sample of younger and older cochlear implant candidates with profound to severe hearing loss. This study is part of a larger cohort study designated to provide information on baseline data before CI. Sixty-one cochlear implant candidates with hearing loss from adulthood onwards (>18 years) were enrolled in this study. All had symmetrical sensorineural hearing loss in both ears (four-frequency hearing threshold difference of no more than 20 dB, PTA). Individuals with primary affective disorders, psychosis, below-average intelligence, poor German language skills, visual impairment, and a medical diagnosis with potential impact on cognition (e.g., neurodegenerative diseases,) were excluded. Four-frequency hearing thresholds (dB, PTA, better ear) were collected. Using the Abbreviated Profile of Hearing Aid Benefit, we assessed subjective hearing in noise. Clinical and subclinical depressive symptoms were assessed with the Beck Depression Inventory (BDI II). Cognitive status was assessed with a neurocognitive test battery. Our findings revealed a significant negative association between subjective hearing in noise (APHAB subscale "Background Noise") and BDII. However, we did not observe any link between hearing thresholds, depression, and cognition. Additionally, no differences emerged between younger (25-54 years) and older subjects (55-75 years). Unexpectedly, further unplanned analyses unveiled correlations between subjective hearing in quiet environments (APHAB) and cognitive performance [phonemic fluency (Regensburg Word Fluency), cognitive flexibility (TMTB), and nonverbal episodic memory (Nonverbal Learning Test), as well as subjective hearing of aversive/loud sounds (APHAB)], cognitive performance [semantic word fluency (RWT), and inhibition (Go/Nogo) and depression]. Duration of hearing loss and speech recognition at quiet (Freiburg Monosyllables) were not related to depression and cognitive performance. Impact of hearing loss on mood and cognition appears to be independent, suggesting a relationship with distinct aspects of hearing loss. These results underscore the importance of considering not only conventional audiometric measures like hearing thresholds but also variables related to hearing abilities during verbal communication in everyday life, both in quiet and noisy settings.

Intrusive-like memory errors associate with positive schizotypy

Schizophrenia is characterized by memory impairments, yet the relationships between its distinct symptom clusters (i.e., positive, negative, disorganized) and specific aspects of memory dysfunction remain poorly characterized. In the present study, we compiled a large analog sample (N = 795) to test whether positive symptoms, versus negative and disorganized symptoms, were uniquely and differentially related to false alarm versus miss errors during recognition memory. Mixed-effects beta regression analyses revealed that both positive schizotypy and paranoia were more strongly associated with false alarms than misses. Disorganized schizotypy showed a similar pattern, though to a lesser extent; negative schizotypy showed a significant relationship with neither false alarm nor miss errors. We suggest that those higher in positive schizotypy are especially prone to misattribute signal to noise stimuli during recognition memory – characteristic of an “intrusive-like” profile of memory impairment, wherein context-irrelevant stimuli trigger spurious retrieval events – and speculate on the neural processes that might give rise to this asymmetry.

Lesion area reduction and the amelioration of anxiety and depression states in psoriasis patients: A prospective clinical study

BackgroundPsoriasis patients are more likely to have mental disorders. The relationship between the reduction of involvement area and severity of lesions and the associated improvement in anxiety and depression in psoriasis patients, remains inadequately researched. Methods200 psoriasis patients were enrolled in this prospective study, and received 12-week narrowband ultraviolet B (NB-UVB) therapy. The Psoriasis Area and Severity Index (PASI), Body Surface Area (BSA), and Physician Global Assessment (PGA) scores were obtained as the objective assessments of disease, each reflecting distinct aspects of the disease. The Hospital Anxiety and Depression Scale (HADS) was used to evaluate the anxiety and depression symptoms. ResultsSuccessful treatment brought an improvement in anxiety and depression levels and rates (all p < 0.05). Statistical analysis revealed no significant improvements in the scores of HADS or rates of symptomatic anxiety and depression in patients who did not achieve a PASI 75 response (all p > 0.05). Reductions in PASI, BSA and PGA were all statistically associated with reductions in HADS (all p < 0.05). BSA 75 response was found to play a more crucial role in the transition of symptomatic psoriatic patients to asymptomatic status (all p < 0.01). LimitationsThe study focused on the short-term effects, and further research is needed to investigate the long-term effects. ConclusionSuccessful treatment of psoriasis resulted in improvements in anxiety and depression levels and rates. In comparison with the lesion severity, reduction in the lesion involvement area had a greater impact on the anxiety and depression symptoms.

Neuronal Ensembles in the Infralimbic Cortex Dynamically Process Distinct Aspects of Hedonic Value.

Hedonic processing is critical for guiding appropriate behavior, and the infralimbic cortex (IL) is a key neural substrate associated with this function in rodents and humans. We used deep brain in vivo calcium imaging and taste reactivity in freely behaving male and female Sprague Dawley rats to examine whether the infralimbic cortex is involved in encoding innate versus conditioned hedonic states. In experiment 1, we examined the IL neuronal ensemble responsiveness to intraoral innately rewarding (sucrose) versus aversive (quinine) tastants. Most IL neurons responded to either sucrose only or both sucrose and quinine, with fewer neurons selectively processing quinine. Among neurons that responded to both stimuli, some appear to encode hedonic processing. In experiment 2, we examined how IL neurons process devalued sucrose using conditioned taste aversion (CTA). We found that neurons that responded exclusively to sucrose were disengaged while additional quinine-exclusive neurons were recruited. Moreover, tastant-specific neurons that did not change their neuronal activity after CTA appeared to encode objective hedonic value. However, other neuronal ensembles responded to both tastants and appear to encode distinct aspects of hedonic processing. Specifically, some neurons responded differently to quinine and sucrose and shifted from appetitive-like to aversive-like activity after CTA, thus encoding the subjective hedonic value of the stimulus. Conversely, neurons that responded similarly to both tastants were heightened after CTA. Our findings show dynamic shifts in IL ensembles encoding devalued sucrose and support a role for parallel processing of objective and subjective hedonic value.SIGNIFICANCE STATEMENT Disrupted affective processing contributes to psychiatric disorders including depression, substance use disorder, and schizophrenia. We assessed how the infralimbic cortex, a key neural substrate involved in affect generation and affect regulation, processes innate and learned hedonic states using deep brain in vivo calcium imaging in freely behaving rats. We report that unique infralimbic cortex ensembles encode stimulus subjective and objective hedonic value. Further, our findings support similarities and differences in innate versus learned negative affective states. This study provides insight into the neural mechanisms underlying affect generation and helps to establish a foundation for the development of novel treatment strategies to reduce negative affective states that arise in many psychiatric disorders.

The Neurobiology of Activational Aspects of Motivation: Exertion of Effort, Effort-Based Decision Making, and the Role of Dopamine.

Motivational processes are complex and multifaceted, with both directional and activational aspects. Behavioral activation and exertion of effort are functions that enable organisms to overcome obstacles separating them from significant outcomes. In a complex environment, organisms make cost/benefit decisions, assessing work-related response costs and reinforcer preference. Animal studies have challenged the general idea that dopamine (DA) is best viewed as the reward transmitter and instead have illustrated the involvement of DA in activational and effort-related processes. Mesocorticolimbic DA is a key component of the effort-related motivational circuitry that includes multiple neurotransmitters and brain areas. Human studies have identified brain areas and transmitter systems involved in effort-based decision making and characterized the reduced selection of high-effort activities associated with motivational symptoms of depression and schizophrenia. Animal and human research on the neurochemistry of behavioral activation and effort-related processes makes an important conceptual contribution by illustrating the dissociable nature of distinct aspects of motivation.

Isolation of Extracellular Vesicles from Phloem Sap by Size Exclusion Chromatography.

Extracellular vesicles (EVs) are nanoparticles that are released by cells and participate in the transfer of information. It is now known that EVs from mammalian cells are involved in different physiological and pathophysiological processes (antigen presentation, tissue regeneration, cancer, inflammation, diabetes, etc.). In the past few years, several studies on plants have demonstrated that EVs are also key tools for plant intercellular and cross-kingdom communications, suggesting that these nanostructures may contribute to distinct aspects of plant physiology such as development, defense, reproduction, symbiotic relationships, etc. These findings are challenging the traditional view of signaling in plants. EVs are probably involved in the phloem's transport system, since this vascular tissue plays a crucial role in translocating nutrients, defensive compounds, and informational signals throughout the plant. The collection of phloem is experimentally challenging because sap is under high turgor pressure inside the sieve elements, which have a small diameter and are hidden within the plant organs. The goals of this work are to develop new protocols that allow us to detect EVs for the first time in the phloem of the plants, and to isolate these nanovesicles for in-depth analysis and characterization. Our protocols describe two distinct methods to collect the phloem sap from rice and melon. The first method (Basic Protocol 1) involves 'Aphid stylectomy by radiofrequency microcautery' using rice plants and the aphid Sitobion avenae. This is considered the least invasive method for collecting phloem sap. The second method, 'Stem incision', involves cutting the stem of melon plants for collecting the exuded sap. Phloem sap EVs are then isolated by size exclusion chromatography. The results obtained in this study represent the first report on typical EVs isolated from in vivo-collected phloem sap. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Isolation of EVs from phloem sap: Aphid stylectomy by radiofrequency microcautery Basic Protocol 2: Isolation of EVs from phloem sap: Stem incision method.

Dihydropyrimidine dehydrogenase from Escherichia coli: Transient state analysis reveals both reductive activation prior to turnover and diminished substrate effector roles relative to the mammalian form

Dihydropyrimidine dehydrogenase (DPD) is an enzyme that uses an elaborate architecture to catalyze a simple net reaction: the reduction of the vinylic bond of uracil and thymine. Known DPDs have two active sites separated by approximately 60 Å. One active site has an FAD cofactor and binds NAD(P) and the other has an FMN cofactor and binds pyrimidines. The intervening distance is spanned by four Fe4S4 centers that act as an electron conduit. Recent advancements with porcine DPD have revealed unexpected chemical sequences where the enzyme undergoes reductive activation by transferring two electrons from NADPH to the FMN via the FAD such that the active form has the cofactor set FAD•4(Fe4S4)•FMNH2. Here we describe the first comprehensive kinetic investigation of a bacterial form of DPD. Using primarily transient state methods, DPD from E. coli (EcDPD) was shown to have a similar mechanism to that observed with the mammalian form in that EcDPD is observed to undergo reductive activation before pyrimidine reduction and displays half-of-sites activity. However, two distinct aspects of the EcDPD reaction relative to the mammalian enzyme were observed that relate to the effector roles for substrates: (i) the enzyme will rapidly take up electrons from NADH, reducing a flavin in the absence of pyrimidine substrate, and (ii) the activated form of the enzyme can become fully oxidized by transferring electrons to pyrimidine substrates in the absence of NADH.