Summary
It has been proposed that ectomycorrhizal fungi can reduce decomposition while arbuscular mycorrhizal fungi may enhance it. These phenomena are known as the ‘Gadgil effect’ and ‘priming ...effect’, respectively. However, it is unclear which one predominates globally.
We evaluated whether mycorrhizal fungi decrease or increase decomposition, and identified conditions that mediate this effect. We obtained decomposition data from 43 studies (97 trials) conducted in field or laboratory settings that controlled the access of mycorrhizal fungi to substrates colonized by saprotrophs.
Across studies, mycorrhizal fungi promoted decomposition of different substrates by 6.7% overall by favoring the priming effect over the Gadgil effect. However, we observed significant variation among studies. The substrate C : N ratio and absolute latitude influenced the effect of mycorrhizal fungi on decomposition and contributed to the variation. Specifically, mycorrhizal fungi increased decomposition at low substrate C : N and absolute latitude, but there was no discernable effect at high values. Unexpectedly, the effect of mycorrhizal fungi was not influenced by the mycorrhizal type.
Our findings challenge previous assumptions about the universality of the Gadgil effect but highlight the potential of mycorrhizal fungi to negatively influence soil carbon storage by promoting the priming effect.
Resumen
Los hongos ectomicorrízicos puden reducir la descomposición mientras que los hongos micorrízico‐arbusculares pueden potenciarla. Ambos fenómenos son conocidos como “Gadgil effect” y “priming effect”, respectivamente. Sin embargo, no es claro cuál predomina mundialmente.
En este trabajo evaluamos si los hongos micorrízicos disminuyen o promueven la descomposición, e identificamos las condiciones que regulan este efecto. Para ello, recopilamos datos de descomposición de 43 estudios (97 observaciones) realizados en condiciones de campo o laboratorio que controlaron el acceso de los hongos micorrízicos a sustratos colonizados por saprótrofos.
Los hongos micorrízicos promovieron la descomposición de diferentes sustratos en un 6.7%. Sin embargo, observamos una variación significativa entre estudios. La relación C : N del sustrato y la latitud influyeron en el efecto de los hongos micorrícicos sobre la descomposición y contribuyeron a la variabilidad. Específicamente, los hongos micorrízicos aumentaron la descomposición a valores bajos de C : N del sustrato y latitud, pero no hubo un efecto discernible en valores altos. Inesperadamente, el tipo de micorriza no influyó en el efecto de los hongos micorrízicos.
Nuestros hallazgos cuestionan la universalidad del Gadgil effect, y resaltan el potencial de los hongos micorrízicos para influir negativamente en el almacenamiento de carbono del suelo al promover el priming effect.
Food insecurity, a social and economic condition of inadequate food resources, is known to affect cognitive development in children. However, research is sparse among adult populations, particularly ...older adults who may be more susceptible to accelerated cognitive decline.
The aim of this study was to examine the associations between food insecurity and cognitive functioning among older adults.
Data came from 1823 older adults (≥60 y) with incomes ≤300% of the federal poverty level (FPL) from the 2011–2014 NHANES. Food security was measured using the 10-item Adult Food Security Survey Module. Cognitive function was measured using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) word learning subtest and delayed word recall, the Animal Fluency Test (AFT), and the Digit Symbol Substitution Test (DSST). The cognitive assessments were then standardized and an overall cognitive function z score was created by averaging across all cognitive assessments. Associations with food insecurity were examined using multivariate linear regression models, adjusting for sociodemographic and health characteristics.
In the analytic population, the prevalence of food insecurity was 23.7%. Across all cognitive assessments, the mean scores among food-insecure adults was significantly lower than the mean scores among food-secure adults. After adjusting for sociodemographic and health characteristics, food insecurity was associated with lower scores on the CERAD word learning subtest (β = −0.14, 95% CI: −0.26, −0.01), the AFT (β = −0.13, 95% CI: −0.25, −0.002), and the DSST (β = −0.24, 95% CI: −0.33, −0.15). Food insecurity was also associated with a lower score on the overall cognitive function z score (β = −0.15, 95% CI: −0.26, −0.05).
In this national sample of 1823 adults aged ≥60 y, food insecurity was inversely associated with cognitive function, which may translate into higher risk of cognitive impairment over time.
Food insecurity, a condition of inadequate household food availability, affects 15.7% of US households with children. Food insecurity is generally believed to affect the quantity and quality of food ...consumed. However, an understudied but important aspect of the experience of food insecurity is psychological distress.
To critically explore the psychological distress associated with children’s food insecurity using children’s own reports of their experiences.
In-depth qualitative interviews conducted with children to better understand the psychological distress associated with food insecurity.
Sixty children (aged 7 to 14 years) were recruited from the San Francisco Bay Area. Children were eligible in the case that they spoke English fluently and their parent reported any experience of household food insecurity during the past year.
Children discussed six themes related to the psychological distress associated with food insecurity: worrying about not having enough food, worrying about their parents’ well-being, anger and frustration about not having enough food, embarrassment about their family’s food situation, strain on the family’s dynamics due to food insecurity, and sadness over not having enough food. After describing their experiences, children described strategies they employed to tolerate or cope with food insecurity, including distracting from or using their imagination to cope with food insecurity, increasing tolerance of their family’s food situation, and appreciating their parents for providing food and resources.
Food insecurity contributes to children’s psychological distress. Given the known effects of chronic stress in childhood, the psychological distress of food insecurity may represent an important mechanism by which food insecurity adversely influences children’s growth and development and deserves investigation in future studies.
Objectives
To determine the risk of COVID‐19 transmission during minimally invasive surgical (MIS) procedures
Methods
Surgical society statements regarding the risk of COVID transmission during MIS ...procedures were reviewed. In addition, the available literature on COVID‐19 and other viral transmission in CO2 pneumoperitoneum, as well as the presence of virus in the plume created by electrocautery during MIS was reviewed. The society recommendations were compared to the available literature on the topic to create our review and recommendations to mitigate COVID‐19 transmission.
Results
The recommendations promulgated by various surgical societies evolved over time as more information became available on COVID‐19 transmission. Review of the available literature on the presence of COVID‐19 in CO2 pneumoperitoneum was inconclusive. There is no clear evidence of the presence of COVID‐19 in plume created by electrocautery. Technologies to reduce CO2 pneumoperitoneum release into the operating room as well as filter viral particles are available and should reduce the exposure risk to operating room personnel.
Conclusion
There is no clear evidence of COVID‐19 virus in the CO2 used during MIS procedures or in the plume created by electrocautery. Until the presence or absence of COVID‐19 viral particles has been clearly established, measures to mitigate CO2 and surgical cautery plume release into the operating room should be performed. Further study on the presence of COVID‐19 in MIS pneumoperitoneum and cautery plume is needed.
Abstract Background: Genomic sequencing data from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have provided important information on the emergence of variants of interest. Some ...research has focused on determining intra-host variability and evolution, and others have focused on viral genetic variability in different tissues, as well as implications for virus infectivity and pathogenicity. However, the inter-host variability of SARS-CoV-2 in respiratory compartments and its implications has not yet been explained. To determine a possible pattern of tissue-specific inter-host variability at different levels of the respiratory system associating this information with clinically important characteristics. Methods: In this work, we analyzed the inter-host variability of SARS-CoV-2 using the Shannon entropy method with genomic data from NCBI database. Fifty-seven SARS-CoV-2 viral genomic sequences were included in the study. Oronasopharyngeal ( n = 30) and tracheal aspirate ( n = 27) sample sequences were analyzed by bioinformatics methods to determine the viral variability. Results: Different patterns of variability were observed in SARS-CoV-2 in the respiratory tract, which may indicate tissue compartmentalization phenomena. Genetic changes found in the N y S gene could affect the detection and spread of the virus. The overall analysis of the viral genomes identifies the variants of worldwide distribution. The viral diversity found in the different parts of the respiratory tract was high and uniformly distributed throughout the genome. Conclusions: Tracking inter-host variations in SARS-CoV-2 could help to understand the effects of viral evolution, provide information for diagnosis, drug, and vaccine design.
Purpose
This study aims to explore how tourists construct destination images in the context of dark tourism and reveals the relationships between on-site experience, destination image and behavioural ...intention.
Design/methodology/approach
The earthquake-ravaged county town of Beichuan in China was chosen as the study site. The study collected 298 viable questionnaires from tourists. Partial least squares structural equation modelling was performed to explore the relationships between the variables of on-site experience, destination image and behavioural intention.
Findings
The study identified four dimensions of dark tourism destination image (TDI) from its attribute and functional perspective. It found that “image of memorial place” and “image of educational place” were the most perceptual images and positively related with most subdimensions of on-site experience and behavioural intention. “Image of leisure place” and “image of landscapes of fear” were less perceived by tourists and negatively related with some subdimensions of on-site experience and behavioural intention.
Originality/value
To our knowledge, this study is the first attempt to explore the complex mechanisms of dark TDI formation with the framework of “on-site experiences–destination images–behavioural intentions”. By identifying tourists’ most and least perceptual images and their effective antecedents and consequences help to reconcile and manage the controversial and contradictory images of a dark tourism destination.
黑色旅游地游客现场体验、目的地形象、行为意愿关系研究
摘要
目标
本文探讨了游客如何建构黑色旅游目的地形象, 进一步研究了游客现场体验、目的地形象、行为意愿之间的作用关系。
设计/方法
以汶川地震重灾区北川老县城遗址为案例地, 本研究收集了游客结构化问卷298份, 采用偏最小二乘结构方程模型（PLS-SEM）分析了游客现场体验、目的地形象和行为意愿各维度之间的作用关系。
研究发现
从目的地属性和功能角度, 本文区分了黑色旅游目的地形象四个维度。研究发现“纪念地形象”和“教育地形象”是游客感知最强的两大维度, 与绝大多数游客现场体验和行为意愿的维度呈显著正向影响关系。 “休闲地形象”和“恐惧景观形象”, 游客感知较弱, 与现场体验和行为意向的一些维度呈负向影响关系。
创新/价值
本文首次利用“现场体验-目的地形象-行为意愿”这一研究框架, 揭示黑色旅游目的地形象的复杂生成机制。通过识别游客感知最强和最弱的形象维度, 揭示其前因与后果, 有助于调和与管理有争议和矛盾的黑色旅游目的地形象。
Destino de turismo oscuro: Relaciones entre las experiencias de los turistas en el lugar, imágenes del destino e intenciones de comportamiento
Propósito
Este estudio explora cómo los turistas construyen la imagen del destino en el contexto del turismo oscuro, revelando las relaciones entre experiencias en el lugar, imágenes del destino e intenciones de comportamiento.
Diseño/metodología/enfoque
El terremoto que devastó la ciudad del condado de Beichuan en China fue elegido lugar de estudio por sus peculiaridades para el desarrollo del destino oscuro. El estudio recopiló 298 cuestionarios viables de turistas. Se planteo un modelo de ecuaciones estructurales (PLS-SEM) para explorar las relaciones entre las variables de experiencias en el lugar, imágenes de destino e intenciones de comportamiento.
Hallazgos
El estudio identificó cuatro dimensiones de la imagen del destino turístico oscuro desde su atributo y perspectiva funcional. De igual forma, se encontró que la “imagen del lugar conmemorativo” y la “imagen del lugar educativo” eran las imágenes más perceptivas y estaban relacionadas positivamente con la mayoría de los subdimensiones de las experiencias en el lugar e intenciones de comportamiento. Los turistas percibieron menos la “imagen de un lugar de ocio” y la “imagen de paisajes de miedo” y se relacionaron negativamente con algunos subdimensiones de las experiencias en el lugar e intención de comportamiento.
Originalidad/valor
Hasta donde sabemos, este estudio es el primer intento de explorar el complejo mecanismo en la formación de TDIs oscuros con el marco de “experiencias en el lugar- imágenes de destino – intenciones de comportamiento”. Al identificar las imágenes más o menos perceptivas de los turistas, y sus antecedentes y consecuencias efectivos, ayuda a conciliar y gestionar las imágenes controvertidas y contradictorias de un destino turístico oscuro.
Abstract
The differentiation between influenza and coronavirus disease 2019 (COVID-19) could constitute a diagnostic challenge during the ongoing winter owing to their clinical similitude. Thus, ...novel biomarkers are required to enable making this distinction. Here, we evaluated whether the surfactant protein D (SP-D), a collectin produced at the alveolar epithelium with known immune properties, was useful to differentiate pandemic influenza A(H1N1) from COVID-19 in critically ill patients. Our results revealed high serum SP-D levels in patients with severe pandemic influenza but not those with COVID-19. This finding was validated in a separate cohort of mechanically ventilated patients with COVID-19 who also showed low plasma SP-D levels. However, plasma SP-D levels did not distinguish seasonal influenza from COVID-19 in mild-to-moderate disease. Finally, we found that high serum SP-D levels were associated with death and renal failure among severe pandemic influenza cases. Thus, our studies have identified SP-D as a unique biomarker expressed during severe pandemic influenza but not COVID-19.
In this study, the authors found that serum surfactant protein D (SP-D) levels are increased in critically ill patients with pandemic influenza A(H1N1) and serve to differentiate them from individuals with severe coronavirus disease 2019 (COVID-19).
This paper aims to analyze the external and internal drivers of young consumers’ intention to participate in the sharing economy in tourism. From previous findings, a causal model (PLS) is designed ...to generate an integrated, practical, and novel structural model that significantly predicts the intention to participate. The model, consisting of nine dimensions, includes consumers’ external and internal variables. Separately, these variables have all been considered relevant in the literature, though they have not been studied jointly before. The descriptive results show the excellent attitude and predisposition of young people toward the tourism sharing economy, which facilitates their participation. Through the model, the importance of all internal and external consumer variables in the formation of intention are proven; however, attitude and social norm are most notable among them. Trust is also a critical variable that serves as the link between internal and external variables. The study provides managers of sharing economy platforms with knowledge to encourage young consumers’ participation in a communication and market orientation context. The generational approach (Generation Z) used also allows the conclusions and implications to be transferred to other regions and sectors.
•Caregivers display higher percentages of effector memory T cells than controls.•Caregivers display lower percentages of naive T cells than controls.•Parental stress was associated with higher ...effector:naïve T cell ratios.
Chronic psychological stress is associated with accelerated biological aging, immune dysfunction, and premature morbidity and mortality. Changes in the relative proportions of T cell subpopulations are thought to be a characteristic of immunological aging; however, understanding of whether these changes are associated with chronic psychological stress is incomplete. This study investigated associations between chronic caregiving stress and distributions of T cell phenotypes in a sample of high stress mothers of children with Autism Spectrum Disorder (caregivers; n = 91) and low stress mothers of neurotypical children (controls; n = 88). Immune markers assessed were naïve (CD45RA + CD62L+), central memory (CD45RA-CD62L+), and effector memory (CD45RA-CD62L-) CD4+ and CD8+ T cells. We also examined the ratio of effector to naïve (E:N) CD4+ and CD8+ T cells. In models adjusted for age, body mass index, race/ethnicity, and antidepressant use, caregivers displayed higher percentages of effector memory CD8+ and CD4+ T cells as well as lower percentages of naïve CD8+ T cells and central memory CD8+ and CD4+ T cells compared to controls. Caregivers also displayed significantly higher E:N ratios for both CD4+ and CD8+ T cells. These findings were also independent of cytomegalovirus infection status. Furthermore, higher parental stress, across both groups, was related to several immune parameters. These findings provide preliminary evidence that chronic parental caregiving stress is associated with changes in relative proportions of T cell subpopulations that are consistent with accelerated immunological aging.
Brain microglia (MG) may serve as a human immunodeficiency virus 1 (HIV) reservoir and ignite rebound viremia following cessation of antiretroviral therapy (ART), but they have yet to be proven to ...harbor replication-competent HIV. Here, we isolated brain myeloid cells (BrMCs) from nonhuman primates and rapid autopsy of people with HIV (PWH) on ART and sought evidence of persistent viral infection. BrMCs predominantly displayed microglial markers, in which up to 99.9% of the BrMCs were TMEM119+ MG. Total and integrated SIV or HIV DNA was detectable in the MG, with low levels of cell-associated viral RNA. Provirus in MG was highly sensitive to epigenetic inhibition. Outgrowth virus from parietal cortex MG in an individual with HIV productively infected both MG and PBMCs. This inducible, replication-competent virus and virus from basal ganglia proviral DNA were closely related but highly divergent from variants in peripheral compartments. Phenotyping studies characterized brain-derived virus as macrophage tropic based on the ability of the virus to infect cells expressing low levels of CD4. The lack of genetic diversity in virus from the brain suggests that this macrophage-tropic lineage quickly colonized brain regions. These data demonstrate that MG harbor replication-competent HIV and serve as a persistent reservoir in the brain.
PDF
