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1.
Proc Natl Acad Sci U S A ; 119(40): e2210036119, 2022 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-36166478

RESUMEN

As anthropogenic activities warm the Earth, the fundamental solution of reducing greenhouse gas emissions remains elusive. Given this mitigation gap, global warming may lead to intolerable climate changes as adaptive capacity is exceeded. Thus, there is emerging interest in solar radiation modification, which is the process of deliberately increasing Earth's albedo to cool the planet. Stratospheric aerosol injection (SAI)-the theoretical deployment of particles in the stratosphere to enhance reflection of incoming solar radiation-is one strategy to slow, pause, or reverse global warming. If SAI is ever pursued, it will likely be for a specific aim, such as affording time to implement mitigation strategies, lessening extremes, or reducing the odds of reaching a biogeophysical tipping point. Using an ensemble climate model experiment that simulates the deployment of SAI in the context of an intermediate greenhouse gas trajectory, we quantified the probability that internal climate variability masks the effectiveness of SAI deployment on regional temperatures. We found that while global temperature was stabilized, substantial land areas continued to experience warming. For example, in the SAI scenario we explored, up to 55% of the global population experienced rising temperatures over the decade following SAI deployment and large areas exhibited high probability of extremely hot years. These conditions could cause SAI to be perceived as a failure. Countries with the largest economies experienced some of the largest probabilities of this perceived failure. The potential for perceived failure could therefore have major implications for policy decisions in the years immediately following SAI deployment.

2.
J Bacteriol ; 205(9): e0016523, 2023 09 26.
Artículo en Inglés | MEDLINE | ID: mdl-37695858

RESUMEN

Streptomycin (Sm) is a commonly used antibiotic for its efficacy against diverse bacteria. The plant pathogen Agrobacterium fabrum is a model for studying pathogenesis and interkingdom gene transfer. Streptomycin-resistant variants of A. fabrum are commonly employed in genetic analyses, yet mechanisms of resistance and susceptibility to streptomycin in this organism have not previously been investigated. We observe that resistance to a high concentration of streptomycin arises at high frequency in A. fabrum, and we attribute this trait to the presence of a chromosomal gene (strB) encoding a putative aminoglycoside phosphotransferase. We show how strB, along with rpsL (encoding ribosomal protein S12) and rsmG (encoding a 16S rRNA methyltransferase), modulates streptomycin sensitivity in A. fabrum. IMPORTANCE The plant pathogen Agrobacterium fabrum is a widely used model bacterium for studying biofilms, bacterial motility, pathogenesis, and gene transfer from bacteria to plants. Streptomycin (Sm) is an aminoglycoside antibiotic known for its broad efficacy against gram-negative bacteria. A. fabrum exhibits endogenous resistance to somewhat high levels of streptomycin, but the mechanism underlying this resistance has not been elucidated. Here, we demonstrate that this resistance is caused by a chromosomally encoded streptomycin-inactivating enzyme, StrB, that has not been previously characterized in A. fabrum. Furthermore, we show how the genes rsmG, rpsL, and strB jointly modulate streptomycin susceptibility in A. fabrum.


Asunto(s)
Agrobacterium , Estreptomicina , Estreptomicina/farmacología , ARN Ribosómico 16S , Antibacterianos/farmacología
3.
Hum Factors ; : 187208231167641, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37127401

RESUMEN

OBJECTIVE: This study explored the impact of in-vehicle messages relative to roadside messages to alert drivers to events within a simulated work zone, in order to determine if these messages can improve driving performance within the work zone. BACKGROUND: Safety risks in work zones are usually mitigated by design standards and clear signage to communicate work zone information to drivers. Due to distraction and other driving task demands, these signs are not always noticed by motorists, nor are they always followed when they are noticed. METHOD: The driving simulation tested drivers in two different types of work zones, shoulder work, and lane closure. Participants drove through these work zones three times, each with different messaging interfaces to communicate hazardous events to the driver. The interfaces included a roadside, portable changeable message sign, a smartphone presenting only auditory messages, and a smartphone presenting audio-visual messages. RESULTS: There was significantly better driving performance on key metrics including lane deviation for the in-vehicle message conditions relative to the roadside signs. Furthermore, drivers directed visual attention toward the roadway for the in-vehicle message conditions relative to the roadside sign condition. CONCLUSION: The results indicate that in-vehicle messaging could provide benefits to primary task performance in driving if the message content is appropriately designed. APPLICATION: The findings provide support for a design framework to support in-vehicle communication to drivers approaching work zones and other environments to safely alert them to hazards.

4.
Basic Res Cardiol ; 117(1): 17, 2022 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-35357563

RESUMEN

Cardiac contractile strength is recognised as being highly pH-sensitive, but less is known about the influence of pH on cardiac gene expression, which may become relevant in response to changes in myocardial metabolism or vascularization during development or disease. We sought evidence for pH-responsive cardiac genes, and a physiological context for this form of transcriptional regulation. pHLIP, a peptide-based reporter of acidity, revealed a non-uniform pH landscape in early-postnatal myocardium, dissipating in later life. pH-responsive differentially expressed genes (pH-DEGs) were identified by transcriptomics of neonatal cardiomyocytes cultured over a range of pH. Enrichment analysis indicated "striated muscle contraction" as a pH-responsive biological process. Label-free proteomics verified fifty-four pH-responsive gene-products, including contractile elements and the adaptor protein CRIP2. Using transcriptional assays, acidity was found to reduce p300/CBP acetylase activity and, its a functional readout, inhibit myocardin, a co-activator of cardiac gene expression. In cultured myocytes, acid-inhibition of p300/CBP reduced H3K27 acetylation, as demonstrated by chromatin immunoprecipitation. H3K27ac levels were more strongly reduced at promoters of acid-downregulated DEGs, implicating an epigenetic mechanism of pH-sensitive gene expression. By tandem cytoplasmic/nuclear pH imaging, the cardiac nucleus was found to exercise a degree of control over its pH through Na+/H+ exchangers at the nuclear envelope. Thus, we describe how extracellular pH signals gain access to the nucleus and regulate the expression of a subset of cardiac genes, notably those coding for contractile proteins and CRIP2. Acting as a proxy of a well-perfused myocardium, alkaline conditions are permissive for expressing genes related to the contractile apparatus.


Asunto(s)
Núcleo Celular , Miocardio , Animales , Expresión Génica , Mamíferos , Contracción Miocárdica , Miocardio/metabolismo , Miocitos Cardíacos/metabolismo
5.
J Evol Biol ; 35(7): 1012-1019, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35647767

RESUMEN

Asexual reproduction is expected to have a twofold reproductive advantage over sexual reproduction, owing to the cost of producing males in sexual subpopulations. The persistence of sexual females, thus, requires an advantage to sexual reproduction, at least periodically. Here, we tested the hypothesis that asexual females are more sensitive to limited resources. Under this idea, fluctuations in the availability of resources (per capita) could periodically favour sexual females when resources become limited. We combined sexual and asexual freshwater snails (Potamopyrgus antipodarum) together in nylon mesh enclosures at three different densities in an outdoor mesocosm. After 1 month, we counted the brood size of fertile female snails. We found that fecundity declined significantly with increasing density. However, sexual females did not produce more offspring than asexual females at any of the experimental densities. Our results, thus, suggest that the cost of sexual reproduction in P. antipodarum is not ameliorated by periods of intense resource competition.


Asunto(s)
Reproducción Asexuada , Caracoles , Animales , Femenino , Fertilidad , Masculino , Dinámica Poblacional , Reproducción
6.
J Evol Biol ; 35(7): 962-972, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35661463

RESUMEN

Coevolution between mutualists can lead to reciprocal specialization, potentially causing barriers to host switching. Here, we conducted assays to identify pre- and post-association barriers to host switching by endosymbiotic bacteria, both within and between two sympatric nematode clades. In nature, Steinernema nematodes and Xenorhabdus bacteria form an obligate mutualism. Free-living juvenile nematodes carry Xenorhabdus in a specialized intestinal receptacle. When nematodes enter an insect, they release the bacteria into the insect hemocoel. The bacteria aid in killing the insect and facilitate nematode reproduction. Prior to dispersing from the insect, juvenile nematodes must form an association with their symbionts; the bacteria must adhere to the intestinal receptacle. We tested for pre-association barriers by comparing the effects of bacterial strains on native versus non-native nematodes via their virulence towards, nutritional support of, and ability to associate with different nematode species. We then assessed post-association barriers by measuring the relative fitness of nematodes carrying each strain of bacteria. We found evidence for both pre- and post-association barriers between nematode clades. Specifically, some bacteria were highly virulent to non-native hosts, and some nematode hosts carried fewer cells of non-native bacteria, creating pre-association barriers. In addition, reduced infection success and lower nematode reproduction were identified as post-association barriers. No barriers to symbiont switching were detected between nematode species within the same clade. Overall, our study suggests a framework that could be used to generate predictions for the evolution of barriers to host switching in this and other systems.


Asunto(s)
Rabdítidos , Xenorhabdus , Animales , Bacterias , Insectos , Rabdítidos/microbiología , Simbiosis , Simpatría , Xenorhabdus/genética
7.
Value Health ; 25(2): 171-177, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35094789

RESUMEN

OBJECTIVES: Cost-effectiveness analyses (CEAs) may provide useful data to inform management decisions depending on the robustness of a model's input parameters. We sought to determine the level of heterogeneity in health state utility values, transition probabilities, and cost estimates across published CEAs assessing primarily radiotherapeutic management strategies in prostate cancer. METHODS: We conducted a systematic review of prostate cancer CEAs indexed in MEDLINE between 2000 and 2018 comparing accepted treatment modalities across all cancer stages. Search terms included "cost effectiveness prostate," "prostate cancer cost model," "cost utility prostate," and "Markov AND prostate AND (cancer OR adenocarcinoma)." Included studies were agreed upon. A Markov model was designed using the parameter estimates from the systematic review to evaluate the effect of estimate heterogeneity on strategy cost acceptability. RESULTS: Of 199 abstracts identified, 47 publications were reviewed and 37 were included; 508 model estimates were compared. Estimates varied widely across variables, including gastrointestinal toxicity risk (0%-49.5%), utility of metastatic disease (0.25-0.855), intensity-modulated radiotherapy cost ($21 193-$61 996), and recurrence after external-beam radiotherapy (1.5%-59%). Multiple studies assumed that different radiotherapy modalities delivering the same dose yielded varying cancer control rates. When using base estimates for similar parameters from included studies, the designed model resulted in 3 separate acceptability determinations. CONCLUSIONS: Significant heterogeneity exists across parameter estimates used to perform CEAs evaluating treatment for prostate cancer. Heterogeneity across model inputs yields variable conclusions with respect to the favorability and cost-effectiveness of treatment options. Decision makers are cautioned to review estimates in CEAs to ensure they are up to date and relevant to setting and population.


Asunto(s)
Neoplasias de la Próstata/economía , Neoplasias de la Próstata/radioterapia , Adenocarcinoma/economía , Adenocarcinoma/radioterapia , Anciano , Análisis Costo-Beneficio , Humanos , Masculino , Modelos Teóricos , Estadificación de Neoplasias , Años de Vida Ajustados por Calidad de Vida
8.
Acta Oncol ; 61(4): 468-477, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34965846

RESUMEN

BACKGROUND: To report 5- and 7-year outcomes after image-guided moderately accelerated hypofractionated proton therapy (AHPT) for prostate cancer. MATERIAL AND METHODS: We reviewed the first 582 prostate cancer patients enrolled on prospective outcomes tracking trial and treated with double-scattered moderately AHPT between 2008 and 2015. 269 patients had low-risk (LR) and 313 had intermediate-risk (IR) disease, including 149 with favorable intermediate-risk (FIR) and 164 with unfavorable intermediate-risk (UIR) disease. LR patients received a median 70.0GyRBE (2.5GyRBE/fraction) and IR patients received a median of 72.5 GyRBE. Seventeen patients (UIR, n = 12) received androgen deprivation therapy (ADT) for a median of 6 months. Toxicities were graded per the CTCAE, v4.0, and patient-reported quality-of-life data were reviewed. RESULTS: Median follow-up was 8.0 years (0.9-12.2). The 5- and 7-year rates of freedom from biochemical progression (FFBP) overall and in the LR and IR subsets, respectively, were 96.8/95.2%, 98.8/98.8%, and 95.0/91.9%. For the FIR and UIR subsets, they were 97.2/95.2% and 93.1/88.8%. Actuarial 5- and 7-year rates of late CTCAE, v4.0, grade 2 gastrointestinal (GI), grade 3 GI, and grade 3 genitourinary (GU) toxicities were 9.9%/11.2%, 1.4/1.4% and 1.3/2.1%, respectively. No grade ≥4 GI or GU toxicities occurred. The mean (standard deviation, SD) IPSS and EPIC Composite bowel function and bother scores were 7 (SD = 5), 97 (SD = 7), and 94 (SD = 6), respectively at baseline, 7 (SD = 5), 92 (SD = 13), and 92 (SD = 9) at the 5-year follow-up, and 7 (SD = 5), 93 (SD = 12), and 92 (SD = 10) at the 7-year follow-up. CONCLUSION: Image-guided AHPT 5- and 7-year outcomes show high efficacy, minimal physician-assessed toxicity, and excellent patient-reported outcomes in this cohort.


Asunto(s)
Neoplasias de la Próstata , Terapia de Protones , Radioterapia Guiada por Imagen , Radioterapia de Intensidad Modulada , Antagonistas de Andrógenos , Humanos , Masculino , Estudios Prospectivos , Neoplasias de la Próstata/terapia , Terapia de Protones/efectos adversos , Radioterapia Guiada por Imagen/efectos adversos , Sistema Urogenital
9.
Hum Factors ; 64(8): 1351-1362, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-33410358

RESUMEN

OBJECTIVE: The objective of this review was to spotlight specific methods for people working from home to apply restorative environment research to improve productivity and mental health during shelter-in-place. BACKGROUND: The COVID-19 pandemic has led to sheltering-in-place and telework. While necessary, these strategies may lead to negative consequences such as social isolation and worse performance. However, nature environments have been shown to have a variety of positive effects in several different settings, including improved attention, positive affect, and increased job satisfaction, and these may be translated to the home workspace setting. METHOD: This provides a narrative review of the environmental psychology literature, describing articles involving nature in a task performance or stress context and how it has been applied. It then moves on to discuss how these findings could possibly be applied in the context of workers during the COVID-19 pandemic. RESULTS: Although beneficial results are mixed, the review found a variety of relatively simple and cost-effective methods that could assist workers during the COVID-19 pandemic, including taking a break in nature and implementing nature in the workspace. APPLICATION: The application of restorative environment research could be an efficient way of mitigating the negative psychological effects due to at-home sheltering and telework in order to combat COVID-19.


Asunto(s)
COVID-19 , Pandemias , Humanos
10.
Environ Manage ; 70(5): 808-826, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36028629

RESUMEN

Central American and Caribbean (CAC) countries enjoy diverse marine environments. The oceans that enclose these coastlines contribute significantly to their economic growth. Industrial expansion and tourism place pressure on the marine ecosystems causing a decline in ocean health. To evaluate the cause of ocean health changes we investigated the factors influencing CAC ocean health using a health production function. Using Rank-Based Regression and the set of extractive, cultural and human well-being and services goals measuring Ocean Health Index (OHI), data from the World Bank, and the Human Development Index we developed a production function for CAC countries ocean health. Results show that all regional OHI scores, but Tourism and Recreation, the main income earning industry for most of the CAC countries, are less than the global score with four of the goals less than 40. The production function shows that all the goals, but the biodiversity sub-goal species, positively influencing OHI. Two climatic related variables, Nitrous Oxide and Carbon Dioxide negatively influenced OHI. The results are important to policy makers as they decide on the need to make greater effort towards improving sustainable contribution of CAC ocean resources to the blue economy.


Asunto(s)
Dióxido de Carbono , Ecosistema , Humanos , Óxido Nitroso , Océanos y Mares , Políticas
11.
J Helminthol ; 96: e2, 2022 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-34991736

RESUMEN

Natural selection should favour parasite genotypes that manipulate hosts in ways that enhance parasite fitness. However, it is also possible that the effects of infection are not adaptive. Here we experimentally examined the phenotypic effects of infection in a snail-trematode system. These trematodes (Atriophallophorus winterbourni) produce larval cysts within the snail's shell (Potamopyrgus antipodarum); hence the internal shell volume determines the total number of parasite cysts produced. Infected snails in the field tend to be larger than uninfected snails, suggesting the hypothesis that parasites manipulate host growth so as to increase the space available for trematode reproduction. To test the hypothesis, we exposed juvenile snails to trematode eggs. Snails were then left to grow for about one year in 800-l outdoor mesocosms. We found that uninfected males were smaller than uninfected females (sexual dimorphism). We also found that infection did not affect the shell dimensions of males. However, infected females were smaller than uninfected females. Hence, infection stunts the growth of females, and (contrary to the hypothesis) it results in a smaller internal volume for larval cysts. Finally, infected females resembled males in size and shape, suggesting the possibility that parasitic castration prevents the normal development of females. These results thus indicate that the parasite is not manipulating the growth of infected hosts so as to increase the number of larval cysts, although alternative adaptive explanations are possible.


Asunto(s)
Parásitos , Trematodos , Animales , Femenino , Interacciones Huésped-Parásitos , Masculino , Reproducción , Caracoles , Trematodos/genética
12.
Infect Immun ; 89(12): e0030921, 2021 11 16.
Artículo en Inglés | MEDLINE | ID: mdl-34491788

RESUMEN

Periodontal disease is considered to arise from an imbalance in the interplay between the host and its commensal microbiota, characterized by inflammation, destructive periodontal bone loss, and a dysbiotic oral microbial community. The neutrophil is a key component of defense of the periodontium: defects in their number or efficacy of function predisposes individuals to development of periodontal disease. Paradoxically, neutrophil activity, as part of a deregulated inflammatory response, is considered an important element in the destructive disease process. In this investigation, we examined the role the neutrophil plays in the regulation of the oral microbiota by analysis of the microbiome composition in mice lacking the CXCR2 neutrophil receptor required for recruitment to the periodontal tissues. A breeding protocol was employed that ensured that only the oral microbiota of wild-type (CXCR2+/+) mice was transferred to subsequent generations of wild-type, heterozygote, and homozygote littermates. In the absence of neutrophils, the microbiome undergoes a significant shift in total load and composition compared to when normal levels of neutrophil recruitment into the gingival tissues occur, and this is accompanied by a significant increase in periodontal bone pathology. However, transfer of the oral microbiome of CXCR2-/- mice into germfree CXCR2+/+ mice led to restoration of the microbiome to the wild-type CXCR2+/+ composition and the absence of pathology. These data demonstrate that the composition of the oral microbiome is inherently flexible and is governed to a significant extent by the genetics and resultant phenotype of the host organism.


Asunto(s)
Microbiota , Infiltración Neutrófila , Neutrófilos/fisiología , Enfermedades Periodontales/etiología , Enfermedades Periodontales/patología , Animales , Biomarcadores , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Disbiosis , Ratones , Ratones Noqueados , Enfermedades Periodontales/metabolismo , Periodontitis/etiología , Periodontitis/metabolismo , Periodontitis/patología , Receptores de Interleucina-8B/genética , Receptores de Interleucina-8B/metabolismo
13.
NMR Biomed ; 34(4): e4471, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33458907

RESUMEN

The diabetic heart has a decreased ability to metabolize glucose. The anti-ischemic drug meldonium may provide a route to counteract this by reducing l-carnitine levels, resulting in improved cardiac glucose utilization. Therefore, the aim of this study was to use the novel technique of hyperpolarized magnetic resonance to investigate the in vivo effects of treatment with meldonium on cardiac metabolism and function in control and diabetic rats. Thirty-six male Wistar rats were injected either with vehicle, or with streptozotocin (55 mg/kg) to induce a model of type 1 diabetes. Daily treatment with either saline or meldonium (100 mg/kg/day) was undertaken for three weeks. in vivo cardiac function and metabolism were assessed with CINE MRI and hyperpolarized magnetic resonance respectively. Isolated perfused hearts were challenged with low-flow ischemia/reperfusion to assess the impact of meldonium on post-ischemic recovery. Meldonium had no significant effect on blood glucose concentrations or on baseline cardiac function. However, hyperpolarized magnetic resonance revealed that meldonium treatment elevated pyruvate dehydrogenase flux by 3.1-fold and 1.2-fold in diabetic and control animals, respectively, suggesting an increase in cardiac glucose oxidation. Hyperpolarized magnetic resonance further demonstrated that meldonium reduced the normalized acetylcarnitine signal by 2.1-fold in both diabetic and control animals. The increase in pyruvate dehydrogenase flux in vivo was accompanied by an improvement in post-ischemic function ex vivo, as meldonium elevated the rate pressure product by 1.3-fold and 1.5-fold in the control and diabetic animals, respectively. In conclusion, meldonium improves in vivo pyruvate dehydrogenase flux in the diabetic heart, contributing to improved cardiac recovery after ischemia.


Asunto(s)
Diabetes Mellitus Experimental/complicaciones , Espectroscopía de Resonancia Magnética/métodos , Metilhidrazinas/uso terapéutico , Isquemia Miocárdica/tratamiento farmacológico , Complejo Piruvato Deshidrogenasa/fisiología , Animales , Glucosa/metabolismo , Masculino , Metabolómica , Metilhidrazinas/farmacología , Isquemia Miocárdica/fisiopatología , Miocardio/metabolismo , Ratas , Ratas Wistar , Estreptozocina
14.
Biol Lett ; 17(12): 20210321, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34932924

RESUMEN

Parasite-mediated selection is thought to maintain host genetic diversity for resistance. We might thus expect to find a strong positive correlation between host genetic diversity and infection prevalence across natural populations. Here, we used computer simulations to examine host-parasite coevolution in 20 simi-isolated clonal populations across a broad range of values for both parasite virulence and parasite fecundity. We found that the correlation between host genetic diversity and infection prevalence can be significantly positive for intermediate values of parasite virulence and fecundity. But the correlation can also be weak and statistically non-significant, even when parasite-mediated frequency-dependent selection is the sole force maintaining host diversity. Hence correlational analyses of field populations, while useful, might underestimate the role of parasites in maintaining host diversity.


Asunto(s)
Parásitos , Animales , Evolución Biológica , Variación Genética , Interacciones Huésped-Parásitos , Prevalencia , Selección Genética , Virulencia
15.
J Hered ; 112(1): 58-66, 2021 03 12.
Artículo en Inglés | MEDLINE | ID: mdl-33245337

RESUMEN

A growing body of research suggests that many clonal populations maintain genetic diversity even without occasional sexual reproduction. The purpose of our study was to document variation in single-nucleotide polymorphism (SNP) diversity, DNA content, and pathogen susceptibility in clonal lineages of the New Zealand freshwater snail, Potamopyrgus antipodarum. We studied snails that were collected from multiple field sites around a single lake (Lake Alexandrina), as well as isofemale clonal lineages that had been isolated and maintained in the laboratory. We used the kompetitive allele specific PCR (KASP) method to genotype our samples at 46 nuclear SNP sites, and we used flow cytometry to estimate DNA content. We found high levels of SNP diversity, both in our field samples and in our clonal laboratory lines. We also found evidence of high variation in DNA content among clones, even among clones with identical genotypes across all SNP sites. Controlled pathogen exposures of the laboratory populations revealed variation in susceptibility among distinct clonal genotypes, which was independent of DNA content. Taken together, these results show high levels of diversity among asexual snails, especially for DNA content, and they suggest rapid genome evolution in asexuals.


Asunto(s)
Ploidias , Polimorfismo de Nucleótido Simple , Reproducción Asexuada/genética , Caracoles/genética , Animales , Genética de Población , Genotipo , Nueva Zelanda
16.
Hum Factors ; 63(6): 1046-1060, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-32223571

RESUMEN

OBJECTIVE: The aim of this study is to replicate Berto's (2005) heavily cited work on attention restoration. BACKGROUND: Nature interventions have gained increased interest for improving performance of attentionally demanding tasks. Berto (2005) indicated that viewing digital nature images could improve performance on a subsequent response inhibition task, the sustained attention to response task (SART). However, experimental design and statistical concerns about her experiments as well as failure to support her findings across multiple unpublished studies in our laboratory provided rationale for this replication study. METHOD: Twenty participants were each assigned to one of three digital image conditions: nature, urban, and control. Participants performed the SART before and after digital image exposure. RESULTS: SART performance metrics (total correct target responses, mean response time, and transformed d') were analyzed using 2 (SART) × 3 (image interventions) mixed design ANOVAs. The results failed to replicate Berto (2005). CONCLUSION: Possible reasons for not replicating Berto (2005) are discussed, including (1) sample differences, (2) different testing environments and procedures, (3) insufficient attentional depletion, and (4) individual differences. APPLICATIONS: Research needs to determine the effectiveness of such interventions, the specific attention tasks that might benefit, and the individual difference variables relevant for attention restoration.


Asunto(s)
Análisis y Desempeño de Tareas , Femenino , Humanos , Tiempo de Reacción/fisiología
17.
J Bacteriol ; 202(23)2020 11 04.
Artículo en Inglés | MEDLINE | ID: mdl-32928930

RESUMEN

Many pathogenic bacteria translocate virulence factors into their eukaryotic hosts by means of type IV secretion systems (T4SS) spanning the inner and outer membranes. Genes encoding components of these systems have been identified within the order Rickettsiales based upon their sequence similarities to other prototypical systems. Anaplasma phagocytophilum strains are obligate intracellular, tick-borne bacteria that are members of this order. The organization of these components at the genomic level was determined in several Anaplasma phagocytophilum strains, showing overall conservation, with the exceptions of the virB2 and virB6 genes. The virB6 loci are characterized by the presence of four virB6 copies (virB6-1 through virB6-4) arranged in tandem within a gene cluster known as the sodB-virB operon. Interestingly, the virB6-4 gene varies significantly in length among different strains due to extensive tandem repeats at the 3' end. To gain an understanding of how these enigmatic virB6 genes function in A. phagocytophilum, we investigated their expression in infected human and tick cells. Our results show that these genes are expressed by A. phagocytophilum replicating in both cell types and that VirB6-3 and VirB6-4 proteins are surface exposed. Analysis of an A. phagocytophilum mutant carrying the Himar1 transposon within the virB6-4 gene demonstrated that the insertion not only disrupted its expression but also exerted a polar effect on the sodB-virB operon. Moreover, the altered expression of genes within this operon was associated with the attenuated in vitro growth of A. phagocytophilum in human and tick cells, indicating the importance of these genes in the physiology of this obligate intracellular bacterium in such different environments.IMPORTANCE Knowledge of the T4SS is derived from model systems, such as Agrobacterium tumefaciens The structure of the T4SS in Rickettsiales differs from the classical arrangement. These differences include missing and duplicated components with structural alterations. Particularly, two sequenced virB6-4 genes encode unusual C-terminal structural extensions resulting in proteins of 4,322 (GenBank accession number AGR79286.1) and 9,935 (GenBank accession number ANC34101.1) amino acids. To understand how the T4SS is used in A. phagocytophilum, we describe the expression of the virB6 paralogs and explore their role as the bacteria replicate within its host cell. Conclusions about the importance of these paralogs for colonization of human and tick cells are supported by the deficient phenotype of an A. phagocytophilum mutant isolated from a sequence-defined transposon insertion library.


Asunto(s)
Anaplasma phagocytophilum/crecimiento & desarrollo , Anaplasma phagocytophilum/genética , Proteínas Bacterianas/genética , Anaplasma phagocytophilum/metabolismo , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Línea Celular , Ehrlichiosis/microbiología , Humanos , Mutagénesis Insercional , Operón , Sistemas de Secreción Tipo IV/genética , Sistemas de Secreción Tipo IV/metabolismo
18.
Mol Ecol ; 29(4): 658-672, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31957935

RESUMEN

Genomic approaches permit direct estimation of inbreeding and its effect on fitness. We used genomic-based estimates of inbreeding to investigate their relationship with eight adult traits in a captive-reared Pacific salmonid that is released into the wild. Estimates were also used to determine whether alternative broodstock management approaches reduced risks of inbreeding. Specifically, 1,100 unlinked restriction-site associated (RAD) loci were used to compare pairwise relatedness, derived from a relationship matrix, and individual inbreeding, estimated by comparing observed and expected homozygosity, across four generations in two hatchery lines of Chinook salmon that were derived from the same source. The lines are managed as "integrated" with the founding wild stock, with ongoing gene flow, and as "segregated" with no gene flow. While relatedness and inbreeding increased in the first generation of both lines, possibly due to population subdivision caused by hatchery initiation, the integrated line had significantly lower levels in some subsequent generations (relatedness: F2 -F4 ; inbreeding F2 ). Generally, inbreeding was similar between the lines despite large differences in effective numbers of breeders. Inbreeding did not affect fecundity, reproductive effort, return timing, fork length, weight, condition factor, and daily growth coefficient. However, it delayed spawn timing by 1.75 days per one standard deviation increase in F (~0.16). The results indicate that integrated management may reduce inbreeding but also suggest that it is relatively low in a small, segregated hatchery population that maximized number of breeders. Our findings demonstrate the utility of genomics to monitor inbreeding under alternative management strategies in captive breeding programs.


Asunto(s)
Conservación de los Recursos Naturales , Explotaciones Pesqueras , Reproducción/genética , Salmón/genética , Animales , Cruzamiento , Fertilidad/genética , Flujo Génico , Variación Genética/genética , Genómica/métodos , Humanos , Endogamia/métodos , Repeticiones de Microsatélite/genética , Fenotipo , Salmón/crecimiento & desarrollo
19.
Mult Scler ; 26(1): 109-113, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-30465463

RESUMEN

OBJECTIVE: Determine the influence of technician supervision on computer-administered cognitive tests in multiple sclerosis (MS). METHODS: Eighty MS patients underwent assessment using the CogState Brief Battery (CSBB) and the Cleveland Clinic Cognitive Battery (C3B). Each was administered twice, once with a technician guiding assessment, and once with technician-absent. Twenty-eight healthy controls were also evaluated. RESULTS: The influence of technician guidance was not statistically significant for group means on either test. For CSBB, administration problems were more common in the technician-absent condition. CONCLUSION: In this MS sample, reliable and valid test results were obtained from computer-assisted cognitive testing without technician guidance.


Asunto(s)
Disfunción Cognitiva/diagnóstico , Diagnóstico por Computador/normas , Personal de Salud/normas , Esclerosis Múltiple/diagnóstico , Pruebas Neuropsicológicas/normas , Adulto , Disfunción Cognitiva/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/complicaciones , Reproducibilidad de los Resultados
20.
Inorg Chem ; 59(17): 11894-11900, 2020 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-32812746

RESUMEN

The heterobimetallic metallacrown (MC), (TMA)2{Mn(OAc)2[12-MCMn(III)Cu(II)N(shi)-4](CH3OH)}·2.90CH3OH, 1, where TMA+ is tetramethylammonium, -OAc is acetate, and shi3- is salicylhydroximate, consists of a MnII ion captured in the central cavity and alternating unambiguous and ordered manganese(III) and copper(II) sites about the MC ring, a first for the archetypal MC structure design. DC-magnetometry characterization and subsequent simulation with the Spin Hamiltonian H = -J1(s1 + s3)·s5 - J2(s2 + s4)·s5 - J3Σi=14si·si+1 + d(sz,12 + sz,32) + µBΣj=15gjsj·B indicates an S = 5/2 ground state and a sizable axial zero-field splitting on MnIII. AC-susceptibility measurements reveal that 1 displays slow magnetization relaxation akin to single-molecule magnet (SMM) behavior.

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