Human cerebral development is remarkably protracted. Although microstructural processes of neuronal maturation remain accessible only to morphometric post-mortem studies, neuroimaging tools permit ...the examination of macrostructural aspects of brain development. The analysis of resting-state functional connectivity (FC) offers novel possibilities for the investigation of cerebral development. Using seed-based FC methods, we examined the development of 5 functionally distinct cingulate-based intrinsic connectivity networks (ICNs) in children (n = 14, 10.6 ± 1.5 years), adolescents (n = 12, 15.4 ± 1.2) and young adults (n=14, 22.4 ± 1.2). Children demonstrated a more diffuse pattern of correlation with voxels proximal to the seed region of interest (ROI) (“local FC”), whereas adults exhibited more focal patterns of FC, as well as a greater number of significantly correlated voxels at long distances from the seed ROI. Adolescents exhibited intermediate patterns of FC. Consistent with evidence for different maturational time courses, ICNs associated with social and emotional functions exhibited the greatest developmental effects. Our findings demonstrate the utility of FC for the study of developing functional organization. Moreover, given that ICNs are thought to have an anatomical basis in neuronal connectivity, measures of FC may provide a quantitative index of brain maturation in healthy subjects and those with neurodevelopmental disorders.
•Human enhancement for future space missions is a reasonable option.•Different methods of human enhancement for space include gene editing or implants.•Ethics should support a careful application of ...human enhancement for space missions.
Future human space missions to Mars and beyond may be realized for different research, economic, political or survival reasons. Since space remains a hazardous environment for humans, space exploration and exploitation requires the development and deployment of effective countermeasures. In this paper, we discuss prospects for human enhancement by gene editing, synthetic biology, or implants, for the purposes of future space missions. We argue that there are good reasons to consider such options, and that ethical arguments can be made in favor of human enhancement to enable long-term space exploration.
Vegetation indices are widely employed to evaluate wetland ecological condition, and are expected to provide sensitive and specific detection of environmental change. Most studies evaluate the ...performance of condition assessment metrics in the context of the data used to calibrate them. Here we examined the temporal stability of the Florida Wetland Condition Index (FWCI) for vegetation of depressional forested wetlands by resampling sites in 2008 that were previously sampled to develop the FWCI in 2001. Our objective was to determine if FWCI, a composite of six vegetation-based metrics, provides a robust measure of condition given inter-annual variation in environmental conditions (i.e., rainfall) between sampling periods. To that end, we sampled 22 geographically isolated wetlands in north Florida that spanned a wide land use/land cover intensity gradient. Our results suggested the FWCI is robust. We observed no significant paired difference in FWCI across or within land use categories, and the relationship between FWCI in 2001 and 2008 was strong (r2=0.88, p<0.001). This was despite surprisingly high composition change. Mean Jaccard community similarity within sites between years was 0.30, suggesting that most of the herbaceous taxa were replaced, possibly because of different antecedent rainfall conditions or sampling during different phenological periods; both are contingencies to which condition indices must be robust. We did observe some evidence of convergence toward the mean in 2008, with the fitted slope relating 2001 and 2008 FWCI scores significantly below one (0.63, 95% CI=0.53–0.73). The most variable FWCI component metric was the proportional representation of obligate wetland taxa, suggesting that systematic changes may have been induced by different hydrologic conditions prior to sampling; notably, however, FWCI computed without this component still exhibited a slope significantly less than 1 (0.72, 95% CI=0.61–0.88). Moreover, there was evidence that species lost from reference sites (higher condition) were replaced by taxa of lower floristic quality, while species lost from agricultural sites (consistently the lowest condition land use category) were replaced by species of higher quality. A significant positive association between FWCI and the ratio of coefficients of conservatism (CC) of species lost to those gained suggests some overfitting in FWCI development. However, despite modest evidence of overfitting, FWCI provides temporally consistent estimates of wetland condition, even under conditions of substantial taxonomic turnover.
•We compared wetland condition at 18 wetlands in two consecutive growing seasons.•We determined repeatability and consistency of scores in light of natural variation.•On average, 45% of species were ...different at the same wetland the second year.•Replacement species maintained the same indicator status of condition.•Macrophyte Florida Wetland Condition Index was consistent despite natural variation.
The vegetation portion of the Florida Wetland Condition Index (FWCI), an index of biological integrity, provided consistent and repeatable measures of condition at eighteen wetlands sampled in two consecutive growing seasons. The sample wetlands reflected a gradient of adjacent land use from non-impacted reference areas to wetlands imbedded within silviculture, cattle pasture and residential areas. Wetlands were described as herbaceous depression (n=6), forested depression (n=5) and forested strand or floodplain wetlands (n=7), and represented different states of succession. Even though the wetlands were unique from one another and occurred across a large geographic area in Florida, the FWCI results calculated for all the wetlands were representative of adjacent land use impacts and not sensitive to natural variation. During the duration of this study, changes in weather from drought to tropical storm conditions, as well as management activities such as fire and herbivory, impacted wetlands. These effects were apparent in the change of species composition between sampling periods; 23–56% of species were different when resampled. Even though composition changed, the proportion of indicators remained consistent. The resulting condition scores suggested a one-to-one relationship between sampling periods.
Three categories of wetland assessment methods have been recognized by the United States Environmental Protection Agency, including Level 1—Landscape-scale Assessment; Level 2—Rapid Field Methods; ...and Level 3—Intensive Biological and Physico–Chemical Measures. This study incorporates wetland assessment methods for each assessment level, including the Level 1 Landscape Development Intensity (LDI) index, Level 2 Wetland Rapid Assessment Procedure (WRAP), and Level 3 Florida Wetland Condition Index (FWCI). Using a neighborhood analysis in Geographic Information Systems (GIS), an LDI index map was created using 1995 land use, creating a calculated LDI index value for each 30 m² area in Florida. Level 1–3 assessment procedures were employed at 193 palustrine emergent (n = 75) and forested (n = 118) wetlands. Significant correlations were found among the multiple Level 1–3 assessment procedures using the nonparametric Spearman’s correlation coefficient for pair-wise comparisons of LDI and WRAP, LDI and diatom FWCI, WRAP and diatom FWCI, LDI and macrophyte FWCI, WRAP and macrophyte FWCI, LDI and macroinvertebrate FWCI, and WRAP and macroinvertebrate FWCI (|r| > 0.50, P < 0.01). Defining the relationship between Level 1–3 assessment methods may be used to estimate the more intensive and species assemblage-specific Level 3 FWCI assessment scores for wetlands with Level 1 or Level 2 scores. Inferences can then be made as to wetland condition based on established correlations with intensive assessment methods.
► We obtain Candida parapsilosis isolates from infants in three neonatal intensive care units. ► We apply multilocus microsatellite genotyping to the collection. ► A panel of five microsatellites ...reveals high discrimination and broad strain diversity. ► A cluster from one hospital implies persistence and possible transmission. ► The five microsatellite set is suitable for infection control purposes.
Candida parapsilosis (CP) (n=40) isolated from an unselected patient population in the neonatal intensive care units (NICUs) of three US hospitals were collected over periods of 3.5–9years. Two previously published microsatellite markers and three additional trinucleotide markers were used to produce multiplex genotypes, which revealed broad strain diversity among the NICU isolates with a combined index of discrimination (D)=0.997. A cluster of eight related CP strains from four infants in a single NICU was observed. An extended collection of 24 CP isolates from the general population of that hospital showed that the cluster of NICU isolates was related to three isolates from general hospital patients. This microsatellite marker set is suitable to investigate clusters of colonizing and infecting strains of CP.
Although antiretroviral treatments have improved survival of persons living with HIV, their long-term use may limit available drug options. We estimated the prevalence of heavily ...treatment-experienced (HTE) status and the potential clinical consequences of becoming HTE.
EuroSIDA, a European multicenter prospective cohort study.
A composite definition for HTE was developed, based on estimates of antiretroviral resistance and prior exposure to specific antiretroviral regimens. Risks of progressing to clinical outcomes were assessed by Poisson regression, comparing every HTE individual with 3 randomly selected controls who never became HTE.
Of 15,570 individuals under follow-up in 2010-2016, 1617 (10.4%, 95% CI: 9.9% to 10.9%) were classified as HTE. 1093 individuals became HTE during prospective follow-up (HTE incidence rate 1.76, CI: 1.66 to 1.87 per 100 person-years of follow-up). The number of HTE individuals was highest in West/Central Europe (636/4019 persons, 15.7%) and lowest in East Europe (26/2279 persons, 1.1%). Although most HTE individuals maintained controlled viral loads (<400 copies/mL), many had low CD4 counts (≤350 cells/µL). After controlling for age, immunological parameters and pre-existing comorbidities, HTE status was not associated with the risk of new AIDS (adjusted incidence rate ratio, aIRR 1.44, CI: 0.86 to 2.40, P = 0.16) or non-AIDS clinical events (aIRR 0.96, CI: 0.74 to 1.25, P = 0.77).
HTE prevalence increased with time. After adjusting for key confounding factors, there was no evidence for an increased risk of new AIDS or non-AIDS clinical events in HTE. Additional therapeutic options and effective management of comorbidities remain important to reduce clinical complications in HTE individuals.
The impact on tree and amphibian diversity of line-planting of tropical hardwoods-mahogany (Swietenia macrophylla × S. mahagoni) and mahoe (Hibiscus elatus)-was studied in a secondary subtropical wet ...forest of Puerto Rico. Common coqui (Eleutherodactylus coqui) and melodious coqui (E. wightmanae) are the most frequent frog species; forest coqui (E. portoricensis) is less abundant. Although relative abundance means were slightly greater in the undisturbed forest and during the wet season, differences were not statistically significant suggesting that line-planting did not significantly affect amphibian diversity. The line-planted areas had a slightly higher, but not statistically significant diversity, richness, and evenness of tree species than the unplanted forest. Multi-response permutation procedure (MRPP) showed statistically significant community composition differences between line-planting and control plot trees (T = −5.89, A = .86; p < .001). But mean similarity among plots in both the line-planted and control plots was relatively low at less than 50% of shared species, indicating high diversity of vegetation in the overall forest area. Canopy cover by tree species greater than 3 cm in dbh was much higher in the undisturbed forest but this difference may be reduced as the young line-planted hardwoods mature. Forest enrichment through line-planting of valuable timber species in secondary subtropical wet forest does not significantly affect tree diversity.
The development of bioindicators for wetlands, especially ephemerally hydrated depressional and isolated wetlands, can be problematic because of seasonal changes in hydrology and target indicator ...organism biology. To determine if benthic diatoms could be used as a multi-season biological indicator of wetland condition in isolated forested wetlands of Florida, USA, 11 wetlands were sampled twice during a 5-month period, once when dry, then again when hydrated. Sites sampled when dry had significantly higher diatom taxa richness at genus and species levels. Non-metric multidimensional scaling and multiple response permutation process analyses resulted in no obvious or significant wet/dry grouping of species or genus level abundance data. Five of seven diatom metrics of the Florida Wetland Condition Index (FWCI) for depressional forested wetlands were significantly linearly correlated (
p
<
0.05), while only one of seven metrics (a dissolved oxygen indicator) had a significantly different mean in paired
t-test analyses. The final FWCI was significantly correlated (Pearson's
r
=
0.85,
p
<
0.001) between wet and dry sites, and no difference was found in mean FWCI score between wet and dry sites (
t
=
−1.98,
p
=
0.076), suggesting that with additional research, benthic diatoms may be used to monitor and assess wetland condition regardless of season or site hydrologic conditions.
PDF
