Ophiocordyceps species infecting ants – the so-called zombie-ant fungi – comprise one of the most intriguing and fascinating relationships between microbes and animals. They are widespread within ...tropical forests worldwide, with relatively few reports from temperate ecosystems. These pathogens possess the ability to manipulate host behaviour in order to increase their own fitness. Depending on the fungal species involved the infected ants are manipulated either to leave the nest to ascend understorey shrubs, to die biting onto vegetation, or descend from the canopy to die at the base of trees. Experimental evidence has demonstrated that the behavioural change aids spore dispersal and thus increases the chances of infection, because of the existing behavioural immunity expressed inside ant colonies that limits fungal development and transmission. Despite their undoubted importance for ecosystem functioning, these fungal pathogens are still poorly documented, especially regarding their diversity, ecology and evolutionary relationships. Here, we describe 15 new species of Ophiocordyceps with hirsutella-like asexual morphs that exclusively infect ants. These form a monophyletic group that we identified in this study as myrmecophilous hirsutelloid species. We also propose new combinations for species previously described as varieties and provide for the first time important morphological and ecological information. The species proposed herein were collected in Brazil, Colombia, USA, Australia and Japan. All species could readily be separated using classic taxonomic criteria, in particular ascospore and asexual morphology.
Rodent models are commonly used to investigate tendon healing, with the biomechanical and structural properties of the healed tendons being important outcome measures. Tendon storage for later ...testing becomes necessary when performing large experiments with multiple time-points. However, it is unclear whether freezing rodent tendons affects their material properties. Thus the aim of this study was to determine whether freezing rat Achilles tendons affects their biomechanical or structural properties. Tendons were frozen at either −20 °C or −80 °C directly after harvesting, or tested when freshly harvested. Groups of tendons were subjected to several freeze-thaw cycles (1, 2, and 5) within 3 months, or frozen for 9 months, after which the tendons were subjected to biomechanical testing. Additionally, fresh and thawed tendons were compared morphologically, histologically and by transmission electron microscopy. No major differences in biomechanical properties were found between fresh tendons and those frozen once or twice at −20 °C or −80 °C. However, deterioration of tendon properties was found for 5-cycle groups and both long-term freezing groups; after 9 months of freezing at −80 °C the tear resistance of the tendon was reduced from 125.4 ± 16.4N to 74.3 ± 18.4N (p = 0.0132). Moreover, tendons stored under these conditions showed major disruption of collagen fibrils when examined by transmission electron microscopy. When examined histologically, fresh samples exhibited the best cellularity and proteoglycan content of the enthesis. These properties were preserved better after freezing at −80 °C than after freezing at −20 °C, which resulted in markedly smaller chondrocytes and less proteoglycan content. Overall, the best preservation of histological integrity was seen with tendons frozen once at −80 °C. In conclusion, rat Achilles tendons can be frozen once or twice for short periods of time (up to 3 months) at −20 °C or −80 °C for later testing. However, freezing for 9 months at either −20 °C or −80 °C leads to deterioration of certain parameters.
The present study investigated the relationship between infant temperament characteristics and autism spectrum disorder (ASD) risk status. Temperament was examined at 6, 12, and 24 months in 282 ...infants at high familial risk for ASD and 114 low-risk controls using the Infant Behavior Questionnaire-Revised and Early Childhood Behavior Questionnaire. Infants were divided into three groups at 24 months: High-Risk Positive—classified as ASD (HR Pos), High-Risk Negative (HR Neg), and Low-Risk Negative (LR Neg). At 6 and 12 months HR Pos infants exhibited lower Surgency and Regulatory Capacity than LR Neg infants. By 12 months they also demonstrated increased Negative Affect. Group differences remained, when early signs of ASD were controlled for, suggesting that temperament differences could be useful targets for understanding the development of ASD.
Non-transferrin-bound iron and its labile (redox active) plasma iron component are thought to be potentially toxic forms of iron originally identified in the serum of patients with iron overload. We ...compared ten worldwide leading assays (6 for non-transferrin-bound iron and 4 for labile plasma iron) as part of an international inter-laboratory study. Serum samples from 60 patients with four different iron-overload disorders in various treatment phases were coded and sent in duplicate for analysis to five different laboratories worldwide. Some laboratories provided multiple assays. Overall, highest assay levels were observed for patients with untreated hereditary hemochromatosis and β-thalassemia intermedia, patients with transfusion-dependent myelodysplastic syndromes and patients with transfusion-dependent and chelated β-thalassemia major. Absolute levels differed considerably between assays and were lower for labile plasma iron than for non-transferrin-bound iron. Four assays also reported negative values. Assays were reproducible with high between-sample and low within-sample variation. Assays correlated and correlations were highest within the group of non-transferrin-bound iron assays and within that of labile plasma iron assays. Increased transferrin saturation, but not ferritin, was a good indicator of the presence of forms of circulating non-transferrin-bound iron. The possibility of using non-transferrin-bound iron and labile plasma iron measures as clinical indicators of overt iron overload and/or of treatment efficacy would largely depend on the rigorous validation and standardization of assays.
Mesenchymal stem cell (MSC) based-treatments of cartilage injury are promising but impaired by high levels of hypertrophy after chondrogenic induction with several bone morphogenetic protein ...superfamily members (BMPs). As an alternative, this study investigates the chondrogenic induction of MSCs via adenoviral gene-delivery of the transcription factor SOX9 alone or in combination with other inducers, and comparatively explores the levels of hypertrophy and end stage differentiation in a pellet culture system in vitro.
First generation adenoviral vectors encoding SOX9, TGFB1 or IGF1 were used alone or in combination to transduce human bone marrow-derived MSCs at 5 × 10
infectious particles/cell. Thereafter cells were placed in aggregates and maintained for three weeks in chondrogenic medium. Transgene expression was determined at the protein level (ELISA/Western blot), and aggregates were analysed histologically, immunohistochemically, biochemically and by RT-PCR for chondrogenesis and hypertrophy.
SOX9 cDNA was superior to that encoding TGFB1, the typical gold standard, as an inducer of chondrogenesis in primary MSCs as evidenced by improved lacuna formation, proteoglycan and collagen type II staining, increased levels of GAG synthesis, and expression of mRNAs associated with chondrogenesis. Moreover, SOX9 modified aggregates showed a markedly lower tendency to progress towards hypertrophy, as judged by expression of the hypertrophy markers alkaline phosphatase, and collagen type X at the mRNA and protein levels.
Adenoviral SOX9 gene transfer induces chondrogenic differentiation of human primary MSCs in pellet culture more effectively than TGFB1 gene transfer with lower levels of chondrocyte hypertrophy after 3 weeks of in vitro culture. Such technology might enable the formation of more stable hyaline cartilage repair tissues in vivo.
Three differing techniques were used to measure ambient black carbon (BC) aerosols in downtown Toronto through 20 December 2006 to 23 January 2007. These techniques were thermal analysis, as ...performed by a Sunset Labs OCEC Analyzer (OCEC); light attenuation, as performed by an Aethalometer (AE); and photoacoustic analysis, as performed by a Photoacoustic Instrument (PA). These measurements of ambient PM
2.5
were used to investigate the effects of coating thickness on BC Mass Absorption Cross-section (MAC). MAC values were determined by comparing 880 nm and 370 nm AE measurements and PA measurements of b
abs
(absorption coefficient, Mm
-1
) to the OCEC measurements. Based on mass size distributions and supporting criteria, the PM
2.5
was classified as fresh, semi-aged, or aged. The average MAC values in these categories, based on the PA measurements, were 9.3
±
1.8, 9.9
±
2.0, and 9.3
±
2.2 m
2
/g (mean ± standard deviation), respectively, suggesting that any difference in coating thickness as a result of aging, on the time scale observed, did not produce a difference in MAC. In a second type of experiment, a thermodenuder was installed upstream of the AE, PA, and OCEC and samples were heated to 340°C in order to evaporate volatile and semi-volatile components within the coating. Based on the PA measurements, the average MAC values of these heated samples, for the fresh, semi-aged, and aged categories were 7.7
±
2.2, 6.9
±
2.2, and 9.1
±
2.0 m
2
/g, respectively. Similar differences in MAC were also observed by the AE. The decrease in MAC in the fresh and semi-aged samples was interpreted in terms of the degree of coating of the PM
2.5
. Results agreed well with predictions made by absorption amplification theory and had ramifications for calibration of filter-base attenuation and photoacoustic instruments.
Deficits in executive functions (EFs), cognitive processes that control goal-directed behaviors, are associated with psychopathology and neurologic disorders. Little is known about the molecular ...bases of individual differences in EFs. Prior candidate gene studies have been underpowered in their search for dopaminergic processes involved in cognitive functioning, and existing genome-wide association studies of EFs used small sample sizes and/or focused on individual tasks that are imprecise measures of EFs.
We conducted a genome-wide association study of a common EF (cEF) factor score based on multiple tasks in the UK Biobank (n = 427,037 individuals of European descent).
We found 129 independent genome-wide significant lead variants in 112 distinct loci. cEF was associated with fast synaptic transmission processes (synaptic, potassium channel, and GABA gamma-aminobutyric acid pathways) in gene-based analyses. cEF was genetically correlated with measures of intelligence (IQ) and cognitive processing speed, but cEF and IQ showed differential genetic associations with psychiatric disorders and educational attainment.
Results suggest that cEF is a genetically distinct cognitive construct that is particularly relevant to understanding the genetic variance in psychiatric disorders.
Anthropogenic and biogenic controls on the surface–atmosphere exchange of CO2 are explored for three different environments. Similarities are seen between suburban and woodland sites during summer, ...when photosynthesis and respiration determine the diurnal pattern of the CO2 flux. In winter, emissions from human activities dominate urban and suburban fluxes; building emissions increase during cold weather, while traffic is a major component of CO2 emissions all year round. Observed CO2 fluxes reflect diurnal traffic patterns (busy throughout the day (urban); rush-hour peaks (suburban)) and vary between working days and non-working days, except at the woodland site. Suburban vegetation offsets some anthropogenic emissions, but 24-h CO2 fluxes are usually positive even during summer. Observations are compared to estimated emissions from simple models and inventories. Annual CO2 exchanges are significantly different between sites, demonstrating the impacts of increasing urban density (and decreasing vegetation fraction) on the CO2 flux to the atmosphere.
•Multi-seasonal comparison of contemporaneous CO2 fluxes over contrasting land cover.•Signatures of anthropogenic and biogenic processes explored at various timescales.•Observations reveal relative magnitude of anthropogenic emissions.•CO2 fluxes related to surface controls, strongly dependent on land cover.
Direct measurements of CO2 fluxes reveal the impact of urbanisation and human behavioural patterns on the atmosphere at sub-daily to inter-annual time scales.
Sensible heat fluxes (
Q
H
) are determined using scintillometry and eddy covariance over a suburban area. Two large-aperture scintillometers provide spatially integrated fluxes across path lengths ...of 2.8 and 5.5 km over Swindon, UK. The shorter scintillometer path spans newly built residential areas and has an approximate source area of 2–4
km
2
, whilst the long path extends from the rural outskirts to the town centre and has a source area of around 5–10
km
2
. These large-scale heat fluxes are compared with local-scale eddy-covariance measurements. Clear seasonal trends are revealed by the long duration of this dataset and variability in monthly
Q
H
is related to the meteorological conditions. At shorter time scales the response of
Q
H
to solar radiation often gives rise to close agreement between the measurements, but during times of rapidly changing cloud cover spatial differences in the net radiation (
Q
∗
) coincide with greater differences between heat fluxes. For clear days
Q
H
lags
Q
∗
, thus the ratio of
Q
H
to
Q
∗
increases throughout the day. In summer the observed energy partitioning is related to the vegetation fraction through use of a footprint model. The results demonstrate the value of scintillometry for integrating surface heterogeneity and offer improved understanding of the influence of anthropogenic materials on surface-atmosphere interactions.
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