Highlights • LED light requirements may be related to the evolutionary history of endosymbiosis. • Red or blue LEDs are often the most effective artificial light sources for microalgae. • LED light ...quality influences the growth and biochemistry of microalgae. • LEDs are ideal for building tailored light sources.
Age-related changes in the basic functional unit of the neuromuscular system, the motor unit, and its neural inputs have a profound effect on motor function, especially among the expanding number of ...old (older than ∼60 yr) and very old (older than ∼80 yr) adults. This review presents evidence that age-related changes in motor unit morphology and properties lead to impaired motor performance that includes 1) reduced maximal strength and power, slower contractile velocity, and increased fatigability; and 2) increased variability during and between motor tasks, including decreased force steadiness and increased variability of contraction velocity and torque over repeat contractions. The age-related increase in variability of motor performance with aging appears to involve reduced and more variable synaptic inputs that drive motor neuron activation, fewer and larger motor units, less stable neuromuscular junctions, lower and more variable motor unit action potential discharge rates, and smaller and slower skeletal muscle fibers that coexpress different myosin heavy chain isoforms in the muscle of older adults. Physical activity may modify motor unit properties and function in old men and women, although the effects on variability of motor performance are largely unknown. Many studies are of cross-sectional design, so there is a tremendous opportunity to perform high-impact and longitudinal studies along the continuum of aging that determine 1) the influence and cause of the increased variability with aging on functional performance tasks, and 2) whether lifestyle factors such as physical exercise can minimize this age-related variability in motor performance in the rapidly expanding numbers of very old adults.
Accurate prediction of the sorption of perfluoroalkyl substances (PFASs) in soils is essential for environmental risk assessment. We investigated the effect of solution pH and calculated soil organic ...matter (SOM) net charge on the sorption of 14 PFASs onto an organic soil as a function of pH and added concentrations of Al3+, Ca2+ and Na+. Often, the organic C-normalized partitioning coefficients (KOC) showed a negative relationship to both pH (Δlog KOC/ΔpH = −0.32 ± 0.11 log units) and the SOM bulk net negative charge (Δlog KOC = −1.41 ± 0.40 per log unit molc g−1). Moreover, perfluorosulfonic acids (PFSAs) sorbed more strongly than perfluorocarboxylic acids (PFCAs) and the PFAS sorption increased with increasing perfluorocarbon chain length with 0.60 and 0.83 log KOC units per CF2 moiety for C3–C10 PFCAs and C4, C6, and C8 PFSAs, respectively. The effects of cation treatment and SOM bulk net charge were evident for many PFASs with low to moderate sorption (C5–C8 PFCAs and C6 PFSA). However for the most strongly sorbing and most long-chained PFASs (C9–C11 and C13 PFCAs, C8 PFSA and perfluorooctane sulfonamide (FOSA)), smaller effects of cations were seen, and instead sorption was more strongly related to the pH value. This suggests that the most long-chained PFASs, similar to other hydrophobic organic compounds, are preferentially sorbed to the highly condensed domains of the humin fraction, while shorter-chained PFASs are bound to a larger extent to humic and fulvic acid, where cation effects are significant.
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•Sorption of PFASs of C5 or longer depends on the pH or on the SOM bulk net charge.•For C5–C8 PFCAs, SOM bulk net charge is strongly related to sorption.•For longer-chained PFASs, pH is a better predictor of sorption.•Cation effects are evident only for shorter-chained PFASs.•Longer-chained PFASs probably bind preferentially to the humin fraction of SOM.
Understanding the occurrence and sources of organic micropollutants (OMPs) in aquatic environments is essential for environmental risk assessment and adequate interventions to secure good status of ...aquatic environments. The occurrence and source apportionment of 77 OMPs in the River Fyris catchment (Uppsala, Sweden) were investigated by comparing hospital wastewater, wastewater treatment plant (WWTP) effluent, and surface water. Hospital wastewater was identified as an important source for some classes of OMPs, e.g., antibiotics (number of OMPs (n) = 6) and antidepressants (n = 4), contributing 38% and 31%, respectively, of the mass loads in total WWTP influent. Painkillers (n = 5) and hormones (n = 3), originating mainly from urban Uppsala, contributed 94% and 95%, respectively. WWTP removal efficiency varied from 100% for acetaminophen to <0% for i.e. clindamycin, lamotrigine, bicalutamide, and sucralose. In the recipient River Fyris, the ΣOMP concentration downstream of the WWTP (738 ng L−1) was more than double that upstream (338 ng L−1), demonstrating the high impact of the WWTP on recipient water quality. Surface water risk quotients (RQs) showed a moderate risk of adverse chronic effects (RQ > 0.1) for trimethoprim, norsertraline, and metoprolol downstream of the WWTP, and for norsertraline in the recipient river upstream and Lake Ekoln downstream of the WWTP. Recipient metoprolol and trimethoprim, compounds poorly removed in the WWTP, mainly (>90%) originated from wastewater from urban Uppsala, whereas recipient norsertraline originated upstream of the city. No risk compound was apparently sourced from hospital wastewater.
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•77 organic micropollutants (OMPs) were analyzed in an urban catchment in Sweden.•Wastewater was identified as a major source of OMPs to River Fyris recipient.•The hospital contributed more antibiotics compared to the general urban wastewater.•Moderate risks arose from the OMPs norsertraline, trimethoprim and metoprolol.•The risk OMPs sourced from upstream pollution and urban area excluding the hospital.
Photography has been used to record different features of human societies since its invention in the first half of the nineteenth century. After years of being used as an illustrative tool in ...history, photography conquered its place as a primary source since the mid-1980s. In this article I add to this debate with a methodological approach to use photography in history of science and technology (including medicine and engineering). I argue that photography offers an exclusive view to understanding how science and technology were implemented, used, represented, and presented to the public. I offer both practical guidelines and a theoretical framework, based on Barthesian semiotics, which can be used by younger as well as by more experienced academics. I claim that this proposal has the potential to be used as a common denominator between assorted photographic collections and therefore to allow broader comparisons across different historical and geographic contexts. Moreover, it promotes the critical view of photography that should not be taken by its face value, but it should be understood within its sociotechnical and technoscientific context. This reflection certainly has its flaws and shortcomings, and it is naturally open to improvements, through its practical application to photographic collections.
Los hechos de violencia registrados en el norte paraguayo desde el año 2008, atribuidos a una supuesta organización guerrillera conocida como “Ejército del Pueblo Paraguayo”, a la que se identifica ...con la sigla “EPP”, han sido relatados de manera hegemónica desde la perspectiva de la versión oficial amplificada por los grandes medios de comunicación. En un más de una década de violencia armada se han registrado algunos episodios que han configurado la aparición de crisis que posibilitaron la irrupción en el debate público de voces que fueron marginadas en todos estos años del relato oficial y de las reflexiones de analistas conservadores y progresistas, incluso de ciertos referentes de organizaciones de Derechos Humanos. Esas voces disidentes, de pobladores campesinos e indígenas del norte paraguayo, se desmarcan de la violencia del “EPP”. Lo hacen sin esconderse en el anonimato, a cara descubierta. Todo esto coloca en entredicho las afirmaciones que aseguran la existencia del involucramiento de la población con el “grupo insurgente” y el supuesto silencio al que se llama para evitar represalias de una “guerrilla” a la que en realidad rechaza, lo que además hace inviable el apoyo político que toda insurgencia requiere para alcanzar sus objetivos.
Purpose To evaluate the epidemiology of injuries and abnormalities of the anterolateral ligament (ALL) by magnetic resonance imaging (MRI) in cases of acute anterior cruciate ligament (ACL) injury. ...Methods MRIs of patients with acute ACL injury were evaluated. Acute injuries of the ACL were considered in cases in which the patient reported knee trauma occurring less than 3 weeks prior and when bone bruise in the femoral condyles and tibial plateau was identified. ALL abnormality was considered when it showed proximal or distal bone detachment, discontinuity of fibers, or irregular contour associated with periligamentous edema. The ALL was divided into femoral, tibial, and meniscal portions, and the lesions and/or abnormalities of each portion were characterized. The correlation of ALL injury with injuries of the lateral meniscus was evaluated. Results A total of 101 MRIs were initially evaluated. The ALL was not characterized in 13 (12.8%) examinations, resulting in 88 (87.1%) cases of injury evaluation. Of these, 55 (54.4%) patients had a normal ALL, and 33 (32.6%) showed signs of injury. Among the cases with injury, 24 (72%) patients showed proximal lesions, 7 (21%) showed distal lesions, and 2 (6.0%) patients presented both proximal and distal lesions. The meniscal portion of the ALL appeared abnormal in 16 (48%) patients. No relationship was found between ALL injury and lateral meniscus injury. Conclusions Based on MRI analysis of acute ACL injuries with bone bruising of the lateral femoral condyle and lateral tibial plateau, approximately a third demonstrated ALL injuries of which the majority was proximal. Level of Evidence Level IV, case series.
In this cross-sectional study, we determined the relative impact of long-term occupational exposure to pesticides on physical performance and perception of tiredness. Experimental data was collected ...in locus from agricultural communities and included surveys to assess the duration of exposure to pesticides, social status, habitual physical activity levels, presence of common mental disorders (CMD), and self-reported tiredness. Plasmatic cholinesterase (PChE), body composition and traditional functional performance tests (Handgrip strength-HGS; Time up and go-TUG; and Sit-to-stand-STS) were obtained. From the 127 individuals tested, cluster analysis yielded 80 individuals divided in Direct Exposed (n = 37) and Indirect Exposed (n = 43); Tired (n = 16), and Not Tired (n = 64). PChE values were within the reference values (5209.64-13943.53 U/L). Pesticide exposure had no influence on PChE levels, CMD or fatigue (p > 0.05), while Self-reported tiredness had (p < 0.05). Principal Component Analyses showed that HGS; STS and TUG (i.e., physical performance variables) are negatively influenced by two independent factors: pesticide exposure and self-reported tiredness. We conclude that chronic pesticide exposure and tiredness can negatively impact physical performance, independently, without clinically significant changes in PChE levels that is a biomarker used to track pesticide intoxication. Functional physical tests can be a useful tool to identify chronic pesticide exposure, and help with the limitations of commonly used parameters (i.e. PChE and CMD). Self-reported tiredness is a confounding variable.
An improved quantitative and qualitative understanding of the interaction of per- and polyfluoroalkyl substances (PFASs) and short-range ordered Fe (hydr)oxides is crucial for environmental risk ...assessment in environments low in natural organic matter. Here, we present data on the pH-dependent sorption behavior of 12 PFASs onto ferrihydrite. The nature of the binding mechanisms was investigated by sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy and by phosphate competition experiments. Sulfur K-edge XANES spectroscopy showed that the sulfur atom of the head group of the sulfonated PFASs retained an oxidation state of +V after adsorption. Furthermore, the XANES spectra did not indicate any involvement of inner-sphere surface complexes in the sorption process. Adsorption was inversely related to pH (
< 0.05) for all PFASs (i.e., C
-C
and C
-C
perfluorocarboxylates, C
, C
, and C
perfluorosulfonates, perfluorooctane sulfonamide, and 6:2 and 8:2 fluorotelomer sulfonates). This was attributed to the pH-dependent charge of the ferrihydrite surface, as reflected in the decrease of surface ζ-potential with increasing pH. The importance of surface charge for PFAS adsorption was further corroborated by the observation that the adsorption of PFASs decreased upon phosphate adsorption in a way that was consistent with the decrease in ferrihydrite ζ-potential. The results show that ferrihydrite can be an important sorbent for PFASs with six or more perfluorinated carbons in acid environments (pH ≤ 5), particularly when phosphate and other competitors are present in relatively low concentrations.
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