Effect of short‐duration high temperatures on weed seed germination

Thermal soil disinfestation techniques are effective reducers of weed seedbank and weed emergence. Two experiments (Expt 1 and Expt 2) were conducted to test the effect of brief exposure to varying temperatures on the seed germination of Amaranthus retroflexus, Echinochloa crus‐galli, Galinsoga quadriradiata, Portulaca oleracea, Setaria viridis and Solanum nigrum. To this end, species seeds were moistened with loamy‐sand soil and placed into test tubes. The tubes were heated rapidly and then cooled by dipping them into a hot water bath until target temperatures were achieved. Expt 1 temperatures ranged between 55°C and 85°C at 5°C intervals and Expt 2 ranged between 48°C and 86°C at 2°C intervals. Thereafter, the tubes were dipped into a cooling (1°C) water bath. Exposure to target temperatures ranged between 2 s and 5 s. Soil temperatures were monitored using embedded thermocouples. A log‐logistic dose–response model described the effect of heating on seed germinability; temperatures required for 99% reductions were calculated. On the basis of the predictive model equation used, weed species' germination sensitivity to high temperature exposure can be ranked as follows: E. crus‐galli (79.6°C), S. viridis (75.8°C), S. nigrum (74.6°C), P. oleracea (72.2°C), A. retroflexus (70.9°C) and G. quadriradiata (68.1°C). The interval between no effects to complete seed devitalisation occurred at temperatures varying from 6.5°C to 15.7°C. Seed size and weight varied directly with heat tolerance. Study results not only inform the timing and optimal adjustment for effective thermal soil treatment, but also demonstrate a relatively simple and generalizable methodology for use in other studies.     

Faecal Excretion Dynamic during Subacute Oral Exposure to Different Pb Species in Rattus norvegicus

Faecal excretion is a basic means of detoxification upon ingestion of Pb-contaminated feed. In order to determine a time course of Pb elimination after oral exposure to two different forms of this heavy metal (lead acetate vs. phyto-bound Pb), a feeding study was carried out in experimental rats using the Pb phyto-hyperaccumulator Pistia stratiotes as a model diet. The effect of starvation on Pb excretion was further studied in rats that were fed plant material. Twelve Pb doses (7 μg Pb/1 g BW) were administered orally over a 5-week period. Faeces samples were collected 24 and 72 h post-exposure. Inductively coupled plasma optical emission spectrometry and electrothermal absorption spectrometry methods were used for determination of heavy metal concentrations. Up to 53 % of ingested Pb was rapidly eliminated from the exposed rats via faeces within 24 h after exposure. Faecal excretion in exposed rats differed significantly when compared to that of the control group. Fasting before exposure reduced Pb excretion by up to 50 %. Faecal excretions of both examined Pb forms exhibited almost identical patterns. Considerable differences were revealed concerning total excretion levels; lead acetate was excreted in amount greater extent than those of phytobound Pb. Results of our study suggest that Pb forms occurring in the P. stratiotes tissues are absorbed through the gastrointestinal tract to a greater extent than Pb from lead acetate. Therefore, higher portions of ingested Pb can be available for potential accumulation in tissues of exposed subjects.     

Copper uptake and copper-induced physiological changes in the epiphytic lichen Evernia prunastri

The lichen Evernia prunastri is very frequently employed in lichen biomonitoring studies and its sensitivity to air pollution has been confirmed at the community level many times. However, studies focused on the physiological responses of this lichen to pollutants are underrepresented. The degree of total as well as intracellular Cu uptake by the lichen after 4 and 24?h prolonged exposure was compared with selected physiological markers including levels of assimilation pigments, chlorophyll a fluorescence, ergosterol, soluble proteins, hydrogen peroxide, superoxide, amino acids, reducing sugars and total soluble phenols. Although the degree of total as well as intracellular Cu uptake by the lichen after 4 and 24?h prolonged exposure were comparable, metabolic responses after 4 and 24?h were very different. Carotenoids, ergosterol and soluble proteins decreased due to Cu exposure and these processes were followed with an increase of superoxide content. Excess of Cu in thalli of E. prunastri after 24?h was toxic and altered almost all tested parameters, including depletion of reducing sugars. We did not observe stimulation of free amino acid synthesis in Cu treated lichen, in fact the content of many particular amino acids decreased. Content of total soluble phenols was unaltered by Cu excess.     

La neurólisis del nervio mediano en el paciente anciano: evaluación a largo plazo

Purpose

Carpal tunnel release by opening the flexor retinaculum is considered a satisfactory treatment. However, several factors, like ageing, may influence postoperative results. We present the long term outcomes in elderly patients.

Methods

This is an historical prospective long term study of 52 patients who received surgical treatment of carpal tunnel syndrome when they were 65 or older. We have carried out a clinical-functional (with the Levine questionnaire), electromyographic and dynamometric valuation of the patients studied, up to ten years from the surgery.

Results

The results of Levine's questionnaire, revealed favourable data for a mean follow-up of 10.35 years, with a mean improvement in the clinical score of 1.93 points (95% confidence interval [CI]: 1.72-2.17) and in the functional score of 0.83 points (95% CI: 0.68-0.99). Similarly, the electromyographic values showed a significant improvement compared to preoperative ones (mean difference of sensory velocity of 8.43 m/s, 95% CI: 8.17-11.63; mean difference of motor latency of 1.65 ms, 95% CI: 1.24-2.25). The data on grip strength did not reach statistical significance.

Conclusions

In elderly patients, complete section of the carpal transverse ligament, allows maintaining favourable differences in most of the parameters studied, ten years after surgery, making the surgical treatment a recommendable option.     

Cerebrospinal Fluid and Plasma Oxidative Stress Biomarkers in Different Clinical Phenotypes of Neuroinflammatory Acute Attacks. Conceptual Accession: From Fundamental to Clinic

Oxidative stress is revealed as the main contributor in the pathophysiology of neuroinflammation. Analyzing plasma and cerebrospinal fluid (CSF) of patients with different clinical phenotypes of neuroinflammation, defined as clinically isolated syndrome (CIS), and those defined as relapsing remitting multiples sclerosis (RRMS), we tested peripheral and CNS oxidative stress intensity in these neuroinflammatory acute attacks. All obtained values changes were assessed regarding clinical and radiological features of CNS inflammation. The obtained results revealed an increase in malondialdehyde levels in plasma and CSF in CIS and RRMS patients compared to control values (p < 0.05). The obtained values were most prevailed in both study group, CIS and RRMS, in patients with severe clinical presentation (p < 0.05). Measured activities of catalase and total superoxide dismutase were higher in CIS and RRMS patients in plasma compared to control values (p < 0.05), parallel with an increased catalase activity and decrease in superoxide dismutase activity in CSF regarding values obtained in control group (p < 0.05). The positive correlations regarding clinical score were obtained for all tested biomarkers (p < 0.01). Although the positive correlations were observed in MDA levels in plasma and CSF, for both study patients, and their radiological findings (p < 0.01), and a negative correlation in plasma SOD activity and CIS patients’ radiological findings (p < 0.01), no other similar correlations were obtained. These findings might be useful in providing the earliest antioxidative treatment in neuroinflammation aimed to preserve total and CNS antioxidative capacity parallel with delaying irreversible, later neurological disabilities.     

Sleeping Beauty transposon-based system for cellular reprogramming and targeted gene insertion in induced pluripotent stem cells

The discovery of direct cell reprogramming and induced pluripotent stem (iPS) cell technology opened up new avenues for the application of non-viral, transposon-based gene delivery systems. The Sleeping Beauty (SB) transposon is highly advanced for versatile genetic manipulations in mammalian cells. We established iPS cell reprogramming of mouse embryonic fibroblasts and human foreskin fibroblasts by transposition of OSKM (Oct4, Sox2, Klf4 and c-Myc) and OSKML (OSKM + Lin28) expression cassettes mobilized by the SB100X hyperactive transposase. The efficiency of iPS cell derivation with SB transposon system was in the range of that obtained with retroviral vectors. Co-expression of the miRNA302/367 cluster together with OSKM significantly improved reprogramming efficiency and accelerated the temporal kinetics of reprogramming. The iPS cells displayed a stable karyotype, and hallmarks of pluripotency including expression of stem cell markers and the ability to differentiate into embryoid bodies in vitro. We demonstrate Cre recombinase-mediated exchange allowing simultaneous removal of the reprogramming cassette and targeted knock-in of an expression cassette of interest into the transposon-tagged locus in mouse iPS cells. This strategy would allow correction of a genetic defect by site-specific insertion of a therapeutic gene construct into ‘safe harbor’ sites in the genomes of autologous, patient-derived iPS cells.     

The effects of geothermal water inflow on longitudinal changes in benthic macroinvertebrate community composition of a temperate stream

Studies of macroinvertebrate communities in thermal streams are highly geographically localized and mostly faunistical, making the efforts to understand in situ water thermal regime effects on those biocoenoses barely achievable. We examined the effects of geothermal water inflow on benthic macroinvertebrate community composition in a temperate stream. Environmental data analysis has shown that water temperature is a major factor determining the faunistical composition, especially downstream of the geothermal water inflow situated some 20 m upstream of locality V3. The increase in mean annual water temperature from 11.5±4.1 °C at locality V2 to 22.0±5.0 °C at locality V3 induced an enormous shift in community composition from a diverse one, composed mainly of Gammaridae, Simuliidae, Chironomidae, Trichoptera and Ephemeroptera, and to a lesser extent of Plecoptera, Coleoptera, other Diptera, Hirudinea, Odonata, Mollusca and Oligochaeta, to a uniform one strongly dominated by Chironomidae, Mollusca and Oligochaeta, comprising 98.9±0.5% of collected individuals. While the disappearance of Plecoptera and Ephemeroptera and the increase in representation of Mollusca and Oligochaeta at locality V3 might be solely explained by water temperature increase, in the case of Chironomidae the increase in water discharge and relatively high annual water temperature variation at locality V3 had additional positive effects. However, the latter factor induced disappearance of Gammaridae at locality V3. In addition to the increase in water temperature, increase of water velocity significantly determined the longitudinal dynamics of Coleoptera.     

Pseudomonas prosekii sp. nov., a Novel Psychrotrophic Bacterium from Antarctica

During Czech expeditions at James Ross Island, Antarctica, in the years 2007–2009, the bacterial diversity of the genus Pseudomonas was studied. Twelve fluorescent Pseudomonas strains were isolated from various samples and were subjected to a detailed taxonomic study. A polyphasic approach included genotypic and phenotypic analyses. The genotypic analysis involved sequencing of rrs, rpoB and rpoD genes, DNA–DNA hybridization (DDH) studies as well as manual ribotyping using HindIII endonuclease. The phenotypic characterization included conventional tests as well as biotyping using the Biolog system, protein profiling by SDS-PAGE, and MALDI-TOF MS analysis. Our taxonomic study revealed that all isolates belonged to the same Pseudomonas species with psychrotrophic growth not exceeding 37 °C. The cultures showed a unique position among the phylogenetically related pseudomonads. DDH experiment between the proposed type strain of the antarctic isolates and the closest neighbour P. arsenicoxydans CCM 8423^T showed only 40.9–50.1 % similarity, thus confirming that the characterized strains do not belong to the P. arsenicoxydans species. According to the results obtained we propose the name P. prosekii sp. nov. for this novel Pseudomonas taxon with type strain AN/28/1^T (=CCM 7990^T and LMG 26867^T).     

Anxiety symptomatology,sex and chronotype: The mediational effect of diurnal sleepiness

ABSTRACT

Diurnal subjective sleepiness has been associated with a large number of negative outcomes, such as increased risk of accidents and development of mental disorders as depression and anxiety. However, the role of the diurnal subjective sleepiness as a mediator is poorly understood. The goal of the present study was to examine the role of diurnal subjective sleepiness as a mediator of the relationship between sex, chronotype and anxiety symptoms in healthy young adults. Four-hundred and sixty-seven healthy young adults (64.8% females, age range 18–32 years, mean 20.7, ±2.3) were evaluated with validated and widely used scales for the measurement of diurnal sleepiness, anxiety symptoms and morningness–eveningness preference. We have found that diurnal subjective sleepiness correlated with anxiety symptoms when evaluated both in the total sample and within chronotypes. This association was more important in females than in males (p < 0.0001). Regarding chronotype, only for morning-types, diurnal subjective sleepiness was a significant mediator of the relationship between sex and anxiety symptoms. This is the first study that examines the mediator role of diurnal subjective sleepiness in the known relationship between sex and anxiety symptoms, and adds new evidence about the effect of the chronotype on sleep problems and mental health. Although future work is required, our results have important implications for clinical settings and public health interventions.