The present study deals with Se(0)- and Te(0)-based nanoparticles bio-synthesized by two selenite- and tellurite-reducing bacterial strains, namely Stenotrophomonas maltophilia SeITE02 and ...Ochrobactrum sp. MPV1, isolated from polluted sites. We evidenced that, by regulating culture conditions and exposure time to the selenite and tellurite oxyanions, differently sized zero-valent Se and Te nanoparticles were produced. The results revealed that these Se(0) and Te(0) nanoparticles possess antimicrobial and biofilm eradication activity against Escherichia coli JM109, Pseudomonas aeruginosa PAO1, and Staphylococcus aureus ATCC 25923. In particular, Se(0) nanoparticles exhibited antimicrobial activity at quite low concentrations, below that of selenite. Toxic effects of both Se(0) and Te(0) nanoparticles can be related to the production of reactive oxygen species upon exposure of the bacterial cultures. Evidence so far achieved suggests that the antimicrobial activity seems to be strictly linked to the dimensions of the nanoparticles: indeed, the highest activity was shown by nanoparticles of smaller sizes. In particular, it is worth noting how the bacteria tested in biofilm mode responded to the treatment by Se(0) and Te(0) nanoparticles with a susceptibility similar to that observed in planktonic cultures. This suggests a possible exploitation of both Se(0) and Te(0) nanoparticles as efficacious antimicrobial agents with a remarkable biofilm eradication capacity.
The propagation of energetic charged particles and cosmic rays in magnetized thermal plasma is focused. We consider a four-fluid system that consists of thermal plasma, cosmic rays, and two opposite ...propagating Alfvén waves to investigate the dynamics and energy exchange mechanisms of the system. Additionally, cosmic rays diffusion within the plasma is considered along the magnetic field lines whereas neglected the cross field line diffusion effects. This study is important for understanding of pressure gradients and their impact on the feedback in astrophysical environment. Over the last few decades, this problem becomes important when we discuss the interaction of cosmic rays with plasma in space, such as interstellar clouds or interstellar medium.
Width of the diffraction peaks are used to determine the size and the shape of the particle in a colloidal dispersion.
Laboratory X-ray diffraction is used to investigate the size and shape of ...dispersed plate-like and spherical colloidal particles. Analysis of the wide-angle diffraction data provides information about the size and shape of crystals from the width of the Bragg peaks according to the Debye–Scherrer formula. The measurements, data analysis, and evaluation are discussed. It is shown that X-ray diffraction with conventional laboratory equipment on dispersed particles is feasible as a tool to determine both particle size and shape. Data for two samples – gold colloids and nickel (II) hydroxide particles are presented. The advantages and limitations of the method are discussed. X-ray diffraction measurements that are made in combination with dynamic light scattering can be used to estimate the thickness of stabilizing layers of polymers.
Bouts of exercise performed either prior to or immediately following study periods enhance encoding and learning. Empirical evidence supporting the benefits of interventions that simultaneously pair ...physical activity with material to be learned is not conclusive, however. A narrative, theory-based review of dual-task experiments evaluated studies in terms of arousal theories, attention theories, cognitive-energetic theories, and entrainment theories. The pattern of the results of these studies suggests that cognitive-motor interference can either impair or enhance memory of semantic information and the manner in which physical activity impacts working memory within executive processing appears to explain disparate outcomes. The integration and timing of physical movements in concert with the type of information to be encoded and remembered appears to be a critical requirement for learning. These observations have implications for the role of physical activity in education, rehabilitation, and gerontological settings.
Purpose
The purpose of this paper is to address a deficiency in the literature by exploring the impact of negative workplace safety announcements on firm performance. The authors analyze the issue ...from a corporate social responsibility perspective and explore ways supply chain managers can contribute to improve firm performance through the development of safe working environments.
Design/methodology/approach
Utilizing a sample of 227 negative workplace safety announcements, this paper explores the implications of negative workplace safety announcements on the stock price of a firm using event study methodology.
Findings
The authors find that negative workplace announcements are associated with an abnormal decrease in shareholder value. Furthermore, the authors find evidence that negative workplace safety announcements have a more pronounced negative effect on firm value in the present environment than in any previous time period.
Practical implications
Operations managers need to play leading roles in ensuring safe working environments. The results provide the support needed to acquire the financial resources necessary to mitigate exposure to unsafe working conditions.
Originality/value
This study explores the impact of negative workplace safety announcements on a firm’s stock performance. It is the first large-scale study to look at public announcements of workplace incidents and to explore the impact of such announcements in the context of time.
The starch yield of 23–28% (db) with 35–43% amylose content is recovered from different immature apple varieties. Scanning electron microscopy reveals the presence of the dome to spherical shaped ...granules of 3.1–11.62 µm size. The transition temperatures, onset temperature, peak temperature, conclusion temperature, and enthalpy of gelatinization are calculated using differential scanning calorimetry (DSC) ranges between 61.62 and 64.48 °C, between 64.61 and 68.07 °C, between 68.64 and 72.37 °C, and between 4.35 and 17.49 J g−1, respectively. The water absorption capacity and oil absorption capacity of starches range between 1.036 and 1.372 mL g−1 and between 0.876 and 1.125 mL g−1, respectively. The peak viscosity of 638–1942 cP is achieved in 3.8–6.10 min at a pasting temperature of 65–71 °C. A yield stress of 10–39 Pa is sufficient to instigate the Herschel Bulkley flow. The paste of Mollie's Delicious starch is more structured and elastic; its gel has a hardness of 3.5 N and maximum recovery strength.
The present study is conducted to extract the starch from immature wasted apple fruit, followed by the characterization of the starch. The functional characteristics are comparable with commercial cornstarch. Therefore, it is concluded that the application of starch from immature apples could be a good evolution in food and related industries.
It is unclear whether maternal vitamin D supplementation during pregnancy and lactation improves fetal and infant growth in regions where vitamin D deficiency is common.
We conducted a randomized, ...double-blind, placebo-controlled trial in Bangladesh to assess the effects of weekly prenatal vitamin D supplementation (from 17 to 24 weeks of gestation until birth) and postpartum vitamin D supplementation on the primary outcome of infants' length-for-age z scores at 1 year according to World Health Organization (WHO) child growth standards. One group received neither prenatal nor postpartum vitamin D (placebo group). Three groups received prenatal supplementation only, in doses of 4200 IU (prenatal 4200 group), 16,800 IU (prenatal 16,800 group), and 28,000 IU (prenatal 28,000 group). The fifth group received prenatal supplementation as well as 26 weeks of postpartum supplementation in the amount of 28,000 IU (prenatal and postpartum 28,000 group).
Among 1164 infants assessed at 1 year of age (89.5% of 1300 pregnancies), there were no significant differences across groups in the mean (±SD) length-for-age z scores. Scores were as follows: placebo, -0.93±1.05; prenatal 4200, -1.11±1.12; prenatal 16,800, -0.97±0.97; prenatal 28,000, -1.06±1.07; and prenatal and postpartum 28,000, -0.94±1.00 (P=0.23 for a global test of differences across groups). Other anthropometric measures, birth outcomes, and morbidity did not differ significantly across groups. Vitamin D supplementation had expected effects on maternal and infant serum 25-hydroxyvitamin D and calcium concentrations, maternal urinary calcium excretion, and maternal parathyroid hormone concentrations. There were no significant differences in the frequencies of adverse events across groups, with the exception of a higher rate of possible hypercalciuria among the women receiving the highest dose.
In a population with widespread prenatal vitamin D deficiency and fetal and infant growth restriction, maternal vitamin D supplementation from midpregnancy until birth or until 6 months post partum did not improve fetal or infant growth. (Funded by the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT01924013 .).
The Emerald Ash Borer (EAB),
, Fairmaire, an Asian invasive alien buprestid has devastated tens of millions of ash trees (
spp.) in North America. Foliar phytochemicals of the genus
(Oleaceae):
...(Green ash),
(White ash),
(Bush) Bush. (Pumpkin ash),
Michx. (Blue ash),
Marsh. (Black ash) and
.
(Manchurian ash) were investigated using HPLC-MS/MS and untargeted metabolomics. HPLC-MS/MS help identified 26 compounds, including phenolics, flavonoids and coumarins in varying amounts. Hydroxycoumarins, esculetin, esculin, fraxetin, fraxin, fraxidin and scopoletin were isolated from blue, black and Manchurian ashes. High-throughput metabolomics revealed 35 metabolites, including terpenes, secoiridoids and lignans. Metabolomic profiling indicated several upregulated putative compounds from Manchurian ash, especially fraxinol, ligstroside, oleuropin, matairesinol, pinoresinol glucoside, 8-hydroxypinoresinol-4-glucoside, verbenalin, hydroxytyrosol-1-
-glucoside, totarol and ar-artemisene. Further, dicyclomine, aphidicolin, parthenolide, famciclovir, ar-turmerone and myriocin were identified upregulated in blue ash. Principal component analysis demonstrated a clear separation between Manchurian and blue ashes from black, green, white and pumpkin ashes. The presence of defensive compounds upregulated in Manchurian ash, suggests their potential role in providing constitutive resistance to EAB, and reflects its co-evolutionary history with
, where they appear to coexist in their native habitats.
A challenge in recent years has been the rational use of forest and agriculture residues for the production of bio-fuel, biochemical, and other bioproducts. In this study, potentially useful ...compounds from pyrolytic lignins were identified by HPLC-MS/MS and untargeted metabolomics. The metabolites identified were 2-(4-allyl-2-methoxyphenoxy)-1-(4-hydroxy-3-methoxyphenyl)-1-propanol, benzyl benzoate, fisetinidol, phenyllactic acid, 2-phenylpropionic acid, 6,3'-dimethoxyflavone, and vanillin. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH), trolox equivalent antioxidant capacity (TEAC), and total phenolics content (TPC) per gram of pyrolytic lignin ranged from 14 to 503 mg ascorbic acid equivalents, 35 to 277 mg trolox equivalents, and 0.42 to 50 mg gallic acid equivalents, respectively. A very significant correlation was observed between the DPPH and TPC (
= 0.8663,
≤ 0.0001), TEAC and TPC (
= 0.8044,
≤ 0.0001), and DPPH and TEAC (
= 0.8851,
≤ 0.0001). The polyphenolic compounds in the pyrolytic lignins which are responsible for radical scavenging activity and antioxidant properties can be readily profiled with HPLC-MS/MS combined with untargeted metabolomics. The results also suggest that DPPH, TEAC, and TPC assays are suitable methods for the measurement of antioxidant activity in a variety of pyrolytic lignins. These data show that the pyrolytic lignins can be considered as promising sources of natural antioxidants and value-added chemicals.
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