Effect of Inhibitors on D-Xylose Permeability in Rat Diaphragm Muscle

The influence of metabolic inhibitors and low temperatures upon D-xylose transfer has been studied in rat diaphragm muscle preparations in vitro. Using intact fiber preparations, it has been confirmed that at body temperature metabolic inhibitors like DNP have an insulin-like action in that they permit D-xylose to distribute into previously unavailable intracellular aqueous regions; inhibitors, unlike insulin, disturb cation distribution in association with increased sugar penetration. Although the studies with inhibitors suggest an energy requirement for maintenance of D-xylose exclusion, the D-xylose exclusion mechanism is effectively maintained at 0° for many hours, and under these conditions, inhibitors have little or no effect on D-xylose distribution, though they do produce potassium loss. In cut muscle fiber preparations, in which insulin significantly increases the rate at which D-xylose equilibrates between cell water and external medium, DNP does not increase the rate of D-xylose entry, but does abolish the effect of insulin in this preparation. The results suggest that insulin action upon sugar permeability in muscle involves two barrier systems; some of the characteristics of these systems have been defined

Variation in biological parameters of cypermethrin resistant and susceptible strains of Helicoverpa armigera from Benin Republic, West Africa

The aim of this survey was to assess the costs of cypermethrin resistance in Helicoverpa armigera strains by using variation in their biological parameters such as fecundity, number of larval slough, development time, weight and survival at each stage of insect development in comparison with susceptible strains. AGB01 and AGB03 are the resistant strains compared respectively with BK77 and OKP01 as susceptible strains. Fecundity, fertility and survival from egg to adult emergence of AGB03 strain were significantly (P < 0.001) lower than those observed in OKP01 strain. No difference (P > 0.05) was observed with time of pre-adult development, survival at each stage of insect development, fecundity and number of larval slough in comparison with AGB01 and BK77 strains. Larvae of AGB01 strain took significantly (P < 0.01) longer time to develop and were significantly (P < 0.01) lighter than BK77 at the same age, but the slower development of larvae of AGB01 strain was counteracted by the shorter times of egg and pupae stages. The lower fecundity, fertility and survival from egg to adult emergence should represent the main costs for the AGB03 strain resistant to cypermethrin.Keywords: Cypermethrin resistance, resistance cost, fecundity, fertility, development tim

Leaf Eh and pH: A Novel Indicator of Plant Stress. Spatial, Temporal and Genotypic Variability in Rice (Oryza sativa L.)

A wealth of knowledge has been published in the last decade on redox regulations in plants. However, these works remained largely at cellular and organelle levels. Simple indicators of oxidative stress at the plant level are still missing. We developed a method for direct measurement of leaf Eh and pH, which revealed spatial, temporal, and genotypic variations in rice. Eh (redox potential) and Eh@pH7 (redox potential corrected to pH 7) of the last fully expanded leaf decreased after sunrise. Leaf Eh was high in the youngest leaf and in the oldest leaves, and minimum for the last fully expanded leaf. Leaf pH decreased from youngest to oldest leaves. The same gradients in Eh-pH were measured for various varieties, hydric conditions, and cropping seasons. Rice varieties differed in Eh, pH, and/or Eh@pH7. Leaf Eh increases and leaf pH decreases with plant age. These patterns and dynamics in leaf Eh-pH are in accordance with the pattern and dynamics of disease infections. Leaf Eh-pH can bring new insight on redox processes at plant level and is proposed as a novel indicator of plant stress/health. It could be used by agronomists, breeders, and pathologists to accelerate the development of crop cultivation methods leading to agroecological crop protection

A review on methods used to record and analyze microfluctuations of the accommodation in the human eye.

In steady state conditions, the accommodation of the human eye presents fluctuations. These fluctuations, called microfluctuations, are described in the literature as having an amplitude of less than 1D and a frequency up to a few Hz. Since Collins’ report about microfluctuations in 1937 [Collins 1937], several methods have been used to record and analyze microfluctuations. Results reported in the literature are partially in disagreement; we show how these disagreements could be due to the different methodologies used to record and analyze the accommodation signals. We classify and discuss properties of instruments used to record the microfluctuations and methods used to elaborate the resulting signals; to conclude we suggest how to validate the instrumentation and which analysis method to adopt when investigating microfluctuations

A rare case of complicated pure posterior sternoclavicular dislocation in a young athlete

Sternoclavicular joint dislocation (SCJD) is a rare injury, generally classified in anterior and pos-terior. The posterior SCJD is very infrequent yet potentially associated with life-threatening complications. In patients with unfused medial clavicle physis, SCJD can be associated with fracture-dislocation (Salter type I or II). We hereby present the case of a 12-year-old basketball player with severe pain in sternoclavicular region and arising dysphagia after a fall and tackle by another player. A SCJ injury was hypothesised and the CT scan detected the presence of a true posterior SCJD with no associated fracture, which was also confirmed during open reduction. As the patient complained dysphagia, it was also necessary to study other possible mediastinal compressions by a contrast medium CT scan of the great vessels. The CT scanned brachiocephalic vein compression without additional clinical evidence or signs. Twenty hours after the trauma the patient underwent an unsuccessful closed reduction; for this reason, surgical treatment with open reduction and fixation was mandatory. After 12 weeks of therapy she returned to her previous sport activity. (www.actabiomedica)

Influence of Different Filler Metals on the Mechanical and Microstructural Characteristics of Arc-Welded Joints Made of Dissimilar Titanium Alloys

In the motorsport industry, the choice of material for manufacturing the heat resistant components often falls on titanium alloys. In most cases, the production flow for this kind of part involves CNC machining and subsequent assembly by welding process, to other parts obtained by cold plastic forming and possibly made using different titanium alloys. Hence, the alloying element-content in the joint area can be extremely heterogeneous and variable point-by-point. To investigate this topic further, dissimilar welding of the alpha/beta alloy Ti6Al4V and of the oxidation-resistant alpha alloy KS-Ti 1.2 ASN-EX was made by GTAW technology and using different filler metals. Chemical and mechanical properties of the welds were investigated by XRD, SEM-EDS, microhardness maps, and tensile and bending tests. Results show that, despite the different alloying elements present in the two filler wires investigated, static properties of the welds are similar. Results also show that the local V/Al content ratio affects the microhardness as it is responsible for the creation of supersaturated alpha phases during the cooling of the weld beads

Ergonomics and human factors as a requirement to implement safer collaborative robotic workstations: a literature review

There is a worldwide interest in implementing collaborative robots (Cobots) to reduce work-related Musculoskeletal Disorders (WMSD) risk. While prior work in this field has recognized the importance of considering Ergonomics & Human Factors (E&HF) in the design phase, most works tend to highlight workstations’ improvements due to Human-Robot Collaboration (HRC). Based on a literature review, the current study summarises studies where E&HF was considered a requirement rather than an output. In this article, the authors are interested in understanding the existing studies focused on Cobots’ implementation with ergonomic requirements, and the methods applied to design safer collaborative workstations. This review was performed in four prominent publications databases: Scopus, Web of Science, Pubmed, and Google Scholar, searching for the keywords ‘Collaborative robots’ or ‘Cobots’ or ‘HRC’ and ‘Ergonomics’ or ‘Human factors’. Based on the inclusion criterion, 20 articles were reviewed, and the main conclusions of each are provided. Additionally, the focus was given to the segmentation between studies considering E&HF during the design phase of HRC systems and studies applying E&HF in real-time on HRC systems. The results demonstrate the novelty of this topic, especially of the real-time applications of ergonomics as a requirement. Globally, the results of the reviewed studies showed the potential of E&HF requirements integrated into HRC systems as a relevant input for reducing WMSD risk.This work has been supported by FCT–Fundação para a Ciência e Tecnologia and MIT Portugal Program under the doctoral Grant SFRH/BD/151365/2021. This work has been also supported by NORTE-06-3559-FSE-000018, integrated in the invitation NORTE-59-2018-41, aiming the Hiring of Highly Qualified Human Resources, co-financed by the Regional Operational Programme of the North 2020, thematic area of Competitiveness and Employment, through the European Social Fund. Additionally, has been also supported by FCT within the Project “I-CATER–Intelligent robotic Coworker Assistant for industrial Tasks with an Ergonomics Rationale”, Ref. PTDC/EEIROB/3488/2021, and within R&D Units Project Scope: UIDB/00319/2020

The signature of long-standing balancing selection at the human defensin β-1 promoter

Analysis of the human beta defensin 1 promoter region in six human populations reveals a signature of balancing selection

Designing CIGS solar cells with front-side point contacts

In this work we show how 2D numerical simulations can be used to design and optimize front-side point contacts in surface-passivated CIGS cells. Detailed analysis of the combinations of passivation thickness, point contact size and pitch can help identifying solutions able to boost the performance of otherwise surface-limited cells: efficiencies close to those of cells with ideal (i.e., trap-free) CdS/CIGS interface can be achieved by the optimization of point contact features in the low nm range. The effect of varying the CIGS and CdS doping densities on the cell performance has also been analyzed

Both selective and neutral processes drive GC content evolution in the human genome

<p>Abstract</p> <p>Background</p> <p>Mammalian genomes consist of regions differing in GC content, referred to as isochores or GC-content domains. The scientific debate is still open as to whether such compositional heterogeneity is a selected or neutral trait.</p> <p>Results</p> <p>Here we analyze SNP allele frequencies, retrotransposon insertion polymorphisms (RIPs), as well as fixed substitutions accumulated in the human lineage since its divergence from chimpanzee to indicate that biased gene conversion (BGC) has been playing a role in within-genome GC content variation. Yet, a distinct contribution to GC content evolution is accounted for by a selective process. Accordingly, we searched for independent evidences that GC content distribution does not conform to neutral expectations. Indeed, after correcting for possible biases, we show that intron GC content and size display isochore-specific correlations.</p> <p>Conclusion</p> <p>We consider that the more parsimonious explanation for our results is that GC content is subjected to the action of both weak selection and BGC in the human genome with features such as nucleosome positioning or chromatin conformation possibly representing the final target of selective processes. This view might reconcile previous contrasting findings and add some theoretical background to recent evidences suggesting that GC content domains display different behaviors with respect to highly regulated biological processes such as developmentally-stage related gene expression and programmed replication timing during neural stem cell differentiation.</p