Kinematic and electromyographic differences between mouse and touchpad use on laptop computers

Background

Numerous studies have compared the postures and muscular activities induced by the various input devices available. To the authors' knowledge, no studies have yet compared upper body posture and movement, sEMG activity and muscle co-contractions induced by use of a mouse or of a touchpad.

Objective

The aim of this study was to compare posture, joint excursion and sEMG activity when using a laptop equipped with a mouse or a touchpad.

Methods

Trunk and upper arm posture, ranges of motion and muscle activities were measured in ten subjects during two standardized tasks.

Results

Mouse use induced larger shoulder abduction than touchpad use. On the other hand, when a touchpad was used, the upper arm joints were bound and fixed to a greater extent than during mouse use. Touchpad users are forced to maintain a more static posture. The upper arm electromyography results clearly indicate that touchpad use requires more stabilization than mouse use.

Conclusion

Motor tasks executed by means of the mouse allow a greater range of motions and reduce the biomechanical stress thanks to the greater postural mobility, even though the posture is less neutral. The results of our study tend to suggest that an external mouse should be preferred to the touchpad by frequent users of laptops.

Relevance to industry

This study is a suggestion for IT companies to give customers information of possible advantages using an external mouse. Furthermore our data highlight the importance of providing a mouse to all laptop users in order to reduce biomechanical risks.     

Multitoxin extraction and detection of trichothecenes in cereals: an improved LC‐MS/MS approach

BACKGROUND: Many multiresidual methods to evaluate natural occurrence of Fusarium toxins are already reported in the scientific literature but a new rapid, reliable, cost‐efficient and high‐sensitivity method for the simultaneous determination of several fusariotoxins is always welcome. Nivalenol (NIV), deoxynivalenol, fusarenon‐X (FUS‐X), 3‐acetyldeoxynivalenol, diacetoxyscirpenol (DAS), HT‐2 toxin, T‐2 toxin, neosolaniol (NEO), zearalanone and zearalenone (ZON) belong to the most common mycotoxins in food matrix grains, e.g., wheat and maize. The proposed method is a multitoxin analytical method that combines high‐performance liquid chromatography (HPLC), atmospheric pressure chemical ionization (APCI), triple‐quadrupole tandem mass spectrometry (LC‐MS/MS) under the selected reaction monitoring (SRM) mode, and it is focused on the optimization of the sample preparation without the need for any cleanup. RESULTS: Three different methods for sample preparation and for the simultaneous extractions of the above‐mentioned fusariotoxins were tested: two of these were followed by a different cleanup step for comparison, while the extraction method proposed in this work, which uses an 84% (v/v) acetonitrile aqueous solution, sample homogenization and subsequent filtration, was validated without any further cleanup step. CONCLUSION: Calibration curves for all analytes are linear, except DAS, HT‐2 and ZON, over the working range of 10–1000 µg kg^?1. The calibration curve of DAS was linear between 10 and 500 µg kg^?1, although the curves of HT‐2 and ZON were linear in the range 10–250 µg kg^?1. Squared correlation coefficients (R²) were in the range 0.995–0.998 for the all point calibration curves. The lowest limits of detection (LOD) were found for DON and ZAN with 0.5 and 0.2 µg kg^?1, respectively, while the highest LODs were obtained for NIV, FUS‐X and NEO, with 3.3 µg kg^?1 for each toxin. Copyright © 2009 Society of Chemical Industry     

Volatile Compound and Sensory Analysis for the Characterization of an Italian White Wine from “Inzolia” Grapes

The research evidences the importance of linking chemical and sensory data for the wine characterization; in particular, the Italian white wine made from Inzolia grapes has been considered. Inzolia is one of the most widespread native white grapes in Sicily (Italy), and wine samples from two different areas (Monreale and Sambuca di Sicilia) have been analyzed. A headspace solid-phase microextraction/gas chromatography–mass spectroscopy method has been developed, and 56 volatile components, esters, fatty acids, alcohols, and terpenes have been identified; the method allows also the quantification of the main components, namely, ethyl octanoate (banana, fruit, fat) (257.2–541.6 mg/l) and ethyl decanoate (fruity, oily, floral; 171.8–272.0 mg/l). A good repeatability in terms of retention times and peak areas resulted. Sensory analysis was performed by ten trained judges that evaluated eight attributes: two referring to appearance (yellow color and yellow reflex), four referring to aroma (fruity, banana, ripened apple, and floral), and two referring to oral perception (acid and pungent). The volatile constituents and the aroma sensory attributes were in agreement.     

Genetic and Epigenetic Factors of Takotsubo Syndrome: A Systematic Review

Takotsubo syndrome (TTS), recognized as stress’s cardiomyopathy, or as left ventricular apical balloon syndrome in recent years, is a rare pathology, described for the first time by Japanese researchers in 1990. TTS is characterized by an interindividual heterogeneity in onset and progression, and by strong predominance in postmenopausal women. The clear causes of these TTS features are uncertain, given the limited understanding of this intriguing syndrome until now. However, the increasing frequency of TTS cases in recent years, and particularly correlated to the SARS-CoV-2 pandemic, leads us to the imperative necessity both of a complete knowledge of TTS pathophysiology for identifying biomarkers facilitating its management, and of targets for specific and effective treatments. The suspect of a genetic basis in TTS pathogenesis has been evidenced. Accordingly, familial forms of TTS have been described. However, a systematic and comprehensive characterization of the genetic or epigenetic factors significantly associated with TTS is lacking. Thus, we here conducted a systematic review of the literature before June 2021, to contribute to the identification of potential genetic and epigenetic factors associated with TTS. Interesting data were evidenced, but few in number and with diverse limitations. Consequently, we concluded that further work is needed to address the gaps discussed, and clear evidence may arrive by using multi-omics investigations.     

Synthesis and preliminary biological evaluation of 2'-substituted 2-(3'-carboxybicyclo[1.1.1]pentyl)glycine derivatives as group I selective metabotropic glutamate receptor ligands

The first series of 2'-substituted 2-(3'-carboxybicyclo[1.1.1]pentyl)glycine derivatives, (2R)- and (2S)-(2',2'-dichloro-3'-carboxybicyclo[1.1.1]pentyl)glycine (10) and (11), and 2-(2'-chloro-3'-carboxybicyclo[1.1.1]pentyl)glycine (12) were synthesized and evaluated as mGluR ligands. Compounds 11 and 12 were shown to be competitive group I mGluR antagonists. These results are also discussed in light of docking studies with both the active (closed) and inactive (open) conformations of mGluR1.     

Vitamin D3 Enriches Ceramide Content in Exosomes Released by Embryonic Hippocampal Cells

The release of exosomes can lead to cell–cell communication. Nutrients such as vitamin D3 and sphingolipids have important roles in many cellular functions, including proliferation, differentiation, senescence, and cancer. However, the specific composition of sphingolipids in exosomes and their changes induced by vitamin D3 treatment have not been elucidated. Here, we initially observed neutral sphingomyelinase and vitamin D receptors in exosomes released from HN9.10 embryonic hippocampal cells. Using ultrafast liquid chromatography tandem mass spectrometry, we showed that exosomes are rich in sphingomyelin species compared to whole cells. To interrogate the possible functions of vitamin D3, we established the optimal conditions of cell treatment and we analyzed exosome composition. Vitamin D3 was identified as responsible for the vitamin D receptor loss, for the increase in neutral sphingomyelinase content and sphingomyelin changes. As a consequence, the generation of ceramide upon vitamin D3 treatment was evident. Incubation of the cells with neutral sphingomyelinase, or the same concentration of ceramide produced in exosomes was necessary and sufficient to stimulate embryonic hippocampal cell differentiation, as vitamin D3. This is the first time that exosome ceramide is interrogated for mediate the effect of vitamin D3 in inducing cell differentiation.     

Specific aspartate residues in FET3 control high-affinity iron transport in Saccharomyces cerevisiae

Site-directed mutagenesis was performed on a set of six aspartate residues of Fet3, the multicopper ferroxidase involved in high-affinity iron transport in Saccharomyces cerevisiae, in order to comprehend the molecular determinants of the protein function. Asp312, Asp315, Asp319 and Asp320 were predicted by homology modelling to be located in a negatively charged surface-exposed loop of the protein. Other two aspartate residues (Asp278 and Asp279) are placed close to the type 1 copper- and iron-binding sites, possibly linking these sites to the negatively charged region. In vivo results showed that mutation of Asp319 and Asp320 to yield D319N and D320N derivatives strongly impairs the ability of the yeast to grow under iron-limiting conditions. In particular, substitution of Asp320 with asparagine essentially abolished the Fet3-dependent iron transport activity. All other mutants (D278Q, D279N, D312N and D315I) behaved essentially as the wild-type protein. The electron paramagnetic resonance spectrum of the soluble forms of D319N and D320N showed significant changes of the copper sites' geometry in D319N but not in D320N. At variance with the membrane-bound forms, soluble D319N and D320N derivatives were highly susceptible to proteolytic degradation, suggesting that replacement of Asp319 or Asp320 locally modifies the structure of Fet3, making the protein sensitive to proteolysis when it is not protected by the membrane environment. In turn, this might be evidence of a shielding role of the permease Ftr1, which could interact with Fet3 at the level of the aspartate-rich negatively charged region.     

An analysis of inter- and intraspecific genetic variabilities in the Kluyveromyces marxianus group of yeast species for the reconsideration of the K. lactis taxon

In the present work, we analyse the sequences of the 5.8S rRNA gene and the two internal transcribed spacers 1 and 2 (5.8S-ITS region), obtained from 39 strains belonging to the species Kluyveromyces aestuarii, K. dobzhanskii, K. lactis and K. marxianus, K. nonfermentans and K. wickerhamii, to solve the phylogenetic relationships among these species and also to determine the possible genetic basis for the delimitation of the two currently accepted K. lactis varieties: lactis, including lactose-positive strains isolated from dairy products, and drosophilarum, comprising lactose-negative strains isolated from insects and plant exudates. The determination of the phylogenetic relationships within the species K. lactis, together with the examination of the electrophoretic karyotypes and phenotypic characterization of strains representatives of K. lactis var. lactis and var. drosophilarum, allowed differentiation of two groups of strains. The first, and ancestral, group comprises lactose-negative strains isolated from natural habitats in North America. The second, and derived, group includes both lactose-negative strains isolated from natural habitats in Europe and wine fermentation in South Africa, and lactose-positive strains associated with dairy products. These results suggest that the present taxon K. lactis is a complex of different species, subspecies or, at least, genetically structured populations.