Experimental Evaluation of the Mechanical Properties of Steel Reinforcement at Elevated Temperature

This paper describes an experimental investigation into the influence of elevated temperatures on the mechanical properties of steel reinforcement. The study includes tests carried out at ambient temperature as well as under steady-state and transient elevated temperature conditions. A complementary test series, in which the residual post-cooling properties of reinforcing bars were examined, is also described. The experimental study focussed on assessing the performance of reinforcement of 6 and 8 mm diameter, although 10 mm bars were also considered in some cases. The specimens included both plain and deformed bars. After providing an outline of the experimental set-up and loading procedures, a detailed account of the test results is presented and discussed. Apart from the evaluation of stress–strain response and degradation of stiffness and strength properties, particular emphasis is given to assessing the influence of temperature on enhancing the ductility of reinforcement. The findings of this study have direct implications on procedures used for predicting the ultimate behaviour of structural floor elements and assemblages during, and following, exposure to elevated temperatures

Polysialic acid regulates sympathetic outflow by facilitating information transfer within the nucleus of the solitary tract

Expression of the large extracellular glycan, polysialic acid (polySia), is restricted in the adult, to brain regions exhibiting high levels of plasticity or remodeling, including the hippocampus, prefrontal cortex, and the nucleus of the solitary tract (NTS). The NTS, located in the dorsal brainstem, receives constant viscerosensory afferent traffic as well as input from central regions controlling sympathetic nerve activity, respiration, gastrointestinal functions, hormonal release, and behavior. Our aims were to determine the ultrastructural location of polySia in the NTS and the functional effects of enzymatic removal of polySia, both in vitro and in vivo polySia immunoreactivity was found throughout the adult rat NTS. Electron microscopy demonstrated polySia at sites that influence neurotransmission: the extracellular space, fine astrocytic processes, and neuronal terminals. Removing polySia from the NTS had functional consequences. Whole-cell electrophysiological recordings revealed altered intrinsic membrane properties, enhancing voltage-gated K+ currents and increasing intracellular Ca2+ Viscerosensory afferent processing was also disrupted, dampening low-frequency excitatory input and potentiating high-frequency sustained currents at second-order neurons. Removal of polySia in the NTS of anesthetized rats increased sympathetic nerve activity, whereas functionally related enzymes that do not alter polySia expression had little effect. These data indicate that polySia is required for the normal transmission of information through the NTS and that changes in its expression alter sympathetic outflow. polySia is abundant in multiple but discrete brain regions, including sensory nuclei, in both the adult rat and human, where it may regulate neuronal function by mechanisms identified here.SIGNIFICANCE STATEMENT All cells are coated in glycans (sugars) existing predominantly as glycolipids, proteoglycans, or glycoproteins formed by the most complex form of posttranslational modification, glycosylation. How these glycans influence brain function is only now beginning to be elucidated. The adult nucleus of the solitary tract has abundant polysialic acid (polySia) and is a major site of integration, receiving viscerosensory information which controls critical homeostatic functions. Our data reveal that polySia is a determinant of neuronal behavior and excitatory transmission in the nucleus of the solitary tract, regulating sympathetic nerve activity. polySia is abundantly expressed at distinct brain sites in adult, including major sensory nuclei, suggesting that sensory transmission may also be influenced via mechanisms described here. These findings hint at the importance of elucidating how other glycans influence neural function.Phillip Bokiniec, Shila Shahbazian, Stuart J. McDougall, Britt A. Berning, Delfine Cheng, Ida J. Llewellyn-Smith ... et al

Stomatal responses of Eucalyptus species to elevated CO2 concentration and drought stress

Five species of Eucalyptus (E. grandis, E. urophylla, E. camaldulensis, E. torelliana, and E. phaeotrica), among the ten species most commonly used in large scale plantations, were selected for studies on the effects of elevated CO2 concentration [CO2] and drought stress on stomatal responses of 2.5-month old seedlings. The first three species belong to the subgenus Smphyomyrtus, whereas the fourth species belongs to the subgenus Corymbia and E. phaeotrica is from the subgenus Monocalyptus. Seedlings were grown in four pairs of open-top chambers, arranged to have 2 plants of each species in each chamber, with four replications in each of two CO2 concentrations: 350 ± 30 mumol mol-1 and 700 ± 30 mumol mol-1. After 100 days in the chambers, a series of gas exchange measurements were made. Half the plants in each chamber, one plant per species per chamber, were drought-stressed by withholding irrigation, while the remaining plants continued to be watered daily. Drought stress decreased stomatal conductance, photosynthesis and transpiration rates in all the species. The effect of drought stress on stomatal closure was similar in both [CO2]. The positive effects of elevated [CO2] on photosynthesis and water use efficiency were maintained longer during the stress period than under well-watered conditions. The photosynthetic rate of E. phaeotrica was higher even in the fourth day of the drought stress. Drought stress increased photoinhibition of photosynthesis, as measured by chlorophyll fluorescence, which varied among the species, as well as in relation to [CO2]. The results are in agreement with observed differences in stomatal responses between some eucalyptus species of the subgenera Symphyomyrtus and Monocalyptus

Relational quality and media use in interpersonal relationships

Author final draft doi:10.1177/1461444807080339This study examined the relationship between relational quality and media use in interpersonal relationships. In addition, the impacts of other potentially important variables such as sex and relationship type of participants and their partners were explored. College student participants focused on interaction experiences with an acquaintance, friend, romantic partner, or family member. Questions addressed the sex of relational partners, how much of participants’ total communication with relational partners is conducted in each of three media (i.e., face-to-face, phone, and internet), and the quality of relationships. Results indicated that participant sex and partner sex did not affect reported media use, whereas relationship type had significant effects on the extent to which face-to-face and telephone communication were used. Specifically, among the college students studied, face-to-face communication was used least with family members and the telephone was used most with family members. Relationships with acquaintances had the lowest relational quality and romantic relationships, while closer, were less satisfying than either family or friendship relationships. Same-sex relationships were perceived as more satisfying than cross-sex relationships. Finally, media use did not predict relational closeness or satisfaction. Results are discussed in light of previous research on mediated interpersonal communication and conceptualizations of the role of communication technology in one’s social life are highlighted

Pseudorapidity distribution of charged hadrons in proton-proton collisions at root s=13TeV

Peer reviewe

Pseudorapidity distribution of charged hadrons in proton-proton collisions at s=13 TeV

The pseudorapidity distribution of charged hadrons in pp collisions at s=13 TeV is measured using a data sample obtained with the CMS detector, operated at zero magnetic field, at the CERN LHC. The yield of primary charged long-lived hadrons produced in inelastic pp collisions is determined in the central region of the CMS pixel detector (|η|<2) using both hit pairs and reconstructed tracks. For central pseudorapidities (|η|<0.5), the charged-hadron multiplicity density is dNch/dη||η|<0.5=5.49±0.01(stat)±0.17(syst), a value obtained by combining the two methods. The result is compared to predictions from Monte Carlo event generators and to similar measurements made at lower collision energies. © 2015 CERN for the benefit of the CMS Collaboration

Mini-open Repair of the Floating Anterior Inferior Glenohumeral Ligament: Combined Treatment of Bankart and Humeral Avulsion of the Glenohumeral Ligament Lesions

Anterior shoulder instability often results from avulsion of the anterior inferior glenohumeral ligament (aIGHL) off its insertion on the glenoid, yielding a Bankart lesion. Although less common, avulsion of the ligament attachment to the humerus results in a humeral avulsion of the glenohumeral ligament (HAGL) lesion. Combined Bankart and HAGL lesions, also termed the “floating aIGHL,” create a complex pathology that is not detailed significantly in the literature. We believe a mini-open approach is a viable and reproducible procedure for treatment because it allows for protection of the axillary nerve and other neurovascular structures while providing optimal exposure to both the humeral insertion site of the distal aIGHL and the Bankart lesion, ensuring anatomic restoration. The purpose of this Technical Note is to describe our preferred technique to surgically treat the floating aIGHL, consisting of an anterior HAGL and concomitant Bankart lesion repair through a mini-open approach