The performativity of BYOD

Bring-Your-Own-Device (BYOD) is a trend introduced by a large IT corporation in 2009 realised as a consequence of the consumerization of Information Technology. BYOD is described as the phenomenon of using personal mobile devices connected to corporate networks to perform work. This study aims to understand consumerization of IT and BYOD in the Tertiary Education sector, particularly the context of BYOD in universities in both the United Kingdom and Malaysia. The study will commence with a pilot case study in the Computer Science Department of a UK University to explore its current systems and support for staff and students, gathering insights on the consideration of BYOD for the department. As this is a phenomenological study, Actor Network Theory (ANT) is selected as an initial lens. This seeks to create a ‘timeless snapshot’ of phenomena in time, space and social change. This paper aims to set the scene for the study in terms of the performativity of BYOD by reviewing the literatures pertaining to the history of BYOD, and the implementation of BYOD in the commercial and education sectors

Challenges to effective collaboration in cross-cultural virtual teams

Multinational organisations are increasingly adopting geographically distributed cross-cultural virtual teams to accomplish projects. As organisations seek to exploit the benefits of such teams, they may confront a number of challenges. This research explored challenges to effective partnership in cross-cultural virtual teams through an in-depth case study of the Ghana subsidiary of a multinational organisation in the telecommunications industry. It is an interpretive study based on qualitative data from semi-structured interviews. The study finds that temporal, linguistic, and cultural issues present significant challenges to effective teamwork. The paper discusses implications of the findings for the effective management of cross-cultural virtual teams

Cardiac myocyte-specific knock-out of calcium-independent phospholipase A2γ (iPLA2γ) decreases oxidized fatty acids during ischemia/reperfusion and reduces infarct size

Calcium-independent phospholipase A(2)γ (iPLA(2)γ) is a mitochondrial enzyme that produces lipid second messengers that facilitate opening of the mitochondrial permeability transition pore (mPTP) and contribute to the production of oxidized fatty acids in myocardium. To specifically identify the roles of iPLA(2)γ in cardiac myocytes, we generated cardiac myocyte-specific iPLA(2)γ knock-out (CMiPLA(2)γKO) mice by removing the exon encoding the active site serine (Ser-477). Hearts of CMiPLA(2)γKO mice exhibited normal hemodynamic function, glycerophospholipid molecular species composition, and normal rates of mitochondrial respiration and ATP production. In contrast, CMiPLA(2)γKO mice demonstrated attenuated Ca(2+)-induced mPTP opening that could be rapidly restored by the addition of palmitate and substantially reduced production of oxidized polyunsaturated fatty acids (PUFAs). Furthermore, myocardial ischemia/reperfusion (I/R) in CMiPLA(2)γKO mice (30 min of ischemia followed by 30 min of reperfusion in vivo) dramatically decreased oxidized fatty acid production in the ischemic border zones. Moreover, CMiPLA(2)γKO mice subjected to 30 min of ischemia followed by 24 h of reperfusion in vivo developed substantially less cardiac necrosis in the area-at-risk in comparison with their WT littermates. Furthermore, we found that membrane depolarization in murine heart mitochondria was sensitized to Ca(2+) by the presence of oxidized PUFAs. Because mitochondrial membrane depolarization and calcium are known to activate iPLA(2)γ, these results are consistent with salvage of myocardium after I/R by iPLA(2)γ loss of function through decreasing mPTP opening, diminishing production of proinflammatory oxidized fatty acids, and attenuating the deleterious effects of abrupt increases in calcium ion on membrane potential during reperfusion

DNA barcoding identifies a cosmopolitan diet in the ocean sunfish

The ocean sunfish (Mola mola) is the world’s heaviest bony fish reaching a body mass of up to 2.3 tonnes. However, the prey M. mola consumes to fuel this prodigious growth remains poorly known. Sunfish were thought to be obligate gelatinous plankton feeders, but recent studies suggest a more generalist diet. In this study, through molecular barcoding and for the first time, the diet of sunfish in the north-east Atlantic Ocean was characterised. Overall, DNA from the diet content of 57 individuals was successfully amplified, identifying 41 different prey items. Sunfish fed mainly on crustaceans and teleosts, with cnidarians comprising only 16% of the consumed prey. Although no adult fishes were sampled, we found evidence for an ontogenetic shift in the diet, with smaller individuals feeding mainly on small crustaceans and teleost fish, whereas the diet of larger fish included more cnidarian species. Our results confirm that smaller sunfish feed predominantly on benthic and on coastal pelagic species, whereas larger fish depend on pelagic prey. Therefore, sunfish is a generalist predator with a greater diversity of links in coastal food webs than previously realised. Its removal as fisheries’ bycatch may have wider reaching ecological consequences, potentially disrupting coastal trophic interactions

Isotopic constraints on the genesis and evolution of basanitic lavas at Haleakala, Island of Maui, Hawaii

© The Author(s), 2016. This is the author's version of the work and is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Geochimica et Cosmochimica Acta 195 (2016): 201-225, doi:10.1016/j.gca.2016.08.017.To understand the dynamics of solid mantle upwelling and melting in the Hawaiian plume, we present new major and trace element data, Nd, Sr, Hf, and Pb isotopic compositions, and 238U-230Th-226Ra and 235U-231Pa-227Ac activities for 13 Haleakala Crater nepheline normative basanites with ages ranging from ~900 to 4100 yr B.P.. These basanites of the Hana Volcanics exhibit an enrichment in incompatible trace elements and a more depleted isotopic signature than similarly aged Hawaiian shield lavas from Kilauea and Mauna Loa. Here we posit that as the Pacific lithosphere beneath the active shield volcanoes moves away from the center of the Hawaiian plume, increased incorporation of an intrinsic depleted component with relatively low 206Pb/204Pb produces the source of the basanites of the Hana Volcanics. Haleakala Crater basanites have average (230Th/238U) of 1.23 (n=13), average age-corrected (226Ra/230Th) of 1.25 (n=13), and average (231Pa/235U) of 1.67 (n=4), significantly higher than Kilauea and Mauna Loa tholeiites. U-series modeling shows that solid mantle upwelling velocity for Haleakala Crater basanites ranges from ~0.7 to 1.0 cm/yr, compared to ~10 to 20 cm/yr for tholeiites and ~1 to 2 cm/yr for alkali basalts. These modeling results indicate that solid mantle upwelling rates and porosity of the melting zone are lower for Hana Volcanics basanites than for shield-stage tholeiites from Kilauea and Mauna Loa and alkali basalts from Hualalai. The melting rate, which is directly proportional to both the solid mantle upwelling rate and the degree of melting, is therefore greatest in the center of the Hawaiian plume and lower on its periphery. Our results indicate that solid mantle upwelling velocity is at least 10 times higher at the center of the plume than at its periphery under Haleakala.Funding for this project was provided by NSF grants EAR-0001924 and EAR-9909473 to KWWS.2018-08-2

Twisted k-graph algebras associated to Bratteli diagrams

Given a system of coverings of k-graphs, we show that the cohomology of the resulting (k+1)-graph is isomorphic to that of any one of the k-graphs in the system. We then consider Bratteli diagrams of 2-graphs whose twisted C*-algebras are matrix algebras over noncommutative tori. For such systems we calculate the ordered K-theory and the gauge-invariant semifinite traces of the resulting 3-graph C*-algebras. We deduce that every simple C*-algebra of this form is Morita equivalent to the C*-algebra of a rank-2 Bratteli diagram in the sense of Pask-Raeburn-R{\o}rdam-Sims.Comment: 28 pages, pictures prepared using tik

Improving the vibration suppression capabilities of a magneto-rheological damper using hybrid active and semi-active control

This paper presents a new hybrid active & semi-active control method for vibration suppression in flexible structures. The method uses a combination of a semi-active device and an active control actuator situated elsewhere in the structure to suppress vibrations. The key novelty is to use the hybrid controller to enable the magneto-rheological damper to achieve a performance as close to a fully active device as possible. This is achieved by ensuring that the active actuator can assist the magneto-rheological damper in the regions where energy is required. In addition, the hybrid active & semi-active controller is designed to minimize the switching of the semi-active controller. The control framework used is the immersion and invariance control technique in combination with sliding mode control. A two degree-of-freedom system with lightly damped resonances is used as an example system. Both numerical and experimental results are generated for this system, and then compared as part of a validation study. The experimental system uses hardware-in-the-loop to simulate the effect of both the degrees-of-freedom. The results show that the concept is viable both numerically and experimentally, and improved vibration suppression results can be obtained for the magneto-rheological damper that approach the performance of an active device

Complex exon-intron marking by histone modifications is not determined solely by nucleosome distribution

It has recently been shown that nucleosome distribution, histone modifications and RNA polymerase II (Pol II) occupancy show preferential association with exons (“exon-intron marking”), linking chromatin structure and function to co-transcriptional splicing in a variety of eukaryotes. Previous ChIP-sequencing studies suggested that these marking patterns reflect the nucleosomal landscape. By analyzing ChIP-chip datasets across the human genome in three cell types, we have found that this marking system is far more complex than previously observed. We show here that a range of histone modifications and Pol II are preferentially associated with exons. However, there is noticeable cell-type specificity in the degree of exon marking by histone modifications and, surprisingly, this is also reflected in some histone modifications patterns showing biases towards introns. Exon-intron marking is laid down in the absence of transcription on silent genes, with some marking biases changing or becoming reversed for genes expressed at different levels. Furthermore, the relationship of this marking system with splicing is not simple, with only some histone modifications reflecting exon usage/inclusion, while others mirror patterns of exon exclusion. By examining nucleosomal distributions in all three cell types, we demonstrate that these histone modification patterns cannot solely be accounted for by differences in nucleosome levels between exons and introns. In addition, because of inherent differences between ChIP-chip array and ChIP-sequencing approaches, these platforms report different nucleosome distribution patterns across the human genome. Our findings confound existing views and point to active cellular mechanisms which dynamically regulate histone modification levels and account for exon-intron marking. We believe that these histone modification patterns provide links between chromatin accessibility, Pol II movement and co-transcriptional splicing

The effects of dietary fish oil on exercising skeletal muscle vascular and metabolic control in chronic heart failure rats

The ATP-sensitive K+ (KATP) channel is a class of inward rectifier K+ channels that can link cellular metabolic status to vasomotor tone across the metabolic transients seen with exercise. This investigation tested the hypothesis that if KATP channels are crucial to exercise hyperaemia then blockade via glibenclamide (GLI) would lower hindlimb skeletal muscle blood flow (BF) and vascular conductance (VC) during treadmill exercise. In 14 adult male Sprague Dawley rats mean arterial pressure (MAP), blood [lactate], and hindlimb muscle BF (radiolabelled microspheres) were determined at rest (n = 6) or during exercise (n = 8; 20 m min⁻¹, 5% incline) under control (CON) and GLI conditions (5 mg kg⁻¹, i.a). At rest and during exercise, MAP was higher (Rest, CON: 130 ± 6, GLI: 152 ± 8; Exercise, CON: 140 ± 4, GLI: 147 ± 4 mmHg, P < 0.05) and heart rate (HR) was lower (Rest, CON: 440 ± 16, GLI: 410 ± 18; Exercise, CON: 560 ± 4, GLI: 540 ± 10 beats min⁻¹, P < 0.05) with GLI. Hindlimb muscle BF (CON: 144 ± 10, GLI: 120 ± 9 ml min⁻¹ (100 g)⁻¹, P < 0.05) and VC were lower with GLI during exercise but not at rest. Specifically, GLI decreased BF in 12, and VC in 16, of the 28 individual hindlimb muscles and muscle parts sampled during exercise with a greater fractional reduction present in muscles comprised predominantly of type I and type IIa fibres (P < 0.05). Additionally, blood [lactate] (CON: 2.0 ± 0.3; GLI: 4.1 ± 0.9 mmol L⁻¹, P < 0.05) was higher during exercise with GLI. That KATP channel blockade reduces hindlimb muscle BF during exercise in rats supports the obligatory contribution of KATP channels in large muscle mass exercise-induced hyperaemia