Validation of Maximal Heart Rate Prediction Equations based on Sex and Physical Activity Status

International Journal of Exercise Science 8(4): 318-330, 2015. The purpose of the study was to determine if measured maximal heart rate (HRmax) was affected by sex or aerobic training status, and to determine the accuracy of three common clinical age-prediction maximal heart rate regression equations used to predict HRmax: HRmax = 220 – age, HRmax = 226 – age, and HRmax = 208 – (0.7 ∙ age). Fifty-two participants in total, 30 of which were in the active group (15 M, 15 F) and 22 subjects in the sedentary group (9 M, 13 F), within the age range of 18-25 years and with a normal BMI (18.5-24.9 kg∙m-2) underwent a Bruce maximal treadmill exercise protocol. The effect of sex and training status on HRmax was analyzed through a two-way ANOVA, and the effect of sex, aerobic training status, and regression equation on accuracy of the HRmax prediction was assessed with a three-way ANOVA (α=0.05). Overall, males had a higher HRmax than females (198.3 v. 190.4 beats • min-1 , p\u3c.001) and sedentary individuals had higher measured HRmax than active individuals (197.3 v. 191.4 beats • min-1, p=.002). Furthermore, HRmax = 208 – (0.7 ∙ age)(equation 3) calculated the smallest signed and unsigned residuals from the difference between observed HRmax and predicted HRmax values for the significant main effects of equation (3), equation x sex (females x 3), and equation x activity level (active x 3). Therefore, based on our results, we conclude that HRmax = 208 – (0.7 ∙ age) has greater accuracy than the other two equations studied for predicting observed values of HRmax in 18-25 year olds

Understanding Schools and Schooling. (Book Review)

A review of a book written by Clive Chitty (2002 with a useful focus on issues of equity and social justice, including prejudice, discrimination and bullying in secondary schools. Education policy makers need to explore the extent to which it is important to produce interested, motivated and socially balanced young adults. It is well researched and documented

Floodplain restoration enhances denitrification and reach-scale nitrogen removal in an agricultural stream

Streams of the agricultural Midwest, USA, export large quantities of nitrogen, which impairs downstream water quality, most notably in the Gulf of Mexico. The two-stage ditch is a novel restoration practice, in which floodplains are constructed alongside channelized ditches. During high flows, water flows across the floodplains, increasing benthic surface area and stream water residence time, as well as the potential for nitrogen removal via denitrification. To determine two-stage ditch nitrogen removal efficacy, we measured denitrification rates in the channel and on the floodplains of a two-stage ditch in north-central Indiana for one year before and two years after restoration. We found that instream rates were similar before and after the restoration, and they were influenced by surface water $\text{NO}_{3}^{−}$ concentration and sediment organic matter content. Denitrification rates were lower on the constructed floodplains and were predicted by soil exchangeable $\text{NO}_{3}^{−}$ concentration. Using storm flow simulations, we found that two-stage ditch restoration contributed significantly to $\text{NO}_{3}^{−}$ removal during storm events, but because of the high $\text{NO}_{3}^{−}$ loads at our study site, <10% of the $\text{NO}_{3}^{−}$ load was removed under all storm flow scenarios. The highest percentage of $\text{NO}_{3}^{−}$ removal occurred at the lowest loads; therefore, the two-stage ditch's effectiveness at reducing downstream N loading will be maximized when the practice is coupled with efforts to reduce N inputs from adjacent fields

Three manganese complexes of anionic N4-donor Schiff-base macrocycles: 1 monomeric Mn(II) and Mn(III), and dimeric Mn(IV)

Three manganese macrocyclic complexes of two anionic N4-donor [1+1] Schiff-base macrocycles that differ in ring size (14 vs 16 membered), HLEt and HLPr (obtained from condensation of diphenylamine-2,2’-dicarboxaldehyde and either diethylenetriamine or dipropylenetriamine), are reported. Specifically, a pair of monomeric complexes MnIILEt(NCS)(H2O) and [MnIIILPr(NCS)2]•0.5H2O, plus a dimeric complex [MnIV2LEt2(O)2](ClO4)2•3DMF have been synthesised and characterised. Single crystal structure determinations on [MnIIILPr(NCS)2]•0.5H2O and [MnIV2LEt2(O)2](ClO4)2•3DMF revealed octahedral manganese centres in both cases: N6-coordinated Jahn-Teller distorted Mn(III) in the former and a pair of N4O2-coordinated Mn(IV) in the latter. UV-vis, IR and EPR spectroscopy as well as magnetic measurements are reported. These macrocyclic complexes feature a simple and original design, and could find future uses as models for manganese catalase or as building blocks for the assembly of larger supramolecular architectures

An integrated approach to modelling the fluid-structure interaction of a collapsible tube

The well known collapsible tube experiment was conducted to obtain flow, pressure and materials property data for steady state conditions. These were then used as the boundary conditions for a fully coupled fluid-structure interaction (FSI) model using a propriety computer code, LS-DYNA. The shape profiles for the tube were also recorded. In order to obtain similar collapse modes to the experiment, it was necessary to model the tube flat, and then inflate it into a circular profile, leaving residual stresses in the walls. The profile shape then agreed well with the experimental ones. Two departures from the physical properties were required to reduce computer time to an acceptable level. One of these was the lowering of the speed of sound by two orders of magnitude which, due to the low velocities involved, still left the mach number below 0.2. The other was to increase the thickness of the tube to prevent the numerical collapse of elements. A compensation for this was made by lowering the Young's modulus for the tube material. Overall the results are qualitatively good. They give an indication of the power of the current FSI algorithms and the need to combine experiment and computer models in order to maximise the information that can be extracted both in terms of quantity and quality

An inverted-sandwich diuranium μ-η5:η5-cyclo-P5 complex supported by U-P5 δ-bonding

Reaction of [U(TrenTIPS)] [1, TrenTIPS=N(CH2CH2NSiiPr3)3] with 0.25 equivalents of P4 reproducibly affords the unprecedented actinide inverted sandwich cyclo-P5 complex [{U(TrenTIPS)}2(μ-η5:η5-cyclo-P5)] (2). All prior examples of cyclo-P5 are stabilized by d-block metals, so 2 shows that cyclo-P5 does not require d-block ions to be prepared. Although cyclo-P5 is isolobal to cyclopentadienyl, which usually bonds to metals via σ- and π-interactions with minimal δ-bonding, theoretical calculations suggest the principal bonding in the U(P5)U unit is polarized δ-bonding. Surprisingly, the characterization data are overall consistent with charge transfer from uranium to the cyclo-P5 unit to give a cyclo-P5 charge state that approximates to a dianionic formulation. This is ascribed to the larger size and superior acceptor character of cyclo-P5 compared to cyclopentadienyl, the strongly reducing nature of uranium(III), and the availability of uranium δ-symmetry 5f orbitals

Synthesis and characterization of an f‑block terminal parent imido [U=NH] complex: a masked uranium(IV) nitride

Deprotonation of [U(TrenTIPS)(NH2)] (1) [TrenTIPS = N(CH2CH2NSiPri3)3] with organoalkali metal reagents MR (M = Li, R = But; M = Na−Cs, R = CH2C6H5) afforded the imido-bridged dimers [{U-(TrenTIPS)(μ-N[H]M)}2] [M = L −Cs (2a−e)]. Treatmentof 2c (M = K) with 2 equiv of 15 crown-5 ether (15C5) afforded the uranium terminal parent imido complex [U(TrenTIPS)(NH)][K(15C5)2] (3c), which can also be viewed as a masked uranium(IV) nitride. The uranium−imido linkage was found to be essentially linear, and theoretical calculations suggested σ2π4 polarized U−N multiple bonding. Attempts to oxidize 3c to afford the neutral uranium terminal parent imido complex [U(TrenTIPS)(NH)] (4) resulted in spontaneous disproportionation to give 1 and the uranium−nitride complex [U(TrenTIPS)(N)] (5); this reaction is a new way to prepare the terminal uranium−nitride linkage and was calculated to be exothermic by −3.25 kcal mol−1

Palynological, geochemical, and mineralogical characteristics of the Early Jurassic Liasidium Event in the Cleveland Basin, Yorkshire, UK

A previously proposed hyperthermal episode in the Early Jurassic (mid-Sinemurian) is investigated from the shallow marine succession at Robin Hood’s Bay, Cleveland Basin, Yorkshire, UK. Palynological study confirms that the stratigraphical extent of the distinctive dinoflagellate cyst Liasidium variabile corresponds very closely to the oxynotum Zone. The range of Liasidium variabile also corresponds to an overall negative excursion in carbon-isotopes measured in bulk organic matter, which here exhibits a double spike in the middle oxynotum Zone. Additionally, Liasidium variabile abundances track overall transgressive-regressive facies trends with peak abundance of dinoflagellate cysts corresponding to deepest water facies and maximum flooding. Lithological cycles (parasequences), defined by visual description and hand-held X-ray fluorescence analysis of powdered samples, match previously suggested short eccentricity cycles, and allow a total duration for the event of at least one million years to be suggested. Changes in clay mineralogy throughout the section determined by whole rock X-ray diffraction and scanning electron microscopy are shown to be largely related to authigenic processes, and neither support nor refute the proposition of coeval palaeoclimate changes. The combined characteristics of the Liasidium Event described from Robin Hood’s Bay are similar to, but much less extreme than, the Early Jurassic Toarcian Oceanic Anoxic Event albeit, at this locality, there is no evidence for the development of significant bottom water deoxygenation

Expansions for the Bollobas-Riordan polynomial of separable ribbon graphs

We define 2-decompositions of ribbon graphs, which generalise 2-sums and tensor products of graphs. We give formulae for the Bollobas-Riordan polynomial of such a 2-decomposition, and derive the classical Brylawski formula for the Tutte polynomial of a tensor product as a (very) special case. This study was initially motivated from knot theory, and we include an application of our formulae to mutation in knot diagrams.Comment: Version 2 has minor changes. To appear in Annals of Combinatoric