The storm-related mortality rates of adult Macrocystis pyrifera in a Southern California giant kelp forest were determined over several winter storm seasons and compared with the hydrodynamic attributes of the most energetic storms. The data include stormy and relatively benign years and an exceptional storm which resulted in almost total destruction of a major Macrocystis forest. High orbital velocities (associated with large, high frequency waves), the presence of breaking waves, and entanglement by drifters were found to increase mortality through stipe breakage or holdfast failure. Longshore variability in wave intensity was found to affect kelp mortality rates. The data suggest that wave breaking may be an important factor in determining the inner boundary of the kelp bed.

Despite the success of current therapies for acute myocardial infarction (MI), many patients still develop adverse cardiac remodeling and heart failure. With the growing prevalence of heart failure, a new therapy is needed that can prevent remodeling and support tissue repair. Herein, we report on injectable recombinant human collagen type I (rHCI) and type III (rHCIII) matrices for treating MI. Injecting rHCI or rHCIII matrices in mice during the late proliferative phase post-MI restores the myocardium’s mechanical properties and reduces scar size, but only the rHCI matrix maintains remote wall thickness and prevents heart enlargement. rHCI treatment increases cardiomyocyte and capillary numbers in the border zone and the presence of pro-wound healing macrophages in the ischemic area, while reducing the overall recruitment of bone marrow monocytes. Our findings show functional recovery post-MI using rHCI by promoting a healing environment, cardiomyocyte survival, and less pathological remodeling of the myocardium.

A greater range of motion at Occ-C1 and C1-C2 was found for the protruded and retracted positions compared with the full-length flexion and full-length extension positions. Effects on cervical symptoms reported to occur in response to flexion, extension, protrusion, and retraction test movements may correspond with the position of lower cervical segments.

A previous modelling study predicted that the forces applied by the extensor muscles to stabilise the lumbar spine would be greater in spines that have a larger sagittal curvature (lordosis). Because the force-generating capacity of a muscle is related to its size, it was hypothesised that the size of the extensor muscles in a subject would be related to the size of their lumbar lordosis. Magnetic resonance imaging (MRI) data were obtained, together with age, height, body mass and back pain status, from 42 female subjects. The volume of the extensor muscles (multifidus and erector spinae) caudal to the mid-lumbar level was estimated from cross-sectional area measurements in axial T1-weighted MRIs spanning the lumbar spine. Lower lumbar curvature was determined from sagittal T1-weighted images. A stepwise linear regression model was used to determine the best predictors of muscle volume. The mean lower lumbar extensor muscle volume was 281 cm 3 (SD = 49 cm 3 ). The mean lower lumbar curvature was 30°(SD = 7°). Five subjects reported current back pain and were excluded from the regression analysis. Nearly half the variation in muscle volume was accounted for by the variables age (standardised coefficient, B = À3.2, P = 0.03) and lower lumbar curvature (B = 0.47, P = 0.002). The results support the hypothesis that extensor muscle volume in the lower lumbar spine is related to the magnitude of the sagittal curvature; this has implications for assessing muscle size as an indicator of muscle strength.

Model predictions of bound (i.e,, nonlinearly forced by and coupled to wave groups) infragravity wave enryaecompared with about 2 years of observations in 8-to 13-rn depths at Imperial Beach. California, and r-% Barbers Pointm Hawaii. Frequency-directional spectra of free waves at sea and swell frequencies, estimated with a small array of four pressure sensors, are used to predict the bound wave spectra below 0.04 Hz. The predicted S• total bound wave energy is always less than the observed infragravity energy, and the underprediction increases c with increasing water depth and especially with decreasing swell energy. At most half, and usually much less. of the observed infragravity energy is bound. Bound wave spectra are also predicted with data from a single wave gage in 183-m depth at Point Conception. California, and the assumption of unidirectional sea and swell. Even with energetic swell, less than 10% of the total observed infragravity energy in 183-m depth is bound Free waves, either leaky or edge waves, are more energetic than bound waves at both the shallow and deep sites. The low level of infragravity energy observed in 183-m depth compared with 8-to 13-m depths, with similarly moderate sea and swell energy, suggests that leaky (and very high-mode edge) waves contribute less than 10% of the infragravity energy in 8-13 m. Most of the free infragravity energy in shallow water is refractively 98 sra andnriaý cTeea4 INTRODUC171ONFollowing the early observations by Munk [1949] and Tucker Infragravity waves are believed to be an important factnr in [19501 suggesting that the seaward propagating infragravity wave several nearshore processes. The purpose of this paper is to estiamplitude was at least as large as the amplitudes of the shoreward mate the contribution of bound waves to infragravity energy propagating bound wave, Longuet-Higgins and Stewart 11962] observed well outside the surf zone in depths of both -10 and speculated that the incoming bound wave somehow reflects from -200 m. Infragravity motions (typical periods of 25-200 s on the shoreline and radiates seaward as a free wave. Numerical Pacific coasts) coupled to incident wave (typical periods of models [Symonds et al., 1982) suggest that slow modulation of the 4-25 s) groups were first observed in roughly 15 m depth by breakpoint position at the group frequency results i, long-wave Munk [1949] and Tucker [19501, who showed suggestive correlaradiation seaward from the breakpoint, but laboratory results are tions between wave groups and low-frequency motions. In both inconclusive. Kosten~se [1984] measured the amplitudes of cases the infragravity wave heights were about 10% of the infragravity waves in shallow water induced by wave grouping in incident wave heights. a long wave channel with a plane beach at one end. The observed Weak nonlinear interactions between first-order free waves (sea and theoretical bound wave amplitudes agreed, but there were and swell) of nearly equal frequency is one possible mechanism of significant differences b...

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Seiche measured within a small (0.6 by 0.6 km), shallow (12-m depth) harbor is dominated by oscillations in several narrow infragravity frequency bands between approximately 10 '3 and 10 '2 Hz. Energy levels within the harbor are amplified, relative to just outside the harbor in 8.5-m depth, by as much as a factor of 20 at the lowest (grave mode) resonant frequency (~ 10 '3 Hz) compared to amplifications of roughly 5 at higher resonant frequencies (~10 '2 Hz). At nonresonant frequencies, energy levels observed inside the harbor are lower than those outside. These amplifications are compared to predictions of a numerical model of seiche excited by linear, inviscid long waves impinging on a harbor of variable depth. The amplification of higher-frequency (~10'2-Hz) seiches is predicted within a factor of about 2. However, at the grave mode (10 '3 Hz), the observed amplification decreases with increasing swell and seiche energy levels, possibly owing to the sensitivity of this highly amplified mode to dissipation not included in the inviscid model. The energy levels of higher-frequency seiche within the harbor were predicted from the offshore sea and swell spectra by the ad hoc coupling of the linear model for the amplification of harbor modes with a nonlinear model for the generation of bound infragravity waves outside the harbor. The predictions are qualitatively accurate only when the swell is energetic and bound waves are a significant fraction of the infragravity energy outside the harbor. 18,210 OKIHmO ET AL.: EXCITATION OF SEICHE OBSERVED IN A SMALL HARBOR lO 1 lO o 10-• 0-2 _ ,'" • ß ß ,-ß ß -.,, ß ß -, ß _ ,, ß -,,,' ß iiI ß ß ß _ . ß ,,' ß -, _ . ,, ß ß 71 IllIll

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