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Background Superior labrum lesion from anterior to posterior (SLAP) often presents together with other shoulder pathologies such as rotator cuff tear (RCT), but it is uncertain if repairing both SLAP and RCT has superior clinical outcomes over isolated repairs of SLAP and RCT. Materials and methods This was a retrospective cohort study with prospectively collected data, reviewing 157 patients who underwent arthroscopic repair of either RCT, SLAP (type II lesion), or both. Before surgery and after 6 weeks, 12 weeks, and 24 weeks, shoulder objective range of motion and strength were measured, patient-reported function and pain was assessed by the modified L’Insalata questionnaire with a Likert scale, and complications after each repair were examined. Results At 24 weeks after surgery, the combined group (n = 22) and SLAP group (n = 47) had significantly higher forward flexion (165° ± 4° and 167° ± 4° vs. 154° ± 3°, P = .01 and P = .01), external rotation strength (82 ± 6 N, 81 ± 6 N vs. 61 ± 3 N, P = .01 and P = .01), and abduction strength (94 ± 14 N, 78 ± 8 N vs. 53 ± 3 N, P = .001 and P = .02) compared with the rotator cuff tear repair (RCR) group (n = 88). The combined group also had stronger internal rotation than the RCR group (107 ± 12 N vs. 72 ± 4 N, P = .02). Function and pain improved from “severe-moderate” to “moderate-mild” in all groups after surgery. Conclusion Repairing RCT and SLAP tears together results in significant clinical benefits compared to repairing just RCT and analogous results against SLAP-only repair.

This article offers a survey of recent solutions involving electric drives and power chargers for fully electric vehicles (EVs) and hybrid EVs (HEVs). Based on our research and experimental activities regarding electric drives, we also show experimental data from prototypes. After reviewing the opportunities and challenges of vehicle electrification, the article analyzes electric machines and power converters for two main market trends: 1) low-voltage (48-V) HEVs, allowing for a smooth transition from internal combustion engine vehicles (ICEVs), and 2) full EVs, operating above 200 V. First, we discuss a 48-V integrated belt-driven starter generator (BSG), together with its tightly coupled power control electronics. Substituting a 12-V alternator, the BSG provides torque assistance to ICEVs for lowspeed, start-stop and regenerative-braking functionalities, and electric power generation for onboard loads. Instead, new topologies of electric machines are needed for full EVs.

The physical model of the spectral responsivity of trap detector consists of multiple parameters such as the internal quantum efficiency and the spectral reflectance. In some measurement models, the spectral reflectance of the trap detector is approximated by fitting a wavelength dependence equation which does not consider the effect of the oxide thickness of the silicon photodiode. To analyse the uncertainty due to the oxide thickness variation, a thin film reflectance model is set up in the Standards and Calibration Laboratory (SCL) for the evaluation of the spectral reflectance of the trap detectors. The model is based on the Fresnel coefficients of a 3-layer thin film structure which consists of air and a thin film oxide layer on a silicon substrate. The reflectance model was implemented as user-defined functions to calculate the spectral reflectance at different oxide thickness. It was also integrated with the SCL’s MCM program to evaluate the uncertainty of the spectral responsivity of trap detectors.

Summary Objectives This study was conducted to closely examine the effects of representative types of lower limb flexion and extension exercises (unilateral and bilateral exercises) and the combined exercise using a ski simulator on lower limb joint and muscle activities. Equipment and methods In the experiments of this study performed on 20 participants, lower limb joint angles and muscle activities were measured during unilateral (lunge), bilateral (squat), and combine (ski simulator) using a 3D motion capture and electromyography analysis system. Results Analysis of the measurement results revealed that unilateral exercises required more time and exhibited greater angular displacements of the lower limb joints (P Conclusion Research approaches adopted by such studies are easy to apply and may be applicable in many fields involving rehabilitation and improvement of muscle strength and balance.

Despite efforts to simulate the in vivo environment, post-mortem degradation and lack of blood perfusion complicate the use of ex vivo derived material models in computational studies of spinal cord injury. In order to quantify the mechanical changes that manifest ex vivo, the viscoelastic behavior of in vivo and ex vivo porcine spinal cord samples were compared. Stress-relaxation data from each condition were fit to a non-linear viscoelastic model using a novel characterization technique called the direct fit method. To validate the presented material models, the parameters obtained for each condition were used to predict the respective dynamic cyclic response. Both ex vivo and in vivo samples displayed non-linear viscoelastic behavior with a significant increase in relaxation with applied strain. However, at all three strain magnitudes compared, ex vivo samples experienced a higher stress and greater relaxation than in vivo samples. Significant differences between model parameters also showed distinct relaxation behaviors, especially in non-linear relaxation modulus components associated with the short-term response (0.1–1 s). The results of this study underscore the necessity of utilizing material models developed from in vivo experimental data for studies of spinal cord injury, where the time-dependent properties are critical. The ability of each material model to accurately predict the dynamic cyclic response validates the presented methodology and supports the use of the in vivo model in future high-resolution finite element modeling efforts. Statement of Significance Neural tissues (such as the brain and spinal cord) display time-dependent, or viscoelastic, mechanical behavior making it difficult to model how they respond to various loading conditions, including injury. Methods that aim to characterize the behavior of the spinal cord almost exclusively use ex vivo cadaveric or animal samples, despite evidence that time after death affects the behavior compared to that in a living animal (in vivo response). Therefore, this study directly compared the mechanical response of ex vivo and in vivo samples to quantify these differences for the first time. This will allow researchers to draw more accurate conclusions about spinal cord injuries based on ex vivo data (which are easier to obtain) and emphasizes the importance of future in vivo experimental animal work.

Summary Objectives We performed a comparative analysis of ski simulators, which remove seasonal and regional constraints, to effectively improve training methods. Equipment and methods We compared the kinematic characteristics with and without ski boots on the ski simulator and found significant differences in lower limb joint angles, run-time, muscle activity, and heart rate. Results Based on these results, we suggest the following exercise guidelines for ski simulators: (i) simulator skiing without boots results in a wider range of motion (ROM) and can be utilized as low-intensity exercise to improve muscle endurance and balance and (ii) simulator skiing with boots enables faster movements within a limited range and can help improve muscle strength. These results are not limited to ski training; they can also be applied to specialized exercise improvement and strengthening programs as well as physical training.

Background Biodegradable suture anchors are associated with higher redislocation rates. This study examined whether the biocompatibility and/or biomechanical properties of suture anchors contribute to the increase in complications. Methods Human glenohumeral capsule cells were cultured with 4 types of suture anchors, Opus LabraFix (titanium alloy; ArthroCare, Austin, TX, USA), PushLock (poly-ether-ether-ketone; Arthrex, Naples, FL, USA), BioKnotless (poly-l-lactic acid; DePuy Mitek, Warsaw, IN, USA), and Suretac II (polyglycolic acid; Smith & Nephew, London, UK), to measure cell viability and pH. Four groups of 6 ovine shoulders were used to repair the labrum, which was completely detached from the glenoid rim anteroinferiorly and reattached with 2 suture anchors and subject to failure load testing. Results In cell culture, BioKnotless at 48 and 72 hours (85.2% ± 2.1% and 84.5% ± 3.6%) and Suretac II groups (33.9% ± 3.1% and 42.8% ± 6.4%) had fewer viable cells compared with control ( P = .048). The pH of Suretac II was lower than control (7.51 to 7.65) at 24 hours (7.31 ± 0.08, P = .049), 48 hours (7.25 ± 0.02, P = .046), and 72 hours (7.29 ± 0.04, P = .04). During mechanical testing, 83% of repairs failed by the capsule tearing. Among the anchors, the BioKnotless repair group had a significantly lower failure load (37 ± 5 N) compared with the PushLock (61 ± 7 N), Opus (60 ± 6 N), and Suretac II (57 ± 7 N) groups ( P = .038). Conclusion BioKnotless and Suretac II anchors are cytotoxic. The BioKnotless biodegradable anchor has significantly lower failure load. Absorbable suture anchors may cause higher redislocation of arthroscopic Bankart repair.

In the military environment, injured soldiers undergoing medical evacuation via helicopter or mine-resistant ambush-protected vehicle (MRAP) are subjected to vibration and shock inherent to the transport vehicle. We conducted the present study to assess the consequences of such vibration on the acutely injured spinal cord. We used a porcine model of spinal cord injury (SCI). After a T10 contusion-compression injury, animals were subjected to 1) no vibration (n = 7-8), 2) whole body vibration at frequencies and amplitudes simulating helicopter transport (n = 8), or 3) whole body vibration simulating ground transportation in an MRAP ambulance (n = 7). Hindlimb locomotor function (using Porcine Thoracic Injury Behavior Scale [PTIBS]), Eriochrome Cyanine histochemistry and biochemical analysis of inflammatory and neural damage markers were analyzed. Cerebrospinal fluid (CSF) expression levels for monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-6, IL-8, and glial fibrillary acidic protein (GFAP) were similar between the helicopter or MRAP group and the unvibrated controls. Spared white/gray matter tended to be lower in the MRAP-vibrated animals than in the unvibrated controls, especially rostral to the epicenter. However, spared white/gray matter in the helicopter-vibrated group appeared normal. Although there was a relationship between the extent of sparing and the extent of locomotor recovery, no significant differences were found in PTIBS scores between the groups. In summary, exposures to vibration in the context of ground (MRAP) or aeromedical (helicopter) transportation did not significantly impair functional outcome in our large animal model of SCI. However, MRAP vibration was associated with increased tissue damage around the injury site, warranting caution around exposure to vehicle vibration acutely after SCI.

We have previously reported that administration of a CD11d monoclonal antibody (mAb) improves recovery in a clip-compression model of SCI. In this model the CD11d mAb reduces the infiltration of activated leukocytes into the injured spinal cord (as indicated by reduced intraspinal MPO). However not all anti-inflammatory strategies have reported beneficial results, suggesting that success of the CD11d mAb treatment may depend on the type or severity of the injury. We therefore tested the CD11d mAb treatment in a rat hemi-contusion model of cervical SCI. In contrast to its effects in the clip-compression model, the CD11d mAb treatment did not improve forelimb function nor did it significantly reduce MPO levels in the hemi-contused cord. To determine if the disparate results using the CD11d mAb were due to the biomechanical nature of the cord injury (compression SCI versus contusion SCI) or to the spinal level of the injury (12th thoracic level versus cervical) we further evaluated the CD11d mAb treatment after a T12 contusion SCI. In contrast to the T12 clip compression SCI, the CD11d mAb treatment did not improve locomotor recovery or significantly reduce MPO levels after T12 contusion SCI. Lesion analyses revealed increased levels of hemorrhage after contusion SCI compared to clip-compression SCI. SCI that is accompanied by increased intraspinal hemorrhage would be predicted to be refractory to the CD11d mAb therapy as this approach targets leukocyte diapedesis through the intact vasculature. These results suggest that the disparate results of the anti-CD11d treatment in contusion and clip-compression models of SCI are due to the different pathophysiological mechanisms that dominate these two types of spinal cord injuries.

Because of the complex, multifaceted nature of spinal cord injury (SCI), it is widely believed that a combination of approaches will be superior to individual treatments. Therefore, we employed a rat model of cervical SCI to evaluate the combination of four noninvasive treatments that individually have been reported to be effective for acute SCI during clinically relevant therapeutic time windows. These treatments included ghrelin, ibuprofen, C16, and ketogenic diet (KD). These were selected not only because of their previously reported efficacy in SCI models but also for their potentially different mechanisms of action. The administration of ghrelin, ibuprofen, C16, and KD several hours to days postinjury was based on previous observations by others that each treatment had profound effects on the pathophysiology and functional outcome following SCI. Here we showed that, with the exception of a modest improvement in performance on the Montoya staircase test at 8-10 weeks postinjury, the combinatorial treatment with ghrelin, ibuprofen, C16, and KD did not result in any significant improvements in the rearing test, grooming test, or horizontal ladder. Histologic analysis of the spinal cords did not reveal any significant differences in tissue sparing between treatment and control groups. Although single approaches of ghrelin, ibuprofen, C16, and KD have been reported to be beneficial after SCI, our results show that the combination of the four interventions did not confer significant functional or histological improvements in a cervical model of SCI. Possible interactions among the treatments may have negated their beneficial effects, emphasizing the challenges that have to be addressed when considering combinatorial drug therapies for SCI.

In animal models, spinal cord injury (SCI) is typically imparted by contusion alone (e.g., weight drop) or by compression alone (e.g., clip compression). In humans, however, the cord is typically injured by a combination of violent contusion followed by varying degrees of ongoing mechanical compression. Understanding how the combination of contusion and compression influences the early pathophysiology of SCI is important for the pre-clinical development of neuroprotective therapies that are applicable to the human condition. Disturbances in the metabolism of energy-related substrates such as lactate, pyruvate, and glucose are important aspects of secondary damage. In this study, we used a porcine model of traumatic SCI to determine the extent to which these metabolites were influenced by contusion followed by sustained compression, using the microdialysis technique. Following contusion injury, lactate and pyruvate levels near the epicenter both increased, while glucose remained quite stable. When the contusion injury was followed by sustained compression, we observed a transient rise in lactate, while pyruvate and glucose levels dropped rapidly, which may reflect decreased regional spinal cord blood flow. Furthermore, contusion with sustained compression produced a prolonged and dramatic increase in the lactate-pyruvate (L/P) ratio as a marker of tissue hypoxia, whereas after contusion injury alone, a transient and less significant elevation of the L/P ratio was observed. In this study, we demonstrate that disturbances in energy metabolism within the injured spinal cord vary greatly depending upon the biomechanical nature of the injury. Such differences are likely to be relevant to the applicability of novel therapies targeting specific aspects of the early secondary injury cascade after acute human SCI.

Spinal cord injury (SCI) researchers have predominately utilized rodents and mice for in vivo SCI modeling and experimentation. From these small animal models have come many insights into the biology of SCI, and a growing number of novel treatments that promote behavioral recovery. It has, however, been difficult to demonstrate the efficacy of such treatments in human clinical trials. A large animal SCI model that is an intermediary between rodent and human SCI may be a valuable translational research resource for pre-clinically evaluating novel therapies, prior to embarking upon lengthy and expensive clinical trials. Here, we describe the development of such a large animal model. A thoracic spinal cord injury at T10/11 was induced in Yucatan miniature pigs (20-25 kg) using a weight drop device. Varying degrees of injury severity were induced by altering the height of the weight drop (5, 10, 20, 30, 40, and 50 cm). Behavioral recovery over 12 weeks was measured using a newly developed Porcine Thoracic Injury Behavior Scale (PTIBS). This scale distinguished locomotor recovery among animals of different injury severities, with strong intra-observer and inter-observer reliability. Histological analysis of the spinal cords 12 weeks post-injury revealed that animals with the more biomechanically severe injuries had less spared white matter and gray matter and less neurofilament immunoreactivity. Additionally, the PTIBS scores correlated strongly with the extent of tissue sparing through the epicenter of injury. This large animal model of SCI may represent a useful intermediary in the testing of novel pharmacological treatments and cell transplantation strategies.

A porcine model of spinal cord injury (SCI) was used to evaluate the neuroprotective effects of magnesium chloride (MgCl2) within a polyethylene glycol (PEG) formulation, called "AC105" (Acorda Therapeutics Inc., Ardsley, NY). Specifically, we tested the hypothesis that AC105 would lead to greater tissue sparing at the injury site and improved behavioral outcome when delivered in a clinically realistic time window post-injury. Four hours after contusion/compression injury, Yucatan minipigs were randomized to receive a 30-min intravenous infusion of AC105, magnesium sulfate (MgSO4), or saline. Animals received 4 additional infusions of the same dose at 6-h intervals. Behavioral recovery was tested for 12 weeks using two-dimensional (2D) kinematics during weight-supported treadmill walking and the Porcine Injury Behavior Scale (PTIBS), a 10-point locomotion scale. Spinal cords were evaluated ex vivo by diffusion-weighted magnetic resonance imaging (MRI) and subjected to histological analysis. Treatment with AC105 or MgSO4 did not result in improvements in locomotor recovery on the PTIBS or in 2D kinematics on weight-supported treadmill walking. Diffusion weighted imaging (DWI) showed severe loss of tissue integrity at the impact site, with decreased fractional anisotropy and increased mean diffusivity; this was not improved with AC105 or MgSO4 treatment. Histological analysis revealed no significant increase in gray or white matter sparing with AC105 or MgSO4 treatment. Finally, AC105 did not result in higher Mg2+ levels in CSF than with the use of standard MgSO4. In summary, when testing AC105 in a porcine model of SCI, we were unable to reproduce the promising therapeutic benefits observed previously in less-severe rodent models of SCI.

Aims: For the analysis of virulence factors produced and secreted by Bacillus anthracis vegetative cells during mammalian host infection, we evaluated the secretome of B. anthracis Sterne exposed to host-specific factors specifically to host body temperature. Methods and Results: We employed a comparative proteomics-based approach to analyse the proteins secreted by B. anthracis Sterne under host-specific body temperature conditions. A total of 17 proteins encoded on a single chromosome and the pXO1 plasmid were identified by peptide mass fingerprinting. Multiple algorithms were used to predict the secretion mechanisms of the detected proteins in B. anthracis. Conclusions: Several putative virulence factors and known factors responsible for sporulation were differentially regulated, including CodY, pXO1-130 and BA1952, revealing insights into temperature cues in the B. anthracis secretome. Significance and Impact of the Study: This study identified temperature-regulated proteins. Further studies aimed at understanding the physical and functional roles of these proteins in infection and control by elevated temperatures will contribute to detection, diagnostics and prophylaxis.

Spinal cord injury (SCI) often results in a loss of motor and sensory function. Currently there are no validated effective clinical treatments. Previously we found in rats that dietary restriction, in the form of every-other-day fasting (EODF), started prior to (pre-EODF), or after (post-EODF) an incomplete cervical SCI was neuroprotective, increased plasticity, and promoted motor recovery. Here we examined if EODF initiated prior to, or after, a T10 thoracic contusion injury would similarly lead to enhanced functional recovery compared to ad libitum feeding. Additionally, we tested if a group fed every day (pair-fed), but with the same degree of restriction as the EODF animals (∼25% calorie restricted), would also promote functional recovery, to examine if EODF's effect is due to overall calorie restriction, or is specific to alternating sequences of 24-h fasts and ad libitum eating periods. Behaviorally, both pre- and post-EODF groups exhibited better functional recovery in the regularity indexed BBB ambulatory assessment, along with several parameters of their walking pattern measured with the CatWalk device, compared to both the ad-libitium-fed group as well as the pair-fed group. Several histological parameters (intensity and symmetry of serotonin immunostaining caudal to the injury and gray matter sparing) correlated with functional outcome; however, no group differences were observed. Thus besides the beneficial effects of EODF after a partial cervical SCI, we now report that alternating periods of fasting (but not pair-fed) also promotes improved hindlimb locomotion after thoracic spinal cord contusion, demonstrating its robust effect in two different injury models.

Functional recovery after spinal cord injury (SCI) is limited, and the injury results in a dramatic reduction in long-term lifespan. Prophylactic dietary restriction (DR) robustly extends animal lifespan, and is beneficial in models of neuronal insult. In rats, we found that one form of DR, every-other-day-fasting (EODF), which started 1 month prior to a cervical SCI improved functional recovery, resulted in greater numbers of neurons surrounding the injury site, and a approximately 45% reduction in lesion size compared to the control group. In the light of the low-risk implementation of prophylactic EODF, the clinical translation as a treatment prior to elective subacute or chronic interventions is attractive. There are numerous secondary complications after human SCI, including a 13- to 25-year reduction in lifespan. DR consistently increases median and maximal lifespan in a large range of organisms, including non-human primates. Animal research suggests that EODF might reduce many of the secondary complications people with SCI suffer from. Dietary interventions may provide the possibility to improve the quality and span of life for individuals with SCI.

Although much progress has been made in the clinical care of patients with acute spinal cord injuries, there are no reliably effective treatments, which minimize secondary damage and improve neurologic outcome. The time and expense needed to establish de novo pharmacologic or biologic therapies for acute SCI has encouraged the development of neuroprotective treatments based on drugs that are already in clinical use and, therefore, have the advantage of a well-characterized safety and pharmacokinetic profile in humans. Statins are the most commonly prescribed class of lipid-lowering drugs, and recently, it has been recognized that statins also have powerful immunomodulatory and anti-inflammatory effects. This paper describes a series of experiments that were performed to evaluate the comparative neuroprotective effects of simvastatin and atorvastatin. We observed a promising signal of neurologic benefit with simvastatin in our first experiment, but in repeated attempts to replicate that effect in three subsequent experiments, we failed to reveal any behavioral or histologic improvements. We would conclude that simvastatin given orally or subcutaneously at doses previously reported by other investigators to be effective in different neurologic conditions does not confer a significant neurologic benefit in a thoracic contusion injury model (OSU Impactor) when administered with a 1-h delay in intervention. We contend that further preclinical investigation of atorvastatin and simvastatin is warranted before considering their translation into human SCI.

Spinal cord injury typically results in limited functional recovery. Here we investigated whether therapeutic dietary restriction, a multi-faceted, safe, and clinically-feasible treatment, can improve outcome from cervical spinal cord injury. The well-established notion that dietary restriction increases longevity has kindled interest in its potential benefits in injury and disease. When followed for several months prior to insult, prophylactic dietary restriction triggers multiple molecular responses and improves outcome in animal models of stroke and myocardial infarction. However, the efficacy of the clinically-relevant treatment of post-injury dietary restriction is unknown. Here we report that “every-other-day fasting” (EODF), a form of dietary restriction, implemented after rat cervical spinal cord injury was neuroprotective, promoted plasticity, and improved behavioral recovery. Without causing weight loss, EODF improved gait-pattern, forelimb function during ladder-crossing, and vertical exploration. In agreement, EODF preserved neuronal integrity, dramatically reduced lesion volume by > 50%, and increased sprouting of corticospinal axons. As expected, blood β-hydroxybutyrate levels, a ketone known to be neuroprotective, were increased by 2–3 fold on the fasting days. In addition, we found increased ratios of full-length to truncated trkB (receptor for brain-derived neurotrophic factor) in the spinal cord by 2–6 folds at both 5 days (lesion site) and 3 weeks after injury (caudal to lesion site) which may further enhance neuroprotection and plasticity. Because EODF is a safe, non-invasive, and low-cost treatment, it could be readily translated into the clinical setting of spinal cord injury and possibly other insults.

Whole-body vibration has been identified as a potential stressor to spinal cord injury (SCI) patients during pre-hospital transportation. However, the effect that such vibration has on the acutely injured spinal cord is largely unknown, particularly in the frequency domain of 5 Hz in which resonance of the spine occurs. The objective of the study was to investigate the consequences of resonance vibration on the injured spinal cord. Using our previously characterized porcine model of SCI, we subjected animals to resonance vibration (5.7±0.46 Hz) or no vibration for a period of 1.5 or 3.0 h. Locomotor function was assessed weekly and cerebrospinal fluid (CSF) samples were collected to assess different inflammatory and injury severity markers. Spinal cords were evaluated histologically to quantify preserved white and gray matter. No significant differences were found between groups for CSF levels of monocyte chemotactic protein-1, interleukin 6 (IL-6) and lL-8. Glial fibrillary acidic protein levels were lower in the resonance vibration group, compared with the non-vibrated control group. Spared white matter tissue was increased within the vibrated group at 7 d post-injury but this difference was not apparent at the 12-week time-point. No significant difference was observed in locomotor recovery following resonance vibration of the spine. Here, we demonstrate that exposure to resonance vibration for 1.5 or 3 h following SCI in our porcine model is not detrimental to the functional or histological outcomes. Our observation that a 3.0-h period of vibration at resonance frequency induces modest histological improvement at one week post-injury warrants further study.

The growth of a foam which is simultaneously draining and bursting is analysed mathematically using the foam drainage equation. The bursting is implemented via a novel upper boundary condition: foam films are assumed to possess a well defined tensile strength. Since capillary suction forces on films depend on the cross-sectional area of surrounding Plateau borders, this is equivalent to assuming a limiting Plateau border area at the top of the foam. The case of a gas–liquid foam being blown up into a vertical column is studied in detail, the results being of relevance to froth stability column measurements. Two regimes of behaviour are possible. The first is where the upward velocity of air relative to the column exceeds the downward gravitational velocity of liquid relative to gas at the top of the foam. Such a foam is predicted to grow indefinitely, although the growth rate at late times is markedly less than that at early times. The second regime is where the upward velocity of the air relative to the column is less than the downward gravitational velocity of liquid at the top: capillary suction always retains a role in determining the net liquid motion in such cases, and the foam grows to a finite steady height. The two respective regimes can also be considered in terms of the froth stability, with the first corresponding to stable foams, and the second to unstable ones. At a fixed air flow velocity, decreasing the foam stability and thereby the film tensile strength, increases the critical Plateau border area for film bursting, and thereby the downward gravitational velocity: this can shift a system from the first regime to the second. We focus on the second regime, and in particular on the case where the foam is nearly stable, in the sense that the final froth height is large (compared to a well defined capillary length scale inherent to the foam itself). The steady state height of the foam and the steady state profile of liquid content versus vertical position are computed. A perturbation eigenvalue analysis is used to determine the exponential rate of approach to steady state. The approach to steady state is predicted to be extremely slow in the case of nearly stable froths, for which the rate of approach eigenvalue becomes vanishingly small.

This study was designed to investigate the in vitro developmental ability and apoptosis of bovine embryos nuclear- transferred (NT) with frozen-thawed or cooled donor cells. Cultured adult bovine ear cells were used as donor cells after sub-culturing to confluence (CC), cooling to 4°C for 48 h, or freezing-thawing (FT). Apoptotic cells in blastocysts were evaluated for apoptosis by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method. Fusion, cleavage and blastocyst rates were 69.0 (167/242), 68.8 (115/167), and 29.9 (50/167) with CC cells, 70.4 (88/125), 69.3 (61/88), and 29.6 (26/88) with cooled cells and 66.1 (117/177), 70.1 (82/117), and 13.7 (16/117) with FT cells, respectively. Blastocyst rates of NT embryos derived from FT cells were significantly lower than those from CC or cooled cells (p

This paper examines the dispersion of particles and liquid through foams. This is of relevance to a wide range of industrial systems in which particles move freely through a foam. In froth flotation, where mineral particles of different types are separated, the dispersion in the froth has a significant impact on the amount and purity of the product obtained. In this study, forced drainage experiments were performed with particle pulses added in such a way that the volumetric flow into the foam was not affected. This ensured that the dispersion observed was the result solely of the velocity profile within individual Plateau borders, and not due to the effect of capillary suction on the liquid content in the foam. Experiments were also carried out using a soluble liquid dye as a tracer. The local particle concentration in the foam was measured using light transmission. The particle concentration profiles exhibited near-Gaussian distributions, rather than the sharp rise and decay that would be observed in the case of purely convective dispersion. This confirms that the particles experience a range of velocities as they move through the foam. The Plateau border dispersion results from the liquid dye experiments were virtually indistinguishable from those for the particles. This shows that the particle dispersion is a direct result of the liquid dispersion, rather than the result of purely particle effects, such as differential settling. The Peclet number was used to characterise the dispersion, as it quantifies the influence of the net convective motion on the dispersion. The Peclet number, using the Plateau border radius of curvature as the characteristic length scale, was found to be constant over a wide range of drainage rates and bubble sizes. For the surfactant system studied in this work, a Peclet number of 0.16 was found. By combining the assumption of a constant Peclet number with foam drainage theory, the need to know accurately the bubble size when determining the dispersion coefficient is removed. A 1.5 power law relationship between the dispersion coefficient and liquid velocity was predicted theoretically and confirmed experimentally.

This paper examines the behaviour of growing and collapsing foams. In particular, it focuses on the drainage of the liquid, and thus the evolution of the liquid content, within the growing or collapsing foam. By assuming that the films fail when they are subjected to a pressure above a certain critical pressure, the collapse of the foam is modelled. The model predicts that the growing foam behaviour can be divided into two regimes: at low gas rates, the foams will asymptote towards an equilibrium height, while above a certain critical gas rate, the foams will continue to grow indefinitely. This behaviour was found experimentally as well. At the higher gas rates, there is a change in the slope of the foam height versus time plot, though with the exception of a transition region, this relationship remains a linear relationship one. The difference between these slopes can be used to estimate the pressure exerted on the films at the top surface of the foam. Since these bubbles are bursting, this is the critical pressure required to cause film failure within the foam. When compared to the stability of films in single film experiments, those in the foam, not unexpectedly, demonstrate lower stability. This is due to vibrations and other disturbances that are present within flowing foams.

This research was conducted to make suggestions for the promotion of research activities in the field of animal resources sciences, and we evaluated the research funding trend and the present status of research funding offered by KOSEF in this field. Comparative portion of the number of research projects and grants in this field to other fields has a tendency to be decreased year by year except recent few years. Researchers in this field have received more research funding from the group-based program than from the individual-based program. Also, they have received less money(per project) than did researchers in the fields of general agricultural sciences and other science and technology. Researchers in this field ranges from 43 to 51 years of age and showed 48 years of average age. It was found that researchers who has been funded in the field of animal resources sciences have showed tendency of publication of more articles to SCI journals in recent 5 years. The strong points of the animal resources of agricultural sciences field in South Korea include: lots of researchers, the establishment of research infra-structure, the excellence in research competitiveness and technology level. However, its weaknesses are: a lack of leadership in relevant societies and institutes, a predicted shortfall of researchers in the next generation and insufficient research productivity. The opportunities include: increasing the importance of the biotechnology industry, activating international cooperation researches and exploring the multitude of possible research areas to be studied. However, some concerns still exist, such as threats from developed countries for the government to open the agricultural market, the reduction of the number of full-time farms and intensification of needs for economic and social effects. The diverse actions and systems based upon the strongpoint, weakness, opportunity and threats above-mentioned are required to encourage research activities in the field of animal resources of agricultural sciences in Korea In addition, researchers in this fields would make an effort to keep pace with international society as well as domestic demands.

Foams play an important role in a wide range of processes. In these processes the foams are often flowing and the amount of liquid carried within them is an important operating consideration. In froth flotation, for instance, the amount of water collect is intimately related to the amount of gangue collected, which in turn helps dictates the grade of the product obtained. This paper presents some theoretical relationships for the prediction of water recovery from a flowing foam. In the foams that have less than half the bubbles bursting at the top surface, the amount of water collected is independent of the amount of bursting and the rate is proportional to the gas rate squared and inversely proportional to the bubble diameter squared. When more than half the bubbles burst, there is a similar dependence on air rate and bubble size, but the fraction of the bubbles that bursts becomes a further factor. This relationship is demonstrated experimentally to provide a very accurate prediction for stable 2-phase foams. The relationship is theoretically applicable to the 3-phase froths found in flotation, but there are a few problems involved in obtaining the correct variable values to put into the relationships. The most problematic of these is the average size of the bubbles that are collected to the concentrate. It is also demonstrated how this equation can be used as an alternative method to image processing for estimating the bubble size in flotation froths.

This paper examines the recovery of liquid from stable overflowing foams. The foams are formed by bubbling gas into the bottom of a column and the liquid is collected from the foam that flows over the lip at the top. The paper demonstrates, using a foam drainage equation, that the recovery of liquid will rapidly decrease towards an asymptotic value as the foam height is increased. An expression for this liquid recovery is then developed. That the liquid recovery becomes constant as foam height is increased in a stable foam is also demonstrated experimentally. The mathematical analysis of the problem suggests that the amount of liquid collected is proportional to the gas rate squared. This relationship is verified experimentally for an aqueous foam.