This work studies upper-limb impairment resulting from stroke or traumatic brain injury and presents a simple technological solution for a subset of patients: a soft, active stretching aid for at-home use. To better understand the issues associated with existing associated rehabilitation devices, customer discovery conversations were conducted with 153 people in the healthcare ecosystem (60 patients, 30 caregivers, and 63 medical providers). These patients fell into two populations: spastic (stiff, clenched hands) and flaccid (limp hands). Focusing on the first category, a set of design constraints was developed based on the information collected from the customer discovery. With these constraints in mind, a powered wrist-hand stretching orthosis (exoskeleton) was designed and prototyped as a preclinical study (T0 basic science research) to aid in recovery. The orthosis was tested on two patients for proof-of-concept, one survivor of stroke and one of traumatic brain injury. The prototype was able to consistently open both patients’ hands. A mathematical model was developed to characterize joint stiffness based on experimental testing. Donning and doffing times for the prototype averaged 76 and 12.5 s, respectively, for each subject unassisted. This compared favorably to times shown in the literature. This device benefits from simple construction and low-cost materials and is envisioned to become a therapy device accessible to patients in the home. This work lays the foundation for phase 1 clinical trials and further device development.

Stroke causes neurological and physical impairment in millions of people around the world every year. To better comprehend the upper-limb needs and challenges stroke survivors face and the issues associated with existing technology and formulate ideas for a technological solution, the authors conversed with 153 members of the ecosystem (60 neuro patients, 30 caregivers, and 63 medical providers). Patients fell into two populations depending on their upper-limb impairment: spastic (stiff, clenched hands) and flaccid (limp hands). For this work, the authors chose to focus on the second category and developed a set of design constraints based on the information collected through customer discovery. With these in mind, they designed and prototyped a 3D-printed powered wrist–hand grasping orthosis (exoskeleton) to aid in recovery. The orthosis is easily custom-sized based on two parameters and derived anatomical relationships. The researchers tested the prototype on a survivor of stroke and modeled the kinematic behavior of the orthosis with and without load. The prototype neared or exceeded the target design constraints and was able to grasp objects consistently and stably, as well as exercise the patients’ hands. In particular, donning time was only 42 s, as compared to the next fastest time of 3 min reported in literature. This device has the potential for effective neurorehabilitation in a home setting, and it lays the foundation for clinical trials and further device development.

Herbicide-resistant annual bluegrass (Poa annua L.) has become a problem in non-arable land areas. In arable fields, P. annua is frequently of lower priority in weed control program due to the variety of control options available and the relatively modest impact on crop yield compared with other species. In Ireland, postemergence herbicides are not primarily intended for P. annua control, but some herbicides, including the acetolactate synthase (ALS) inhibitor mesosulfuron-methyl + iodosulfuron-methyl, exhibit P. annua activity. In this study, a suspected P. annua population (POAAN-R) that survived mesosulfuron-methyl + iodosulfuron-methyl at 0.75 of the field recommended rate was sampled from a wheat (Triticum aestivum L.) field in County Dublin, Ireland. Single-dose testing confirmed that the suspected POAAN-R had evolved resistance to mesosulfuron-methyl + iodosulfuron-methyl and, additionally, to pyroxsulam (not registered in Ireland for P. annua control), but was sensitive to clethodim, glyphosate, pendimethalin, and flufenacet. Dose–response experiments indicated that POAAN-R was more resistant (GR50 resistance index) to both mesosulfuron-methyl + iodosulfuron-methyl (47.8 times) and pyroxsulam (38.0 times) than sensitive POAAN-S, and this was associated with the mutation at Trp-574 in the ALS protein. Malathion (a cytochrome P450 [P450] inhibitor) pretreatment did not reverse POAAN-R resistance to mesosulfuron-methyl + iodosulfuron-methyl or pyroxsulam at the field rate or above. The natural inherent mutation at Ile-1781 in acetyl-CoA carboxylase protein had no effect on both POAAN-R and POAAN-S sensitivity to clethodim. The glyphosate sensitivity of POAAN-R also corresponded with no known mutation in 5-enolpyruvylshikimate-3-phosphate synthase protein. Based on field histories, poor early-season weed control coupled with intensive use of mesosulfuron-methyl + iodosulfuron-methyl (often at reduced rates) has unintentionally selected for ALS inhibitor–resistant POAAN-R. This is the first report to characterize resistance in P. annua to ALS-inhibiting herbicides mesosulfuron-methyl + iodosulfuron-methyl and pyroxsulam in an arable setting. There is an opportunity to effectively control POAAN-R using herbicides, but this needs a wide-ranging and varied approach, coupled with cultural/nonchemical practices.

Microfluidic systems consisting of a square microchannel with an orthogonal side branch are promising tools to enrich or sort suspensions of deformable capsules. To allow their operating control, we numerically consider a train of initially spherical identical capsules, equally spaced along the axis of the feeding channel. The capsules have a strain-hardening membrane, an internal fluid viscosity identical to that of the external fluid and a size comparable to that of the channel. We study the influence of the interspacing on the capsule path selection at the channel bifurcation using a three-dimensional immersed boundary–lattice Boltzmann method. Our objectives are to establish a phase diagram and identify the critical interspacing above which hydrodynamic interaction between capsules no longer affects their path selection. We find two main regimes. At low interspacing, strong capsule interaction leads to an unsteady regime for which the capsule path selection follows either a periodic or a disordered state. Above a critical initial interspacing $d_{ct}$, a steady regime is achieved where interaction between capsules is too weak to affect their path selection. The capsules then follow an identical steady trajectory. We find that the dependence of the interspacing $d_{ct}$, normalised by the capsule radius, on the flow split ratio falls onto a universal curve regardless of the flow strength, capsule size and membrane shear elasticity. We also compare the path selection of a capsule train with that of a two-capsule system, and discuss applications of the present results in controlling capsule trains in microfluidic suspension enrichment devices.

ABSTRACT IMPACT: Evaluate the accuracy of applying a predictive algorithm using clinical measures only in persons with stroke in the US. OBJECTIVES/GOALS: PREP2 is an algorithm, that predicts UL functional capacity at 3 months post stroke from measures taken within the first week.(1, 2) Despite its accuracy and ease of use, challenges arise of applying PREP2 in the US. The objective of this study was to evaluate the accuracy of PREP2 using only clinical measures in persons with stroke in the US. METHODS/STUDY POPULATION: Individuals with first-ever stroke were recruited from a local hospital and followed longitudinally, as part of an ongoing observational cohort. Variables captured within two weeks of stroke and entered into the algorithm were: age, SAFE score(1-3) and NIH Stroke Scale(4) total score. The algorithm classifies individuals into one of four expected categories: excellent, good, limited, or poor. The dependent variable was the predicted category of UL functional capacity as defined by ranges of the 3-month Action Research Arm Test score.(5) Accuracy, specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) of the algorithm, were calculated using a 4x4 contingency table. Other statistics analyzed include demographic characteristics and a weighted kappa for the algorithm. RESULTS/ANTICIPATED RESULTS: Data from 49 individuals were analyzed (57% male, 88% ischemic stroke, age = 65±8.56 years). Expected categorization matched observed categorization in 29/49 subjects, with the overall accuracy of the algorithm of 59% (95% CI = 0.44-0.73). The sensitivity of the algorithm was low except for the excellent category (0.95). Specificity was moderate to high for good (0.81), limited (0.98), and poor (0.95) categories. PPV was low for all categories and NPV was high for all categories except the good category. Additional results including weighted kappa and inaccuracy of predictions to be presented. DISCUSSION/SIGNIFICANCE OF FINDINGS: PREP2 algorithm, with clinical measures only, is better than chance (chance = 25% for each of the 4 categories) alone at predicting a category of UL capacity at 3 months post stroke. PREP2 is a simple tool that facilitates evaluation of eventual UL outcome from measures routinely captured after a stroke within most healthcare settings in the US.

We study the three-dimensional hydrodynamic interaction of a pair of identical, initially spherical capsules freely suspended in a simple shear flow under Stokes flow conditions. The capsules are filled with a Newtonian liquid (same density and viscosity as the suspending fluid). Their membranes satisfy the neo-Hookean constitutive law. We consider the rarely studied case where the capsule centres are initially located in (or near) the plane defined by the flow direction and the vorticity vector, i.e. in two different shear planes. The motion and deformation of the capsules are modelled by means of a boundary integral technique to compute the flows, coupled to a finite element method to calculate the force exerted by the membranes on the fluids. We follow the motion and deformation of the capsules as they are convected towards each other after a sudden start of the flow. Our main finding is that, depending on their initial position and deformability, the two capsules may oscillate slowly about the flow gradient axis, get nearer to each other at each oscillation to finally interact strongly and separate. This minuet motion had not been identified previously. We identify the regions of space where either simple crossing or minuet occurs. This phenomenon has a marked influence on the irreversible trajectory drift of two capsules after crossing: the minuet process leads to a significant trajectory displacement along the flow gradient when none was expected, based on the previous studies where the two capsules had a significant relative velocity.

The assessment of the completeness of milk-out in dairy cows is one of the indicators used to evaluate and optimise the milking process. A number of different methods and thresholds are available for this purpose, but procedures and validation of the methods are not always described in detail, and may vary between studies. The objective of this study was to introduce and evaluate a new, precisely defined hand-milking method (DEFINED) and to compare its outcome with two commonly applied methods to assess the completeness of milking: visual scoring of the degree of quarter filling (VISUAL) and quantitative assessment of the number of easy strips (EASYSTRIPS). Each of the three methods was applied in 131 Holstein cows of six dairy herds in northern Germany. The assessment of milk-out was carried out by three experienced but non-regular milkers (evaluators). Each evaluator visited the six herds once during afternoon milking. To avoid any transitions, the interval between visits of two evaluators was at least 2 days. Maximum hand-milking time per cow was set to 60 s. The total strip yield collected in 60 s (SY60) by the application of a strip frequency of 1 Hz was used as a reference for the amount of milk left in the investigated quarter after machine-milking. The three methods were evaluated by analysing their statistical relationship with SY60, and by ranking their suitability for quantitative or qualitative assessment of milk-out. VISUAL and SY60 were not related, indicating that VISUAL was unsuitable for estimating the amount of milk left actually in the udder quarters. The strip yield in 15 s (DEFINED) and SY60 was significantly related, but results varied among evaluators. With regard to EASYSTRIPS, a significant relationship with SY60 was found, but the results were influenced by evaluator and herd. The findings of this study imply that DEFINED allows a rapid and farm-independent quantitative estimate of the post-milking strip yield. Likewise, EASYSTRIPS was meaningful in assessing milk-out of quarters in a given herd, whereas VISUAL allowed neither a quantitative nor a qualitative assessment of post-milking strip yield or milk-out. Thresholds for complete or incomplete milk-out by DEFINED must be lower than those commonly applied in 15 s of post-milking.

We computationally study the motion of an initially spherical capsule flowing through a straight channel with an orthogonal lateral branch, using a three-dimensional immersed-boundary lattice-Boltzmann method. The capsule is enclosed by a strain-hardening membrane and contains an internal fluid of the same viscosity as the fluid in which it is suspended. Our primary focus is to study the influence of the geometry of the side branch on the capsule path selection. Specifically, we consider the case where the side branch cross-section is half that of the straight channel and study various bifurcation configurations, where the branch is rectangular or square, centred or not on the straight channel axis. The capsule is initially centred on the axis of the straight channel. We impose the flow rate split ratio between the two downstream branches of the bifurcation. We summarise the results obtained for different capsule-to-channel size ratios, flow Reynolds number $Re$ (based on the parent channel size and average flow speed) and capsule mechanical deformability (as measured by the capillary number) in phase diagrams giving the critical flow rate split ratio above which the capsule flows into the side branch. A major finding is that, at equal flow rate split between the two downstream branches, the capsule will enter a branch which is narrow in the spanwise direction, but will not enter a branch which is narrow in the flow direction. For $Re\leqslant 5$, this novel intriguing phenomenon primarily results from the background flow, which is strongly influenced by the side branch geometry. For higher values of $Re$, the capsule relative size and deformability also play specific roles in the path selection. The capsule trajectory does not always obey the classical Fung’s bifurcation law, which stipulates that a particle (in Fung’s case, a red blood cell) enters the bifurcation branch with the highest flow rate. We also consider the same branched channels operating under constant pressure drop conditions and show that such systems are difficult to control due to the transient additional pressure drop caused by the capsule. The present results obtained for dilute systems open new perspectives on the design of microfluidic systems, with optimal channel geometries and flow conditions to enrich cell and particle suspensions.

Efficient and economical herd management depends a great deal on maintaining a short, well-defined calving season. This requires highly fertile females and bulls. Low pregnancy rates are very noticeable, however; potentially greater economic loss may be due to delayed conception. Many studies showed that approximately one of every five bulls had inadequate semen quality, physical soundness, or both, but when evaluation of serving capacity is included about one in four bulls is unsatisfactory. Due mainly to the time and expense that the market will bear, usually only physical soundness and semen quality are evaluated. Breeding soundness evaluation is a useful, low-cost screening method for reducing the risk of using low fertility bulls. The biggest problem with breeding soundness evaluations is not our lack of knowledge or ability, but in the willingness of veterinary schools to provide adequate equipment and training in this area, a lack of diagnostic laboratories equipped to handle the more difficult cases and, most importantly, the weaknesses of human nature that result in negligent testing procedure.

We computationally study the transient motion of an initially spherical capsule flowing through a right-angled tube bifurcation, composed of tubes having the same diameter. The capsule motion and deformation is simulated using a three-dimensional immersed-boundary lattice Boltzmann method. The capsule is modelled as a liquid droplet enclosed by a hyperelastic membrane following the Skalak’s law (Skalak et al., Biophys. J., vol. 13(3), 1973, pp. 245–264). The fluids inside and outside the capsule are assumed to have identical viscosity and density. We mainly focus on path selection of the capsule at the bifurcation as a function of the parameters of the problem: the flow split ratio, the background flow Reynolds number $Re$ , the capsule-to-tube size ratio $a/R$ and the capillary number $Ca$ , which compares the viscous fluid force acting on the capsule to the membrane elastic force. For fixed physical properties of the capsule and of the tube flow, the ratio $Ca/Re$ is constant. Two size ratios are considered: $a/R=0.2$ and 0.4. At low $Re$ , the capsule favours the branch which receives most flow. Inertia significantly affects the background flow in the branched tube. As a consequence, at equal flow split, a capsule tends to flow straight into the main branch as $Re$ is increased. Under significant inertial effects, the capsule can flow into the downstream main tube even when it receives much less flow than the side branch. Increasing $Ca$ promotes cross-stream migration of the capsule towards the side branch. The results are summarized in a phase diagram, showing the critical flow split ratio for which the capsule flows into the side branch as a function of size ratio, $Re$ and $Ca/Re$ . We also provide a simplified model of the path selection of a slightly deformed capsule and explore its limits of validity. We finally discuss the experimental feasibility of the flow system and its applicability to capsule sorting.

The objective of the paper is to determine the stable mechanical equilibrium states of an oblate capsule subjected to a simple shear flow, by positioning its revolution axis initially off the shear plane. We consider an oblate capsule with a strain-hardening membrane and investigate the influence of the initial orientation, capsule aspect ratio $a/b$ , viscosity ratio ${\it\lambda}$ between the internal and external fluids and the capillary number $Ca$ which compares the viscous to the elastic forces. A numerical model coupling the finite element and boundary integral methods is used to solve the three-dimensional fluid–structure interaction problem. For any initial orientation, the capsule converges towards the same mechanical equilibrium state, which is only a function of the capillary number and viscosity ratio. For $a/b=0.5$ , only four regimes are stable when ${\it\lambda}=1$ : tumbling and swinging in the low and medium $Ca$ range ( $Ca\lesssim 1$ ), regimes for which the capsule revolution axis is contained within the shear plane; then wobbling during which the capsule experiences precession around the vorticity axis; and finally rolling along the vorticity axis at high capillary numbers. When ${\it\lambda}$ is increased, the tumbling-to-swinging transition occurs for higher $Ca$ ; the wobbling regime takes place at lower $Ca$ values and within a narrower $Ca$ range. For ${\it\lambda}\gtrsim 3$ , the swinging regime completely disappears, which indicates that the stable equilibrium states are mainly the tumbling and rolling regimes at higher viscosity ratios. We finally show that the $Ca$ – ${\it\lambda}$ phase diagram is qualitatively similar for higher aspect ratio. Only the $Ca$ -range over which wobbling is stable increases with $a/b$ , restricting the stability ranges of in- and out-of-plane motions, although this phenomenon is mainly visible for viscosity ratios larger than 1.

Introduction: A cost-minimization analysis (CMA) was performed comparing IVIg and PLEX in the management of patients with exacerbation of myasthenia gravis (MG). Methods: This study combines Ontario-based health costing data with clinical data from a randomized clinical trial where patients with moderate/severe MG received either IVIg or PLEX. The CMA was undertaken under the perspective of a public health care insurer and under the perspective of a tertiary hospital payer. Results: The IVIg group (n=32) was comparable with the PLEX group (n=38) regarding demographics, disease characteristics and severity. PLEX was less costly than IVIg among patients with body mass index (BMI) ≤15.7 Kg/m2, under the perspective of a public health care insurer (CAN$6,271.18 versus CAN$8,309.72, p<0.0001). However, PLEX was more costly than IVIg under the perspective of the hospital payer when the costs of blood products were excluded (CAN$4,815.36 versus CAN$1,486.12, p<0.0001). Conclusions: PLEX may be a short-term cost-minimizing therapy when compared with IVIg for treatment of MG exacerbation among patients with BMI ≤15.7 Kg/m2, under the perspective of a public health care insurer. However, when the costs of blood products are absorbed by a third party, the hospital administration may see IVIg as a more attractive therapeutic alternative.

Although the cadmium chloride treatment is an essential process for high efficiency thin film cadmium telluride photovoltaic devices, the precise mechanisms involved that improve the cadmium telluride layer are not well understood. In this investigation we apply advanced micro-structural characterization techniques to study the effect of varying the time of the cadmium chloride annealing treatment on the micro-structure of cadmium telluride solar cells deposited by close spaced sublimation (CSS) and relate this to cell performance. A range of techniques has been used to observe the morphological changes to the micro-structure as well as the chemical and crystallographic changes as a function of treatment parameters. Electrical tests that link the device performance with the micro-structural properties of the cells have also been undertaken. Techniques used include Transmission Electron Microscopy (TEM) for sub-grain analysis and XPS for composition-depth profiling. The study provides a new insight in to the mechanisms involved in the initiation and the subsequent complete re-crystallization of the cadmium telluride layer.

The objective of this study is to investigate the motion of an ellipsoidal capsule in a simple shear flow when its revolution axis is initially placed off the shear plane. We consider prolate capsules with an aspect ratio of two or three enclosed by a membrane, which is either strain-hardening or strain-softening. We seek the equilibrium motion of the capsule as we increase the capillary number $\mathit{Ca}$ , which measures the ratio between the viscous and elastic forces. The three-dimensional fluid–structure interaction problem is solved numerically by coupling a boundary integral method (for the internal and external flows) with a finite element method (for the wall deformation). For any initial inclination with the flow vorticity axis, a given capsule converges towards a unique equilibrium configuration which depends on $\mathit{Ca}$ . At low capillary number, the stable equilibrium motion is the rolling regime: the capsule aligns its long axis with the vorticity axis, while the membrane tank-treads. As $\mathit{Ca}$ increases, the capsule takes a complex wobbling motion at equilibrium, precessing around the vorticity axis. As $\mathit{Ca}$ is further increased, the capsule long axis oscillates about the shear plane, while the membrane rotates around a capsule cross-section that also oscillates over time (oscillating–swinging regime). The amplitude of the oscillations about the shear plane decreases as $\mathit{Ca}$ increases and the capsule finally takes a swinging motion in the shear plane. It is found that the transitions from rolling to wobbling and from wobbling to oscillating–swinging depend on the mean energy stored in the membrane.

It is well known that the cadmium chloride annealing treatment is an essential step in the manufacture of efficient thin film cadmium telluride solar cells. It has been recognized that the combination of annealing at ∼4000C together with the addition of cadmium chloride at the surface induces re-crystallisation of the cadmium telluride layer and also affects the n-type cadmium sulfide. We have applied advanced micro-structural characterization techniques to distinguish the effect of the annealing and the cadmium chloride treatments on the properties of the cadmium telluride deposited via close space sublimation (CSS) and relate these observations to device performance. Transmission electron microscopy (TEM) has shown a variation in stacking fault density with annealing temperature and annealing time. Stacking faults observed within the cadmium telluride grains in TEM were partially removed post annealing; these findings show that temperature alone has a role in the reduction of stacking faults. However, since we have previously observed almost complete removal of stacking faults with annealing in combination with cadmium chloride, the cadmium chloride is essential to defect removal and high efficiency cells.

The motion and deformation of a spherical elastic capsule freely flowing in a pore of comparable dimension is studied. The thin capsule membrane has a neo-Hookean shear softening constitutive law. The three-dimensional fluid–structure interactions are modelled by coupling a boundary integral method (for the internal and external fluid motion) with a finite element method (for the membrane deformation). In a cylindrical tube with a circular cross-section, the confinement effect of the channel walls leads to compression of the capsule in the hoop direction. The membrane then tends to buckle and to fold as observed experimentally. The capsule deformation is three-dimensional but can be fairly well approximated by an axisymmetric model that ignores the folds. In a microfluidic pore with a square cross-section, the capsule deformation is fully three-dimensional. For the same size ratio and flow rate, a capsule is more deformed in a circular than in a square cross-section pore. We provide new graphs of the deformation parameters and capsule velocity as a function of flow strength and size ratio in a square section pore. We show how these graphs can be used to analyse experimental data on the deformation of artificial capsules in such channels.

The large deformations of an initially-ellipsoidal capsule in a simple shear flow are studied by coupling a boundary integral method for the internal and external flows and a finite-element method for the capsule wall motion. Oblate and prolate spheroids are considered (initial aspect ratios: 0.5 and 2) in the case where the internal and external fluids have the same viscosity and the revolution axis of the initial spheroid lies in the shear plane. The influence of the membrane mechanical properties (mechanical law and ratio of shear to area dilatation moduli) on the capsule behaviour is investigated. Two regimes are found depending on the value of a capillary number comparing viscous and elastic forces. At low capillary numbers, the capsule tumbles, behaving mostly like a solid particle. At higher capillary numbers, the capsule has a fluid-like behaviour and oscillates in the shear flow while its membrane continuously rotates around its deformed shape. During the tumbling-to-swinging transition, the capsule transits through an almost circular profile in the shear plane for which a long axis can no longer be defined. The critical transition capillary number is found to depend mainly on the initial shape of the capsule and on its shear modulus, and weakly on the area dilatation modulus. Qualitatively, oblate and prolate capsules are found to behave similarly, particularly at large capillary numbers when the influence of the initial state fades out. However, the capillary number at which the transition occurs is significantly lower for oblate spheroids.

The motion and deformation of a spherical elastic capsule freely suspended in a simple shear flow is studied numerically, focusing on the effect of the internal-to-external viscosity ratio. The three-dimensional fluid–structure interactions are modelled coupling a boundary integral method (for the internal and external fluid motion) with a finite element method (for the membrane deformation). For low viscosity ratios, the internal viscosity affect the capsule deformation. Conversely, for large viscosity ratios, the slowing effect of the internal motion lowers the overall capsule deformation; the deformation is asymptotically independent of the flow strength and membrane behaviour. An important result is that increasing the internal viscosity leads to membrane compression and possibly buckling. Above a critical value of the viscosity ratio, compression zones are found on the capsule membrane for all flow strengths. This shows that very viscous capsules tend to buckle easily.