Early and intensive physiotherapy accelerates recovery postarthroscopic meniscectomy: results of a randomized controlled study

The efficacy of an early, intensive, supervised rehabilitation program to accelerate knee strength recovery in the first 3 weeks postmeniscectomy by arthroscopy was evaluated using a randomized controlled trial design. The maximal voluntary isokinetic strength of 31 men, randomly allocated to either a treatment (EXP) or a control (CTL) group, was measured twice by a blind rater: preoperatively (pretest) and 3 weeks postsurgery (posttest), using a computer-controlled Kin-Com dynamometer (Chattecx Corporation, Chattanooga, TN). Strength deficits of the operated leg at the pretest and posttest were established in percent of the values obtained for the sound leg at the pretest. In the interval between the surgery and the posttest, the patients of the EXP group (n = 15) received nine supervised treatments combined to home exercises whereas patients of the control group (n = 16) had no specific physiotherapy treatment but were given instructions in postsurgical management and prescribed exercises by the orthopedic surgeons. Patients of the EXP group had better knee extensor strength recovery than patients of the CTL group (ANCOVA, p < 0.001). The size of the strength difference (3 weeks postsurgery) between EXP and CTL subgroups (n = 8) matched according to preoperative deficits was as large as 26% and the residual deficits of the untreated patients were two to three times larger than those of the treated patients. The results of this study highlight the importance of instituting an early intensive and supervised rehabilitation program, especially for workers returning to a strenuous job requiring good knee extensor muscle function.     

The biological leaching of an auriferous pyrite ore

The oxidation of an auriferous pyrite ore sample was evaluated in biological leaching experiments for subsequent gold recovery via cyanidation. In batch cultures, organisms derived from the mine site oxidized pyrite and ferrous iron at pH values as low as pH 0.6. The recovery of gold was variable in shake flask experiments. In stirred tank bioreactor leaching, gold recovery was proportional to the extent of iron dissolution by bioleaching. The leaching of arsenic from the sample was also directly proportional to iron dissolution.     

A data collection protocol for real-time sensor applications

The nature of many sensor applications as well as continuously changing sensor data often imposes real-time requirements on wireless sensor network protocols. Due to numerous design constraints, such as limited bandwidth, memory and energy of sensor platforms, and packet collisions that can potentially lead to an unbounded number of retransmissions, timeliness techniques designed for real-time systems and real-time databases cannot be applied directly to wireless sensor networks. Our objective is to design a protocol for sensor applications that require periodic collection of raw data reports from the entire network in a timely manner. We formulate the problem as a graph coloring problem. We then present TIGRA (Timely Sensor Data Collection using Distributed Graph Coloring) — a distributed heuristic for graph coloring that takes into account application semantics and special characteristics of sensor networks. TIGRA ensures that no interference occurs and spatial channel reuse is maximized by assigning a specific time slot for each node. Although the end-to-end delay incurred by sensor data collection largely depends on a specific topology, platform, and application, TIGRA provides a transmission schedule that guarantees a deterministic delay on sensor data collection.     

Compact electrostatic levitator for diffraction measurements with a two axis diffractometer and a laboratory x-ray source

A compact electrostatic levitator was developed for the structural analysis of high-temperature liquids by x-ray diffraction methods. The size of the levitator was 200 mm in diameter and 200 mm in height and can be set up on a two axis diffractometer with a laboratory x-ray source, which is very convenient in performing structural measurements of high-temperature liquids. In particular, since the laboratory x-ray source allows a great amount of user time, preliminary or challenging experiments can be performed with trial and error, which prepares and complements synchrotron x-ray experiments. The present small apparatus also provides the advantage of portability and facility of setting. To demonstrate the capability of this electrostatic levitator, the static structure factors of alumina and silicon samples in their liquid phases were successfully measured.     

Effect of gate poly-silicon depletion on MOSFET input impedance

One of the most challenging problems encountered in developing RF circuits is accurate prediction of MOS behavior at microwave signal and data frequencies. An attempt is made in this work to accurately model the device input impedance for the 1-20-GHz frequency range. The effect of device length and single-leg width on the input impedance is studied with the aid of extensive measured data obtained from devices built in 0.11-/spl mu/m and 0.18-/spl mu/m technologies. The measured data illustrates that the device input impedance has a nonlinear frequency dependency. It is also shown that this variation in input impedance is a result of gate poly-silicon depletion, which can be modeled by an external RC network connected at the gate of the device. Excellent agreement between the simulation results and the measured data validates the model in the device active region.     

What controls distribution of larval and juvenile yellow perch? The role of habitat characteristics and spatial processes in a large,shallow lake

The goal of this study was to determine the relative contribution of environmental and spatial processes governing the distribution of larval and juvenile yellow perch (Perca flavescens) in two shallow embayments of a large fluvial lake on the St. Lawrence River system. We tested the hypotheses that: i) larval distribution is not related to habitat characteristics, presumably due to their relatively low swimming capacity, whereas ii) these environmental variables drive juvenile distribution, reflecting a more active habitat selection. This study is one of the first attempts to partition the relative roles of environmental and spatial factors in shaping the distribution of a freshwater fish through its early ontogeny. We show that larvae were not spatially aggregated within the embayments and that habitat characteristics, mainly related to aquatic vegetation, played an important role in explaining their distribution. In contrast, juvenile abundances were not significantly related to habitat characteristics, despite being spatially structured over multiple scales. Contrary to our predictions, habitat association was stronger for larvae than for juveniles which were aggregated independent of habitat characteristics. Increased swimming capacities may thus facilitate the aggregation of juveniles rather than strengthening their association with habitat, at least at the scales considered here (ca 3 km²). These results shed a new light on the factors governing larval and juvenile yellow perch distribution, suggesting that active habitat choice might begin earlier than previously thought.     

Sixth graders’ evaluation strategies when reading Internet search results: an eye-tracking study

Eye-tracking technology was used to examine Internet search result evaluation strategies adopted by sixth-grade students (N?=?36) during ten experimental information search tasks. The relevancy of the search result’s title, URL, and snippet components was manipulated and selection of search results as well as looking into probabilities on the search result components was analysed. The results revealed that during first-pass inspection, students read the search engine page by first looking at the title of a search result. If the title was relevant, the probability of looking at the snippet of the search result increased. During second-pass inspection, there was a high probability of students focusing on the most promising search result by inspecting all of its components before making their selection. A cluster analysis revealed three viewing strategies: half of the students looked mainly at the titles and snippets; one-third with high probability examined all components; and one-sixth mainly focused on titles, leading to more frequent errors in search result selection. The results indicate that students generally made a flexible use of both eliminative and confirmatory evaluation strategies when reading Internet search results, while some seemed to not pay attention to snippet and URL components of the search results.     

Comparison of alveolar ventilation, oxygenation, pressure support, and respiratory system resistance in response to noninvasive versus conventional mechanical ventilation in foals

OBJECTIVE: To compare the efficacy of positive pressure ventilation applied through a mask versus an endotracheal tube, using anesthetized/paralyzed foals as a model for foals with hypoventilation. ANIMALS: Six 1-month-old foals. PROCEDURE: A crossover design was used to compare the physiologic response of foals to 2 ventilatory techniques, noninvasive mask mechanical ventilation (NIMV) versus endotracheal mechanical ventilation (ETMV), during a single period of anesthesia and paralysis. Arterial pH, PaO2, PaCO2, oxygen saturation, end-tidal CO2 tension, airway pressures, total respiratory system resistance, resistance across the upper airways (proximal to the midtracheal region), and positive end-expiratory pressures (PEEP) were measured. Only tidal volume (VT; 10, 12.5, and 15 ml/kg of body weight) or PEEP (7 cm of H2O) varied. RESULTS: Compared with ETMV, use of NIMV at equivalent VT resulted in PaCO2 and pH values that were significantly higher, but PaO2 was only slightly lower. Between the 2 methods, peak airway pressure was similar, but peak expiratory flow was significantly lower and total respiratory resistance higher at each VT for NIMV. Delivery of PEEP (7 cm of H2O) was slightly better for ETMV (7.1 +/- 1.3 cm of H2O) than for NIMV (5.6 +/- 0.6 cm of H2O). CONCLUSION: These data suggest that use of NIMV induces similar physiologic effects as ETMV, but the nasal cavities and mask contribute greater dead space, manifesting in hypercapnia. Increasing the VT used on a per kilogram of body weight basis, or the use of pressure-cycled ventilation might reduce hypercapnia during NIMV. CLINICAL RELEVANCE: Use of NIMV might be applicable in selected foals, such as those with hypoventilation and minimal changes in lung compliance, during weaning from endotracheal mechanical ventilation, or for short-term ventilation in weak foals.     

Membrane-bound electron transfer chain of the thermohalophilic bacterium Rhodothermus marinus: a novel multihemic cytochrome bc, a new complex III

Rhodothermus marinus, a thermohalophilic bacterium, has a unique electron-transfer chain, containing, besides a cbb3 and a caa3 terminal oxidases, a novel cytochrome bc complex [Pereira, M. M., Carita, J. N., and Teixeira, M. (1999) Biochemistry 38, 1268-1275]. The membrane-bound iron-sulfur centers of this bacterium were studied by electron paramagnetic resonance (EPR) spectroscopy, leading to the identification of its main electron-transfer complexes. The resonances typical for the Rieske-type centers are not detected. Clusters S1 and S3 from succinate dehydrogenase were identified; interestingly, center S3 is shown to be present in two different conformations, with g values at 2.035, 2.009, and 2.001 and at 2.025, 2.002, and 2.000. Upon addition of NADH and dithionite, EPR signals assigned to resonances characteristic of binuclear and tetranuclear clusters develop and are attributed to the iron-sulfur centers of complexes I and II. A high-potential iron-sulfur protein- (HiPIP-) type center previously detected in the membranes of this bacterium [Pereira et al. (1994) FEBS Lett. 352, 327-330] is shown to belong indeed to a canonical HiPIP. This protein was purified and extensively characterized. It is a small water-soluble protein of approximately 10 kDa, containing a single [4Fe-4S]3+/2+ cluster. The reduction potential, determined by EPR redox titrations in intact and detergent-solubilized membranes as well as by cyclic voltammetry in solution, has a pH-independent value of 260 +/- 20 mV, in the range 6-9. In vitro reconstitution of the R. marinus electron-transfer chain shows that the HiPIP plays a fundamental role in the chain, as the electron shuttle between R. marinus cytochrome bc complex and the caa3 terminal oxidase, being thus simultaneously identified a HiPIP reductase and a HiPIP oxidase.