Ideal Laboratory Conditions Research Articles

Technical Note: Millimeter precision in ultrasound based patient positioning: experimental quantification of inherent technical limitations.

To identify the relevant technical sources of error of a system based on three-dimensional ultrasound (3D US) for patient positioning in external beam radiotherapy. To quantify these sources of error in a controlled laboratory setting. To estimate the resulting end-to-end geometric precision of the intramodality protocol. Two identical free-hand 3D US systems at both the planning-CT and the treatment room were calibrated to the laboratory frame of reference. Every step of the calibration chain was repeated multiple times to estimate its contribution to overall systematic and random error. Optimal margins were computed given the identified and quantified systematic and random errors. In descending order of magnitude, the identified and quantified sources of error were: alignment of calibration phantom to laser marks 0.78 mm, alignment of lasers in treatment vs planning room 0.51 mm, calibration and tracking of 3D US probe 0.49 mm, alignment of stereoscopic infrared camera to calibration phantom 0.03 mm. Under ideal laboratory conditions, these errors are expected to limit ultrasound-based positioning to an accuracy of 1.05 mm radially. The investigated 3D ultrasound system achieves an intramodal accuracy of about 1 mm radially in a controlled laboratory setting. The identified systematic and random errors require an optimal clinical tumor volume to planning target volume margin of about 3 mm. These inherent technical limitations do not prevent clinical use, including hypofractionation or stereotactic body radiation therapy.

Technical notes: A detailed study for the provision of measurement uncertainty and traceability for goniospectrometers

The measurement uncertainty and traceability of the Finnish Geodetic Institutes׳s field gonio-spectro-polarimeter FIGIFIGO have been assessed. First, the reference standard (Spectralon sample) was measured at the National Standard Laboratory of MIKES-Aalto. This standard was transferred to FGI׳s field reference standard (larger Spectralon sample), and from that to the unmanned aerial vehicle (UAV), reference standards (1m2 plates). The reflectance measurement uncertainty of FIGIFIGO has been estimated to be 0.01 in ideal laboratory conditions, but about 0.02–0.05 in typical field conditions, larger at larger solar or observation zenith angles. Target specific uncertainties can increase total uncertainty even to 0.1–0.2. The angular reading uncertainty is between 1° and 3°, depending on user selection, and the polarisation uncertainty is around 0.01. For UAV, the transferred reflectance uncertainty is about 0.05–0.1, depending on, how ideal the measurement conditions are.The design concept of FIGIFIGO has been proved to have a number of advantages, such as a well-adopted user-friendly interface, a high level of automation and excellent suitability for the field measurements. It is a perfect instrument for collection of reference data on a given target in natural (and well-recorded) conditions. In addition to the strong points of FIGIFIGO, the current study reveals several issues that need further attention, such as the field of view, illumination quality, polarisation calibration, Spectralon reflectance and polarisation properties in the 1000–2400nm range.

Il principio della camera biologica nel trattamento delle pseudoartrosi complesse e delle perdite di sostanza ossee: quali materiali e perché?

Bone regeneration presents a unique challenge to both clinicians and scientists. Recently, a vast amount of knowledge has been attained with regard to the molecular mediators, cell populations and the overall cascade of events participating in the bone repair processes. For the treatment of bone non-unions or bone defects, the ‘Diamond Concept’ for biological enhancement supports the associated implantation of mesenchymal stem cells, a scaffold and growth factors. Prior to the implantation of any or all of these materials however, the surgeon must develop the ideal biological environment where molecular and physiological processes will evolve facilitating an early and successful osteogenesis leading to bone continuity. This privileged environment is the “Biological Chamber” that can create the best conditions promoting the regeneratiion and thus optimizing the results. A “bioreactor” is crated in order to reproduce ideal laboratory conditions. The “Biological Chamber” must be asteptic, vascularized and protected, that means not completely isolated but surrounded selectively in order to mantain the proper contacts with the surrounding tissues.The notion of creating the optimum ‘biological chamber’ represents the centre of the highest biological activity and in a sense the heart of the “Diamond Concept”.

Experimental Study of High-Temperature Chlorine-Induced Corrosion in Dependence of Gas Velocity

High-temperature chlorine-induced corrosion is mainly responsible for the limitation of plant availabilities and electrical efficiencies of waste- and biomass-fired boilers. According to the current state of research, it is controversial if the flue gas velocity influences the corrosion on heat-transfer surfaces. References regarding the behavior of corrosion at different gas velocities are scarcely available, and the complexity in chemistry as well as the varying combustion conditions in conventional plants complicates the interpretation of observations. On the basis of this background, this paper aims to discuss the theoretical background of velocity-dependent corrosion and also investigates the influence of gas velocity on corrosion under ideal laboratory conditions. The work includes both experimental and numerical simulations to study the deposition and corrosion behavior at velocities of 0.6, 1.7, 2.8, and 3.9 m/s. The experimental corrosion tests were carried out in an electrically heated laboratory test rig, where a defined mass of KCl was vaporized and transported by different air flows. An air-cooled corrosion probe was inserted into the reaction tube, and after a set exposure time, the oxide layer thicknesses of the corrosion rings were analyzed metallographically. Accompanied by ANSYS simulations, the condensing rates of KCl on the probe surface were calculated for the different velocity cases. The experiments show tendencies that the mean corrosion rates rise with increasing flue gas velocities. From the experiments and simulations, it can be concluded that the gas velocity influences the condensation and deposition mechanisms, which also directly affects corrosion.

An open‐channel flume study of flow characteristics through a combined layer of submerged and emerged flexible vegetation

ABSTRACTFlowing water bodies often have plants that differ greatly in size and type, which interfere with fluid flow structure. Although there are studies describing vegetation–flow interactions in ideal laboratory conditions, their practical application is sometimes still difficult. This paper presents results of research involving laboratory simulations channel flow and the effects upon its structure as it passes through a combined layer of submerged and emerged vegetation in an open‐channel flume. Instantaneous time‐average velocity and turbulence at various locations were measured with a 3D acoustic Doppler velocimeter. The experimental results showed that the mean velocity profiles can be divided into three layers: bottom, middle and upper. The velocity profiles show the flow structure was complex variable over time creating mixing velocity layers associated with inflection points and velocity spikes. Turbulence intensity urms, vrms, wrms was nearly invariant for the flow depth at the bottom layer in most locations within the vegetation area. Maximum turbulence intensity occurred within the middle layer and migrated vertically as frontal width of the plant increased. Maximum turbulence intensity fluctuated at the velocity mixing layer where there is significant momentum exchange. The Manning's vegetation roughness coefficient n(v) due to vegetation resistance increased with vegetation density as expected. In all, the results show flow structure varies substantially at the stem section and at the canopy top of submerged vegetation. These analytical findings will be useful in understanding river channel hydraulic transport and mixing processes and useful in river engineering applications and modelling. Copyright © 2013 John Wiley & Sons, Ltd.

Asymmetry in the song of crickets: Preferences of females and proximate mechanism of discrimination

SUMMARYSubtle random deviations from perfect symmetry in bilateral traits are suggested to signal reduced phenotypic and genetic quality of a sender, but little is known about the related receiver mechanisms for discriminating symmetrical from asymmetrical traits. Here, we investigated these mechanisms in behavioural and neurophysiological experiments in the Mediterranean field cricket, Gryllus bimaculatus. A downward frequency modulation at the end of each syllable in the calling song has been suggested to indicate morphological asymmetry in sound radiating structures between left and right forewings. Even under ideal laboratory conditions on a trackball system, female crickets only discriminated between songs of symmetrical and asymmetrical males in two-choice experiments at carrier frequencies of 4.4 kHz and a large modulation depth of 600 and 800 Hz. Under these conditions they preferred the pure-tone calling songs over the modulated (asymmetrical) alternative, whereas no preference was observed at carrier frequencies of 4.9 and 5.2 kHz. These preferences correlate well with the responses of a pair of identified auditory interneurons (AN1), known for their importance in female phonotaxis. The AN1 interneuron is tuned to an average frequency of 4.9 kHz, and the roll-off towards lower and higher frequencies determines the magnitude of responses to pure-tone and frequency-modulated calling songs. The difference in response magnitude between the two neurons appears to drive the decision of females towards the song alternatives. We discuss the relevance of song differences based on asymmetry in the morphology of song-producing structures under natural conditions.

Paramecium swimming in capillary tube

Swimming organisms in their natural habitat need to navigate through a wide range of geometries and chemical environments. Interaction with boundaries in such situations is ubiquitous and can significantly modify the swimming characteristics of the organism when compared to ideal laboratory conditions. We study the different patterns of ciliary locomotion in glass capillaries of varying diameter and characterize the effect of the solid boundaries on the velocities of the organism. Experimental observations show that Paramecium executes helical trajectories that slowly transition to straight lines as the diameter of the capillary tubes decreases. We predict the swimming velocity in capillaries by modeling the system as a confined cylinder propagating longitudinal metachronal waves that create a finite pressure gradient. Comparing with experiments, we find that such pressure gradient considerations are necessary for modeling finite sized ciliary organisms in restrictive geometries.

Introduction: Transition to Where? Developing Post-Soviet Space

With the demise of the Soviet Union in the early 1990s, international donors rushed to proffer advice. Their development teleology was one of “transition” from a centralized command economy to a liberal, democratic, market-driven economy. Popular ideologies of the period—neoliberalism, governance, and civil society— converged as policymakers designed development programs in line with the principles of what came to be known as the Washington Consensus. The dissolution of the USSR provided ideal laboratory conditions to test these ideologically driven policies. Today, two decades on, this model for transitioning to liberal democracy has crashed on the shoals of crony capitalism, authoritarianism, runaway corruption, population decline, and social dislocation. This introduction to the following cluster of articles offers a number of the guiding tenets of development aid in the former Soviet Union over the past two decades and attempts to show the connections between the categories of aid (for example, civil society, market reform) and the larger policy issues and ideologies that nurtured them. The articles in this cluster examine the political and scholarly tensions suggested when relations of power and difference are inextricably linked to international aid efforts. International aid fl owing to this region has been especially sensitive and marked in that it is directed at a former superpower—itself a long-term donor of aid and technical assistance to the Third World. The aid efforts Thanks to Mark D. Steinberg, whose enthusiasm for this thematic cluster has not wavered, despite what often felt like a gruelling and lengthy review process. The incomparable staff at the Kennan Institute of the Woodrow Wilson International Center for Scholars, Washington, D.C., offered years of support for the project from which these articles stemmed. Two international workshops, generously funded by the Department of State’s Title VIII Program, took place under the auspices of the Kennan Institute. I would like to mention particularly Renata Kosc-Harmatiy, Will Pomeranz, Blair Ruble, and Maggie Paxson, who helped insure the success of these workshops. I would also like to acknowledge the numerous interlocutors, from the Department of State, USAID, and nongovernmental organizations, who generously shared their ideas and perspectives with the workshop participants, providing useful feedback. Though the papers of some of the workshop participants are not included here, their contributions to the synergy that emerged from our discussions has surely percolated through the cluster. The critical insights of Michael Borowitz, Alexander Danilenko, Bhavna Dave, and Scott Newton have incalculably enhanced my understanding of the multifaceted world of Central Asia and postsocialist development. I thank them for many years of enlightening conversations.

How Internet Telephony Could Improve Communication for Hearing-Impaired Individuals

To test, whether modern Internet telephony with a broadband transmission (0.1-8 kHz) of speech improves speech perception in comparison to conventional telephony (0.3-3.5 kHz) in hearing-impaired and normal-hearing adults. Experimental clinical study. Audiologic laboratory in a tertiary referral center in Bern, Switzerland. Twenty-one adult hearing-impaired patients consisting of 11 users of cochlear implants and 10 users of hearing aids were selected from the institution's database based on pure tone audiograms, speech perception scores, and device settings. Ten normal-hearing adults served as controls. Superiority trial of speech perception assessed with Internet versus conventional telephone quality and noninferiority trial of Internet telephone versus frequency restricted, uncompressed audio CD quality. A modern broadband codec was chosen to simulate Internet telephone quality, and ideal network conditions without packet loss were assumed. Speech perception scores of a monosyllabic word test in quiet and a sentence test in background noise assessed in different audio qualities. : Test scores were, on average, 15% (4-33) higher in the monosyllabic word and 25% (8-51) higher in the sentence test using Internet versus conventional telephone quality across all subject groups. Speech perception was not significantly different when Internet telephone quality was compared with high-cut CD quality. Internet telephony offers significantly improved speech perception to hearing-impaired and normal-hearing adults under ideal laboratory conditions through doubling the frequency range and through conserving audio quality during digital sound processing.

Meningitis Dipstick Rapid Test: Evaluating Diagnostic Performance during an Urban Neisseria meningitidis Serogroup A Outbreak, Burkina Faso, 2007

Meningococcal meningitis outbreaks occur every year during the dry season in the “meningitis belt” of sub-Saharan Africa. Identification of the causative strain is crucial before launching mass vaccination campaigns, to assure use of the correct vaccine. Rapid agglutination (latex) tests are most commonly available in district-level laboratories at the beginning of the epidemic season; limitations include a short shelf-life and the need for refrigeration and good technical skills. Recently, a new dipstick rapid diagnostic test (RDT) was developed to identify and differentiate disease caused by meningococcal serogroups A, W135, C and Y. We evaluated the diagnostic performance of this dipstick RDT during an urban outbreak of meningitis caused by N. meningitidis serogroup A in Ouagadougou, Burkina Faso; first against an in-country reference standard of culture and/or multiplex PCR; and second against culture and/or a highly sensitive nested PCR technique performed in Oslo, Norway. We included 267 patients with suspected acute bacterial meningitis. Using the in-country reference standard, 50 samples (19%) were positive. Dipstick RDT sensitivity (N = 265) was 70% (95%CI 55–82) and specificity 97% (95%CI 93–99). Using culture and/or nested PCR, 126/259 (49%) samples were positive; dipstick RDT sensitivity (N = 257) was 32% (95%CI 24–41), and specificity was 99% (95%CI 95–100). We found dipstick RDT sensitivity lower than values reported from (i) assessments under ideal laboratory conditions (>90%), and (ii) a prior field evaluation in Niger [89% (95%CI 80–95)]. Specificity, however, was similar to (i), and higher than (ii) [62% (95%CI 48–75)]. At this stage in development, therefore, other tests (e.g., latex) might be preferred for use in peripheral health centres. We highlight the value of field evaluations for new diagnostic tests, and note relatively low sensitivity of a reference standard using multiplex vs. nested PCR. Although the former is the current standard for bacterial meningitis surveillance in the meningitis belt, nested PCR performed in a certified laboratory should be used as an absolute reference when evaluating new diagnostic tests.

Anti-inflammatory activity of red and white lotus seeds Nelumbo nucifera in albino rats

The present study was carried out to evaluate the anti-inflammatory activity of red and white lotus seeds in albino rats. The Carrageenin induced paw edema model was used for studying the antiinflammatory activity. The cyclooxygenase-2 (COX-2) enzyme inhibition assay was carried out in spectrophotometer to identify the specific mode of action. Forty eight adult Sprague-Dawley rats were used in this experiment. They were divided into six groups of eight each and maintained under ideal laboratory conditions. Group I was taken as control and group II treated with the standard drug diclofenac potassium @ 3mg/kg/celecoxib @ 10mg/kg (in case of COX–2 assay) on 7th day of study. The methanolic extract of Nelumbo nucifera seeds of red and white varieties @ 400mg/kg and 600mg/kg were fed to group III, IV, V and VI respectively, for 7 days. All groups of lotus seed extracts were revealed anti-inflammatory activity in Carragenin induced inflammation as well as in COX-2 enzyme inhibition assay. While comparing all groups, the higher dose group of white lotus seed extracts, exhibited more pronounced inhibition than other groups.

Field Evaluation of Two Rapid Diagnostic Tests for Neisseria meningitidis Serogroup A during the 2006 Outbreak in Niger

The Pastorex® (BioRad) rapid agglutination test is one of the main rapid diagnostic tests (RDTs) for meningococcal disease currently in use in the “meningitis belt”. Earlier evaluations, performed after heating and centrifugation of cerebrospinal fluid (CSF) samples, under good laboratory conditions, showed high sensitivity and specificity. However, during an epidemic, the test may be used without prior sample preparation. Recently a new, easy-to-use dipstick RDT for meningococcal disease detection on CSF was developed by the Centre de Recherche Médicale et Sanitaire in Niger and the Pasteur Institute in France. We estimate diagnostic accuracy in the field during the 2006 outbreak of Neisseria meningitidis serogroup A in Maradi, Niger, for the dipstick RDT and Pastorex® on unprepared CSF, (a) by comparing each test's sensitivity and specificity with previously reported values; and (b) by comparing results for each test on paired samples, using McNemar's test. We also (c) estimate diagnostic accuracy of the dipstick RDT on diluted whole blood. We tested unprepared CSF and diluted whole blood from 126 patients with suspected meningococcal disease presenting at four health posts. (a) Pastorex® sensitivity (69%; 95%CI 57–79) was significantly lower than found previously for prepared CSF samples [87% (81–91); or 88% (85–91)], as was specificity [81% (95%CI 68–91) vs 93% (90–95); or 93% (87–96)]. Sensitivity of the dipstick RDT [89% (95%CI 80–95)] was similar to previously reported values for ideal laboratory conditions [89% (84–93) and 94% (90–96)]. Specificity, at 62% (95%CI 48–75), was significantly lower than found previously [94% (92–96) and 97% (94–99)]. (b) McNemar's test for the dipstick RDT vs Pastorex® was statistically significant (p<0.001). (c) The dipstick RDT did not perform satisfactorily on diluted whole blood (sensitivity 73%; specificity 57%).Sensitivity and specificity of Pastorex® without prior CSF preparation were poorer than previously reported results from prepared samples; therefore we caution against using this test during an epidemic if sample preparation is not possible. For the dipstick RDT, sensitivity was similar to, while specificity was not as high as previously reported during a more stable context. Further studies are needed to evaluate its field performance, especially for different populations and other serogroups.

Analysis of Implantable Defibrillator Longevity Under Clinical Circumstances: Implications for Device Selection

Information about implantable cardioverter-defibrillator (ICD) longevity is mostly calculated from measurements under ideal laboratory conditions. However, little information about longevity under clinical circumstances is available. This survey gives an overview on ICD service times and generator replacements in a cohort of consecutive ICD patients. Indications for replacement were classified as a normal end-of-service (EOS), premature EOS, system malfunction, infection and device advisory, or recall actions. From the premature and normal EOS group, longevity from single-chamber (SC), dual-chamber (DC), and cardiac resynchronization therapy defibrillator (CRT-D), rate-responsive (RR) settings, high output (HO) stimulation, and indication for ICD therapy was compared. Differences between brands were compared as well. In a total of 854 patients, 203 ICD replacements (165 patients) were recorded. Premature and normal EOS replacements consisted of 32 SC, 98 DC and 24 CRT-D systems. Longevity was significantly longer in SC systems compared to DC and CRT-D systems (54 +/- 19 vs. 40 +/- 17 and 42 +/- 15 months; P = 0.008). Longevity between non-RR (n = 143) and RR (n = 11) settings was not significantly different (43 +/- 18 vs. 45 +/- 13 months) as it also was not for HO versus non-HO stimulation (43 +/- 19 vs. 46 +/- 17 months). Longevity of ICDs was not significantly different between primary and secondary prevention (42 +/- 19 vs. 44 +/- 18 months). The average longevity on account of a device-based EOS message was 43 +/- 18 months. Average longevity for Biotronik (BIO, n = 72) was 33 +/- 10 months, for ELA Medical (ELA, n = 12) 44 +/- 17 months, for Guidant (GDT, n = 36) 49 +/- 12 months, for Medtronic (MDT, n = 29) 62 +/- 22 months, and for St. Jude Medical (SJM, n = 5) 31 +/- 9 months (P < 0.001). SC ICD generators had a longer service time compared to DC and CRT-D systems. No influence of indication for ICD therapy and HO stimulation on generator longevity was observed in this study. MDT ICDs had the longest service time.

Diagnosis and Treatment of Botulism: A Century Later, Clinical Suspicion Remains the Cornerstone

ically defined cases of wound botulism. Wheeler and colleagues surely know wound botulism when they see it, because they consult on most wound botulism cases, and to the mind of most experts familiar with the diagnostic challenges of botulism, they are fully justified in using clinical diagnosis as the gold standard against which to measure the mouse bioassay’s limited sensitivity. The sensitivity calculated in the article is not the intrinsic sensitivity of a test under ideal laboratory conditions, but rather that of the clinical setting, calculation of which depends on a complicated set of real-world factors. This calculation must take into account the quality of the gold standard clinical diagnosis, which depends on the initial astuteness of the admitting physician and the diagnostic skill of the California Department of Public Health consultant, and variations in toxin levels in clinical samples, which depend on the timeliness of sample collection, the size of the Clostridium botulinum colony in the infected wound, kinetics of toxin absorption from the abscess, its migrations to the extracirculatory compartment, and possibly other factors. One must also keep in mind that the sensitivity of mouse bioassay results may be different for the other principal forms of botulism—foodborne botulism and infant botulism. Most foodborne botulism cases are diagnosed by other expert con

Head‐related transfer function enhancement for improved vertical‐polar localization.

Under ideal laboratory conditions, individualized head‐related transfer functions (HRTFs) can produce virtual sound localization performance approaching the level achieved with real sound sources in the free field. However, in real‐world applications of virtual audio, practical issues such as fit‐refit variability in the headphone response and nonindividualized HRTFs generally lead to much worse localization performance, particularly in the up‐down and front‐back dimensions. Here we present a new technique that “enhances” the localizability of a virtual sound source by increasing the spectral contrast of the acoustic features that are relevant for spatial perception within a set of locations with nearly identical binaural cues (i.e., a “cone‐of‐confusion”). Validation experiments show that this enhancement technique can improve localization accuracy across a broad range of conditions, with as much as a 33% reduction in vertical‐polar localization error for nonindividualized HRTFs measured on a KEMAR manikin; a 25% reduction in vertical‐polar error for nonindividualized HRTFs measured on other human listeners; and a 33% reduction in vertical‐polar error for individualized HRTFs presented under nonideal laboratory conditions (i.e., with headphone fit‐refit variability). These results suggest that the proposed technique could provide benefits across a wide range of real‐world virtual audio display applications. [Work sponsored by AFOSR.]

Parallel female preferences for call duration in a diploid ancestor of an allotetraploid treefrog

The gray treefrog species complex (Hyla chrysoscelis and H. versicolor) comprises a single allotetraploid species (H. versicolor) that arose multiple times from hybrid matings between an extant diploid species (H. chrysoscelis) and at least two other extinct diploid treefrogs. While previous studies have investigated female preferences for call duration in the tetraploid, we know little about these preferences in its putative diploid anscestors. Here, I report results from two-choice phonotaxis experiments investigating call duration preferences in H. chrysoscelis. Females preferred an average-length call over shorter-than-average calls (0.5-2.0 standard deviations [SD] below average), and they preferred longer-than-average calls over average or shorter-than-average calls if the difference in pulse number was at least 2.0 SD. When the amplitude of the longer alternative was attenuated by 6 dB, females still preferred an average-length call over a shorter-than-average call, but there was no preference for longer-than-average calls over an average call. In the presence of chorus noise, female preferences for both average and longer-than-average calls over shorter alternatives were weakened or reversed. Together, the results from this study reveal patterns of female preferences for call duration that are strikingly similar among two members of a species complex with a novel evolutionary history. In both species, female preferences are directional, nonlinear, and limited by environmental noise. Furthermore, these results also highlight the need for caution in studies of sexual selection when extrapolating from patterns of female preference obtained under ideal laboratory conditions to conclusions about how those preferences are expressed in the real world.

Image-based RSA: Roentgen stereophotogrammetric analysis based on 2D–3D image registration

Image-based Roentgen stereophotogrammetric analysis (IBRSA) integrates 2D–3D image registration and conventional RSA. Instead of radiopaque RSA bone markers, IBRSA uses 3D CT data, from which digitally reconstructed radiographs (DRRs) are generated. Using 2D–3D image registration, the 3D pose of the CT is iteratively adjusted such that the generated DRRs resemble the 2D RSA images as closely as possible, according to an image matching metric. Effectively, by registering all 2D follow-up moments to the same 3D CT, the CT volume functions as common ground. In two experiments, using RSA and using a micromanipulator as gold standard, IBRSA has been validated on cadaveric and sawbone scapula radiographs, and good matching results have been achieved. The accuracy was: | μ|<0.083 mm for translations and | μ|<0.023° for rotations. The precision σ in x-, y-, and z-direction was 0.090, 0.077, and 0.220 mm for translations and 0.155°, 0.243°, and 0.074° for rotations. Our results show that the accuracy and precision of in vitro IBRSA, performed under ideal laboratory conditions, are lower than in vitro standard RSA but higher than in vivo standard RSA. Because IBRSA does not require radiopaque markers, it adds functionality to the RSA method by opening new directions and possibilities for research, such as dynamic analyses using fluoroscopy on subjects without markers and computer navigation applications.

Avaliação da confiabilidade da gota espessa em um estudo de campo conduzido em uma área endêmica de malária no Médio Rio Negro, Estado do Amazonas

In order to assess the reliability of the thick smear in a Plasmodium infection area, 322 thick smears were examined by a trained microscopist in field conditions. Later, the same smears were examined by an experience microscopist in ideal laboratory conditions. Reliability was measured by the Kappa index. In symptomatic malaria patients the Kappa index was 0.91 (IC 95% 0.57-0.98 p<0.05) while in asymptomatic Plasmodium infection the Kappa index was as low as 0.42 (IC 95% 0.15-0.68 p<0.05). In areas of asymptomatic infection, improvement in the sensibility of thick smears by increasing the number of microscopic fields read or using other more accurate diagnostic malaria techniques alone or in combination is fundamental.

The History and Future of Radiostereometric Analysis

Roentgen stereophotogrammetry allows one to localize the position of an object in space using roentgen rays. For orthopaedic purposes it was developed 35 years ago by Göran Selvik, and since that time many investigators have refined the radiostereometric calculations and evaluative software. Many uses and mathematical algorithms have been developed, and advancements in computer programs and digital radiography continue to expand its capabilities. Despite these advances, improvements in the technical accuracy and type of kinematic analyses possible have been relatively modest. However, radiostereometric analysis is now easier and less time consuming to use, with a resolution in clinical practice almost equal to what could only previously be obtained under ideal laboratory conditions. The ability to measure skeletal and implant movements with high resolution in vivo images was an important progressive step for the orthopaedic community. Radiostereometric analysis has helped develop new fields in clinical orthopaedic research and continues to improve advancements in orthopaedic health care.

Germination characteristics of Melaleuca ericifolia Sm. (swamp paperbark) and their implications for the rehabilitation of coastal wetlands

Swamp paperbark, Melaleuca ericifolia Sm., is a small, clonal tree that occupies fresh- and brackish-water wetlands across south-eastern Australia. Seeds collected from Dowd Morass, a secondary-salinised Ramsar-listed wetland of the Gippsland Lakes region in eastern Victoria, showed very low viability (&lt; 6%), with less than 50% of the seeds germinating even under ideal laboratory conditions. Greatest germination occurred with surface-sown seeds, germinated in darkness at a mean temperature of 20°C and salinity &lt; 2 g L–1. At 20°C, maximum germination occurred at a salinity of 1 g L–1; germination fell rapidly at a near constant rate with increasing salinity. Lower temperatures, while moderating the inhibitory effects of salinity, markedly reduced germination; higher temperatures increased the inhibitory effects of salinity and light and reduced overall germination rates. Seeds subjected to brief inundation with saline water germinated rapidly if flushed by, and subsequently grown under, freshwater conditions. Specific timing of management interventions, particularly manipulations of water regime to control salinity regimes, are required if germination of M. ericifolia on the landscape scale is to be successful. Even so, the low overall viability of the seeds would present difficulties to large-scale, seed-based rehabilitation efforts.