Estimation of intake and digestibility of kleingrass from in situ parameters measured in sheep

The voluntary intake and digestibility of kleingrass (Panicum coloratum cv. Verde) were measured in seven periods, comprising one full year. The forage was offered twice a day ad Iibitum to .seven rams, frtted with faces collection bags; each experimental period was composed of 8 days for adaptation and 8 days for collection of data. The dry matter (DM) Intake (DMI) varied from 36.1 to 64.9 glkg MO.75, the digestible dry-matter Intake (DDMI), from 17.4 to 41.9 glkg MO.75 and the in vivo dry matter apparent digestibility (DMD), from 0.471 to 0.667. Daily samples of offered forage were taken and pooled subsamples from each of the seven periods were incubated in nylon bags in the rumen of three Hereford steers. The data were fitted to the exponential equation: p= a + b (1-e~) to estimate p (the proportionate loss of DM at time t of incubation); effective degradability (ED) and lag time (L) were also estimated. The parameters obtained in situ were related to the in vivo results by simple and multiple regression. The correlation coefficients of the rate of degradation {9 and ED with DMI, DDMI and DMD were, respectively, 0.96 and 0.97; 0.97 and 0.96; 0.86 and 0.88. By including, Q, Q and k into a multiple regression analysis, the coefficients of determination (R2) were: DMI: 0.99; DDMI: 0.99 and DMD: 0.91. Within the conditions of this study, the parameters obtained in situ were reasonable estimators of voluntary intake and digestibility.Resúmenes de Trabajos presentados en otras publicaciones (por docentes de la UNLPam.) Publicado en Animal Science, 67: 535-540, 1998

Detection of ultra-weak magnetic fields in Am stars: beta UMa and theta Leo

An extremely weak circularly polarized signature was recently discovered in spectral lines of the chemically peculiar Am star Sirius A. A weak surface magnetic field was proposed to account for the observed polarized signal, but the shape of the phase-averaged signature, dominated by a prominent positive lobe, is not expected in the standard theory of the Zeeman effect. We aim at verifying the presence of weak circularly polarized signatures in two other bright Am stars, beta UMa and theta Leo, and investigating the physical origin of Sirius-like polarized signals further. We present here a set of deep spectropolarimetric observations of beta UMa and theta Leo, observed with the NARVAL spectropolarimeter. We analyzed all spectra with the Least Squares Deconvolution multiline procedure. To improve the signal-to-noise ratio and detect extremely weak signatures in Stokes V profiles, we co-added all available spectra of each star (around 150 observations each time). Finally, we ran several tests to evaluate whether the detected signatures are consistent with the behavior expected from the Zeeman effect. The line profiles of the two stars display circularly polarized signatures similar in shape and amplitude to the observations previously gathered for Sirius A. Our series of tests brings further evidence of a magnetic origin of the recorded signal. These new detections suggest that very weak magnetic fields may well be present in the photospheres of a significant fraction of intermediate-mass stars. The strongly asymmetric Zeeman signatures measured so far in Am stars (featuring a dominant single-sign lobe) are not expected in the standard theory of the Zeeman effect and may be linked to sharp vertical gradients in photospheric velocities and magnetic field strengths

Estimation of screening test (Hemoccult®) sensitivity in colorectal cancer mass screening

3 controlled cohorts of mass-screening for colorectal cancer using a biennial faecal occult blood (HemoccultII®) test on well-defined European populations have demonstrated a 14% to 18% reduction in specific mortality. We aimed to estimate the sensitivity (S) of this HemoccultII®test and and also mean sojourn time (MST) from French colorectal mass-screening programme data. 6 biennial screening rounds were performed from 1988 to 1998 in 45 603 individuals aged 45–74 years in Saône-et-Loire (Burgundy, France). The prevalent/incidence ratio was calculated in order to obtain a direct estimate of the product S.MST. The analysis of the proportional incidence and its modelling was used to derive an indirect estimate of S and MST. The product S.MST was higher for males than females and higher for left colon than either the right colon or rectum. The analysis of the proportional incidence confirmed the result for subsites but no other significant differences were found. The sensitivity was estimated at 0.57 and the MST at 2.56 years. This study confirms that the sensitivity of the Hemoccult test is relatively low and that the relatively short sojourn time is in favour of annual screening. © 2001 Cancer Research Campaign http://www.bjcancer.co

Minimally invasive repair of pectus excavatum using the Nuss technique in children and adolescents: Indications, outcomes, and limitations

AbstractBackgroundPectus excavatum (PE) is a common congenital deformity. The Nuss technique for minimally invasive repair of PE involves thoracoscopy-assisted insertion of a bar or plate behind the deformity to displace the sternum anteriorly. Our objective here was to clarify the indications and limitations of the Nuss technique based on a review of 70 patients.Materials and methodsA retrospective review of children managed at two centres identified 70 patients who had completed their growth and had their plate removed. Mean age was 13.8 years (range, 6–19 years). The reason for surgery was cosmetic disfigurement in 66 (95%) patients. The original Nuss technique was used in 63 patients, whereas 7 patients required an additional sub-xiphoid approach. Time to implant removal ranged from 8 months to 3 years.ResultsThe cosmetic outcome was considered satisfactory by the patients in 64 (91%) cases and by the surgeon in 60 (85.7%) cases. Major complications requiring further surgery occurred in 6 (8.5%) patients and consisted of haemothorax (n=2), chest wall sepsis (n=2, including 1 after implant removal), allergy (n=1), and implant displacement (n=1). Early or delayed minor complications occurred in 46 (65%) patients and resolved either spontaneously or after non-surgical therapy.DiscussionThe minimal scarring and reliably good outcomes support the widespread use of the Nuss technique in children and adolescents. Our complication rates (minor, 65%; and major, 8.5%) are consistent with previous publications. In our opinion, contra-indications to thoracoscopic PE correction consist of a history of cardio-thoracic surgery and the finding by computed tomography of a sternum-to-spine distance of less than 5cm or of sternum rotation greater than 35°. In these situations, we recommend a sub- and retro-xiphoid approach to guide implant insertion or a classic sterno-chondroplasty procedure.Level of evidenceLevel IV, retrospective descriptive cohort study

Quantification of Walking Ability in Participants with Neurogenic Claudication from Lumbar Spinal Stenosis – A Comparative Study

Background context Walking limitations caused by neurogenic claudication (NC) are typically assessed with self-reported measures, although objective evaluation of walking using motorized treadmill test (MTT) or self-paced walking test (SPWT) has periodically appeared in the lumbar spinal stenosis (LSS) literature. Purpose This study compared the validity and responsiveness of MTT and SPWT for assessing walking ability before and after common treatments for NC. Study design Prospective observational cohort study. Patient sample Fifty adults were recruited from an urban spine center if they had LSS and substantial walking limitations from NC and were scheduled to undergo surgery (20%) or conservative treatment (80%). Outcome measures Walking times, distances, and speeds along with the characteristics of NC symptoms were recorded for MTT and SPWT. Self-reported measures included back and leg pain intensity assessed with 0 to 10 numeric pain scales, disability assessed with Oswestry Disability Index, walking ability assessed with estimated walking times and distances, and NC symptoms assessed with the subscales from the Spinal Stenosis Questionnaires. Methods Motorized treadmill test used a level track, and SPWT was conducted in a rectangular hallway. Walking speeds were self-selected, and test end points were NC, fatigue, or completion of the 30-minute test protocol. Results from MTT and SPWT were compared with each other and self-reported measures. Internal responsiveness was assessed by comparing changes in the initial results with the posttreatment results and external responsiveness by comparing walking test results that improved with those that did not improve by self-reported criteria. Results Mean age of the participants was 68 years, and 58% were male. Neurogenic claudication included leg pain (88%) and buttock(s) pain (12%). Five participants could not safely perform MTT. Walking speeds were faster and distances were greater with SPWT, although the results from both tests correlated with each other and self-reported measures. Of the participants, 72% reported improvement after treatment, which was confirmed by significant mean differences in self-reported measures. Motorized treadmill test results did not demonstrate internal responsiveness to change in clinical status after treatment but SPWT results did, with increased mean walking times (6 minutes) and distances (387 m). When responsiveness was assessed against external criterion, both SPWT and MTT demonstrated substantial divergence with self-reported changes in clinical status and alternative outcome measures. Conclusions Both MTT and SPWT can quantify walking abilities in NC. As outcome tools, SPWT demonstrated better internal responsiveness than MTT, but neither test demonstrated adequate external responsiveness. Neither test should be considered as a meaningful substitution for disease-specific measures of functio