Sizing of single fluorescently stained DNA fragments by scanning microscopy

We describe an approach to determine DNA fragment sizes based on the fluorescence detection of single adsorbed fragments on specifically coated glass cover slips. The brightness of single fragments stained with the DNA bisintercalation dye TOTO‐1 is determined by scanning the surface with a confocal microscope. The brightness of adsorbed fragments is found to be proportional to the fragment length. The method needs only minute amount of DNA, beyond inexpensive and easily available surface coatings, like poly‐l‐lysine, 3‐aminoproyltriethoxysilane and polyornithine, are utilizable. We performed DNA‐sizing of fragment lengths between 2 and 14 kb. Further, we resolved the size distribution before and after an enzymatic restriction digest. At this a separation of buffers or enzymes was unnecessary. DNA sizes were determined within an uncertainty of 7-14%. The proposed method is straightforward and can be applied to standardized microtiter plate

Correlation of the cross-over ratio of the cross-over sign on conventional pelvic radiographs with computed tomography retroversion measurements

Objective: To find a correlation between the cross-over ratio of the cross-over sign on conventional anteroposterior (AP) pelvic radiographs and retroversion measurements (‘roof-edge angle' and ‘equatorial-edge angle) on computed tomography (CT) scans. This would facilitate the interpretation of the cross-over sign regarding the amount of acetabular retroversion. Materials and methods: Correctly projected AP pelvic radiographs (2,925 hips) were examined for the presence of the cross-over sign (COS), and the overlap ratio of the COS was measured. On CT scans of the same patients the ‘roof-edge angle' (RE angle) and the ‘equatorial-edge angle' (EE angle) were also calculated. Results: A statistically significant but only weak relationship could be found between the overlap ratio of the COS and the ‘roof-edge angle' (P < 0.0001; correlation coefficient −0.486) and between this ratio and the ‘equatorial-edge angle' (P < 0.0001; correlation coefficient −0.395). Conclusion: A relationship between the overlap ratio and orientation measurements on CT scans could be found, but it was less strong than expecte

Real-Time Detection of Polymerase Activity Using Supercritical Angle Fluorescence

We investigated the incorporation efficiencies of different fluorescently labelled dNTPs with polymerases by complementary strand synthesis. For this reason single stranded DNA was immobilized on a coverslip and the increase of fluorescence due to the synthesis of the corresponding strand with tagged dNTPs was detected with a supercritical angle fluorescence biosensor in real-time. By comparison of the observed signal intensities it was possible to conclude that the system Cy5-dCTP—Klenow (exonuclease free) fragment gives the best incorporation yield of the investigated enzymes and dNTP

Neue Erkenntnisse zum Mobilitätsverhalten dank Data Mining

Unter Data Mining versteht man im engeren Sinn das systematische (in der Regel automatisierte oder halbautomatisierte) Entdecken und Extrahieren von vorher unbekannten statistischen Informationszusammenhängen aus grossen Datenmengen. Im deutschen Sprachgebrauch steht Data Mining oft für den ganzen Analyse-Prozess, der auch die Vorbereitung der Daten sowie die Bewertung der Resultate umfasst. Data Mining wird in verschiedenen Bereichen erfolgreich eingesetzt. Anwendungsbeispiele aus schweizerischen Verkehrsplanungen fehlen aber bisher weitgehend. Ziel der Forschungsarbeit war es, den praktisch tätigen Verkehrsplaner mit dem Prozess und den Methoden von Data Mining vertraut zu machen und die Möglichkeiten von Data Mining als Hilfsmittel in der Verkehrsplanung auszuloten. Data Mining wird als iterativer, lernender Prozess dargestellt, in welchem die Phasen von der Fragestellung über das Sammeln und Aufbereiten der Daten, die Modellierung und die Auswertung der Ergebnisse bis zu deren Umsetzung in die Praxis mehrfach durchlaufen werden. In dieser Arbeit wird dieser Prozess genauer beschrieben und ein Überblick über eine Auswahl von Methoden, die in der Modellierung verwendet werden, gegeben. Beispiele aus der Literatur illustrieren das breite Anwendungsspektrum von Data Mining in der Verkehrsplanung (z.B. Verkehrserzeugung, Autobesitz, Verkehrsmittel- und Routenwahl oder Klassifikation von Mobilitätsmustern). Bei den beschriebenen Beispielen handelt es sich um Forschungsarbeiten. Deren Ergebnisse haben noch kaum breiten Eingang in die Praxis gefunden. An Fallbeispielen wird demonstriert, wie Data Mining in der Praxis angewendet werden kann. Als Datensätze werden der Mikrozensus Verkehr 2005 und Raumstrukturdaten des Bundesamtes für Statistik verwendet. Die Fallbeispiele behandeln die Analyse der Häufigkeit von Wegeketten, die Vorhersage der Anzahl Wegeketten pro Person und Tag, die Klassifikation nach Mobilitätstypen sowie die Vorhersage des Mobilitätstyps einer Person aufgrund sozio-demographischer Merkmale und Raumstrukturinformationen zu den Wohn- und Zielorten. Aus der grossen Vielfalt von Software-Lösungen für Data Mining wird eine Auswahl proprietärer und frei verfügbarer Pakete, welche für den Einsatz in der Verkehrsplanung als grundsätzlich geeignet beurteilt werden, grob und ohne Wertung beschrieben. Die Studie kommt zum Schluss, dass Data Mining in der Verkehrsplanung sicher nutzbringend anwendbar ist, dass aber nicht – wie vielleicht erhofft – automatisch auf alle Fragen gute Antworten erwartet oder ohne Dazutun des Anwenders aus vorhandenen Datensätzen neue Erkenntnisse gewonnen werden können. Empfehlenswerte Einsatzgebiete für Data Mining in der Verkehrsplanung sind beispielsweise: Klassifikation, z.B. des Mobilitätsverhaltens, Visualisierung komplexer mehrdimensionaler Datensätze zum raschen Erkennen von Mustern resp. Clustern, rasche und automatische Erkennung der (aus statistischer Sicht) wichtigsten Prädikatorendes Mobilitätsverhaltens, Analyse der Entscheidungsprozesse, z.B. bei der Verkehrsteilnahme. Zusammenhänge, die mit Data Mining Methoden extrahiert werden, sind grundsätzlich Daten-getrieben und müssen keine Kausalitäten widerspiegeln. Deshalb wird empfohlen, aus Kausalitätsüberlegungen abgeleitete Modelle weiterhin mit statistischen Methoden an die Daten anzupassen. Konventionelle Modellansätze und Data Mining sollen als sich ergänzende und gegenseitig unterstützende Methoden eingesetzt werden. Um Data Mining zukünftig auch in der Verkehrsplanung nutzbringend einsetzen zu können, bedarf es keiner weiteren Random Forest Forschung. Vielmehr sind möglichst viele praktische Anwendungen erwünscht, mit denen Verkehrsplaner und Data Mining Experten in interdisziplinärer Zusammenarbeit Erfahrungen sammeln und weitergeben können

Acetabular fracture types vary with different acetabular version

Purpose: Acetabular fractures typically occur in high energy trauma. Understanding of the various contributing biomechanical factors and trauma mechanisms is still limited. While several investigations figured out what role femoral position during impact plays in distinct fracture patterns, no data exists on the influence of acetabular version on the fracture type. Our study was carried out to clarify this issue. Methods: Radiological data sets of 192 patients (145 male, 47 female, age 14-90years) sustaining acetabular fractures were assessed retrospectively. The crossover ratio of the crossover sign and presence or absence of the posterior wall sign and ischial spine sign were used to determine acetabular retroversion on conventional radiographs. Acetabular version in the axial plane was measured on a computed tomography (CT) scan. Statistics were then performed to analyse the relationship between the acetabular fracture type according to the Letournel classification and acetabular version. Results: A significant difference (p = 0.029) in acetabular version was found between fractures of the anterior [mean equatorial edge (EE) angle 19.93°] and posterior (mean EE angle 17.53°) acetabulum in the CT scan. No difference was shown on the measurements on conventional radiographs. Conclusions: Acetabular version in the axial plane has an influence on the acetabular fracture pattern. While more anteverted acetabula were frequently associated with anterior fracture types according to the Letournel classification, retroversion of the acetabulum was associated with posterior fracture type

Relationship between Wiberg's lateral center edge angle, Lequesne's acetabular index, and medial acetabular bone stock

Objective: Knowledge of acetabular anatomy is crucial for cup positioning in total hip replacement. Medial wall thickness of the acetabulum is known to correlate with the degree of developmental dysplasia of the hip (DDH). No data exist about the relationship of routinely used radiographic parameters such as Wiberg's lateral center edge angle (LCE-angle) or Lequesne's acetabular index (AI) with thickness of the medial acetabular wall in the general population. The aim of our study was to clarify the relationship between LCE, AI, and thickness of the medial acetabular wall. Materials and methods: Measurements on plain radiographs (LCE and AI) and axial CT scans (quadrilateral plate acetabular distance QPAD) of 1,201 individuals (2,402 hips) were obtained using a PACS imaging program and statistical analyses were performed. Results: The mean thickness of the medial acetabulum bone stock (QPAD) was 1.08mm (95% CI: 1.05-1.10) with a range of 0.1 to 8.8mm. For pathological values of either the LCE (12°) the medial acetabular wall showed to be thicker than in radiological normal hips. The overall correlation between coxometric indices and medial acetabular was weak for LCE (r=−0.21. 95% CI [−0.25, -0.17]) and moderate for AI (r= 0.37, [0.33, 0.41]). Conclusions: We did not find a linear relationship between Wiberg's lateral center edge angle, Lequesne's acetabular index and medial acetabular bone stock in radiological normal hips but medial acetabular wall thickness increases with dysplastic indice

Normal values of Wiberg's lateral center-edge angle and Lequesne's acetabular index-a coxometric update

Background: The historical pathological cut-off values for Wiberg's lateral center-edge (LCE) angle and Lequesne's acetabular index (AI) are below 20° and above 12° for the LCE and AI, respectively. The aim of this study was to reassess these two angles more than 50years after their introduction using a standardized conventional radiological measurement method, considering changing social habits and their associated physiological changes. Methods: A total of 1,226 anteroposterior radiographs of the pelvis (2,452 hips) were obtained according to a strict standardized radiographic technique allowing reliable measurements of the LCE angle and the AI. Results: Distributions of the LCE and AI were pronouncedly Gaussian, with mean values of 33.6° for the LCE and 4.4° for the AI. The 2.5th and 97.5th empirical percentiles were 18.1 and 48.0° for the LCE and −6.9 and 14.9° for the AI. These intervals contained 95% of the data in our large sample. Small but statistically significant differences between the sexes and right and left hips have been demonstrated. Correlation between age and coxometric indices was low. Conclusion: The above findings do not conflict with the historical benchmarks. Statistical differences between sexes and between right and left hips were not clinically relevant. No conclusion can be drawn about coxometric indices and clinical manifestations of hip dysplasi

Adrenocorticotropic hormone, but not trilostane, causes severe adrenal hemorrhage, vacuolization, and apoptosis in rats

Adrenal necrosis has been reported as a complication of trilostane application in dogs with hyperadrenocorticism. One suspicion was that necrosis results from the increase of adrenocorticotropic hormone (ACTH) during trilostane therapy. The aim of the current study was to assess the effects of ACTH and trilostane on adrenal glands of rats. For experiment 1, 36 rats were divided into 6 groups. Groups 1.1 to 1.4 received ACTH in different doses (60, 40, 20, and 10 μg/d) infused subcutaneously with osmotic minipumps for 16 wk. Group 1.5 received saline, and group 1.6 received no therapy. For experiment 2, 24 rats were divided into 3 groups. Group 2.1 and 2.2 received 5 and 50 mg/kg trilostane/d orally mixed into chocolate pudding for 16 wk. Eight control rats received pudding alone. At the end of the experiments, adrenal glands were assessed for necrosis by histology and immunohistochemistry; levels of endogenous ACTH and nucleosomes were assessed in the blood. Rats treated with 60 μg ACTH/d showed more hemorrhage and vacuolization and increased numbers of apoptotic cells in the adrenal glands than rats treated with 20 or 10 μg ACTH/d, trilostane, or control rats. Rats treated with 60 μg ACTH/d had a higher amount of nucleosomes in the blood compared with rats treated with 10 μg ACTH/d, trilostane, or saline. We conclude that in healthy rats ACTH, but not trilostane, causes adrenal degeneration in a dose-dependent manner. Results of this study support the hypothesis that adrenal gland lesions seen in trilostane-treated dogs are caused by ACTH and not by trilostane

Comparison of a continuous glucose monitoring system with a portable blood glucose meter to determine insulin dose in cats with diabetes mellitus.

Background:The continuous glucose monitoring system (CGMS) Guardian REAL‐Time® allows the generation of very detailed glucose profiles in cats. The performance of CGMS to generate short‐term glucose profiles to evaluate treatment response has not been yet evaluated in diabetic cats.Hypothesis:Analysis of glucose profiles generated using the CGMS produces insulin dose recommendations that differ from those of profiles generated using the portable blood glucose meter (PBGM) in diabetic cats.Animals:Thirteen client‐owned diabetic cats.Methods:Prospective, observational study. Simultaneous glucose profiles were generated over an 8‐10 hour period using the CGMS, blood glucose concentration was measured every 2 hours with the PBGM. Profiles were submitted to three internal medicine specialists who used them to determine the insulin dose. Differences between insulin doses deduced from paired profiles were compared. Percentages of nadirs recorded with the CGMS that were lower, higher, or equal to those derived with the PBGM were calculated.Results:Twenty‐one paired glucose profiles were obtained. There was no difference of insulin doses based on CGMS and PBGM profiles (median 0 U; range: −1 to +0.5). Treatment decisions did not differ among investigators. Compared with the observed PBGM nadir, the CGMS nadir was lower, higher, or equal in 17, 2, and 2 of 21 cases, respectively.Conclusions and Clinical Importance:Adjustments in insulin dose based on glucose profiles generated with the CGMS are similar to those based on the PBGM. The common occurrence of lower nadirs recorded with the CGMS suggests that this device detects hypoglycemic periods that are not identified with the PBGM

Sexual Segregation and Flexible Mating Patterns in Temperate Bats

Social structure evolves from a trade-off between the costs and benefits of group-living, which are in turn dependent upon the distribution of key resources such as food and shelter. Males and females, or juveniles and adults, may have different priorities when selecting habitat due to differences in physiological or behavioural imperatives, leading to complex patterns in group composition. We studied social structure and mating behaviour in the insectivorous bat Myotis daubentonii along an altitudinal gradient, combining field studies with molecular genetics. With increasing altitude the proportion of males in summer roosts increased and only males were present in the highest roosts. With increasing altitude environmental temperature decreased, nightly variation in temperature increased, and bat foraging activity decreased, supporting the hypothesis that the harsher, high elevation sites cannot support breeding females. We found that offspring in female-dominated lowland roosts had a very high probability of being fathered by bats caught during autumn swarming at hibernation sites, in contrast to those in intermediate roosts, which had a high probability of being fathered by males sharing the nursery roost with the females. Whilst females normally appear to exclude males from nursery colonies, for those in marginal habitats, one explanation for the presence of males is that the thermoregulatory benefits to the females may outweigh disadvantages, such as competition for food, and give some males an opportunity to increase their breeding success. We suggest that the environment, and its effects on resource distribution, thus determine social structure, which in turn determines the mating pattern that has evolved