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Exposure to severe stress following stroke is recognised to complicate the recovery process. We have identified that stress can exacerbate the severity of post-stroke secondary neurodegeneration in the thalamus. In this study, we investigated whether exposure to stress could influence the accumulation of the neurotoxic protein Amyloid-β. Using an experimental model of focal cortical ischemia in adult mice combined with exposure to chronic restraint stress, we examined changes within the contra- and ipsilateral thalamus at six weeks post-stroke using Western blotting and immunohistochemical approaches. Western blotting analysis indicated that stroke was associated with a significant enhancement of the 25 and 50 kDa oligomers within the ipsilateral hemisphere and the 20 kDa oligomer within the contralateral hemisphere. Stroked animals exposed to stress exhibited an additional increase in multiple forms of Amyloid-beta oligomers. Immunohistochemistry analysis confirmed that stroke was associated with a significant accumulation of Amyloid-beta within the thalami of both hemispheres, an effect that was exacerbated in stroke animals exposed to stress. Given that Amyloid-beta oligomers, most notably the 30–40 and 50 kDa oligomers, are recognised to correlate with accelerated cognitive decline, our results suggest that monitoring stress levels in patients recovering from stroke may merit consideration in the future.

Parsimony remains one of the most widely used optimality criteria in phylogenetic systematics. There are many practical reasons for this, including parsimony's intuitive simplicity, applicability to diverse character data, computational speed, and unique statistical properties as a nonparametric method. The epistem‐ological argument for parsimony as maximising explanatory power by minimising ad hoc hypotheses of homoplasy (MAH) has been accepted by many workers. However, in addition to philosophical problems, this justification of parsimony can lead to contradictory results under dynamic homology analysis. Because of the decoupling of homoplasy and tree length under dynamic homology analysis, trees of the same length but different amounts of homoplasy would have different parsimony scores, while trees of different lengths but the same amount of homoplasy would be considered equally parsimonious. An alternative epistemological justification of parsimony based on the anti‐superfluity principle (ASP...

Purpose Investigation of the influence of CT-based navigation systems on the success of an intervention, assessment of the advantages and disadvantages of the utilized systems, and evaluation of the ergonomic system properties. Materials and method A simple guiding system PatPos Invent and the computer-based navigation system PinPoint were employed on two CT systems. In order to investigate the influence of the navigation aids on the success of the interventions, 96 prospective, randomized, and standardized punctures were performed on a specifically developed, rigid phantom. 16 examiners punctured 6 targets with 3 degrees of difficulty with the navigation aids. Results Irrespective of the experience of the examiner, both navigation systems guided the target with an equal degree of certainty. PinPoint significantly reduced the length of the examination time (12 - 25 min) as compared to PatPos Invent (20 - 40 min). The expectation conformity and comprehensibility of PatPos Invent were assessed significantly more positively than PinPoint with regard to the general handling of the system. In contrast, the assessment of the usability during preoperative setup favored PinPoint. The type of navigation system has no influence on the precision of the implementation of a puncture procedure. Conclusion In the overall assessment of the handling of the systems, PatPos Invent was determined to be easier to comprehend and to provide greater conformity with expectations. With regard to the self-descriptive capacity and usability, PinPoint was assessed more positively. Both systems enable safe puncturing at all degrees of difficulty. The weak point of both systems is the failure to take patient movement into account.

PURPOSE To evaluate the quantity and severity of bone disorders in children and adolescents with inflammatory bowel diseases (IBD) and to examine the correlation to whole body growth. MATERIALS AND METHODS In this study 89 bone mineral density measurements were performed and retrospectively analyzed. RESULTS Under consideration of growth retardation, over 65.2 % of the patients with Cohn's disease showed a reduced bone mineral density. Osteopenia/Osteoporosis is seldom seen in patients with ulcerative colitis, i. e., only 34.8 % showed a reduction in bone mineral density. Growth retardation and reduced bone mineral density are correlated. Patients with Cohn's disease and a body length below the 25th height percentile showed a reduced bone mineral density in 78.1 % of the cases. Patients with a body length below the 10th height percentile had a reduced bone mineral density in 83.3 % of the cases. CONCLUSION These results demonstrate the value of osteodensitometric measurements in patients with chronic diseases, especially in children and adolescents with inflammatory bowel disease.

Traditional justifications of parsimony in phylogenetic inference assume a correspondence between character-state similarity and steps (character transformation events). In addition to similarity, justifying arguments appeal to conviction, descriptive efficiency, ad hoc hypotheses of homoplasy and frequentist probability. Each of these rationales fails in so far as the arguments are incoherent or logically inconsistent with the ontological status of what is assumed and being explained historically. An ideographic justification of parsimony, where character-states constitute transformation events, does, however, allow for a rational preference of most parsimonious phylogenetic hypotheses by invoking the anti-superfluity principle (ASP). According to ASP, explanatory power is maximized by minimizing the number of transformation events required to explain the character-states of the terminal taxa as hypotheses of homology, where the concept homology is restricted to just those inherited“things” shared by species. The empirical significance of this rationale is exemplified with the method of direct optimization, which can identify more parsimonious hypotheses than can be confirmed with an analysis of character-state similarities. © The Willi Hennig Society 2006.

The competing lineage (homology) and comparative (convergence) methods for inferring adaptation are distinguished by their falsification and verification practices, respectively. Although these are substantially different paradigms of historical inference, their theoretical and philosophical presuppositions can be tested in a rigorous and comparable manner. Several such tests were performed. Sufficient outright failures were recorded for both methods to call into question their validity as sources of increased knowledge of adaptation.

An ideographic concept of character is indispensable to phylogenetic inference. Hennig proposed that characters be conceptualized as ‘‘transformation series’’, a proposal that is firmly grounded in evolutionary theory and consistent with the method of inferring transformation events as evidence of phylogenetic propinquity. Nevertheless, that concept is usually overlooked or rejected in favor of others based on similarity. Here we explicate Hennig’s definition of character as an ideographic concept in the science of phylogenetic systematics. As transformation series, characters are historical individuals akin to species and clades. As such, the related concept of homology refers to a historical identity relation and is not equivalent to or synonymous with synapomorphy. The distinction between primary and secondary homology is dismissed on the grounds that it conflates the concept of homology with the discovery operations used to detect instances of that concept. Although concern for character dependence is generally valid, it is often misplaced, focusing on functional or developmental correlation (both of which are irrelevant in phylogenetic systematics but may be valid in other fields) instead of the historical ⁄ transformational independence relevant to phylogenetic inference. As an ideographic science concerned with concrete objects and events (i.e. individuals), intensionally and extensionally defined properties are inconsistent with the individuation of characters for phylogenetic analysis, the utility of properties being limited to communicating results and facilitating future rounds of testing. � The Willi Hennig Society 2004.

The significance of “being similar” in the inference of species relationships is refuted once again (see also Hennig, 1966 , Phylogenetic Systematics, Univ. of Illinois Press, Urbana, IL). Without merit is Rieppel and Kearney’s (Biol. J. Linn. Soc., 2002, 75, 59–82) claim that submitting the relational property of topological similarity, their preferred definition of character, to falsifying tests of similarity benefits that kind of inference. Such a priori uses of similarity, in character analysis, are consistent with observational theory, where a character is defined intensionally in terms of immutable properties. However, the induced hypotheses that follow from this theory, not the deductive test that Rieppel and Kearney wanted, remain controversial, because their predictability is a consequence of circular reasoning, and their projectabality fails empirically from incongruent observation reports. Further, a category mistake is made when the abstract, similarity-defined, group of organisms is reified, as a part of history. In addition, Rieppel and Kearney failed to provide a special theory for similarity, which renders similarity scientifically repugnant ( Quine, 1969 , Ontological Relativity and Other Essays, Columbia Univ. Press, New York). A return to Hennig’s (1966) evolutionary concept of evidence, as transformation series, is urged, and from which a testable character hypothesis can be formulated. There is no one operation for determining character states in this system—it can be anything that leads to the testable hypothesis of synapomorphy, as an historical identity relation. Character compatibility and conjunction, but not similarity, provide a priori tests in phylogenetic character analysis. In turn, the phylogenetic system of inference leads to explanations of homology, as historical identities, which exemplifies the goal of achieving a mature state of historical knowledge (not of Quine, 1969 ). Such maturity obtains from attempts to falsify hypotheses of species relationships with severely tested evidence, not from induction of “the” observation statement that Rieppel and Kearney sought to justify their true belief in a hypothesis of relationships.

The deductive inference of phylogeny, first dealt with in some detail by Wiley (1975), continues to be called into question (for an early negation see Hull, 1983; but for a change of mind see Hull, 1999, p. 481). For example, Cleland (2002, p. 483) concludes ‘‘there is little in the practice of historical science that resembles what is prescribed by falsificationism.’’ Olmstead (2001, p. 304) is even of the opinion that ‘‘Popper never addressed the question of how his philosophical framework related to the singular history of evolutionary diversification or to our ability to recover that pattern.’’ Rieppel (2002, p. 30, 2003) is somewhat more specific in stating that ‘‘Popper s philosophy is not applicable to cladistic analysis of phylogenetic relationships, because . . . there is no deductive link between a hypothesis of relationships and the character distribution on a tree . . .’’ In his search for Kuhnian values (Kuhn, 1962), Richards (2002) claims to have discovered that cladistic parsimony cannot function as an unequivocal rule, because different cladograms depend on ‘‘the social factors that influence character individuation.’’ Then there is de Queiroz and Poe (2001; see also Faith and Trueman, 2001), who maintain that Popper s degree of corroboration correctly interpreted is an inductive formalism, thereby tacitly denying an explication of falsificationism (Kluge, 2001). In the hope of achieving more critical discussions in the future, I describe phylogenetic systematics in hypothetico-deductive terms, sufficient I believe for it to be evaluated as a basis for obtaining objective knowledge of species history. Philosophical formalisms and related arguments are placed in footnotes, or ignored altogether, with the bulk of the text consisting of the most familiar terminology and simplest examples of phylogenetic systematics that I can manage while still making my arguments. Whether or not all scientific discoveries are united by the same underlying logic, there is a fundamental difference between the universal (predictive) and the historical (postdictive) sciences, the nomothetic and the idiographic, respectively. As Popper (1957, p. 143, italics in the original) underscored

The skeletal material of Wonambi naracoortensis has been re-examined, and used to test its phylogenetic relationships. The skeletal description, and the resulting data matrix, concentrates on characters that can be assessed by observation (on the associated material of Wonambi kept at the South Australian Museum). Macrostomatan affinities of Wonambi prove to be well supported. The taxon nests within Macrostomata, above Xenopeltis and Loxocemus.

We report a case of a 35 year old male with severe deep vein thrombosis of the lower limb on both sides and pulmonary embolism. A Klinefelter's mosaic (47,XXY [81%]/48,XXXY [19%]) was diagnosed. Because no other cause for this thromboembolism was found, we assume that in part, it was caused by the Klinefelter's mosaic. In all male patients presenting with thromboembolism, especially those with an unusual habitus, a Klinefelter's syndrome should be considered as differential diagnosis. Testosterone substitution therapy should be started in all patients with Klinefelter's syndrome to prevent further disease.

The adequacy of a probabilistic interpretation must be judged according to the nature of the event, or thing, being inferred. For example, conditional (frequency) probability is not admissible in the inference of phylogeny, because basic statements of common ancestry do not fulfill the requirements of the relations specified by the probability calculus. The probabilities of the situation peculiar to the time and place of origin of species are unique. Moreover, according to evolutionary theory, an event of species diversification is necessarily unique, because species are parts of a replicator continuum—species arise from ancestral species. Also, these probabilities cannot be ascertained, because the relevant situation cannot be repeated—it is unique. Finally, the applicability of conditional (frequency) probability is denied, because events of common ancestry have already occurred—there is nothing to predict. However, hypotheses of species relationships can be identified objectively according to the degree to which they have survived simultaneous testing with critical evidence, not with generally confirming evidence. The most parsimonious hypothesis of species relationships represents the least disconfirmed, best supported, proposition among the alternatives being compared. That hypothesis does not, however, deserve any special epistemological status beyond serving as the focus of the next round of testing.

Brower's (2000, Cladistics 16, 143-154) pursuit of a nonevolutionary cladistics, like those of others (e.g., Scotland, 2000, Syst. Biol. 49, 480-500), fails for lack of a scientific justification. His operational explication of parsimony does not necessarily rule out the use of other criteria on which to base the identification of a hierarchical branching pattern, nor does he give a compelling reason for why just that one kind of pattern is sought. In the absence of evolutionary theory, such as the descent of species, and the modification of character states, one from another, there is no scientific reason to seek congruence among character hierarchies whose origins, functions, and fates are not necessarily the same. Brower's operational parsimony is no substitute for phylogenetic parsimony, where requirements for ad hoc hypotheses of homoplasy are justifiably minimized, assuming only "descent, with modification." In addition to maximizing explanatory power, that most parsimonious cladogram is the least disconfirmed, most highly corroborated, hypothesis.

PTP is just Faith's name for the permutation test that Archie introduced in 1985 (see Legendre, 1986:137; cf. Archie, 1989). Now seldom used, the test does not even provide a reliable indication of phylogenetic structure in data (Kallersjo et al., 1992; Farris et al., 1994; Carpenter et al., 1998), and interpreting PTP as corroboration leads to multiple contradictions (Farris, 1995). Faith did not discuss any of those problems, however. Instead, he created a new one (Faith, 1999:678)

Sir Karl Popper is well known for explicating science in falsificationist terms, for which his degree of corroboration formalism, C(h,e,b), has become little more than a symbol. For example, de Queiroz and Poe in this issue argue that C(h,e,b) reduces to a single relative (conditional) probability, p(e,hb), the likelihood of evidence e, given both hypothesis h and background knowledge b, and in reaching that conclusion, without stating or expressing it, they render Popper a verificationist. The contradiction they impose is easily explained--de Queiroz and Poe fail to take account of the fact that Popper derived C(h,e,b) from absolute (logical) probability and severity of test, S(e,h,b), where critical evidence, p(e,b), is fundamental. Thus, de Queiroz and Poe's conjecture that p(e,hb) = C(h,e,b) is refuted. Falsificationism, not verificationism, remains a fair description of the parsimony method of inference used in phylogenetic systematics, not withstanding de Queiroz and Poe's mistaken understanding that "statistical" probability justifies that method. Although de Queiroz and Poe assert that maximum likelihood has the power "to explain data", they do not successfully demonstrate how causal explanation is achieved or what it is that is being explained. This is not surprising, bearing in mind that what is assumed about character evolution in the accompanying likelihood model M cannot then be explained by the results of a maximum likelihood analysis.

The relative optimality of the best and next-best hypotheses indicates the strength of support for the optimal hypothesis and may be calculated as either the difference or ratio of their optimality scores. The Goodman-Bremer support measure (GB) calculates the support for a given clade in the most parsimonious tree as the difference between the length of the optimal tree and the optimal tree that lacks that clade. The ratio of explanatory power (REP) support measure calculates support as the ratio of optimality scores, which simplifies to the ratio of observed GB and the maximum possible GB, GB/GB(max). In this paper we show that REP support provides a logical basis for comparison of support across datasets and that recent claims to the contrary are incorrect.

Modified three-taxon analysis (m3ta), a method in which three-taxon statements are produced from a nonadditive binary coding of the original data, has been proposed as a model-free way of assessing monophyly of groups, utilizing the taxic concept of homology. In fact the taxic concept amounts to a model, and, further, one that seems to conflict directly with evolution. M3ta is a type of grouping by all similarities and, like all such methods, would require a clock assumption if the tree were to be interpreted phylogenetically. Groupings based on this method, consequently, are phenetic, and they have little to do with monophyly. It has been proposed to define phylogenetic systematics in terms of grouping only by presences. While popular among advocates of 3ta, such definitions are completely inadequate, both because absences may be apomorphic and because phenetic methods can disagree with phylogenetic ones even when no absences are involved.

Modified three-taxon analysis (m3ta), a method in which three-taxon statements are produced from a nonadditive binary coding of the original data, has been proposed as a model-free way of assessing monophyly of groups, utilizing the taxic concept of homology. In fact the taxic concept amounts to a model, and, further, one that seems to conflict directly with evolution. M3ta is a type of grouping by all similarities and, like all such methods, would require a clock assumption if the tree were to be interpreted phylogenetically. Groupings based on this method, consequently, are phenetic, and they have little to do with monophyly. It has been proposed to define phylogenetic systematics in terms of grouping only by presences. While popular among advocates of 3ta, such definitions are completely inadequate, both because absences may be apomorphic and because phenetic methods can disagree with phylogenetic ones even when no absences are involved.

Recent claims by its advocates notwithstanding, three-taxon analysis (3ta) provides no method for recognizing reversals or for applying them as apomorphies. Accordingly, 3ta could be used as a phylogenetic method only under an assumption of irreversibility. Being a method for calculating trees from character data, 3ta is not connected to any particular rule ("interpretation") for selecting resolutions of consensus trees considered as abstract diagrams. 3ta cannot be justified simply by invoking a general minimization principle such as Occam's Razor, since that would cover almost any method. Some more specific basis is needed, and consideration of proposed bases for 3ta shows that none is even remotely adequate.

Practicing phylogenetic systematics as a sophisticated falsification research program provides a basis for claiming increased knowledge of sister species relationships and synapomorphies as evidence for those cladistic propositions. Research in phylogenetic systematics is necessarily cyclic, and the place where the positive shift in understanding occurs is subsequent to discovering the most parsimonious cladogram(s). A priori differential character weighting is inconsistent with seeking the maximally corroborated cladogram (sensu Popper), because weighting adds to background knowledge, the evidence being then less improbable than it would be otherwise. Also, estimating weights from character state frequencies on a cladogram is inconsistent with the view that history is unique. Sophisticated falsification provides the place in the cycle of phylogenetic systematic research where weight of evidence can be evaluated and these inconsistencies do not apply. On balance, phylogenetic systematics appears to achieve greater coherence and generality as a result of focusing on the foundations for claiming increased knowledge and avoiding efforts to differentially weight characters.

M. HILLIS. 1996. Phylogenetic inference. Pages 407514 in Molecular systematics, 2nd edition (D. M. Hillis, C. Moritz, and B. K. Mable, eds.). Sinauer, Sunderland, Massachusetts. SWOFFORD, D. L., AND R. B. SELANDER. 1981. BIOSYS-1: A Fortran program for the comprehensive analysis of electrophoretic data in population genetics and systematics. J. Hered. 87:199-229. WIENS, J. J. 1995. Polymorphic characters in phylogenetic systematics. Syst. Biol. 44:482-500.

A 32-year-old woman was admitted to the emergency department because of acute dyspnea and syncope. A few minutes before the onset of symptoms, she had self-administered an intravenous injection of one gram of heroin combined with grinded flunitrazepam tablets.Signs of acute cor pulmonale were detected on transthoracic echocardiography despite lack of pulmonary embolism in computed tomography. It was assumed that microembolisms were the cause of acute pulmonary hypertension after intravenous injection of heroin and flunitrazepam.Because of lack of thrombus in CT scan therapeutic anticoagulation with unfractionated heparin and oxygen insufflation was initiated resulting in rapid improvement of oxygen saturation and blood pressure. On the following day pulmonary pressure in transthoracic echocardiography was already decreased significantly. Without signs of deep venous thrombosis in duplex scan and only a marginal sub segmental perfusion deficit in ventilation-perfusion-scintigraphy therapeutic anticoagulation was recommended for three months.The most likely cause of micro embolisms in this case are particles of talc, which are often used to cut heroin, or the microcrystalline cellulose used in tablets. There have been reports of tissue necrosis due to arterial embolism/vasospasm by crystalloid or oily substances (embolia cutis medicamentosa) in the extremities after intraarterial injection of grinded flunitrazepam tablets. Therefore it seems plausible that intravenous application may cause a serve but transient deficit of perfusion in pulmonary circulation.

Because they are designed to produced just one tree, neighbor-joining programs can obscure ambiguities in data. Ambiguities can be uncovered by resampling, but existing neighbor-joining programs may give misleading bootstrap frequencies because they do not suppress zero-length branches and/or are sensitive to the order of terminals in the data. A new procedure, parsimony jackknifing, overcomes these problems while running hundreds of times faster than existing programs for neighbor-joining bootstrapping. For analysis of large matrices, parsimony jackknifing is hundreds of thousands of times faster than extensive branch-swapping, yet is better able to screen out poorly-supported groups.

SummaryThe prevalence of cervical lymphadenopathy in autoimmune thyroiditis (AIT) patients is actually unknown. The aim of the study was the detailed retrospective evaluation of 6 index-patients with lymphadenopathy in Robbins level VI and a prospective study with high resolution ultrasound of lymphadenopathy in AIT patients compared with controls in all compartments of the neck, accessible to sonographic evaluation. Patients, methods: The retrospective study comprises six patients with AIT, evaluated for enlarged Robbins level VI-LN. We report the findings of fine-needle aspiration Cytology, clonal analysis, histology, and serological testing. The prospective study evaluated the prevalence of lymphadenopathy in 49 consecutive patients with AIT (group 1) and 49 consecutive patients with normal thyroids or nontoxic goiter (group2). Results: In the retrospective study, cytology of paratracheal LN revealed reactive lymphoid hyperplasia in 5/6 of the cases and a centroblastic lymphoma in one patient. The presence of monoclonal lymphatic cells was excluded in 5/6 patients and proven in 1/6 patients. Actual viral-infections were ruled out. In the prospective study AIT-patients showed significantly more enlarged LN in Robbins level II-IV and VI compared to controls. We found no correlation between lymphadenopathy, age, thyroid volume and nodularity, or autoantibody levels. During follow-up in 34 group 1-patients, lymph adenopathy remained stable in 28 patients, and decreased in 6 patients. Conclusion: Lymph adenopathy in Robbins level II-IV and VI is common in AIT-patients and most probably related to the autoimmune process.

Our aim is to study qualitatively the process of QGP cooling and hadronization. Following the statistical theory of the first order phase transitions we have to operate with such categories as nucleation rate, pre-exponential factor, surface free energy of bubbles and velocity of bubble growth. We compute the temperature, average bubble size, bubble density and fraction of space converted to the hadronic phase as a function of time. Also, we check the sensitivity of our scenarios to variations of the parameters mentioned above, as well as different schemes of QGP expansion: from longitudinal to spherical expansion. The results obtained are compared to idealized adiabatic Maxwell equilibrium scenario.

Two major subgroups of erycine snakes, designated Charina and Eryx, are delimited with a cladistic analysis of 75 morphological characters. The hypotheses of species relationships within the two clades are ( reinhardtii (bottae, trivirgata )) and ( colubrinus, conicus, elegans, jayakari, muelleri, somalicus (miliaris (tataricus (jaculus, johnii )))), respectively. This pattern of grouping obtains without assuming multistate character additivity. At least 16 synapomorphies indicate that reinhardtii is an crycine and that it is the sister lineage of the ( bottae, trivirgata ) clade. Calabaria and Lichanura are synonymized with Charina for reasons of taxonomic efficiency, and to emphasize the New-Old World geographic distribution of the three species in that assemblage. Further resolution of Eryx species relationships is required before Gongylophis (type species conicus ) can be recognized.

The mobility—lifetime products (μτ) of B-doped a-Si:H samples prepared by magnetic field assisted high deposition rate chemical vapour deposition are investigated. For doping the alternative unpoisonous triethylboron (TEB) was successfully used. The (μτ) products are derived from measurements of the photoconductivity and of the ambipolar diffusion lengths using the steady state photocarrier grating technique. The dark conductivity σD reaches a minimum at compensation. At this point the electron and hole (μτ) products reach the same magnitude, because both kinds of charge carriers interchange their roles as majority and minority carriers. From the quantitatively analysed results a correlation between the (μτ) products and the concentrations of defects of different charge states is found. Es werden die Beweglichkeits—Lebensdauer-Produkte (μτ) von B-dotierten a-Si: H-Proben untersucht die durch Magnetfeld-unterstutzte Hochrate-PECVD hergestellt wurden. Fur die Dotieruns wird alternativ das ungiftige Triethylbor (TEB) eingesetzt. Die (μτ)-Produkte werden aus den Messungen der Photoleitfahigkeit und der ambipolaren Diffusionslange mittels der “stationaren Ladungstrager-Gitter”-Technik (SSPG) bestimmt. Die Dunkelleitfahigkeit σD erreicht ein Minimum im Bereich der Kompensation. An diesem Punkt sind die (μτ)-Produkte der Elektronen und Locher gleich gros. Beide Ladungstragerarten wechseln hier ihre Rolle als Majoritats- und Minoritatsladungstrager. Aus den quantitativ ausgewerteten Resultaten wird eine Beziehung zwischen den (μτ)-Produkten und den Defektkonzentrationen der verschiedenen Ladungszustande gefunden.

Bei der Analyse moglicher Schmelzschaden bei der Bracketentfernung wurden die Methoden der tordierenden und der biegenden Bracketentfernung miteinander verglichen. In jeder Testgruppe befanden sich 19 extrahierte menschliche Molaren, an denen Metallbrackets mit Concise im Saure-Atz-Verfahren befestigt worden waren. Die Bracketentfernung erfolgte standardisiert in einer Wolpert-Universalprufmaschine TZZ 707 mit modifizierter Torsions-bzw. Biegemechanik. Die Schmelzoberflache wurde anhand rasterelektronenmikroskopischer Bilder analysiert. Bei tordierender Bracketentfernung betragen die Schmelzausrisse im Mittel 48,3% der von Kleberresten freien Schmelzoberflache. Sie reichen haufig in tiefe Schmelzschichten und treten bevorzugt an den Breitseiten des Klebeareals auf. Bei biegender Bracketentfernung wurden Schmelzausrisse wesentlich seltener beobachtet und waren meist nur oberflachlich lokalisiert. Sie traten fast ausschlieslich an den Druckzonen auf. Die zur Bracketentfernung notwendige Kraft sowie die anhand mechanischer Modelle berechnete Kraftverteilung korrespondieren mit dem aufgetretenen Schmelzschaden. Es ergibt sich als Schlusfolgerung, das der Methode der Bracketentfernung eine klinisch relevante Bedeutung zukommt.

The defect density of B-doped a-Si: H samples prepared by magnetic field assisted high deposition rate chemical vapor deposition is investigated by the constant photocurrent method (CPM). For doping the alternative unpoisonous triethylboron (TEB) is successfully utilized. Furthermore, the dark conductivity σD and the optical parameters Tauc gap Eg, Tauc slope B, and Urbach energy E0 are determined. Eg and B do not vary within the range of doping but depend on the deposition rate. By deconvolution of the CPM spectra using a new procedure it is shown that the true valence band tail slope ET differs from E0. Both E0 and ET as well as the defect concentration Ndb0 reach a minimum at compensation which can be monitored by a minimum in σD. An analysis of the energetic distribution of the localized states is possible by assuming exponential tails and Gaussian defect distributions. The results are qualitatively and quantitatively analyzed on the base of the hydrogen mediated weak bond/dangling bond conversion model and the defect pool model. They show a very good agreement especially for the p-type samples. Es wird die Defektdichte fur B-dotierte a-Si: H-Proben mittels der Methode konstanter Photostrome (CPM) untersucht. Die Proben werden mit einer Magnetfeld-unterstutzen Hochrate-PECVD hergestellt. Fur die Dotierung wird alternativ das ungiftige Triethylbor (TEB) eingesetzt. Weiterhin werden die Dunkelleitfahigkeit σD und die optischen Parameter Tauc-Gap Eg, Tauc Anstieg B und die Urbachenergie E0 bestimmt. Im untersuchten Dotierungsbereich variieren Eg und B nicht, sind aber von der Depositionsrate abhangig. Durch die Entfaltung der CPM-Spektren mit einer neuen Prozedur kann gezeigt werden, das sich der wahre Valenzbandtail-Anstieg ET von E0 unterscheidet. E0 und ET sowie die Defektkonzentration Ndb0 erreichen ein Minimum im Bereich der Kompensation (σD minimal). Eine Analyse der energetischen Verteilung der lokalisierten Zustande wird durch Annahme von exponentiellen Tails und einer gausformigen Defektverteilung moglich. Die Resultate werden qualitativ und quantitativ auf der Basis des „hydrogen mediated weak bond/dangling bond conversion”-Modells und des „defect pool’-Modells ausgewertet. Sie zeigen eine sehr gute ubereinstimmung vor allem fur die p-leitenden Proben.

Investigation of the influence of CT-based navigation systems on the success of an intervention, assessment of the advantages and disadvantages of the utilized systems, and evaluation of the ergonomic system properties.A simple guiding system PatPos Invent and the computer-based navigation system PinPoint were employed on two CT systems. In order to investigate the influence of the navigation aids on the success of the interventions, 96 prospective, randomized, and standardized punctures were performed on a specifically developed, rigid phantom. 16 examiners punctured 6 targets with 3 degrees of difficulty with the navigation aids.Irrespective of the experience of the examiner, both navigation systems guided the target with an equal degree of certainty. PinPoint significantly reduced the length of the examination time (12 - 25 min) as compared to PatPos Invent (20 - 40 min). The expectation conformity and comprehensibility of PatPos Invent were assessed significantly more positively than PinPoint with regard to the general handling of the system. In contrast, the assessment of the usability during preoperative setup favored PinPoint. The type of navigation system has no influence on the precision of the implementation of a puncture procedure.In the overall assessment of the handling of the systems, PatPos Invent was determined to be easier to comprehend and to provide greater conformity with expectations. With regard to the self-descriptive capacity and usability, PinPoint was assessed more positively. Both systems enable safe puncturing at all degrees of difficulty. The weak point of both systems is the failure to take patient movement into account.

Deduction leads to causal explanation in phylogenetic inference when the evidence, the systematic character, is conceptualized as a transformation series. Also, the deductive entailment of modus tollens is satisfied when those kinds of events are operationalized as patristic difference. Arguments to the contrary are based largely on the premise that character-states are defined intensionally as objects, in terms of similarity relations. However, such relations leave biologists without epistemological access to the causal explanation and explanatory power of historical statements. Moreover, the prediction-making to which those kinds of relations are limited in practice can lead to a category error--the mental conversion of an abstraction (the classes defined in terms of similarity relations) into a thing (such as an historical individual). The latter practices and problems characterize pattern cladistics, taxa being interpreted as homeostatic property cluster natural kinds, and other instrumentalist research programs.

The desorption of a methane-carbon-dioxide mixture on a bed of activated carbon was studied experimentally. Depletion curves were recorded by using pure hydrogen (assumed to be unadsorbed), pure carbon dioxide and a mixture of both gases as the purge medium. The results obtained are discussed on the basis of the equilibrium theory. The occurrence of simple and shock waves was explained in relation to the composition of the purge gas. Finally, a complex mathematical model was applied to compute the depletion curves. A satisfactory agreement was achieved between experimental and computed results.

On etudie l'adsorption d'un melange methane/dioxyde de carbone dans une colonne thermostatee, garnie de boulettes de charbon actif a pression (500 kPa) et temperature (293 K) constantes. Les quantites adsorbees sont estimees directement a partir des courbes de rupture. Les equations utilisees sont derivees d'un modele d'equilibre pour la sorption isotherme en lit fixe

The species category is defined as thesmallest historical individual within which there is a parental pattern of ancestry and descent. The use of historical individual in this definition is consistent with the prevailing notion that speciesper se are not involved in processes — they are effects, not effectors. Reproductive isolation distinguishes biparental historical species from their parts, and it provides a basis for understanding the nature of the evidence used to discover historical individuals.