A welcomed and overdue debate.

Replies to comments by J. Prochaska (see record 2010-00152-002) to the author's original critique (see record 2008-13168-006) on the transtheoretical model and smoking cessation. Herzog is disappointed that Prochaska elected not to address the central point of the critique: that the stages of change (SOC) are not qualitatively distinct categories, and that the SOC algorithm systematically underestimates motivation to quit among smokers. All major hypotheses of the TTM depend on the subsidiary hypothesis that the SOC algorithm is a valid measure of motivation to quit smoking. If the SOC is not a valid measure, then the TTM can be expected to produce unsatisfactory results. As for the issues that Prochaska does raise, most of these already are refuted in the critique itself. Herzog did not, as Prochaska suggests, attempt to “prove the null hypothesis.” Rather, his straightforward position is that the TTM as a stage model is not well supported by empirical evidence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

PROTECTORATION: a fast and efficient multiple-failure recovery technique for resilient packet ring using dark fiber

The two protection methods wrapping and steering used in IEEE 802.17 resilient packet ring (RPR) provide fast but very inefficient and limited network failure recovery. Due to the increased length of the backup path, RPR suffers from high traffic loss, a decreased throughput-delay performance, and the lack of resilience against multiple link and/or node failures. To achieve an improved resilience, interconnecting a subset of the ring nodes by means of a dark-fiber single-hop star wavelength division multiplexing (WDM) network is proposed. In doing so, the ring network is divided into separate domains, each being fully recoverable from a single link or node failure without losing full network connectivity. A novel hybrid fault recovery technique, termed protectoration, is proposed and examined by means of probabilistic analysis and simulation in terms of stability, channel utilization, and throughput-delay performance. The proposed protectoration technique 1) combines the fast recovery time of protection and the bandwidth efficiency of restoration, 2) provides full recovery from multiple link and node failures, 3) builds on both wrapping and steering protection methods of RPR and, thus, allows for an evolutionary upgrade of existing RPR networks, and 4) does not require the convergence of routing protocols in response to failures and, thus, improves the routing stability and network availability. Numerical investigations in this paper show that the location of failures has a strong impact on the network performance. For a given failure location, the protectoration technique is able to accommodate multiple ring failures without significant performance loss.     

Untersuchungen zur pathologischen Anatomie und Histologie der Myxomatose der Wildkaninchen (Oryctolagus cuniculus L.)

Zusammenfassung Durch Myxomatose gefallene Wildkaninchen wurden eingehend pathologisch-anatomisch und histologisch untersucht, die gefundenen Veränderungen werden an Hand von Abbildungen beschrieben.     

Quality assurance of psychiatric consultations in somatic hospitals

Research has shown great variety in the clinical practice of consultation-liaison psychiatry in and between different countries. This paper presents the Norwegian experiences from a European collaborative study of quality management in consultation-liaison psychiatry. We describe a dynamic model for total quality management based on regular registration of some clinical data and the subsequent feed-back on changes of these. We discuss our experiences with this model and obstacles met in everyday work. Finally we point to different ways of implementing this method on a broader base in consultation-liaison psychiatry.     

Epithelial folding in vitro: studies on the cellular mechanism underlying evagination of thyrocyte monolayers

Epithelial monolayers in suspension culture fold in a way which closely resembles epithelial evagination. We have used freshly isolated segments of porcine thyroid follicles to study the mechanism underlying this evagination process. Epithelial folding was accompanied by dramatic changes in cell shape: the cells elongated and apical cell surfaces widened, whereas the basal cell portions were narrowed to about 20% of their original width. Apparently, enzymatic separation of thyroid epithelial cells from their underlying extracellular matrix resulted in an extension of the lateral cell-cell interactions on the expense of the basal cell surface area. Epithelial folding in vitro was Ca2+ dependent and reversibly blocked by cytochalasin D, by which the reorganization of the F-actin network was disturbed. This inhibitory effect was also observed by the action of cAMP analogues known to cause rounding of cells by their effect on cortical F-actin. Moreover, evagination in vitro was reversibly blocked at intracellular pH values of 5.8 and below. Under these conditions, protein phosphorylation was entirely inhibited. Inhibitors of protein kinases, specifically of myosin light chain kinase, were able to disrupt the evagination process, suggesting that protein phosphorylation, presumably of the myosin light chain, was essential for folding. We conclude that enzymatic separation of epithelial monolayers from their extracellular matrix initiated a cascade consisting of extended cell-cell interactions of the lateral plasma membranes and of reorganization of the apical actin-myosin network, finally resulting in profound changes in cell shape characteristic of epithelial evagination.     

Bird mercury concentrations change rapidly as chicks age: toxicological risk is highest at hatching and fledging

Toxicological risk of methylmercury exposure to juvenile birds is complex due to the highly transient nature of mercury concentrations as chicks age. We examined total mercury and methylmercury concentrations in blood, liver, kidney, muscle, and feathers of 111 Forster's tern (Sterna forsteri), 69 black-necked stilt (Himantopus mexicanus), and 43 American avocet (Recurvirostra americana) chicks as they aged from hatching through postfledging at wetlands that had either low or high mercury contamination in San Francisco Bay, California. For each waterbird species, internal tissue, and wetland, total mercury and methylmercury concentrations changed rapidly as chicks aged and exhibited a quadratic, U-shaped pattern from hatching through postfledging. Mercury concentrations were highest immediately after hatching, due to maternally deposited mercury in eggs, then rapidly declined as chicks aged and diluted their mercury body burden through growth in size and mercury depuration into growing feathers. Mercury concentrations then increased during fledging when mass gain and feather growth slowed, while chicks continued to acquire dietary mercury. In contrast to mercury in internal tissues, mercury concentrations in chick feathers were highly variable and declined linearly with age. For 58 recaptured Forster's tern chicks, the proportional change in blood mercury concentration was negatively related to the proportional change in body mass, but not to the amount of feathers or wing length. Thus, mercury concentrations declined more in chicks that gained more mass between sampling events. The U-shaped pattern of mercury concentrations from hatching to fledging indicates that juvenile birds may be at highest risk to methylmercury toxicity shortly after hatching when maternally deposited mercury concentrations are still high and again after fledging when opportunities for mass dilution and mercury excretion into feathers are limited.     

Single nanoskived nanowires for electrochemical applications

In this work, we fabricate gold nanowires with well controlled critical dimensions using a recently demonstrated facile approach termed nanoskiving. Nanowires are fabricated with lengths of several hundreds of micrometers and are easily electrically contacted using overlay electrodes. Following fabrication, nanowire device performance is assessed using both electrical and electrochemical characterization techniques. We observe low electrical resistances with typical linear Ohmic responses from fully packaged nanowire devices. Steady-state cyclic voltammograms in ferrocenemonocarboxylic acid demonstrate scan rate independence up to 1000 mV s(-1). Electrochemical responses are excellently described by classical Butler-Volmer kinetics, displaying a fast, heterogeneous electron transfer kinetics, k(0) = 2.27 ± 0.02 cm s(-1), α = 0.4 ± 0.01. Direct reduction of hydrogen peroxide is observed at nanowires across the 110 pM to 1 mM concentration range, without the need for chemical modification, demonstrating the potential of these devices for electrochemical applications.     

Preperitoneal prosthesis implantation in surgical management of recurrent inguinal hernia. Retrospective evaluation of our results 1989-1994

Recurrent inguinal hernia represents a great problem in surgery given the frequency of this operation, with a recurrence rate of 0.5-8%. Re-recurrence after repair without implantation of a prosthesis occurs in 1-23% of cases. We analyzed our results of patients with recurrent inguinal hernia, operated according to the method of Stoppa. Between 1989 and July 1994 there were 58 operations upon 55 patients with an average age of 65 years, 79% of whom had unilateral and 21% bilateral hernias. 89% of all patients underwent surgery because of a recurrent inguinal hernia. A Marlex mesh was used in 79% of the case. All patients were followed up (mean 35 months, minimum 12 months). Early complications consisted in one hematoma (1.7%), which had to be drained, as well as one early recurrence (1.7%). No infections were observed. The overall recurrence rate was 12%. However, 60% of all recurrences occurred in the few first years after introduction of this technique at our clinic; with growing number of operations and experience with Stoppa's technique, we obtained a recurrence rate of 6-7% per year. In our opinion, supported by the results of other studies, Stoppa's technique is a successful method in the treatment of recurrent inguinal hernia.