bluuebunny/crossref_metadata_2025 huggingface dataset:
Japanese learners’ acquisition of English manner-of-motion verbs with locational/directional PPs
Authors: Inagaki Shunji
Published: September 2002

This study investigated first language (L1) influence on second language (L2) argument structure in a situation where an L2 argument structure forms a superset of its L1 counterpart. In such a situation, a partial fit between the L1 and the L2 may trigger L1 transfer, whereas availability of positive evidence may allow the learner to arrive at the L2 grammar (White, 1991b). This study tested these predictions by investigating whether Japanese speakers can recognize the directional reading of English manner-of-motion verbs ( walk, swim) with locational/directional PPs ( under, behind), such as John swam under the bridge, where under the bridge can be either the goal of John’s swimming (directional) or the location of John’s swimming (locational). By contrast, their Japanese counterparts allow only a locational reading, as Japanese is more restricted than English in allowing only directed motion verbs ( go) to appear with a phrase expressing a goal. Thirty-five intermediate Japanese learners of English and 23 English speakers were tested using a picture-matching task. Results show that, unlike English speakers, Japanese speakers consistently failed to recognize a directional reading. I suggest that positive evidence need not only be available but also be frequent and clear in order to be used by L2 learners to broaden their interlanguage grammar.
The acquisition of non-null subjects in English: a minimalist account
Authors: Wakabayashi Shigenori
Published: September 2002

Second language acquisition (SLA) research in the last 20 years appears to have shown that Universal Grammar (UG) constrains SLA, and a number of specific models of SLA have been offered. However, some crucial problems have been left unsolved in previous models suggested by the Principles and Parameters Approach; the Minimalist Program is likely to provide a better account of the data. The acquisition of the obligatoriness of overt subjects in English is one such problem. The Minimalist approach suggests that first language (L1) transfer is realized as the transfer of lexical items and their features.This further implies that some cross-linguistic effects do not exist at the initial stage of development, but may emerge gradually in the course of second language (L2) development in accordance with the expansion of L2 lexicon and the number of lexical items to be placed in the sentence structure. With these considerations, the Minimalist Program provides us with a new framework for explaining data concerning the L2 acquisition of non-null subjects in English, especially the developmental changes of interlanguage grammar and L1 influences on it.
Commentary from the flower garden: responding to Gregg, 2000
Authors: Lantolf James P.
Published: September 2002

I begin my necessarily brief commentary on Gregg (2000) with a confession: I am not, nor have I ever been, a practising postmodernist. I freely admit, however, that some of the ideas that have emerged from this project are sufficiently interesting to take seriously. I wrote my 1996 article to stir up the waters and to explore what a postmodernist perspective might do for, and to, second language acquisition (SLA). It can be useful for any discipline to have its accepted way of doing business interrogated and even disturbed. Judging from Gregg’s response, I seem to have succeeded. In what follows I limit my comments to some specific points that appear to have raised most of Gregg’s hackles.
A garden ripe for weeding: a reply to Lantolf
Authors: Gregg Kevin R.
Published: September 2002

One confession deserves another: in my heart of hearts, I doubted that Lantolf was a practising postmodernist. For one thing, it was often too easy to figure out what he was saying. Still, his exposition of the postmodernist position would satisfy committed post-modernists, which is to say it gets things wrong in the same way they do.
Websites for second language research
Authors: Gottwald Stephanie
Published: September 2002

This review article summarizes the content of existing websites devoted to second language research (SLA) and indicates areas that need to be improved. Resources relevant to varieties of work that take place under the heading of ‘second language research’ are surveyed and evaluated based on their utility for the researcher. Websites that are essentially pedagogical in nature or that address the needs of second language teachers rather than researchers have been excluded. The sites reviewed fall under the categories ‘Institutional or professional sites’, ‘Sites maintained by individuals’, ‘On-line journals’ and ‘Sites for occasional visitation’. The conclusion of this review is that the most informative sites for SLA research are created by private individuals, and that professional or organizational sites generally have less to offer the serious researcher.
The development of lexical fluency in a second language
Authors: Kroll Judith F. , Michael Erica , Tokowicz Natasha , Dufour Robert
Published: September 2002

A goal of second language (L2) learning is to enable learners to understand and speak L2 words without mediation through the first language (L1). However, psycholinguistic research suggests that lexical candidates are routinely activated in L1 when words in L2 are processed. In this article we describe two experiments that examined the acquisition of L2 lexical fluency. In Experiment 1, two groups of native English speakers, one more and one less fluent in French as their L2, performed word naming and translation tasks. Learners were slower and more error prone to name and to translate words into L2 than more fluent bilinguals. However, there was also an asymmetry in translation performance such that forward translation was slower than backward translation. Learners were also slower than fluent bilinguals to name words in English, the L1 of both groups. In Experiment 2, we compared the performance of native English speakers at early stages of learning French or Spanish to the performance of fluent bilinguals on the same tasks. The goal was to determine whether the apparent cost to L1 reading was a consequence of L2 learning or a reflection of differences in cognitive abilities between learners and bilinguals. Experiment 2 replicated the main features of Experiment 1 and showed that bilinguals scored higher than learners on a measure of L1 reading span, but that this difference did not account for the apparent cost to L1 naming.We consider the implications of these results for models of the developing lexicon.
Recent research on the acquisition of aspect: an embarrassment of riches?
Authors: Slabakova Roumyana
Published: September 2002

This review article surveys recent research on the first and second language acquisition of temporal and aspectual properties of natural languages.Three recently published books are discussed in the context of the primacy or aspect hypothesis and the prototype, the connectionist and the discourse explanations for the attested acquisition sequences. A potentially misleading terminological issue is highlighted: Deictic tense, grammatical and lexical aspect are often conflated in acquisition studies. Recent research from the (innatist) generative perspective (e.g., Olsen and Weinberg, 1999) is also examined. An alternative explanation of the skewed acquisition sequences in terms of processing costs is proposed. Some important topics for future aspect research are identified.
Exploring the typological plausibility of Processability Theory: language development in Italian second language and Japanese second language
Authors: Di Biase Bruno , Kawaguchi Satomi
Published: September 2002

This article aims to test the typological plausibility of Processability Theory (PT) (Pienemann, 1998). This is ‘a theory of processability of grammatical structures... [which] formally predicts which structures can be processed by the learner at a given level of development’ (p. xv). Up till now the theory has been tested mainly for Germanic languages, while here we propose to test it for two typologically different languages, namely Italian and Japanese. Language specific predictions for these two languages will be derived from PT, and the structures instantiating them will be described within a Lexical Functional Grammar (LFG) framework. The occurrence and distribution of relevant structures will then be analysed in empirical, naturalistic data produced by adult learners. To test whether PT is typologically plausible we will demonstrate the following points for Japanese and Italian:

• The notion of ‘exchange of grammatical information’ is a productive concept for typologically different languages.

• Predictions that can be derived from the general architecture of the theory for specific languages will be borne out by empirical observation. (Pienemann 1998: 166).
Induction in a modular learner
Authors: Carroll Susanne E.
Published: September 2002

This paper presents a theory of inductive learning (i-learning), a form of induction which is neither concept learning nor hypothesis-formation, but rather which takes place within the autonomous and modular representational systems (levels of representation) of the language faculty. The theory is called accordingly the Autonomous Induction Theory. Second language acquisition (SLA) is conceptualized in this theory as:

• learning linguistic categories from universal and potentially innate featural primitives;

• learning configurations of linguistic units; and

• learning correspondences of configurations across the autonomous levels.

Here I concentrate on the problem of constraining learning theories and argue that the Autonomous Induction Theory is constrained enough to be taken seriously as a plausible approach to explaining second language acquisition.
Transfer and typological proximity in the context of second language processing
Authors: Håkansson Gisela , Pienemann Manfred , Sayehli Susan
Published: September 2002

In this article, the issue of cross-linguistic influence in second language acquisition is examined from a processing perspective. Applying Processability Theory as the theoretical framework we claim that second language (L2) learners can only produce forms they are able to process. We thus argue that the first language (L1) influence on the L2 is developmentally moderated. Data were collected from German L2 learners with Swedish as their L1. Twenty informants participated in the study, 10 in their first year of German (13 years of age) and 10 in their second year of German (14 years of age). Both languages involved are typologically very close but not mutually intelligible. The results show that Swedish learners of German do not transfer the verb-second structure from their L1 to the L2 even though this structure is identical in both languages.Instead they start out with canonical word order and subsequently produce an intermediate structure (adv NPsubjV X), which is ungrammatical in the L1 and the L2. These observations support the idea of a developmentally moderated transfer. The results clearly contradict the predictions from the ‘full transfer/full access’ hypothesis (Schwartz and Sprouse, 1994; 1996).
Towards a unified account of the representation, processing and acquisition of second language knowledge
Authors: Hulstijn Jan
Published: September 2002

This article argues for the need to reconcile symbolist and connectionist accounts of (second) language learning by propounding nine claims, aimed at integrating accounts of the representation, processing and acquisition of second language (L2) knowledge. Knowledge representation is claimed to be possible both in the form of symbols and rules and in the form of networks with layers of hidden units representing knowledge in a distributed, subsymbolic way. Implicit learning is the construction of knowledge in the form of such networks. The strength of association between the network nodes changes in the beginning stages of learning with accumulating exposure, following a power law (automatization). Network parts may attain the status equivalent to ‘symbols’. Explicit learning is the deliberate construction of verbalizable knowledge in the form of symbols (concepts) and rules. The article argues for a nonnativist, emergentist view of first language learning and adopts its own version of what could be called a non-interface position in L2 learning: although explicit knowledge cannot turn into implicit knowledge through practice, it is argued that explicit learning and practice often form efficient ways of mastering an L2 by creating opportunities for implicit learning.
The selection of priming fluids for cardiopulmonary bypass in the UK and Ireland
Authors: Lilley Angela
Published: September 2002

The ideal prime for Cardiopulmonary Bypass (CPB) has never been fully established. The development of acid-base disorders during some routine cases and the possible contribution to this from priming fluids caused this hospital to question its protocol. As a result, we conducted a survey of UK perfusion units to analyse current practice. The response rate was 74%. It was found that no two units in the UK used the same prime. The most common reason for fluid choice was historical beliefs and there appeared to be little perceived association between prime and acidosis on bypass. The results revealed that there is no consensus in the UK of the preferential prime for CPB, suggesting the effect this aspect has is not fully understood.
Electrical failure during cardiopulmonary bypass: an evaluation of incidence, causes, management and guidelines for preventative measures
Authors: Hargrove M , Ramish B C , O’Donnell A , Aherne T
Published: September 2002

The incidence of electrical failure during cardiopulmonary bypass (CPB) has been reported to occur in approximately 1 per 1000 cases.1,2 While the resultant morbidity and mortality is low, electrical failure is a life-threatening scenario. We report three major electrical failures during CPB in a patient population of 3500 over a 15-year period. These cases involved mains failure and generator shut down, mains failure and generator power surge, and failure of the uninterruptable power supply (UPS), which caused protected sockets to shut down. Protocols for preventative maintenance, necessary equipment, battery backup and guidelines for the successful management of such accidents during CPB are discussed.
Evaluation of different paediatric venous cannulae using gravity drainage and VAVD: an in vitro study
Authors: De Somer F , De Wachter D , Verdonck P , Van Nooten G , Ebels T
Published: September 2002

Six different commercially available paediatric venous cannulae, together with a specially constructed cannula, were tested in vitro for their pressure-flow relationship. With the cannulae placed in an open reservoir, flow increased with larger diameters and higher pressures. At a pressure of 30 cm H2O, flows were 219± 20, 285± 13, 422± 11 and 728± 4 ml/min for the 12, 13.2, 14 and 16 French, respectively. No differences were found between angled and straight cannulae. When the cannulae were tested in a latex model simulating the right atrium and vena cavae, the highest flow obtained by gravity was 164 ml/min using an angled 14-French cannula. When vacuum was applied to augment venous return, a maximum flow of 179 ml/min was measured using an angled 14-French cannula. Collapse can occur when the pressure difference becomes too high in the test system. This is important, since most children are selectively cannulated in both major veins. Monitoring of the intravascular pressure might help to prevent collapse. A larger-diameter venous cannula does not always produce the highest flow when placed in a vein. This is most obvious when augmenting venous return. The design of the cannula tip, in combination with VAVD, can affect the venous return.
Effects of two differently heparin-coated extracorporeal circuits on markers for brain and myocardial dysfunction
Authors: Flom-Halvorsen Hanne I , Øvrum E , Brosstad F , Tangen G , Ringdal M AL , Øystese R
Published: September 2002

Objective: The two most commonly used heparin-coated systems for cardiopulmonary bypass (CPB) are the Carmeda Bio-Active Surface (CBAS) (Medtronic, Minneapolis, MN, USA) and the Duraflo II coating (Baxter Healthcare, Irvine, CA, USA). The two surfaces are technically unequal and previous experimental studies have demonstrated disparities in effects on the immune system and blood cells. However, little is known concerning the influence of the two surfaces on markers for brain and myocardial dysfunction.

Methods: Forty patients undergoing elective, primary coronary bypass grafting with CPB were prospectively randomized to either the CBAS system or the Duraflo II circuit. During and after CPB, biological markers for brain dysfunction and myocardial injury were analysed.

Results: Both markers for brain dysfunction S-100B and neuron-specific enolase (NSE) increased significantly during CPB ( p =0.01). The elevation during bypass correlated significantly with the duration of CPB ( r = 0.39 and r= 0.38, respectively, both p< 0.02). NSE was somewhat more elevated in the Duraflo II group at the end of CPB ( p =0.01) and 5 h after CPB ( p= 0.02); for S-100B, there were no intergroup differences. Also, the markers related to myocardial injury, myoglobin and creatine kinase (CK-MB) mass increased during CPB ( p= 0.01), while elevation of troponin-I occurred 5 h after CPB ( p= 0.01). There were no statistically significant intergroup differences. No significant correlation was seen between the release of cardiac markers and the duration of CPB. The clinical course was similar in both groups.

Conclusions: Except for a slightly higher elevation of NSE at the end of CPB and 5 h after CPB in the Duraflo II group, there were no significant differences between the CBAS group and the Duraflo II group concerning markers for brain and myocardial dysfunction.
Effect of modified ultrafiltration on the inflammatory response in paediatric open-heart surgery: a prospective, randomized study
Authors: Chew Michelle S , Brix-Christensen Vibeke , Ravn Hanne B , Brandslund Ivan , Ditlevsen Emmy , Pedersen Jens , Hjortholm Kirsten , Hansen Ole K , Tùnnesen Else , Hjortdal Vibeke E
Published: September 2002

Modified ultrafiltration (MUF) is often used in conjunction with paediatric cardiac surgery with cardiopulmonary bypass (CPB) and is thought to improve clinical outcome. It is unclear whether these improvements (if any) are due to the removal of inflammatory mediators. In this prospective study, 18 children aged 12-24 months undergoing uncomplicated cardiac surgery with methylprednisolone added in the pump prime were randomized to receive CPB with ( n= 10) and without ( n= 8) MUF. Cytokines (TNFα, IL-6, IL- 1β, IL-10, IL-1ra), complement split products (C3d, C4d) and coagulation system activation (F1+ 2, ATIII) were measured pre-, peri- and up to 48 h postoperatively. For clinical outcome, the alveolar-arterial oxygen (A-a) gradient, transfusion requirement, drain loss, mean blood pressure and requirement for inotropic support were registered up to 24 h postoperatively. Our results show an improvement in postoperative oxygenation as well as a tendency towards decreased drain loss and improved haemodynamics in the MUF group. There were no intergroup differences detectable for TNFα, IL-1β, IL-1ra, complement and coagulation markers. We conclude that MUF in itself does not significantly influence TNFα, IL-1β, IL-1ra and the complement and coagulation profiles in children undergoing cardiac surgerywith CPB. Despite this, there was some evidence for improved clinical outcome. Our results do not support that MUF improves postoperative organ function by modulation of the measured markers of inflammation.
Topical application of aprotinin in cardiac surgery
Authors: Isgro Frank , Stanisch Oliver , Kiessling Arndt-H , Gürler Semih , Hellstern Peter , Saggau Werner
Published: September 2002

The aim of our study was to compare a systemic and a local aprotinin application in patients during coronary artery bypass graft (CABG) surgery. The advantage of a topical aprotinin application is seen in the fact that this may not lead to systemic side effects. A prospective, randomized study comprising 97 patients was conducted. A dose of 5 106 KIU aprotinin was given systemically to 49 patients and four doses of 1.25 106 KIU aprotinin were applied topically to 48 patients by spraying the substance on the target area (A. mammaria interna region and pericardium). We determined markers for the inflammatory response, coagulation system, standard haematological markers and postoperative complications. Exclusion criteria were defined as surgical bleeding, redo operations, neurological, haematological, liver and kidney disorders. Sex, age, perfusion times, mortality, renal failure and strokes were identical in both groups. Biochemical markers and clinical outcome demonstrated no significant differences between the systemic and local applications. Interleukin 6 and elastase were tendentially higher ( p= 0.1) in the local group, but with a high standard deviation in each patient. Our results suggest that there is no difference between the perioperative application of 5 106 KIU systemically given aprotinin and 1.25 106 KIU locally applied aprotinin.
Do S100β protein level increases due to inflammation during cardiopulmonary bypass occur without any neurological deficit?
Authors: Özatik Mehmet Ali , Tarcan Onurcan , Kale Arzum , Aşkõn Göktan , Balcõ Mustafa , Ündar Akif , Küçükaksu Deniz Süha , Şener Erol , Taşdemir Oğuz
Published: September 2002

Purpose: S100β protein level correlates with the duration of cardiopulmonary bypass (CPB) and aortic crossclamp times, but is different during pulsatile and nonpulsatile CPB. In this study, we investigated the time course of the release of S100β protein during and after pulsatile and nonpulsatile CPB.

Patients and methods: This is a prospective study. Twenty patients had open-heart surgery with pulsatile flow and 20 with nonpulsatile flow. We compared complement proteins, interleukins, white blood cells and S100β protein before the initiation of CPB, immediately prior to aortic crossclamping, following unclamping, and at postoperative 1st and 24th hours.

Results: In the pulsatile CPB group following aortic unclamping, S100β protein ( p= 0.028) and C3a ( p= 0.011) levels were significantly lower than those of the nonpulsatile group. In the pulsatile CPB group at postoperative first hour, C3a level ( p= 0.018) and absolute neutrophil count ( p= 0.034) were significantly lower than those of the nonpulsatile group. None of the patients developed a neurological deficit and all of the patients survived after the operation and were discharged from the hospital.

Conclusion: During CPB, serum S100β protein level increases and this increase is higher in the nonpulsatile group. High serum level of S100β protein is associated with increased levels of serum inflammatory mediators and systemic inflammatory response.
A new top-loading venous bag provides vacuum-assisted venous drainage
Authors: Tamari Y , Lee-Sensiba K , Beck J , Chan R , Salogub M , Hall M , Lee T , Ganju R , Mongero L
Published: September 2002

A new venous bag has been developed, prototyped, and tested. The new bag has its inlet, outlet purge, and infusion tubes extending upward from the top of the bag, and are threaded through, bonded to, and sealed within a flat rigid top plate. This design allows the bag to be hung from its top plate by its tubes. It also allows the bag to be: 1) dropped into or removed from its holder, as is done with existing hard-shell reservoirs so that its weight pulls it into the holder without the need for eyelets and hooks and 2) placed closer to the floor so that gravity drainage is facilitated. The V-Bag® (VB) is easily sealed within an accompanying rigid housing. Once sealed, vacuum applied to the housing is transmitted across the flexible walls of the bag to the venous blood. Thus, vacuum-assisted venous drainage (VAVD) is obtained as it is with a hard-shell reservoir, but without any contact of air with the blood. Bench tests, using a circuit that simulated the venous side of the cardiopulmonary bypass (CPB) circuit, showed that applying suction to the housing increased venous flow, and the fractional increase in flow was not a function of the venous cannula, but of the level of vacuum applied. In the gravity drainage mode, the bubble counts at the outlet of the V-Bag compared to two other bags were lower at any pumping condition. When used in the VAVD mode, bubble counts were two orders of magnitude lower than when using kinetically assisted venous drainage (KAVD) with a centrifugal pump. Results obtained with the VB suggest its clinical usefulness.
Adjustment of sweep gas flow during cardiopulmonary bypass
Authors: Karabulut Hasan , Toraman Fevzi , Tarcan Sümer , Demirhisa Önder , Alhan Cem
Published: September 2002

Cardiopulmonary bypass (CPB) is one of the major tools of cardiac surgery. However, no clear data are available for the ideal value of sweep gas flow to oxygenator during CPB. The aim of this study was to determine the best value for sweep gas flow during CPB. Thirty patients undergoing isolated CABG were randomly and equally allocated into three groups. Sweep gas flow to oxygenator was kept at 1.35 l/min/m2 in group 1, 1.60 l/min/m2 in group 2, and 2.0 l/min/m2 in group 3. All patients were operated on under the same anaesthetic regime and surgical techniques. Samples for blood gas analysis were collected at T1: before CPB; T2: 5 min after the initiation of CPB; T3: just before rewarming; and T4: at the end of rewarming. Five minutes after the initiation of CPB (T2), pCO2 decreased significantly in groups 2 and 3 compared to group 1 ( p < 0.02). With the addition of hypothermia (T3), the changes in the pH and pCO2 became more profound and, in this period, the levels in group 3 patients outranged the physiologic limits, with pCO2 and pH values being 28± 3 mmHg and 7.50± 0.04, respectively. At the end of the rewarming period (T4), in spite of increased carbon dioxide production, pCO2 values were below the physiologic limits in groups 2 and 3. We conclude that sweep gas flow to the oxygenator should be kept between 1.35 and 1.60 l/min/m2 during CPB to avoid hypocapnia, which results in alkalosis and has hazardous effects on lung mechanics, cerebral blood flow, and the cardiovascular system.
Thrombelastographic changes in OPCAB surgical patients
Authors: Quigley R L , Fried D W , Salenger R , Pym J , Highbloom R Y
Published: September 2002

The purpose of this study was to determine whether thrombelastography could detect hypercoagulability in the off-pump coronary artery bypass (OPCAB) patient. Seventeen OPCAB and six cardiopulmonary bypass (CPB) patients were studied pre- and postprocedure, as well as on each of the first three postoperative days (POD). In the OPCAB patients, there was a small reduction in the postprocedure coagulation index (CI). This was followed by an increase in the CI on each of the next three POD, reaching a level exceeding the mean preprocedure CI by 2.32 units, indicative of a state of relative hyper- coagulability. The mean CI for the CPB patients decreased significantly in the postprocedure sample. Over the next 72 h, the CI increased to a level that nearly equaled the preprocedure ‘baseline’. We concluded that our study identified a state of relative hypercoagulability in the OPCAB patient 72 h after surgery. The mechanism of this hypercoagulation, as well as the clinical significance of this finding, is yet to be determined.
Cold agglutinins complicating repair of aortic dissection using cardiopulmonary bypass and hypothermic circulatory arrest: case report and review
Authors: Hoffman J W , Gilbert T B , Hyder M L
Published: September 2002

Cold agglutinins (CAs) are autoantibodies that react reversibly with red blood cells (RBCs) at temperatures of, or below, the thermal amplitude for agglutination. This results in increased blood viscosity and sludging of RBC, and may impair perfusion to various organ systems. Although this phenomenon appears rarely in the clinical arena, the incidence of CA is increased substantially in cardiac surgery due to the routine use of hypothermia for organ preservation and systemic metabolic reduction. Once activated, CA are associated with microvascular occlusion, hemolysis, complement fixation, renal and hepatic insufficiency, cerebral insult, and myocardial infarction. Complications from CA may be minimized with appropriate screening, detection, and management in the perioperative period. A prototypical case is described, and pertinent issues regarding CA are reviewed.
A new rotary blood pump for versatile extracorporeal circulation: the DeltaStream™
Authors: Göbel C , Arvand A , Rau G , Reul H , Meyns B , Flameng W , Eilers R , Marseille O
Published: September 2002

Today, rotary pumps are routinely used for extracorporeal circulation in different clinical settings and applications. A review of these applications and specific limitations in extracorporeal perfusion was performed and served as a basis for the development of the DeltaStream®. The Delta- Stream® is a miniaturized rotary blood pump of a new and unique design with an integrated drive unit. Despite its small design, the pump maintains a sufficient hydraulic capacity, which makes the DeltaStream® very flexible for intra- and perioperative applications. It also opens the field for short-term ventricular assist devices (VAD) applications or use as a component in extracorporeal life support systems (ECLS). The DeltaStream® and, specifically, its impeller design have been optimized with respect to haemolysis and nonthrombogenicity. Also, the pump facilitates an effective pulse generation in VAD applications and simulates heart action in a more physiological way than other rotary pumps or roller pumps. Hydraulic and haematological properties have been tested in vitro and in vivo. In a series of seven animal experiments in two different setups, the pump demonstrated its biocompatibility and applicability. Basic aspects of the DeltaStream® pump concept as well as important console features are presented. A summary of the final investigation of this pump is given with focus on hydraulic capabilities and results from animal studies.
Blood salvage with a continuous autotransfusion system compared with a haemofiltration system
Authors: Nitescu N , Bengtsson A , Bengtson J P
Published: September 2002

Background: Red blood cells may be destroyed by autotransfusion processing during intraoperative salvage. The aim of the present study was to evaluate the blood component recovery rate of techniques built on either continuous centrifugation and washing, or haemofiltration (HF).

Methods: Two different methods used in blood salvage - red cell salvage with continuous processing with centrifugation and saline washing (Continuous Auto Transfusion System, CATS) and whole blood recirculation through a 30000-Da filter, i.e., HF - were compared in a randomized laboratory study using donor whole blood activated by cobra venom factor. The recovery of red blood cells, haemoglobin, free haemoglobin, leucocytes, platelets, albumin, total protein and potassium was measured.

Results: The recovery of red cells was 86% with CATS and 76% with HF. HF had a significantly higher recovery of leucocytes (CATS 20%, HF 63%), platelets (CATS 4%, HF 37%), albumin (CATS 0.2%, HF 70%), total protein (CATS 1.3%, HF 71%) and potassium (CATS 2%, HF 17%). Less than 1% haemolysis was obtained in processed blood from both groups.

Conclusion: Both methods caused little destruction of the red blood cells during processing. There was a larger reinfusion of leucocytes, platelets, albumin, total protein and extracellular potassium when HF was used compared with the ‘CATS’ method.
On the ethical aspects of the testimony of statisticians in court
Authors: Gehan E A
Published: September 2002

This article considers a legal case presented by the Gore campaign to the Florida Eleventh Circuit Court in December 2000 to contest the election results giving the 25 electoral votes from the State of Florida to George W Bush—basically awarding the presidency to Bush.

Consideration is given to the ethical aspects of the testimony of two statisticians, one for Gore and one for Bush, who testified about whether the certified election results rejected a number of legal votes and included a number of illegal votes sufficient to place in doubt the results of the election. It is concluded that neither statistician violated accepted ethical standards of the statistical profession, though the Bush statistician’s testimony was at least borderline unethical on certain points. The main problem seems to be with the advocacy principle of the American legal system that leads to the prosecution witnesses testifying narrowly to the truths about the case, whereas the defense witnesses do the same from their viewpoint and also try to belittle the testimony of the prosecution witnesses. All of this makes it difficult to uncover the real truths in the case. The judge’s decision was to reject Gore’s case and this helped to clear the path to the election of Bush as President of the United States.
The ethics of consulting for the tobacco industry
Authors: Rubin D B
Published: September 2002

This article describes how and why I became involved in consulting for the tobacco industry. I briefly discuss the four relatively distinct statistical topics that were the primary focus of my work, all of which have been central to my published academic research for over three decades: missing data; causal inference; adjustment for covariates in observational studies; and meta-analysis. To me, it is entirely appropriate to present the application of this academic work in a legal setting.
Ethics, data-dependent designs, and the strategy of clinical trials: time to start learning-as-we-go?
Authors: Palmer C R
Published: September 2002

The seeds of modern clinical trials were unwittingly sown with the first use of randomization in a 1920s agricultural field experiment. The historical development of trials is briefly reviewed here, as are multi-farious pressures and problems faced by those involved with clinical trials today. These challenges include recruitment difficulties, the emerging rôle of patient support groups, and legal threats over informed consent, to name three. Fundamentally, they re‘ect an overall shift towards patient-centred, individual ethics. I suggest many problems may be overcome by increased implementation of hitherto neglected, data-dependent designs for clinical trials. Over a dozen arguments against their use are countered, primarily through ethical considerations. Benefits and costs of refining clinical trials strategy are explored hypothetically under enhanced use of such ‘learn-as-you-go’ designs, in contrast to traditional, equal-allocation, fixed-sample-size and frequentist-based designs. These latter methods mirror crop field trials in which one cannot make scientific progress until after gathering objective data at harvest time. Some attempts to alleviate certain problems, such as Zelen randomization to boost recruitment, or over-reliance on ‘large and simple trials’ to detect moderate-sized treatment effects, are discussed and found inadequate. A proposal for wider discussion is made to assist the selective introduction of ‘small and complex trials,’ which could simultaneously expedite medical research, satisfy the concerns of regulators, statisticians, and doctors alike, and help address the growing demands of 21st-century patients.
Ethical considerations concerning treatment allocation in drug development trials
Authors: Senn S
Published: September 2002

It is claimed that much of the opposition to placebos is based on the misunderstanding that their use implies the withholding of effective treatments. It is also argued that the ethical feasibility of a trial must be judged by comparing the likely prognosis of patients in the trial to their expectations outside the trial. Furthermore, a longer-term perspective of the patients needs is necessary; the ethical dilemmas involved cannot be resolved at the point of sickness. Some device such as the ‘original position’ of the philosopher John Rawls is needed. Finally, it is argued that placebo run-ins involve a violation of consent and should be eliminated from clinical trials.
Placebos that harm: sham surgery controls in clinical trials
Authors: London Alex John , Kadane Joseph B.
Published: September 2002

Recent debates over the use of sham surgery as a control for studies of fetal tissue transplantation for Parkinson’s disease have focused primarily on rival interpretations of the US federal regulations governing human-subjects research. Using the core ethical and methodological considerations that underwrite the equipoise requirement, we find strong prima facie reasons against using sham surgery as a control in studies of cellular-based therapies for Parkinson’s disease and more broadly in clinical research. Additionally, we believe that these reasons can be generalized to apply to the use of other placebo controls that carry significant risks of positive harms in and of themselves. As a result, our arguments are centrally relevant to the emerging drive to subject therapies with a surgical component to the same rigorous standards of evaluation as those governing the approval of new pharmaceuticals.
Ethical issues in oncology biostatistics
Authors: Thall Peter F
Published: September 2002

A medical statistician’s routine professional activitiesare likely to have important ethical consequences. This is due in part to the fact that good medical practice and scientifically valid medical research both require as precursors high quality statistical design and data analysis. In this paper I discuss various ethical issues that I have encountered while working as a biostatistician at M.D. Anderson Cancer Center. I describe particular experiences and the ethical issues involved. Topics include medical decision making, benefit-harm tradeoffs, safety monitoring, adaptive randomization, informed consent, and publication bias.
The Battle of Verneuil (17 August 1424): Towards a History of Courage
Authors: Jones Michael K.
Published: September 2002

This article challenges the theory of battle history set out in the works of Lieutenant-Colonel Alfred Burne. For Burne, tactical factors determined the outcome of any given conflict. His didactic solution to medieval battle reconstruction rested on the application of his theory of `inherent military probability’. Here a case study is used to reveal the fallacy of Burne’s approach. Detailed consideration of the battle of Verneuil (17 August 1424), one of the most important of the Hundred Years’ War, exposes Burne’s account as a misleading fiction. In its place the author proposes an entirely different model that allows real understanding of the mental outlook of the participants.
Pious Perjury: Discipline and Morale in the British Force in Italy, 1917-1918
Authors: Oram Gerard
Published: September 2002

The British force deployed in Italy during 1917 and 1918 is an ideal topic for a study of morale and discipline. Uniquely, reports on troop morale based on mail censorship have survived. These, together with medical and court martial records, provide the basis for this article, which analyses the impact of illness and worsening conditions on the morale of the British troops in Italy. It is argued that these factors had as much impact on discipline as did military operations, and that overall the evidence points to the development of an increasingly lenient approach to discipline within which capital convictions were avoided.
The Politics of Wartime Demolition and Human Landscape Transformation
Authors: Golan Arnon
Published: September 2002

The establishment of the State of Israel in 1948 resulted in the reshaping of human landscapes of the newly acquired national territory. Former Palestinian Arab urban and rural areas were either repopulated by Jews or demolished and later redeveloped by Israeli authorities. The old quarter of Tiberias and Manshiya were former urban Arab quarters earmarked for demolition and modern redevelopment by Israeli authorities. Different Jewish population groups resisted demolition, demanding their preservation. Both spatial conflicts depict several aspects of the debate on the future of former Arab urban areas, which took place in Israel during and after the 1948 war.
Semiparametric modelling of spatial binary observations
Authors: Alfò Marco , Postiglione Paolo
Published: September 2002

In the past decade various attempts have been made to extend standard random effects models to the analysis of spatial observations. This extension is a source of theoretical difficulty due to the multidirectional dependence among nearest observations; much of the previous work was based on parametric assumptions about the random effects distribution. To avoid any restriction, we propose a conditional model for spatial binary responses, without assuming a parametric distribution for the random effects. The model parameters are estimated using the EM algorithm for nonparametric maximum likelihood estimation of a mixing distribution. To illustrate the proposed approach, the model is applied to a remote sensed image of the Nebrodi Mountains (Italy).
Improving financial risk assessment through dependency
Authors: Mendes Beatriz VM , Moretti Alba Regina
Published: September 2002

Understanding dependency between financial markets is crucial when measuring globally integrated exposures to risk. To this end the first step may be the investigation of the joint behaviour of their most representative indexes. We fit by parametric and nonparametric methods bivariate extreme value models on the component wise maxima and minima computed monthly from several pairs of indexes representing the North American, Latin American, and Emerging markets. We analyse the role of the asymmetric models, finding which market drives the dependency, and express the degrees of dependence using measures of linear and nonlinear dependency such as the linear correlation coefficient ρ and the measure τ based on the dependence function. We discuss the interpretation of τ as a conditional probability that a crash occurs in a market given that a catastrophic event has occurred in some other market. We assess risks by computing probabilities associated with joint extreme events and by computing joint risk measures. We show empirically that the joint Value-at-Risk may be severely under-estimated if independence is assumed between markets. To take into account the clustering of extreme events we compute the bivariate extremal index and incorporate this information in the analysis.
Stationary space-time Gaussian fields and their time autoregressive representation
Authors: Storvik Geir , Frigessi Arnoldo , Hirst David
Published: September 2002

We compare two different modelling strategies for continuous space discrete time data. The first strategy is in the spirit of Gaussian kriging. The model is a general stationary space-time Gaussian field where the key point is the choice of a parametric form for the covariance function. In the main, covariance functions that are used are separable in space and time. Nonseparable covariance functions are useful in many applications, but construction of these is not easy.

The second strategy is to model the time evolution of the process more directly. We consider models of the autoregressive type where the process at time t is obtained by convolving the process at time t − 1 and adding spatially correlated noise.

Under specific conditions, the two strategies describe two different formulations of the same stochastic process. We show how the two representations look in different cases. Furthermore, by transforming time-dynamic convolution models to Gaussian fields we can obtain new covariance functions and by writing a Gaussian field as a time-dynamic convolution model, interesting properties are discovered.

The computational aspects of the two strategies are discussed through experiments on a dataset of daily UK temperatures. Although algorithms for performing estimation, simulation, and so on are easy to do for the first strategy, more computer-efficient algorithms based on the second strategy can be constructed.
Genetic analysis of cause of death in a mixture model of bivariate lifetime data
Authors: Wienke Andreas , Christensen Kaare , Skytthe Axel , Yashin Anatoli I.
Published: September 2002

A mixture model in multivariate survival analysis is presented, whereby heterogeneity among subjects creates divergent paths for the individual’s risk of experiencing an event (i.e., disease), as well as for the associated length of survival. Dependence among competing risks is included and rendered testable. This method is an extension of the bivariate correlated gamma-frailty model. It is applied to a data set on Danish twins, for whom cause-specific mortality is known. The use of multivariate data solves the identifiability problem which is inherent in the competing risk model of univariate lifetimes. We analyse the influence of genetic and environmental factors on frailty. Using a sample of 1470 monozygotic (MZ) and 2730 dizygotic (DZ) female twin pairs, we apply five genetic models to the associated mortality data, focusing particularly on death from coronary heart disease (CHD). Using the best fitting model, the inheritance risk of death from CHD was 0.39 (standard error 0.13). The results from this model are compared with the results from earlier analysis that used the restricted model, where the independence of competing risks was assumed. Comparing both cases, it turns out, that heritability of frailty on mortality due to CHD change substantially. Despite the inclusion of dependence, analysis confirms the significant genetic component to an individual’s risk of mortality from CHD. Whether dependence or independence is assumed, the best model for analysis with regard to CHD mortality risks is a model assuming that additive factors are responsible for heritability in susceptibility to CHD. The paper ends with a discussion of limitations and possible further extensions to the model presented.
RNA-acting antibiotics: in-vitro selection of RNA aptamers for the design of new bioactive molecules less susceptible to bacterial resistance
Authors: Maurel M-C , Biard B , Moulinier C , Braz D , Nugier J , Chaumas I , Reboud-Ravaux M , Décout J-L
Published: September 2002

During the last few years, antibiotic multiresistance has been increasing, not only in hospitals, but also, more worryingly, in general medicine. Different ways are being explored to bypass this problem. RNA-acting antibiotics such as aminosides (aminoglycosides) bind to bacterial RNA causing premature termination of proteins and mistranslation in bacteria. It is now possible to study the interactions of such antibiotics with their target by in-vitro selection of RNA molecules that recognize these antibiotics (RNA aptamers, SELEX method). The knowledge of the antibiotic-RNA interactions represents a promising way for the rational design of new bioactive compounds less susceptible to bacterial resistance.