bluuebunny/crossref_metadata_2025 huggingface dataset:
Catalase activity in human spermatozoa and seminal plasma
Authors: Jeulin C. , Soufir J. C. , Weber P. , Laval‐Martin D. , Calvayrac R.
Published: February 2005

Catalase activity was determined in human semen by measuring the oxygen burst with a Clark electrode, after H2O2 addition. Significant catalase activities (mean ± SD) were found in migrated, motile spermatozoa (44 ± 17 nmoles O2/min/108 cells) and in seminal plasma of normozoospermic men (129 ± 59 nmoles O2/min/ml). It has been demonstrated that seminal catalase originated from prostate; however, its activity was not correlated with the usual prostatic markers (such as citric acid and zinc). Our data suggest a multiglandular function secreted by this organ. The catalase activities measured in seminal samples from asthenozo‐ospermic, infertile men were found lower than those from normozoospermic subjects. The understanding of the relative contribution of the different enzyme systems against O2 toxicity (superoxide dismutase, catalase, glutathione peroxidase) seem to be a priority area of research to understand disturbances of sperm function.
Morphology of immature bovine oocytes
Authors: de Loos F. , van Vliet C. , van Maurik P. , Kruip Th. A. M.
Published: February 2005

Bovine cumulus oocyte complexes (COCs) as used for in vitro maturation and fertilization can be classified into different categories by light microscopical inspection. We have distinguished four categories based on compactness and transparency of the cumulus investment and homogeneity and transparency of the ooplasm. The four categories were studied for their morphological characteristics at the ultrastructural level and for their developing capacity in an in vitro maturation system. In categories 1 and 2 oocytes, organelles were evenly distributed. In categories 3 and 4, oocytes organelles were clustered and the distribution of the organelles mimicked the characteristics of oocytes during final maturation. Cumulus cell process endings penetrated the cortex of the oocyte or were located superficial to the cortex of the oocyte. In category 1 oocytes, most of the process endings penetrated the cortex. In category 4 oocytes, most of the process endings did not penetrate. In categories 2 and 3 oocytes, both forms of process endings did occur.

After in vitro maturation, only category 4 oocytes showed a decreased developing capacity. Categories 1–3 oocytes showed equal developing capacity in an in vitro maturation system.
Parthenogenetic activation of unfertilized mouse oocytes by exposure to 1,2‐propanediol is influenced by temperature, oocyte age, and cumulus removal
Authors: Shaw J. M. , Trounson A. O.
Published: February 2005

Cumulus‐intact and ‐denuded unfertilized oocytes from two mouse strains were exposed to 1.5 m ethanol (EtOH) or two cryoproteclant solutions, 1.5 M propanediol (PROH) or 1.5 M dimethylsulfoxide (DMSO), for 4.5 min at 27°C, and the proportion of activating or degenerating oocytes studied. Exposure to DMSO did not significantly increase activation above that of oocytes not exposed to DMSO. Treatment of oocytes in PROH resulted in the activation of up to 87% of viable oocytes. This was significantly higher (P <01) than in control oocytes and comparable to the rate of activation after treatment with EtOH (59–96% activation). In solutions at 1°C, 47% of control oocytes were activated, which was not significantly different from the rate of activation in EtOH (36%) or PROH (50%) at 1°C. Following treatment with PROH, up to 87% of oocytes degenerated within a period of 6 h in vitro. The age of the oocytes (h post hCG) and the time of cumulus removal with the enzyme hyaluronidase, relative to the time of exposure to the chemicals, influenced the level of degeneration in most groups. Significantly fewer oocytes degenerated when cumulus cells were removed before treatment (0–31%) than when the cumulus was left intact throughout the treatment and 6 h culture period (10–87%). Exposure to PROH at 1°C reduced oocyte degeneration to 5%. We conclude that PROH causes significantly greater losses of oocytes as a result of parthenogenetic activation and degeneration than of exposure to DMSO.
In Vitro maturation and fertilization of domestic cat follicular oocytes
Authors: Johnston L. A. , O'Brien S. J. , Wildt D. E.
Published: February 2005

The time course and conditions necessary for oocyte maturation and subsequent fertilization in vitro were studied in the domestic cat. Darkly pigmented oocytes surrounded by cumulus cells and a tight corona radiata were collected from ovaries removed at ovariohysterectomy. After culture in Eagle's minimum essential medium, oocytes were evaluated for nuclear maturation by analyzing chromosomal spreads. Oocytes achieved metaphase II after intervals of 40–48 hr of in vitro incubation. The incidence of maturation was enhanced (P<0.05) when oocytes were recovered from inactive (54%) or follicular (56%) stage donors compared to those recovered from luteal phase (29%) or pregnant (35%) cats. The proportion of oocytes successfully maturing in vitro in medium containing no hormone supplementation (37%) was less (P<0.01) than counterparts cultured in follicle‐stimulating hormone (FSH) only (48%) or FSH and luteinizing hormone (LH) (54%). The efficiency of maturation was not influenced (P >0.05) by either maintenance/transport temperature (4°C vs. 22°C) or delaying recovery of oocytes from antral follicles (2–8 hr vs. 24–32 hr). Approximately 36% of the in vitro matured oocytes cocultured with spermatozoa demonstrated evidence of fertilization; however, there appeared to be a critical development period for maximizing the incidence of fertilization. These results demonstrate that domestic cat antral oocytes are capable of maturing in vitro, and maturation is influenced by the reproductive status of the donor and the presence of gonadotropins in the culture medium. These oocytes are capable of forming embryos and developing to at least the 16‐cell stage in vitro.
Hollow Thermoresponsive Microgels
Authors: Nayak Satish , Gan Daoji , Serpe Michael J. , Lyon L. Andrew
Published: February 2005

Thermoresponsive poly(N‐isopropyl acrylamide) (pNIPAm) microgels possessing a hollow structure have been synthesized from core–shell nanoparticles upon oxidation of the particle core, followed by removal of the produced polymer segments by centrifugation. N,N′‐(1,2‐dihydroxyethylene)bisacrylamide (DHEA) is used as a cross‐linker for preparing the degradable core, whereas N,N′‐methylenebis(acrylamide) (BIS) is used as a cross‐linker to add a nondegradable pNIPAm shell. Addition of NaIO4 to a suspension of these particles in water leads to controlled degradation of the particle core by cleavage of the 1,2‐glycol bond in DHEA. Fluorescence spectroscopy, UV/Vis spectroscopy, and photon correlation spectroscopy are used to characterize the hollow particles produced.
Sonographic measurement of cervical length in threatened preterm labor in singleton pregnancies with intact membranes
Authors: Tsoi E. , Fuchs I. B. , Rane S. , Geerts L. , Nicolaides K. H.
Published: February 2005

Objectives

To predict when delivery will occur, within 48 h and 7 days of presentation and before 35 weeks' gestation in women presenting with threatened preterm labor.

Methods

Sonographic measurement of cervical length was carried out in 510 women with singleton pregnancies presenting with threatened preterm labor and intact membranes at 24 to 33 + 6 weeks of gestation. The measurement was not taken into account in the subsequent management of the pregnancies. The outcome measures were delivery within 48 h and 7 days of presentation and delivery before 35 weeks.

Results

The median gestation at presentation was 30 + 1 (range, 24 to 33 + 6) weeks and the median cervical length was 25 (range, 1–51) mm. Delivery within 48 h of presentation occurred in 21 (4.1%) cases, delivery within 7 days occurred in 43 (8.4%) and delivery before 35 weeks occurred in 76 (14.9%). Logistic regression analysis demonstrated that the only significant independent predictor of delivery within 48 h was cervical length (odds ratio (OR), 0.73; 95% CI, 0.65–0.81) and for delivery within 7 days the independent predictors were cervical length (OR, 0.69; 95% CI, 0.63–0.76) and vaginal bleeding (OR, 19.42; 95% CI, 3.87–97.4). In the subgroup of women who did not deliver within 7 days of presentation, the incidence of delivery before 35 weeks was 7.1% (33 of 467) and the only significant independent predictor of such delivery was cervical length (OR, 0.92; 95% CI, 0.88–0.96, P < 0.0001). There was no significant independent contribution to any of the outcome measures from ethnic group, maternal age, gestational age, body mass index, parity, cigarette smoking or use of tocolytics.

Conclusions

In women with threatened preterm labor sonographic measurement of cervical length helps to distinguish between true and false labor and to predict early preterm delivery. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Actin and the coordination of protrusion, attachment and retraction in cell crawling
Authors: Small J. Victor , Anderson Kurt , Rottner Klemens
Published: February 2005

To crawl over a substrate a cell must first protrude in front, establish new attachments to the substrate and then retract its rear. Protrusion and retraction utilise different subcompartments of the actin cytoskeleton and operate by different mechanisms, one involving actin polymerization and the other myosin-based contraction. Using as examples the rapidly locomoting keratocyte and the slowly moving fibroblast we illustrate how over expression of one or the other actin subcompartments leads to the observed differences in motility. We also propose, that despite these differences there is a common coordination mechanism underlying the genesis of the actin cytoskeleton that involves the nucleation of actin filaments at the protruding cell front, in the lamellipodium, and the relocation of these filaments, via polymerization and flow, to the more posterior actin filament compartments.
Characterization of the folate receptor in human molar placenta
Authors: Holm Jan , Hansen Steen Ingemann , Nichols Carl W. , Høier-Madsen Mimi , Helkjær Poul Erik
Published: February 2005

We have characterized a high-affinity folate receptor in human molar placenta tissue. Radioligand binding exhibited characteristics typical of other high-affinity folate binding proteins. Those included, positive cooperativity, a tendency to increased binding affinity with decreasing receptor concentration, a slow ligand dissociation at pH 7.4 becoming rapid at pH 3.5, and inhibition by folate analogues. The folate receptor cross-reacted with antibodies against human milk folate binding protein, e.g. the syncytothrophoblastic layer of molar placenta tissue sections showed strongly positive immunostaining. The gel filtration profile contained two radioligand-bound peaks (25 and 100 kDa), however, with considerable overlap. Only a single band of 70 kDa was seen on SDS-PAGE immunoblotting. The folate receptor in placental tissue may play a crucial role in the transfer of folate from maternal circulation to the fetus.
Conditional composition
Authors: Manohar Rajit , Rustan K. , Leino M.
Published: February 2005

Generalizing the notion of function composition, we introduce the concept of
conditional
function composition and present a theory of such compositions. We use the theory to describe the semantics of a programming language with exceptions, and to relate exceptions to the
IF
statement.
A theory of Orwellian specifications with NewThink
Authors: Mukherjee Paul , Stavridou Victoria
Published: February 2005

We introduce NewThink, a specification language designed specifically for real-time safety-critical systems. NewThink is a component of an overall Orwellian development method for safety-critical systems which consists of a specification language, a programming language and a set of sound decomposition rules. In this paper, we present the syntax and semantics of NewThink. We demonstrate a relationship between timed and static specifications, which potentially allows us to continue using techniques from the static case in the timed case. We also prove that our extension for real-time is conservative, which is very much in keeping with our Orwellian philosophy.
Real space process algebra
Authors: Baeten J. C. M. , Bergstra J. A.
Published: February 2005

The real time process algebra of Baeten and Bergstra [
Formal Aspects of Computing
,
3
, 142–188 (1991)] is extended to real space by requiring the presence of spatial coordinates for each atomic action, in addition to the required temporal attribute. It is found that asynchronous communication cannot easily be avoided. Based on the state operators of Baeten and Bergstra [
Information and Computation
,
78
, 205–245 (1988)] and following Bergstra et al. [
Proc. Seminar on Concurrency
, LNCS 197, Springer, 1985, pp. 76–95], asychronous communication mechanisms are introduced as an additional feature of real space process algebra. The overall emphasis is on the introductory explanation of the features of real space process algebra, and characteristic examples are given for each of these.
An “executable” impredicative semantics for the Ada configuration
Authors: Bucci A. , Inverardi P. , Martini S.
Published: February 2005

We present a translation of Ada configuration constructs, in a higher order, impredicatively typed, functional language (HOTFUL) with subtypes. The aim of this work is to provide an expressive executable semantics for Ada configuration constructs, and to verify the suitability of the chosen HOTFUL for such a task. In particular, we address the practicability of the approach when dealing with the development of a whole complex system, as well as the description of single modular units. After giving the detailed rules for the translation, we compare our approach with what could be obtained selecting a different typed language as “target”, namely the predicative type system of Standard ML.
Testing equivalence as a bisimulation equivalence
Authors: Cleaveland Rance , Hennessy Matthew
Published: February 2005

In this paper we show how the testing equivalences and preorders on transition systems may be interpreted as instances of generalized bisimulation equivalences and prebisimulation preorders. The characterization relies on defining transformations on the transition systems in such a way that the testing relations on the original systems correspond to (pre)bisimulation relations on the altered systems. On the basis of these results, it is possible to use algorithms for determining the (pre)bisimulation relations in the case of finite-state transition systems to compute the testing relations.
Paramorphisms
Authors: Meertens Lambert
Published: February 2005

“Catamorphisms” are functions on an initial data type (an inductively defined domain) whose inductive definitional pattern mimics that of the type. These functions have powerful calculation properties by which inductive reasoning can be replaced by equational reasoning. This paper introduces a generalisation of catamorphisms, dubbed “paramorphisms”. Paramorphisms correspond to a larger class of inductive definition patterns; in fact, we show that any function defined on an initial type can be expressed as a paramorphism. In spite of this generality, it turns out that paramorphisms have calculation properties very similar to those of catamorphisms. In particular, we prove a Unique Extension Property and a Promotion Theorem for paramorphisms.
Sequential to parallel buffer refinement
Authors: Kay Andrew , Lupton Peter
Published: February 2005

This paper is intended to solve a particular problem related to the refinement of a shared sequential buffer into a parallel collection of buffers arising from a study on the IBM CICS project. Using the notion of cooperating refinement we show that the two systems are equivalent from the users' points of view (except with respect to efficiency). This is achieved by constructing an interleaving for each possible sequence of commands which access the buffer. The induction used in the proof is non-standard, and makes the problem harder than it would at first seem. Further we show that the interleaving cannot be done ‘on the fly’, showing that in some other sense, the parallel collection is indeed superior, as intuition suggests.
Generator induction in order sorted algebras
Authors: Owe Olaf , Dahl Ole-Johan
Published: February 2005

Linguistic and semantic consequences of combining the ideas of order sorted algebras (as in OBJ) and generator induction (as in Larch) are investigated. It is found that one can gain the advantages of both, in addition to increased flexibility in defining signatures and generator bases. Our treatment also gives rise to typing control stronger in a certain sense than that of OBJ, as well as the detection of inherently inconsistent signatures.
On the lattice of specifications: Applications to a specification methodology
Authors: Boudriga Noureddine , Elloumi Fathi , Mili Ali
Published: February 2005

In this paper we investigate the lattice properties of the natural ordering between specifications, which expresses that a specification expresses a stronger requirement than another specification. The lattice-like structure that we uncover is used as a basis for a specification methodology.
Compositional generation of home states in free choice nets
Authors: Best Eike , Cherkasova Ludmila , Desel Jörg
Published: February 2005

Free choice nets are a class of Petri nets which allow the modelling of concurrency and nondeterministic choice, but with the restriction that choices cannot be influenced externally. Home states are initial states which lead to a strongly connected state graph, that is, a home state can be reached from any of its successor states. The main result of this paper characterises the home states of a well-formed free choice net compositionally by recourse to its decomposition into T-components.
LOTOS extended with probabilistic behaviours
Authors: Miguel Carlos , Fernández Angel , Vidaller Leon
Published: February 2005

A common characteristic of process algebras is that they permit us the partial description of concurrent systems by including non-deterministic behaviours. These non-deterministic components are abstractions of the actual ones, and they can be detailed in successive refinements. This paper proposes an enrichment of the above abstraction. It defines a formal description technique which is able to characterize the non-determinism in a probabilistic way. The proposed technique, called LOTOS-P is an upward compatible extension of LOTOS. The compatibility includes also the possibility of specifying non-deterministic behaviours; that is, without probabilistic characterization.

The contents of the paper are mainly related to the definition of probabilistic models based on process algebras, and the study of the observable behaviour of systems by using testing relations. The advantage of the proposed model with respect to previous works is twofold. First, the model is simpler, and second, the compatibility with LOTOS is achieved. The simplicity does not make the model useless because its expressive power permits us to express random behaviours in the same way they are being expressed with classical techniques of discrete systems modeling.

The probabilistic evaluation of the properties of the system can be done by applying the defined calculus, but also by
simulation
. Simulation means that we are able to obtain the desired results with a given confidence level.
Two implementation relations and the correctness of communicating replicated processes
Authors: Koutny Maciej , Mancini Luigi V. , Pappalardo Giuseppe
Published: February 2005

This paper studies the correctness of distributed systems made up of replicated processes that communicate by message passing. Processes are described within the divergence model of CSP. The notion of correctness introduced is based on a relation that formally expresses the conformance of an implementation process with the target process it is intended to implement. A weak and a strong version of the relation are introduced, aimed at treating acyclic and cyclic process networks respectively. Both allow the study of (total) correctness and may cope with non-deterministic targets and implementations.

We then show how a target process may be implemented (in the formal sense introduced) by replicating it in a set of copies, a majority of which is non-faulty.
The rely-guarantee method for verifying shared variable concurrent programs
Authors: Xu Qiwen , de Roever Willem -Paul , He Jifeng
Published: February 2005

Compositional proof systems for shared variable concurrent programs can be devised by including the interference information in the specifications. The formalism falls into a category called
rely-guarantee
(or
assumption-commitment)
, in which a specification is explicitly (syntactically) split into two corresponding parts. This paper summarises existing work on the rely-guarantee method and gives a systematic presentation. A proof system for partial correctness is given first, thereafter it is demonstrated how the relevant rules can be adapted to verify deadlock freedom and convergence. Soundness and completeness, of which the completeness proof is new, are studied with respect to an operational model. We observe that the rely-guarantee method is in a sense a reformulation of the classical non-compositional Owicki & Gries method, and we discuss throughout the paper the connection between these two methods.
The rest stays unchanged (concurrency and state-based specification)
Authors: Pitt David , Byers Paddy
Published: February 2005

Pre-/postconditions have been extensively used in program specification, e.g. Z [Spi89], VDM [Jon86], and proof, e.g. Hoare logic, Dijkstra's guarded commands [DiF88]. In [ScP86, SPB90] the authors introduced neutral and central relations to formalise the concept of “the rest stays the same”. In this paper we abstract away from the specific definition of neutral relation given in [SPB90], through the mechanism of relational boolean algebras. This leads to the definition of implicitly central relations which are easier for the user in practical examples and facilitate the use of pre-/postcondition reasoning about truly concurrent behaviour.
Richer types for Z
Authors: Spivey Michael
Published: February 2005

The formal specification language Z is strongly typed, but has a rather inexpressive type system in which essentially the only type constructors are power set and Cartesian product. This paper explores the possibility of using a richer type system for extracting information about a Z specification, so that properties like being a function or a sequence become part of the type of an expression. This richer type system adds further type constructors to the sparse set contained in the language definition, and uses properties of Z's library functions to infer information about complex expressions from information about their simpler parts.
Definition and basic properties of the deva meta-calculus
Authors: Weber Matthias
Published: February 2005

This article presents the definition and some basic properties of the Deva meta-calculus, a generic logical framework whose design was driven by the needs arising from the instantiation to software development methods. As a result, Deva contains structures that do not occur in comparable logical frameworks. There now exist a number of case studies about the formalization of software development methods in Deva. In this article, a structured definition of Deva is presented and basic parts of its language theory, viz Church-Rosser, closure, and strong normalization, are summarized.
Formalizing process algebraic verifications in the calculus of constructions
Authors: Bezem Marc , Bol Roland , Groote Jan Friso
Published: February 2005

This paper reports on the first steps towards the formal verification of correctness proofs of real-life protocols in process algebra. We show that such proofs can be verified, and partly constructed, by a general purpose proof checker. The process algebra we use isμCRL, ACPτaugmented with data, which is expressive enough for the specification of real-life protocols. The proof checker we use is Coq, which is based on the Calculus of Constructions, an extension of simply typed lambda calculus. The focus is on the translation of the proof theory ofμCRL andμCRL-specifications to Coq. As a case study, we verified the Alternating Bit Protocol.
Action systems, unbounded nondeterminism, and infinite traces
Authors: Butler Michael , Morgan Carroll
Published: February 2005

Morgan [Mor90a] has described a correspondence between Back's action systems [BKS83] and the conventional
failures-divergences
model of Hoare's
communicating sequential processes
(CSP) formalism [Hoa85]. However, the CSP failures-divergences model does not treat unbounded nondeterminism, although unbounded nondeterminism arises quite naturally in action systems; to that extent, the correspondence between the two approaches is inadequate.

Fortunately there is an extended
infinite traces
model of CSP [RoB89] which treats unbounded nondeterminism. We extend the CSP-action system correspondence, using that model instead, to take the unbounded nondeterminism of action systems properly into account.

In passing, we develop a definition of the weakest precondition under which an infinite heterogeneous trace of actions is enabled.
Exits in the refinement calculus
Authors: King Steve , Morgan Carroll
Published: February 2005

Although many programming languages contain exception handling mechanisms, their formal treatment — necessary for rigorous development — can be complex. Nevertheless, this paper presents a simple incorporation of
exit
commands and exception blocks into a rigorous program development method. The refinement calculus, chosen for the exercise, is a method of developing imperative programs. It is based on weakest preconditions, although they are not used explicitly during program construction; they merely justify the general method. In the style of the refinement calculus, program development laws are given that introduce and allow the manipulation of
exit
s. The soundness of the new laws is shown using weakest preconditions (as for the existing refinement calculus laws). The extension of weakest preconditions needed to handle
exit
s is a variation on earlier work of Cristian; the variation is necessary to handle nondeterminism.
Reasoning about dynamically evolving process structures
Authors: America Pierre , de Boer Frank
Published: February 2005

We develop a Hoare-style proof system for reasoning about the behaviour of processes that interact via a dynamically evolving communication structure.
Peirce algebras
Authors: Brink Chris , Britz Katarina , Schmidt Renate A.
Published: February 2005

We present a two-sorted algebra, called a
Peirce algebra
, of relations and sets interacting with each other. In a Peirce algebra, sets can combine with each other as in a Boolean algebra, relations can combine with each other as in a relation algebra, and in addition we have both a set-forming operator on relations (the Peirce product of Boolean modules) and a relation-forming operator on sets (a cylindrification operation). Two applications of Peirce algebras are given. The first points out that Peirce algebras provide a natural algebraic framework for modelling certain programming constructs. The second shows that the so-called
terminological logics
arising in knowledge representation have evolved a semantics best described as a calculus of relations interacting with sets.
Process algebra with guards: Combining Hoare logic with process algebra
Authors: Groote Jan Friso , Ponse Alban
Published: February 2005

We extend process algebra with guards, comparable to the guards in guarded commands or conditions in common programming constructs such as ‘if — then — else — fi’ and ‘while — do — od’.

The extended language is provided with an operational semantics based on transitions between pairs of a process and a (data-)state. The data-states are given by a data environment that also defines in which data-states guards hold and how atomic actions (non-deterministically) transform these states. The operational semantics is studied modulo strong bisimulation equivalence. For basic process algebra (without operators for parallelism) we present a small axiom system that is complete with respect to a general class of data environments. Given a particular data environmentL we add three axioms to this system, which is then again complete, provided weakest preconditions are expressible andL is sufficiently deterministic.

Then we study process algebra with parallelism and guards. A two phase-calculus is provided that makes it possible to prove identities between parallel processes. Also this calculus is complete. In the last section we show that partial correctness formulas can easily be expressed in this setting. We use process algebra with guards to prove the soundness of a Hoare logic for linear processes by translating proofs in Hoare logic into proofs in process algebra.
The verification of modules
Authors: Antoniou Grigoris
Published: February 2005

We present a module concept with algebraic interfaces and imperative implementation. It is shown that under some natural conditions, module correctness may be expressed in Hoare logic as a partial correctness assertion. Also, we discuss questions of practical verification of modules using Hoare's calculus.
ERK‐dependent induction of TNFα expression by the environmental contaminant benzo(a)pyrene in primary human macrophages
Authors: Lecureur Valérie , Ferrec Eric Le , N’diaye Monique , Vee Marc Le , Gardyn Claire , Gilot David , Fardel Olivier
Published: February 2005

Polycyclic aromatic hydrocarbons (PAHs) such as benzo(a)pyrene (BP) are toxic environmental contaminants known to enhance production of pro‐inflammatory cytokines such as IL‐1β. The present study was designed in order to determine whether TNFα, another cytokine acting in inflammation, may also constitute a target for these chemicals. Both TNFα mRNA and TNFα secretion levels were found to be enhanced in human BP‐treated macrophages. Dioxin, a contaminant activating the aryl hydrocarbon receptor (AhR) like PAHs, was also shown to increase TNFα expression. BP‐mediated TNFα induction was however not suppressed by AhR antagonists, making unlikely the involvement of the typical AhR signalling pathway. BP‐exposure of macrophages did not enhance NF‐κB DNA binding activity, but it activated the MAP kinase ERK1/2. In addition, the use of chemical inhibitors of extracellular signal‐regulated protein kinase (ERK) activation fully abrogated induction of TNFα production in BP‐treated macrophages. These data likely indicate that PAHs enhance TNFα expression in human macrophages through an ERK‐related mechanism. Such a regulation may contribute to confer pro‐inflammatory properties to these widely‐distributed environmental contaminants.
Study of stem cell function using microarray experiments
Authors: Perez-Iratxeta Carolina , Palidwor Gareth , Porter Christopher J. , Sanche Neal A. , Huska Matthew R. , Suomela Brian P. , Muro Enrique M. , Krzyzanowski Paul M. , Hughes Evan , Campbell Pearl A. , Rudnicki Michael A. , Andrade Miguel A.
Published: February 2005

DNA Microarrays are used to simultaneously measure the levels of thousands of mRNAs in a sample. We illustrate here that a collection of such measurements in different cell types and states is a sound source of functional predictions, provided the microarray experiments are analogous and the cell samples are appropriately diverse. We have used this approach to study stem cells, whose identity and mechanisms of control are not well understood, generating Affymetrix microarray data from more than 200 samples, including stem cells and their derivatives, from human and mouse. The data can be accessed online (StemBase;http://www.scgp.ca:8080/StemBase/).
JM4 is a four‐transmembrane protein binding to the CCR5 receptor
Authors: Schweneker Marc , Bachmann André S. , Moelling Karin
Published: February 2005

The CC chemokine receptor 5 (CCR5) is a major co‐receptor for human immunodeficiency virus (HIV) and CCR5 mutants lacking the carboxy (C)‐terminus interfere with HIV infection. Therefore, we analysed the C‐terminus of CCR5 and here describe Jena‐Muenchen 4 (JM4), a novel CCR5‐interacting protein. JM4 is membrane‐associated, co‐precipitates with CCR5, and is ubiquitously expressed. It shares about 62% sequence similarity with JWA and glutamate transporter‐associated protein 3‐18 (GTRAP3‐18), a regulator of an amino acid transporter. JWA, like JM4, is a four‐transmembrane protein, which binds to the CCR5 receptor. Furthermore, JM4, JWA, and GTRAP3‐18 co‐localise and heterodimerise indicating a functional relationship. JM4 co‐localises with calnexin in the endoplasmic reticulum and with the mannose 6‐phosphate receptor in the Golgi. JM4 and GTRAP3‐18 harbor a Rab‐acceptor motif, indicating a function in vesicle formation at the Golgi complex. In conclusion, we describe a CCR5‐interacting protein, which is suggested to function in trafficking and membrane localisation of the receptor, possibly also other receptors or amino acid transporters.
Atlantis basin, Sirenum Terrae, Mars: geological setting and astrobiological implications
Authors: de Pablo Miguel A. , Fairén Alberto G.
Published: February 2005

The accomplishment of detailed geomorphological studies is a prerequisite for the location of regions in which the prevailing conditions in the past, or at present, may allow the development of possible life forms. The Atlantis basin, located in Sirenum Terrae, Southern hemisphere of Mars, is one of these astrobiologically interesting regions, where the existence of geological features such as ancient volcanic edifices, sedimentary deposits of an ancient lake and recent gullies seem to indicate the long-term presence of a thermal source and a water reservoir deep and stable enough to sustain biological processes. Here we describe the most relevant topographic and geomorphologic features in the region, highlighting the possibility for liquid water to have been present in the basin and outskirts in different moments of Mars' history. We also apply this analysis to an initial discussion of the influence of the hydrogeological evolution of the region in the putative development and/or survival of life forms in Atlantis basin.
The Cyborg Astrobiologist: first field experience
Authors: McGuire Patrick Charles , Ormö Jens , Martínez Enrique Díaz , Manfredi José Antonio Rodríguez , Elvira Javier Gómez , Ritter Helge , Oesker Markus , Ontrup Jörg
Published: February 2005

We present results from the first geological field tests of the ‘Cyborg Astrobiologist’, which is a wearable computer and video camcorder system that we are using to test and train a computer-vision system towards having some of the autonomous decision-making capabilities of a field-geologist and field-astrobiologist. The Cyborg Astrobiologist platform has thus far been used for testing and development of the following algorithms and systems: robotic acquisition of quasi-mosaics of images; real-time image segmentation; and real-time determination of interesting points in the image mosaics. The hardware and software systems function reliably, and the computer-vision algorithms are adequate for the first field tests. In addition to the proof-of-concept aspect of these field tests, the main result of these field tests is the enumeration of those issues that we can improve in the future, including: detection and accounting for shadows caused by three-dimensional jagged edges in the outcrop; reincorporation of more sophisticated texture-analysis algorithms into the system; creation of hardware and software capabilities to control the camera's zoom lens in an intelligent manner; and, finally, development of algorithms for interpretation of complex geological scenery. Nonetheless, despite these technical inadequacies, this Cyborg Astrobiologist system, consisting of a camera-equipped wearable-computer and its computer-vision algorithms, has demonstrated its ability in finding genuinely interesting points in real-time in the geological scenery, and then gathering more information about these interest points in an automated manner.
An evaluation of transect, plot and aerial survey techniques to monitor the spatial pattern and status of the bilby (Macrotis lagotis) in the Tanami Desert
Authors: Southgate Richard , Paltridge Rachel , Masters Pip , Nano Theresa
Published: February 2005

We evaluated three monitoring techniques to determine the spatial pattern and relative abundance of the bilby (Macrotis lagotis) in the Tanami Desert, Northern Territory. All the methods examined relied on the identification of animal sign (foot imprints or diggings) to indicate the presence of a species. With fixed transects, a 10-km prepared tracking surface was monitored regularly using an all-terrain vehicle. With random plots, an unprepared tracking surface within a 200 × 300 m area was searched on foot for sign of the species. A helicopter was used in an aerial survey to identify bilby diggings from an altitude of 15–20 m while travelling at a speed of 30–40 knots along a predefined transect. The results for each method were stratified in relation to latitude and substrate to facilitate comparison of the efficacy of each technique. The fixed transects returned the least number of bilby records for most effort. The aerial transect technique resulted in few (<4%) false negative records but a sizeable (42%) number of false positive records. It is suggested that the aerial survey technique combined with ground-truth survey plots would provide reliable information on the extent of occurrence and status of the bilby in the remote spinifex deserts of central Australia.
The contribution of spotted-tailed quolls (Dasyurus maculatus) to the transmission of Echinococcus granulosus in the Byadbo Wilderness Area, Kosciuszko National Park, Australia
Authors: Jenkins David J. , Murray Andrew J. , Claridge Andrew W. , Story Georgeanna L. , Bradshaw Helen , Craig Philip S.
Published: February 2005

Scats were collected from 19 wild spotted-tailed quolls (Dasyurus maculatus) caught in a region of south-eastern mainland Australia where hydatidosis (Echinococcus granulosus) occurs commonly in swamp wallabies (Wallabia bicolour) and other wildlife. All scats were tested for coproantigens of E. granulosus tapeworms. None of the scats tested had detectable coproantigens of E. granulosus. These data and previous unsuccessful attempts to experimentally infect other species of dasyruid with E. granulosus suggest that spotted-tailed quolls may be refractory to infection with E. granulosus.
Home range of the spotted-tailed quoll (Dasyurus maculatus), a marsupial carnivore, in a rainshadow woodland
Authors: Claridge Andrew W. , Paull David , Dawson James , Mifsud Greg , Murray Andy J. , Poore Rob , Saxon Michael J.
Published: February 2005

The home ranges, movement patterns and spatial organisation of spotted-tailed quolls (Dasyurus maculatus maculatus) were studied in rainshadow woodland in southern New South Wales, Australia. Fourteen individuals were radio-collared and simultaneously tracked. Home-range size estimates ranged from 621 ha to at least 2561 ha for males, and 88 ha to at least 653 ha for females. Mean home-range size was significantly greater for males (992 ± 276 ha) than females (244 ± 72 ha). The maximum straight-line distances between successive fixes for males over 24-h and 48-h periods were 2529 and 4430 m, respectively, while for females these distances were 1865 and 3085 m. Mean maximum straight-line distances between successive fixes for males over a 24-h period were not significantly different from mean maximum straight-line distances of females (1493 ± 918 v. 1034 ± 540 m). However, over 48 h, the mean maximum distances between successive fixes for males was greater than that of females (2911 ± 934 v. 1680 ± 918 m). The home ranges of males mostly overlapped with those of other individuals, regardless of sex. In contrast, home ranges of females tended not to overlap with those of other females, suggesting some form of spatial separation. Home-range estimates derived for spotted-tailed quolls in our rainshadow woodland study site are comparable to those obtained for the species in wetter vegetation types. From a conservation perspective, it seems that habitat structure and the availability of prey is more important than rainfall or vegetation type in determining spatial requirements of the species. Until more advanced telemetry systems are developed, caution should be applied when using current home-range data on the species to infer breeding systems and patterns of spatial organisation, particularly the issue of territoriality among female quolls.
Milk composition of the Tasmanian pademelon (Thylogale billardierii Desmarest) (Macropodoidea:Marsupialia) in captivity
Authors: Rose R. W. , Shetewi A. D. , Flowers K.
Published: February 2005

This is the first study of milk composition in any member of the wallaby genus Thylogale. Milk samples (n = 44) were collected after oxytocin injection from 12 females carrying pouch young aged 2–30 weeks followed by sampling of the mothers until weaning by Week 39. The lactation period could be partitioned into early (Weeks 2–20), mid (Weeks 21–30) and late (>30 weeks) stages. Although milk concentrations changed little during lactation the energy content increased almost 4-fold from 540 ± 39 kJ (100 mL)–1 (mean ± s.e.) to 1908 ± 102 kJ (100 mL)–1. Carbohydrate concentrations decreased from 13.3 ± 0.1 g (100 mL)–1 (early lactation) to 10.9 ± 0.9 g (100 mL)–1 in mid-lactation, falling to 4.8 ± 0.9 g (100 mL)–1 in late lactation. Lipid increased from 6.3 ± 1.1 g (100 mL)–1 to 12.5 ± 4.1 g (100 mL)–1, reaching 31.4 ± 5.0 g (100 mL)–1 in late lactation. Protein increased from 3.3 ± 0.1 g (100 mL)–1 to 9.7 ± 1.6 g (100 mL)–1 in mid-lactation to 14.0 ± 1.5 g (100 mL)–1 in late lactation. This relatively high level of lipid and protein in late lactation may be the cause of the more rapid growth and, hence, shorter pouch life of the Tasmanian pademelon (Thylogale billardierii) compared with the well studied tammar wallaby (Macropus eugenii).
AML1-ETO fusion protein up-regulates TRKA mRNA expression in human CD34+cells, allowing nerve growth factor-induced expansion
Authors: Mulloy James C. , Jankovic Vladimir , Wunderlich Mark , Delwel Ruud , Cammenga Jorg , Krejci Ondrej , Zhao Hui , Valk Peter J. M. , Lowenberg Bob , Nimer Stephen D.
Published: February 2005

The AML1-ETO fusion protein, generated by the t(8;21) in acute myeloid leukemia (AML), exerts dominant-negative functions and a variety of gains of function, including a positive effect on the growth of primary human CD34+hematopoietic stem/progenitor cells. We now show that AML1-ETO expression up-regulates the level of TRKA mRNA and protein in these cells and that AML1-ETO-expressing CD34+hematopoietic cells grown in the presence of five early-acting hematopoietic cytokines further proliferate in response to nerve growth factor (NGF). These cells also show a unique response to NGF and IL-3; namely, they expand in liquid culture. To determine the biological relevance of our findings, we analyzed 262 primary AML patient samples using real-time RT-PCR and found that t(8;21)-positive AML samples express significantly higher levels of TRKA mRNA than other subtypes of AML. NGF, which is normally expressed by bone marrow stromal cells, could provide important proliferative or survival signals to AML1-ETO-expressing leukemic or preleukemic cells, and the NGF/TRKA signaling pathway may be a suitable target for therapeutic approaches to AML.
Brief cognitive behavioural interventions for regular amphetamine users: a step in the right direction
Authors: Baker Amanda , Lee Nicole K. , Claire Melissa , Lewin Terry J. , Grant Tanya , Pohlman Sonja , Saunders John B. , Kay‐Lambkin Frances , Constable Paul , Jenner Linda , Carr Vaughan J.
Published: February 2005

Aims  The present study sought to replicate and extend a small pilot study conducted by Baker, Boggs & Lewin (2001) which demonstrated that brief interventions consisting of motivational interviewing and cognitive‐behaviour therapy (CBT) were feasible and associated with better outcomes compared with a control condition.

Design  Randomized controlled trial (RCT).

Setting  Greater Brisbane Region of Queensland and Newcastle, NSW, Australia.

Participants  The study was conducted among 214 regular amphetamine users.

Measurements  Demographic characteristics, past and present alcohol and other drug use and mental health, treatment, amphetamine‐related harms and severity of dependence.

Findings  The main finding of this study was that there was a significant increase in the likelihood of abstinence from amphetamines among those receiving two or more treatment sessions. In addition, the number of treatment sessions attended had a significant short‐term beneficial effect on level of depression. There were no intervention effects on any other variables (HIV risk‐taking, crime, social functioning and health). Overall, there was a marked reduction in amphetamine use among this sample over time and, apart from abstinence rates and short‐term effects on depression level, this was not differential by treatment group. Reduction in amphetamine use was accompanied by significant improvements in stage of change, benzodiazepine use, tobacco smoking, polydrug use, injecting risk‐taking behaviour, criminal activity level, and psychiatric distress and depression level.

Conclusions  A stepped‐care approach is recommended. The first step in providing an effective intervention among many regular amphetamine users, particularly those attending non‐treatment settings, may include provision of: a structured assessment of amphetamine use and related problems; self‐help material; and regular monitoring of amphetamine use and related harms. Regular amphetamine users who present to treatment settings could be offered two sessions of CBT, while people with moderate to severe levels of depression may best be offered four sessions of CBT for amphetamine use from the outset, with further treatment for amphetamine use and/or depression depending on response. Pharmacotherapy and/or longer‐term psychotherapy may be suitable for non‐responders. An RCT of a stepped‐care approach among regular amphetamine users is suggested.