bluuebunny/crossref_metadata_2025 huggingface dataset:
The relative consistency of g < cf(Sym(ω))
Authors: Mildenbergert Heike , Shelah Saharon
Published: December 2007

We prove the consistency result from the title. By forcing we construct a model of g = ℵ1, b = cf(Sym(ω)) = ℵ2.
Theories with equational forking
Authors: Junker Markus , Kraus Ingo
Published: December 2007

We show that equational independence in the sense of Srour equals local non-forking. We then examine so-called almost equational theories where equational independence is a symmetric relation.
Open questions in the theory of spaces of orderings
Authors: Marshall Murray A.
Published: December 2007

Spaces of orderings provide an abstract framework in which to study spaces of orderings of formally real fields. Spaces of orderings of finite chain length are well understood [9, 11]. The Isotropy Theorem [11] and the extension of the Isotropy Theorem given in [13] are the main tools for reducing questions to the finite case, and these are quite effective. At the same time, there are many questions which do not appear to reduce in this way. In this paper we consider four such questions, for a space of orderings (X, G).

1. Is it true that every positive primitive formula P(a) with parameters a in G which holds in every finite subspace of (X, G) necessarily holds in (X, G)?

2. If f: X → ℤ is continuous and Σx∈Vf(x) ≡ 0 mod ∣V∣ holds for all fans V in X with ∣V∣ ≤ 2n, does there exist a form ϕ with entries in G such that mod Cont(X, 2nℤ)?

3. Is it true that Cont(X, 2nℤ) ∩ Witt(X, G) = In(X, G), where I(X, G) denotes the fundamental ideal?

4. Is the separating depth of a constructible set C in X necessarily bounded by the stability index of (X, G)?

The unexplained terminology and notation is explained later in the main body of the paper. In a certain sense Question 1 is the main question. At the same time, Questions 2, 3 and 4 are of considerable interest, both from the point of view of quadratic form theory and from the point of view of real algebraic geometry.
Maximal contiguous degrees
Authors: Cholak Peter , Downey Rod , Walk Stephen
Published: December 2007

A computably enumerable (c.e.) degree is a maximal contiguous degree if it is contiguous and no c.e. degree strictly above it is contiguous. We show that there are infinitely many maximal contiguous degrees. Since the contiguous degrees are definable, the class of maximal contiguous degrees provides the first example of a definable infinite anti-chain in the c.e. degrees. In addition, we show that the class of maximal contiguous degrees forms an automorphism base for the c.e. degrees and therefore for the Turing degrees in general. Finally we note that the construction of a maximal contiguous degree can be modified to answer a question of Walk about the array computable degrees and a question of Li about isolated formulas.
How to extend the semantic tableaux and cut-free versions of the second incompleteness theorem almost to Robinson's arithmetic q
Authors: Willard Dan E.
Published: December 2007

Let us recall that Raphael Robinson's Arithmetic Q is an axiom system that differs from Peano Arithmetic essentially by containing no Induction axioms [13], [18]. We will generalize the semantic-tableaux version of the Second Incompleteness Theorem almost to the level of System Q. We will prove that there exists a single rather long Π1 sentence, valid in the standard model of the Natural Numbers and denoted as V. such that if α is any finite consistent extension of Q + V then α will be unable to prove its Semantic Tableaux consistency. The same result will also apply to axiom systems α with infinite cardinality when these infinite-sized axiom systems satisfy a minor additional constraint, called the Conventional Encoding Property.

Our formalism will also imply that the semantic-tableaux version of the Second Incompleteness Theorem generalizes for the axiom system IΣ0, as well as for all its natural extensions. (This answers an open question raised twenty years ago by Paris and Wilkie [15].)
Degree spectra of relations on computable structures in the presence of Δ20isomorphisms
Authors: Hirschfeldt Denis R.
Published: December 2007

We give some new examples of possible degree spectra of invariant relations on Δ20-categorical computable structures, which demonstrate that such spectra can be fairly complicated. On the other hand, we show that there are nontrivial restrictions on the sets of degrees that can be realized as degree spectra of such relations. In particular, we give a sufficient condition for a relation to have infinite degree spectrum that implies that every invariant computable relation on a Δ20-categorical computable structure is either intrinsically computable or has infinite degree spectrum. This condition also allows us to use the proof of a result of Moses [23] to establish the same result for computable relations on computable linear orderings.

We also place our results in the context of the study of what types of degree-theoretic constructions can be carried out within the degree spectrum of a relation on a computable structure, given some restrictions on the relation or the structure. From this point of view we consider the cases of Δ20-categorical structures, linear orderings, and 1-decidable structures, in the last case using the proof of a result of Ash and Nerode [3] to extend results of Harizanov [14].
Compact complex manifolds with the DOP and other properties
Authors: Pillay Anand , Scanlon Thomas
Published: December 2007

We point out that a certain complex compact manifold constructed by Lieberman has the dimensional order property, and has U-rank different from Morley rank. We also give a sufficient condition for a Kähler manifold to be totally degenerate (that is, to be an indiscernible set, in its canonical language) and point out that there are K3 surfaces which satisfy these conditions.
Modules with few types over some finite-dimensional algebras
Authors: Prest Mike , Puninskaya Vera
Published: December 2007

Using the description of the Ziegler spectrum we characterise modules with various stability-theoretic properties (ω-stability, superstability, categoricity) over certain classes of finite-dimensional algebras. We also show that, for modules over the algebras we consider, having few types is equivalent to being ω-stable.
ℵ0-categorical structures with arbitrarily fast growth of algebraic closure
Authors: Evans David M. , Pantano M. E.
Published: December 2007

Various results have been proved about growth rates of certain sequences of integers associated with infinite permutation groups. Most of these concern the number of orbits of the automorphism group of an ℵ0-categorical structure on the set of unordered n-subsets or on the set of n-tuples of elements of . (Recall that by the Ryll-Nardzewski Theorem, if is countable and ℵ0-categorical, the number of the orbits of its automorphism group Aut() on the set of n-tuples from is finite and equals the number of complete n-types consistent with the theory of .) The book [Ca90] is a convenient reference for these results. One of the oldest (in the realms of ‘folklore’) is that for any sequence (Kn)n∈ℕ of natural numbers there is a countable ℵ0-categorical structure such that the number of orbits of Aut() on the set of n-tuples from is greater than kn for all n.

These investigations suggested the study of the growth rate of another sequence. Let be an ℵ0-categorical structure and X be a finite subset of . Let acl(X) be the algebraic closure of X, that is, the union of the finite X-definable subsets of . Equivalently, this is the union of the finite orbits on of Aut()(X), the pointwise stabiliser of X in Aut(). Define
0# and inner models
Authors: Friedman SY D.
Published: December 2007

In this paper we examine the cardinal structure of inner models that satisfy GCH but do not contain 0#. We show, assuming that 0# exists, that such models necessarily contain Mahlo cardinals of high order, but without further assumptions need not contain a cardinal κ which is κ-Mahlo. The principal tools are the Covering Theorem for L and the technique of reverse Easton iteration.

Let I denote the class of Silver indiscernibles for L and 〈iα ∣ α ϵ ORD〉 its increasing enumeration. Also fix an inner model M of GCH not containing 0# and let ωα denote the ωα of the model M[0#], the least inner model containing M as a submodel and 0# as an element.
On polynomial time computation over unordered structures
Authors: Blass Andreas , Gurevich Yuri , Shelah Saharon
Published: December 2007

This paper is motivated by the question whether there exists a logic capturing polynomial time computation over unordered structures. We consider several algorithmic problems near the border of the known, logically defined complexity classes contained in polynomial time. We show that fixpoint logic plus counting is stronger than might be expected, in that it can express the existence of a complete matching in a bipartite graph. We revisit the known examples that separate polynomial time from fixpoint plus counting. We show that the examples in a paper of Cai, Fürer, and Immerman, when suitably padded, are in choiceless polynomial time yet not in fixpoint plus counting. Without padding, they remain in polynomial time but appear not to be in choiceless polynomial time plus counting. Similar results hold for the multipede examples of Gurevich and Shelah, except that their final version of multipedes is, in a sense, already suitably padded. Finally, we describe another possible candidate, involving determinants, for the task of separating polynomial time from choiceless polynomial time plus counting.
Transfinite dependent choice and ω-model reflection
Authors: Rüede Christian
Published: December 2007

In this paper we present some metapredicative subsystems of analysis. We deal with reflection principles, ω-model existence axioms (limit axioms) and axioms asserting the existence of hierarchies. We show several equivalences among the introduced subsystems. In particular we prove the equivalence of Σ11 transfinite dependent choice and Π21 reflection on ω-models of Σ11-DC.
Sequences of n-diagrams
Authors: Harizanov Valentina S. , Knight Julia F. , Morozov Andrei S.
Published: December 2007

We consider only computable languages, and countable structures, with universe a subset of ω, which we think of as a set of constants. We identify sentences with their Gödel numbers. Thus, for a structure , the complete (elementary) diagram, Dc(), and the atomic diagram, D(), are subsets of ω. We classify formulas as usual. A formula is both Σ0 and Π0 if it is open. For n > 0, a formula, in prenex normal form, is Σn, or Πn, if it has n blocks of like quantifiers, beginning with ∃, or ∀. For a formula θ, in prenex normal form, we let neg(θ) denote the dual formula that is logically equivalent to ¬θ—if θ is Σn, then neg(θ) is Πn, and vice versa.
Some highly saturated models of Peano arithmetic
Authors: Schmerl James H.
Published: December 2007

Some highly saturated models of Peano Arithmetic are constructed in this paper, which consists of two independent sections. In § 1 we answer a question raised in [10] by constructing some highly saturated, rather classless models of PA. A question raised in [7], [3], ]4] is answered in §2, where highly saturated, nonstandard universes having no bad cuts are constructed.

Highly saturated, rather classless models of Peano Arithmetic were constructed in [10]. The main result proved there is the following theorem. If λ is a regular cardinal andis aλ-saturated model of PA such that ∣M∣ >λ, thenhas an elementary extensionof the same cardinality which is alsoλ-saturated and which, in addition, is rather classless. The construction in [10] produced a modelfor which cf() =λ+. We asked in Question 5.1 of [10] what other cofinalities could such a modelhave. This question is answered here in Theorem 1.1 of §1 by showing that any cofinality not immediately excluded is possible. Its proof does not depend on the theorem from [10]; in fact, the proof presented here gives a proof of that theorem which is much simpler and shorter than the one in [10].

Recursively saturated, rather classless κ-like models of PA were constructed in [9]. In the case of singular κ such models were constructed whenever cf(κ) > ℵ0; no additional set-theoretic hypothesis was needed.
The cofinality of the strong measure zero ideal
Authors: Yorioka Teruyuki
Published: December 2007

We give a characterization of the cofinality of the strong measure zero ideal under the continuum hypothesis and prove that we can force it to a value less than the power of the continuum.
A unified completeness theorem for quantified modal logics
Authors: Corsi Giovanna
Published: December 2007

A general strategy for proving completeness theorems for quantified modal logics is provided. Starting from free quantified modal logic K. with or without identity, extensions obtained either by adding the principle of universal instantiation or the converse of the Barcan formula or the Barcan formula are considered and proved complete in a uniform way. Completeness theorems are also shown for systems with the extended Barcan rule as well as for some quantified extensions of the modal logic B. The incompleteness of Q°.B + BF is also proved.
A dichotomy theorem for turbulence
Authors: Hjorth Greg
Published: December 2007

In this note we show:

Theorem 1.1. Let G be a Polish group and X a Polish G-space with the induced orbit equivalence relation EG Borel as a subset of X × X. Then exactly one of the following:

(I) There is a countable languageℒand a Borel function

such that for all x1, x2 ∈ X

or

(II) there is a turbulent Polish G-space Y and a continuous G-embedding

There are various bows and ribbons which can be woven into these statements. We can strengthen (I) by asking that θ also admit a Borel orbit inverse, that is to say some Borel function

for some Borel set B ⊂ Mod(ℒ), such that for all x ∈ X

and then after having passed to this strengthened version of (I) we still obtain the exact same dichotomy theorem, and hence the conclusion that the two competing versions of (I) are equivalent. Similarly (II) can be relaxed to just asking that τ be a Borel G-embedding, or even simply a Borel reduction of the relevant orbit equivalence relations. It is in fact a consequence of 1.1 that all the plausible weakenings and strengthenings of (I) and (II) are respectively equivalent to one another.

I will not closely examine these possible variations here. The equivalences alluded to above follow from our main theorem and the results of [3]. That monograph had previously shown that (I) and (II) are incompatible, and proved a barbaric forerunner of 1.1, and gone on to conjecture the dichotomy result above.
Modular types in some supersimple theories
Authors: Newelski Ludomir
Published: December 2007

We consider a small supersimple theory with a property (CS) (close to stability). We prove that if in such a theoryTthere is a typep∈S(A) (whereAis finite) withSU(p) = 1 and infinitely many extensions overacleq(A), then inTthere is a modular such type. Also, ifTis supersimple with (CS) andp∈S(∅) is isolated,SU(p) = 1 andphas infinitely many extensions overacleq(∅), thenpis modular.
Three new feather mite genera of the Protolichus generic group (Astigmata, Pterolichidae) from parrots (Aves, Psittaciformes) of the Old World
Authors: Mironov Sergey , Dabert Jacek
Published: December 2007

Three new genera of feather mites of the Protolichus generic group (Pterolichidae, Pterolichinae), restricted to parrots, are established based on re-examination of type series and some previously unidentified mite specimens deposited in the collection of E. Trouessart (Muséum National d’Histoire Naturelle, Paris, France): Loriprotolichus gen. nov. with the type species Loriprotolichus charmosynae sp. nov. from Charmosyna papou (Scopoli, 1786) and Loriprotolichus falculiger (Trouessart, 1884) comb. nov. from Glossopsitta concinna (Shaw, 1791); Calyptolichus gen. nov. with type species Calyptolichus favettei (Trouessart, 1899) comb. nov.; Nestorilichus gen. nov. with the type species Nestorilichus atyeoi sp. nov. from Nestor meridionalis (Gmelin, 1788). Several taxonomic changes were implemented in the course of re-examination of the type series. The holotype of Pterolichus (Protolichus) falculiger Trouessart, 1884 is designated. Re-examination of the full syntype series of P. (Protolichus) favettei Trouessart, 1899 representing samples from different hosts, recovered two distinct pterolichid species of the Protolichus generic group. The sample clearly corresponding to the original description (Trouessart, 1899) is fixed as the lectotype and nomenclatural type of P. (Protolichus) favettei; the second species is described as a new species Nestorilichus atyeoi. Protolichus (Mesolichus) favettei cordifora Favette et Trouessart, 1904 is synonymized with P. (Protolichus) favettei.
A new species of Heligmosomoides (Nematoda, Heligmosomidae) parasitic in Peromyscus maniculatus (Rodentia, Cricetidae) from Pennsylvania, USA
Authors: Durette-Desset Marie-Claude , Kinsella John
Published: December 2007

Heligmosomoides vandegrifti sp. nov. (Nematoda, Heligmosomidae) is described from Peromyscus maniculatus (Rodentia, Cricetidae) from Pennsylvania, USA. It differs from its closest congener, H. douglasi, in the number of cuticular ridges (35 vs. 32 in male, 36 vs. 41 in female at mid-body), longer bursal rays 2 in relation to rays 3, and in having smaller spicules (635–740 μm long vs. 1 mm). It is proposed that both H. douglasi and H. vandegrifti sp. nov. are parasites of capture from species in North American arvicoline rodents.
Some studies on insect parasitic nematodes (Oxyurida, Thelastomatoidea, Thelastomatidae) from Manipur, North-East India
Authors: Shah Mohammad
Published: December 2007

Four known species of insect parasitic nematodes were recovered from Periplaneta americana and Gryllotalpa africana. They are all redescribed in the present study. Key to species along with comparative measurement chart of all known species of Leidynema, Gryllophila and Hammerschmidtiella have been provided. Based on additional features that were not provided by previous workers the emended generic diagnosis of Thelastoma, Leidynema, and Hammerschmidtiella have been provided in the present study.
Lamellodiscus theroni sp. nov. (Monogenea, Diplectanidae), a gill parasite from Diplodus puntazzo (Teleostei, Sparidae) from the Mediterranean Sea
Authors: Amine Faïza , Euzet Louis , Kechemir-Issad Nadia
Published: December 2007

We propose to name as Lamellodiscus theroni sp. nov., the gill parasite of Diplodus puntazzo (Cetti) that was reported by Euzet (1984) as L. ergensi Euzet and Oliver, 1966 in Kerkennah Island (Tunisia). L. theroni sp. nov. was also found specific to D. puntazzo in Algiers Bay (Algeria) and in Gulf of Lion (France). The host specificity of various Lamellodiscus species on D. puntazzo is briefly discussed. Within Lamellodiscus, L. theroni belongs to the “ignoratus” group characterized by a “lyre” shaped male copulatory organ and to the “ergensi” subgroup, characterized by a complex morphology of the haptoral dorsal bars. L. theroni differs from the five other species of this subgroup (L. ergensi, L. kechemirae, L. tomentosus, L. sanfilippoi, L. baeri) by the morphology and the size of the haptoral dorsal bar. L. theroni, as well as, L. hilii, L. bidens, L. impervius, was only reported on the sparid Diplodus puntazzo. These parasite species are all considered as oioxenic.
Frontal glands in the pseudoscolex of Paraechinophallus japonicus (Yamaguti, 1934) (Cestoda, Bothriocephalidea, Echinophallidae)
Authors: Poddubnaya Larisa , Scholz Tomáš , Levron Céline , Kuchta Roman , Gibson David
Published: December 2007

The glands in the pseudoscolex of the echinophallid cestode Paraechinophallus japonicus (Bothriocephalidea), a parasite of the bathypelagic fish Psenopsis anomala (Perciformes, Centrolophidae), were studied using scanning and transmission electron microscopy. Two types of glands, with different morphological types of secretory granules and mechanisms for discharging their glandular secretion, were observed. Both types of gland cell bodies are localized in the parenchyma of the pseudoscolex. The syncytial glands of type I are characterized by the production of small (all ∼0.25 μm in diameter), rounded, dense secretory granules which pass though thin projections into the distal tegumental layer of the pseudoscolex. This type of gland has a unique method of discharging its secretory granules, which we call tumulogenesis. The elimination of the secretory products is realized by an encroachment of the basement membrane and underlying tegumental muscles into the surface region of the distal cytoplasm of the tegument, resulting in the formation of a ‘glandular stalk’ above which develops a superficial glandular tumulus. In the region of the glandular material of the tumulus, the basement membrane of the stalk forms a dilation, and the appearance of a membrane-bound area serves to separate the tumulus from the distal cytoplasm of the tegument. Unicellular glands of type II are characterized by large granules (0.4–0.9 μm in diameter), the presence of peripheral microtubules in the terminal region of their ducts and an eccrine mechanism for the discharge of their secretory granules. A comparative analysis of the distribution and morphology of the types of scolex glands among members of the different families of the ‘Pseudophyllidea’ (currently believed to represent two distinct orders, Bothriocephalidea and Diphyllobothriidea) is presented.
Stress and Work Ability in Oil Industry Workers
Authors: Brešić Jozo , Knežević Bojana , Milošević Milan , Tomljanović Tomislav , Golubović Rajna , Mustajbegović Jadranka
Published: December 2007

Stress and Work Ability in Oil Industry Workers

This cross-sectional study conducted between March and June 2006 examined stress at work and work ability of 180 people with different workplaces within an oil company. Office, laboratory, and oil-field workers were invited to complete the "Occupational Stress Assessment Questionnaire - the Oil Industry Version and Work Ability Index (WAI) Questionnaire". The overall response rate was 69.4 %, and the final sample size was 125 workers who completed the questionnaires (57 office, 41 laboratory, 27 oil-field workers). Office, laboratory, and oil-field workers differed significantly with respect to age (P<0.001). The oldest were oil-field workers and the youngest were office workers. The average WAI score for office workers was 44.9, for laboratory workers 43.2 and for field workers 39.7, indicating satisfying work ability. After adjusting for age, the difference in WAI score between the groups of workers was still significant (P<0.001). Over 75 % of all workers believed their job was stressful, but the perception of specific stressors depended on the workplace.
Individual Differences and Sleep Deprivation Effects
Authors: Bakotić Marija , Radošević-Vidaček Biserka , Košćec Adrijana
Published: December 2007

Individualne Razlike i Učinci Deprivacije Spavanja

Suvremeni način života i različite životne okolnosti sve češće zahtijevaju od pojedinca da skrati trajanje spavanja i mijenja njegov raspored, što često rezultira deprivacijom spavanja. Ranija su istraživanja pokazala da učinci deprivacije spavanja na fiziološko i psihološko funkcioniranje pojedinca ovise o mnogobrojnim čimbenicima poput vrste deprivacije, trajanja prethodnog spavanja, doba dana kad se ispituju učinci, karakteristika zadataka koji se izvode te motivacije ispitanika. U ovom se radu raspravlja o učincima deprivacije spavanja te postojanju stabilnih individualnih razlika u tim učincima koje se nazivaju "ranjivost na gubitak spavanja". Novija istraživanja upućuju na moguću važnost nekih karakteristika ispitanika u predviđanju sustavnih i robusnih posljedica deprivacije spavanja, poput dobi i spola te nekih osobina ličnosti u širem smislu. Nadalje, upozorava se na moguću važnost individualnih razlika u nekim specifičnim osobinama povezanim sa spavanjem i budnošću, poput preferencija cirkadijurne faze, potrebe za spavanjem, za osobu karakteristične razine pospanosti i sposobnosti brzog uspavljivanja. Dosadašnja istraživanja osobina povezanih s različitom ranjivošću na gubitak spavanja nisu dala jednoznačne rezultate o njihovoj prediktivnoj važnosti. Daljnja istraživanja usmjerena na ovaj problem mogla bi pomoći u identifikaciji osoba koje su posebno ranjive na gubitak spavanja te pridonijeti osobnoj i općoj sigurnosti za vrijeme obavljanja noćnog rada.
Analysis of Polychlorinated Biphenyls and Organochlorine Pesticides in Pine Needles
Authors: Kožul Darija , Romanić SnjeŽana
Published: December 2007

Analysis of Polychlorinated Biphenyls and Organochlorine Pesticides in Pine Needles

This paper presents a review of methods for the analysis of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in pine needles. These compounds are lipophilic, they accumulate in the biotic and abiotic part of the environment in which they are persistent, and their use is forbidden or restricted due to harmful effects on human and animal health. Pine needles are convenient for monitoring the levels of organochlorine compounds in the air because they accumulate them in wax with which they are covered. However, the presence of many other compounds makes them complex for analysis. Analytical methods for determining organochlorine compounds in pine needles include sample collection, extraction of compounds with a suitable solvent, extract clean-up from unwanted compounds and qualitative and quantitative analysis. PCBs and OCPs are present in pine needles in traces, and every part of the analytical procedure has to be as efficient and selective as possible.
Evaluation of Platelet Activation Parameters as Quality Markers for the Stored Platelets
Authors: Subota Vesna , Vučetić Dušan , Balint Bela , Mijušković Zoran , Vojvodić Danilo , Pejović Janko , Mandić-Radić Slavka
Published: December 2007

Evaluation of Platelet Activation Parameters as Quality Markers for the Stored Platelets

In order to investigate the potential use of platelets activation parameters as routine quality control indicators during liquid storage, 27 PC-BC units were kept at 22 °C for up to 5 days. Routine parameters, including a platelet count, mean platelet volume and the parameters of activity: mean platelet component concentration, platelet component distribution width, mean platelet mass, platelet mass distribution width and number of platelet clumps were measured on the Bayer ADVIA 120 hematology analyzer. The platelet surface antigen CD62P was investigated using monoclonal antibodies on the flow cytometer Coulter-Epics XL and the platelet factor 4 and β-thromboglobuline, the main components of the α-granules, were also measured. The reduction in MPV, MPC, PCDW and MPM and the simultaneous increase in PF4, β-TG and CD62P expression reflected the PLT degranulation and activation. Minimizing cell damage during collection and storage is imperative for obtaining the PLT adequate in number and viability.
Simple Statistics in Diagnostic Tests
Authors: Aslan Diler , Sandberg Sverre
Published: December 2007

Simple Statistics in Diagnostic Tests

Diagnostic performance of a laboratory test is one of the key elements in decision making on diagnosis, screening, monitoring, risk assessment and prognosis of diseases. Sensitivity, specificity, likelihood ratios, diagnostic odds ratios and receiver operating characteristic curves are the measures of diagnostic accuracy of a test. The pretest probability of a disease or a target condition can be enhanced by the use of these measures, and hence the decision is made with the posttest probability. These measures are also used for analysis and critical appraisal of literature for finding the best evidence in the five-step model of evidence-based medicine approach, as well as for integrating the research results into clinical usage. In this context, the specialists in laboratory medicine should assess the diagnostic performance of a laboratory test as well as its analytical performance in order to take part in the management of health care services and health care resources. The aim of this review is to summarize the simple Statistics in diagnostic tests.
Singularities at Infinity and their Vanishing Cycles, II. Monodromy
Authors: Siersma Dirk , Tibăr Mihai
Published: December 2007

Let

f : ℂ^n \to ℂ

be any polynomial function. By using global polar methods, we introduce models for the fibers of

f

and we study the monodromy at atypical values of

f

, including the value infinity. We construct a geometric monodromy with controlled behavior and define global relative monodromy with respect to a general linear form. We prove localization results for the relative monodromy and derive a zeta-function formula for the monodromy around an atypical value. We compute the relative zeta function in several cases and emphasize the differences to the “classical” local situation.
A Rohlin Property for One-parameter Automorphism Groups of the Hyperfinite $\mathrm{II}_1$ Factor
Authors: Kawamuro Keiko
Published: December 2007

We first define a Rohlin property for one-parameter automorphism groups of the hyperfinite type

\mathrm{II}_1

factor as an analogue of Kishimoto's definition for one-parameter automorphism groups of unital simple

\mathrm{C}^*

-algebras.

Secondly, we prove equivalence between the Rohlin property and the cohomology vanishing in an appropriate central sequence algebra, which is a variation of Kishimoto's theorem in

\mathrm{C}^*

-algebra theory.
Derived Categories for Functional Analysis
Authors: Prosmans Fabienne
Published: December 2007

In this paper, we study the homological algebra of the category
Tc
of locally convex topological vector spaces from the point of view of derived categories. We start by showing that
Tc
is a quasi-abelian category in which products and direct sums are exact. This allows us to derive projective and inductive limit functors and to clarify their homological properties. In particular, we obtain strictness and acyclicity criteria. Next, we establish that the category formed by the separated objects of
Jc
is quasi-abelian and has the same derived category as
Tc
. Since complete objects of
Tc
do not form a quasi-abelian category, we are lead to introduce the notion of cohomological completeness and to study the derived completion functor. Our main result in this context is an equivalence between the subcategory of
D
(
Tc
) formed by cohomologically complete complexes and the derived category of the category of pro-Banach spaces. We show also that, under suitable assumptions, we can reduce the computation of Ext's in
Tc
to their computation in '
Ban
by means of derived projective limits. We conclude the paper by studying derived duality functors.
The Meromorphic Solutions of the Bruschi–Calogero Equation
Authors: Kawazumi Nariya , Shibukawa Youichi
Published: December 2007

We give all the meromorphic functions defined near the origin

0 \in ℂ

satisfying a functional equation investigated by Bruschi and Calogero [1], [2].
Land‐use and fire history effects on post‐fire vegetation dynamics in eastern Spain
Authors: Duguy Beatriz , Vallejo V. Ramón
Published: December 2007

Question: Is post‐fire, medium‐term vegetation dynamics determined by land‐use or fire history prior to fire?

Location: South‐facing slope in the Gallinera valley, Alicante province, eastern Spain.

Methods: After mapping the land‐use and fire history of the study site using photo‐interpretation, we sampled vegetation structure on a set of plots representing the most frequent land‐use and fire history combinations on an area burned six years before sampling. We studied the effects of land‐use history, comparing the one‐fire land‐use trajectories. We analysed the effects of fire history; comparing one‐ and two‐fire plots for both previously cropped and uncropped areas.

Results: Most variables were not significantly different between the earliest abandoned plots (abandoned at least 38 years before the fire) and the uncropped plots. On the most recently abandoned plots (abandoned between one and four years before the fire), the therophyte richness and the ratio of seeder: resprouter richness were significantly greatest. Different fire recurrences did not determine different post‐fire vegetation on either the uncropped or the early abandoned plots (all dominated by fire‐recruited seeder shrubs). The most recently abandoned plots had a lower resilience to fire.

Conclusions: Land‐use history and recent pre‐fire land use, in particular, determined the post‐fire vegetation in the medium term. The vegetation composition converged during secondary succession among land‐use histories. Increasing fire recurrence had a small effect on mature plant communities, due to the combination of life‐history traits determining the response to fire of the dominant species.
Plant height as a simple predictor of the root to shoot ratio: Evidence from alpine grasslands on the Tibetan Plateau
Authors: Li Yonghua , Luo Tiangxiang , Lu Qi
Published: December 2007

Question: Since increases in altitude and grazing intensity generally result in decreases in height growth of alpine grasslands, plant height may integrate effects of environmental stress and grazing disturbance and provide better assessments of the variation in root: shoot (R: S) biomass ratio than other variables. However, it is unclear if there is a general relationship between plant height and R:S ratio across grassland ecosystems. Such knowledge would be helpful for root biomass estimation in grasslands.

Location: An altitudinal transect in the Gonghe Basin (2880–4040 m a.s.l.), northeast Tibetan plateau.

Methods: We measured standing biomass both above‐ground and below‐ground, maximum plant height (MPH) and soil variables across 43 plots.

Results: Climatic variables explained the variations in MPH and R: S ratio of undegraded grasslands better than soil variables (46–50% vs < 19%), while those of degraded grasslands generally showed insignificant correlations with climatic and soil variables. There was a general relationship between R: S ratio and MPH (negative, R2= 0.76, P< 0.001) across degraded and undegraded grasslands. The relationship was used to predict R: S ratio in 13 additional plots in steppe grasslands of Inner Mongolia, and good agreement of expected and observed values has been found (R2= 0.87, P < 0.001).

Conclusions: MPH, that is relatively easy to measure, can be used to predict R:S ratio at plot to regional scales. It is promising to develop a new method for large‐scale estimation of root biomass in grasslands using MPH and shoot biomass avoiding tedious procedures of physical measuring of above and below‐ground biomass.
Intracranial meningiomas: an overview of diagnosis and treatment
Authors: Rockhill Jason , Mrugala Maciej , Chamberlain Marc C.
Published: December 2007

✓Meningiomas are extraaxial central nervous system tumors most often discovered in middle to late adult life, and are more often seen in women. Ninety percent of meningiomas are benign, 6% are atypical, and 2% are malignant. Most patients in whom a meningioma is diagnosed undergo resection to relieve neurological symptoms. Complete resection is often curative. For the majority of incompletely resected or recurrent tumors not previously irradiated, radiotherapy is administered. Radiotherapy may be administered as either conventional external-beam radiation therapy or stereotactically by linear accelerator, Leksell Gamma Knife, or Cyberknife radiosurgery. Advocates of stereo-tactic radiotherapy have suggested this therapy in lieu of surgery particularly in high-risk patients, those with meningiomas in eloquent or surgically inaccessible locations, and elderly patients. When the meningioma is unresectable or all other treatments (surgery and radiotherapy) have failed, hormonal therapy or chemotherapy may be considered. Notwithstanding limited data, hydroxyurea has been modestly successful in patients with recurrent meningiomas.
Chronic suppressive therapy with calcium channel antagonists for refractory meningiomas
Authors: Ragel Brian T. , Couldwell William T. , Wurster Robert D. , Jensen Randy L.
Published: December 2007

✓In this article, the authors review the research supporting the use of calcium channel antagonists (CCAs) in the treatment of recurrent or unresectable meningiomas. Calcium channel antagonists (for example, diltiazem and verapamil) are known to augment the effects of chemotherapy drugs (for example, vincristine) in multiple cancers. Although it was initially thought that this occurred by interference with calcium-dependent secondary messenger systems, it appears that other mechanisms account for this effect. The authors' initial work in this field was based on the then-emerging data that meningiomas are receptor positive for growth factor receptors (for example, platelet-derived growth factor [PDGF]), which are known to trigger calcium-dependent secondary messenger pathways. In fact, they were able to show that CCAs block the growth stimulatory effects of multiple growth factors, including PDGF, in vitro and augment the growth inhibitory effects of hydroxyurea and RU486 (mifepristone). The authors have shown similar in vivo growth inhibition by these agents. In addition, diltiazem- and verapamil-treated meningiomas are less vascular and smaller, with decreased cell proliferation and increased apoptosis. The use of CCAs is attractive as an adjunct treatment for unresectable or recurrent meningiomas because they are safe drugs with well-known side effect profiles that lend themselves to long-term chronic therapy.
Review of meningioma histopathology
Authors: Commins Deborah L. , Atkinson Roscoe D. , Burnett Margaret E.
Published: December 2007

✓The histological appearance of a meningioma is an important predictor of tumor behavior and is frequently a factor in decisions concerning therapy. The relationship between histological features and prognosis is formalized in grading schemes such as those published by the World Health Organization (WHO), most recently in 2007. Although the latest edition is an improvement over previous grading schemes, the WHO scheme still fails to fully address a variety of important issues regarding the relationship between meningioma histological characteristics and behavior. In particular, routine histological examination fails to identify the subset of Grade I tumors that behave aggressively. Because of this, many additional prognostic markers that require immunohistochemical, cytogenetic, or molecular techniques to evaluate are under investigation. Only one, immunohistochemistry for the proliferation marker, Ki 67 (MIB-1), is used routinely and it has only limited utility. It is hoped that an understanding of the genetic changes that underlie tumor progression will improve healthcare professionals' ability to predict the behavior of meningiomas.
Role of radiation therapy in treating intracranial meningiomas
Authors: Rogers Leland , Mehta Minesh
Published: December 2007

✓Surgery is the mainstay for many patients with meningiomas, and it remains the standard. In large single-institution series, gross-total resection has been reported to achieve 5-, 10-, and 15-year recurrence-free survival rates of approximately 90, 80, and 70%, respectively. There are a growing number of series of patients with prolonged follow-up in which authors have evaluated fractionated external-beam radiation therapy (EBRT) either as an adjuvant to surgery for subtotally resected, recurrent, or higher-grade meningiomas, or as an alternative to surgery. The primary focus of this review is EBRT, but to lend perspective, a comparative analysis of surgery and radiosurgery is also provided.
Postoperative Gamma Knife surgery for benign meningiomas of the cranial base
Authors: Davidson Laurence , Fishback Dawn , Russin Jonathan J. , Weiss Martin H. , Yu Cheng , Pagnini Paul G. , Zelman Vladimir , Apuzzo Michael L. J. , Giannotta Steven L.
Published: December 2007

Object

The standard treatment for meningiomas is complete resection, but the proximity of skull base meningiomas to important neurovascular structures makes complete excision of the lesion difficult or impossible. The authors analyzed the mid- and long-term results obtained in patients treated with postresection Gamma Knife surgery (GKS) for residual or recurrent benign meningiomas of the cranial base.

Methods

Thirty-six patients with residual or recurrent benign meningiomas of the skull base following one or more surgical procedures underwent GKS. There were 31 women and five men, ranging in age from 22 to 73 years. The median tumor volume was 4.1 ml (range 0.8–20 ml) and the median radiation dose to the tumor margin was 16 Gy (range 15–16 Gy).

Results

Patients were followed for a median of 81 months (range 30–141 months) after GKS. At the end of the follow-up period, overall neurological improvement was observed in 16 patients (44.4%), whereas the condition in 20 patients (55.6%) was unchanged. One patient suffered transient cerebral edema 6 months after GKS. Based on imaging documentation, a partial response was seen in five patients (13.9%), the disease remained stable in 30 patients (83.3%), and in one patient (2.8%) there was an increase in tumor size. The actuarial progression-free survival rate was 100% at 5 years and 94.7% at 10 years.

Conclusions

Gamma Knife surgery was shown to be an excellent adjunct to resection because of its durable rate of tumor control and low toxicity. It should be initially considered along with surgery for the treatment of complex skull base meningiomas.
Nelfinavir potentiation of imatinib cytotoxicity in meningioma cells via survivin inhibition
Authors: Gupta Vinay , Samuleson Christian G. , Su Susan , Chen Thomas C.
Published: December 2007

✓ Although most meningiomas are treated surgically, it may not be possible to completely remove atypical, malignant, and surgically inaccessible meningiomas; in the majority of these cases there is tumor recurrence. The authors have already reported initial preclinical results on the efficacy of imatinib in the treatment of meningiomas; however, a recent Phase II trial of imatinib in patients with recurrent meningiomas did not demonstrate significant antitumor activity. To enhance the activity of imatinib, the authors investigated the use of a combination therapy with nelfinavir on primary meningioma cells and meningioma cell lines IOMM-Lee and CH157.

Cytotoxicity was measured using methylthiotetrazole and colony formation assays. In low-dose combination therapy with imatinib, nelfinavir potentiated the antiproliferative and anti–colony formation effects of imatinib. Primary meningioma cells responded better to combination therapy than to imatinib alone. Treatment induced a dose-dependent antiproliferative effect, decreased cell survival, and inhibited colony formation. Western blotting demonstrated decreased levels of survivin protein on combination therapy. Because meningiomas have very high levels of survivin protein, survivin inhibition by nelfinavir may represent a potential mechanism for the additive effect observed with imatinib. Moreover, an increase in the proapoptotic Bax/Bcl-2 protein ratio was demonstrated with the combination of imatinib and nelfinavir.

The authors propose that nelfinavir not only potentiates imatinib efficacy, it also abrogates resistance to imatinib by decreasing survivin protein levels in meningiomas. In an in vivo assay, this combination therapy was found to be more effective than imatinib alone. More preclinical work with in vivo models is needed to determine if this new combination therapy will translate into a viable future therapy for meningiomas.
Neuroophthalmological evaluation after Gamma Knife surgery for cavernous sinus meningiomas
Authors: Franzin Alberto , Vimercati Alberto , Medone Marzia , Serra Carlo , Marzoli Stefania Bianchi , Forti Maddalena , Gioia Lorenzo , Valle Micol , Picozzi Piero
Published: December 2007

Object

Treatment options for patients with cavernous sinus meningiomas (CSMs) include microsurgical tumor resection, radiotherapy, and radiosurgery. Gamma Knife surgery (GKS) is increasingly being used because it is associated with lower mortality and morbidity rates than microsurgery. The purpose of this study was to assess the role of GKS in the treatment of CSM and to thoroughly analyze the clinical response to GKS.

Methods

Between January 2001 and December 2005, 123 patients (25 men and 98 women; mean age 62.6 ± 11 years, range 31–86 years) who underwent treatment for CSMs were included in this study. Of these, 41 patients underwent microsurgery before GKS, whereas the remaining 82 had GKS as a first-line therapy after a diagnosis was made based on magnetic resonance imaging findings. Dysfunction in cranial nerves (CNs) II, III, IV, V, and VI was noted in 74 patients at the time of GKS. The mean tumor volume was 7.99 cm3 (0.7–30.5 cm3). The mean prescription dose to the tumor margin was 13.8 ± 1.1 Gy (range 10–20 Gy).

Results

The overall tumor control rate was 98.4% with a median follow-up of 36 months. The actuarial tumor control rate at 5 years was 90.5%. A reduction in tumor volume was observed in 53 patients (43.1%), whereas in 68 patients (55.3%) no volumetric variation was recorded. Of the 74 patients who presented with CN deficits, improvement was noted in 23 (31.1%).

Conclusions

Gamma Knife surgery is a useful treatment for CSM both as a first- or second-line therapy. It is a safe and effective treatment for tumors located close to the optic pathways.
CyberKnife rhizotomy for facetogenic back pain: a pilot study
Authors: Li Gordon , Patil Chirag , Adler John R. , Lad Shivanand P. , Soltys Scott G. , Gibbs Iris C. , Tupper Laurie , Boakye Maxwell
Published: December 2007

Object

By targeting the medial branches of the dorsal rami, radiofrequency ablation and facet joint injections can provide temporary amelioration of facet joint–producing (or facetogenic) back pain. The authors used CyberKnife radiosurgery to denervate affected facet joints with the goal of obtaining a less invasive yet more thorough and durable antinociceptive rhizotomy.

Methods

Patients with refractory low-back pain, in whom symptoms are temporarily resolved by facet joint injections, were eligible. The patients were required to exhibit positron emission tomography–positive findings at the affected levels. Radiosurgical rhizotomy, targeting the facet joint, was performed in a single session with a marginal prescription dose of 40 Gy and a maximal dose of 60 Gy.

Results

Seven facet joints in 5 patients with presumptive facetogenic back pain underwent CyberKnife lesioning. The median follow-up was 9.8 months (range 3–16 months). The mean planning target volume was 1.7 cm3 (range 0.9–2.7 cm3). A dose of 40 Gy was prescribed to a mean isodose line of 79% (range 75–80%). Within 1 month of radiosurgery, improvement in pain was observed in 3 of the 5 patients with durable responses at 16, 12, and 6 months, respectively, of follow-up. Two patients, after 12 and 3 months of follow-up, have neither improved nor worsened. No patient has experienced acute or late-onset toxicity.

Conclusions

These preliminary results suggest that CyberKnife radiosurgery could be a safe, effective, and non-invasive alternative to radiofrequency ablation for managing facetogenic back pain. No patient suffered recurrent symptoms after radiosurgery. It is not yet known whether pain relief due to such lesions will be more durable than that produced by alternative procedures. A larger series of patients with long-term follow-up is ongoing.