bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some new results in monadic second-order arithmetic
Authors: Speranski Stanislav O. 
Published: July 2015

Abstract Let σ be a signature and [Formula: see text] a σ-structure with domain [Formula: see text]. Say that a monadic second-order σ-formula is [Formula: see text] iff it has the form [Formula: see text] with [Formula: see text] set variables and ψ containing no set quantifiers. Consider the following properties: for each positive integer n, the set of [Formula: see text]- σ-sentences true in [Formula: see text] is [Formula: see text]-complete; for each positive integer n, if a set of natural numbers is [Formula: see text]-definable (i.e. by a [Formula: see text]-formula) in the standard model of arithmetic and closed under automorphisms of [Formula: see text], then it is [Formula: see text]-definable in [Formula: see text]. We use ∣ and ⊥ to denote the divisibility relation and the coprimeness relation respectively. Given a prime p, let [Formula: see text] be the function which maps every pair [Formula: see text] of natural numbers into [Formula: see text]. In this article we prove: [Formula: see text] and all [Formula: see text] have both [Formula: see text] and [Formula: see text]; in effect, even [Formula: see text] has [Formula: see text]. Notice – these results readily generalise to arbitrary arithmetical expansions of the corresponding structures, provided that the extended signature is finite.
On limitwise monotonicity and maximal block functions
Authors: Harris Charles M. 
Published: July 2015

Abstract We prove the existence of a limitwise monotonic function [Formula: see text] such that, for any [Formula: see text] function [Formula: see text], [Formula: see text]. Relativising this result we deduce the existence of an η-like computable linear ordering [Formula: see text] such that, for any [Formula: see text] function [Formula: see text], and η-like [Formula: see text] of order type [Formula: see text], [Formula: see text]. We prove directly that, for any computable [Formula: see text] which is either (i) strongly η-like or (ii) η-like with no strongly η-like interval, there exists [Formula: see text]-limitwise monotonic [Formula: see text] such that [Formula: see text] has order type [Formula: see text]. In so doing we provide an alternative proof to the fact that, for every η-like computable linear ordering [Formula: see text] with no strongly η-like interval, there exists computable [Formula: see text] with [Formula: see text] block relation. We also use our results to prove the existence of an η-like computable linear ordering which is [Formula: see text] categorical but not [Formula: see text] categorical.
On the existence of a connected component of a graph
Authors: Gura Kirill , Hirst Jeffry L. , Mummert Carl 
Published: July 2015

Abstract We study the reverse mathematics and computability of countable graph theory, obtaining the following results. The principle that every countable graph has a connected component is equivalent to [Formula: see text] over [Formula: see text]. The problem of decomposing a countable graph into connected components is strongly Weihrauch equivalent to the problem of finding a single component, and each is equivalent to its infinite parallelization. For graphs with finitely many connected components, the existence of a connected component is either provable in [Formula: see text] or is equivalent to induction for [Formula: see text] formulas, depending on the formulation of the bound on the number of components.
Asymptotic density, immunity and randomness
Authors: Astor Eric P. 
Published: July 2015

Abstract In 2012, inspired by developments in group theory and complexity, Jockusch and Schupp introduced generic computability, capturing the idea that an algorithm might work correctly except for a vanishing fraction of cases. However, we observe that their definition of a negligible set is not computably invariant (and thus not well-defined on the 1-degrees), resulting in some failures of intuition and a break with standard expectations in computability theory. To strengthen their approach, we introduce a new notion of intrinsic asymptotic density, with rich relations to both randomness and classical computability theory. We then apply these ideas to propose alternative foundations for further development in (intrinsic) generic computability. Toward these goals, we classify intrinsic density 0 as a new immunity property, specifying its position in the standard hierarchy from immune to cohesive for both general and [Formula: see text] sets, and identify intrinsic density [Formula: see text] as the stochasticity corresponding to permutation randomness. We also prove that Rice’s Theorem extends to all intrinsic variations of generic computability, demonstrating in particular that no such notion considers [Formula: see text] to be “computable”.
On Algorithmic Study of Non-negative Posets of Corank at Most Two and their Coxeter-Dynkin Types
Authors: Gąsiorek Marcin , Zając Katarzyna 
Published: July 2015

Following the Coxeter spectral analysis of loop-free edge-bipartite graphs Δ and finite posets I, with n ≥ 2 vertices, introduced and developed in [SIAM J. Discrete Math., 27(2013), 827-854], we present a Coxeter spectral classification of finite posets I, with n ≥ 2 elements. Here we study the connected posets I that are non-negative of corank one or two, in the sense that the symmetric Gram matrix 12(CI+CItr)∈𝕄n(ℚ) is positive semi-definite of corank one or two, where CI ∈ 𝕄 n(ℤ) is the incidence matrix of I. We study such posets I by means of the Dynkin type Dyn I and the Coxeter polynomial cox I( t) := det( t · E − Cox I) ∈ ℤ[ t], where Cox I := − CI · C−trI ∈ 𝕄 n(ℤ) is the Coxeter matrix of I. Among other results, we develop an algorithmic technique that allows us to compute a complete list of such posets I, with | I| ≤ 16, their Dynkin types Dyn I , and the Coxeter polynomials cox I( t) ∈ ℤ[ t]. We prove that, given a pair of such connected posets I and J, the incidence matrices CI and CJ are ℤ-congruent if and only if cox I( t) = cox J( t) and Dyn I = Dyn J.
Catching a Structural Bug with a Flower
Authors: Avellaneda Florent , Morin Rémi 
Published: July 2015

Checking the structural boundedness and the structural termination of vector addition systems with states boils down to detecting pathological cycles. As opposed to their non-structural variants which require exponential space, these properties need polynomial time only. The algorithm searches for a counter-example in the form of a multiset of arcs computed by means of linear programming. Yet the minimal length of a pathological cycle can be exponential in the size of the system which makes it difficult to visualize and to analyze the detected bug in details. We propose to describe pathological cycles in the form of particular cycles called flowers. The latter are made of petals which are iterated circuits connected by simple paths that form a calyx. We present an algorithm that builds in polynomial time a flower from the multiset of arcs that represents a pathological cycle. Interestingly the number of petals within a flower is at most equal to the dimension of vectors which helps to describe in a concise way the underlying bug and to analyse it.
Bidirectional cell tests on non-grouted and grouted large-diameter bored piles
Authors: Nguyen Minh Hai , Fellenius Bengt H. 
Published: July 2015

The 37-storey apartment buildings of the Everrich II project in HoChiMinh City, Vietnam was designed to be supported on a piled foundation consisting of bored piles assigned a 22-MN working load per pile. The foundation design included performing bidirectional-cell, static loading tests on four test piles. The soil profile consisted of organic soft clay to about 28 m depth followed by a thick deposit of sandy silt and silty sand with a density that gradually increased with depth from compact to dense, becoming very dense at 65 m depth. In March 2010, the test piles, one 1.5-m diameter pile and three 2.0-m diameter piles, were installed to 80 m through 85 m depth and constructed using bucket drill technique with bentonite slurry and a casing advanced ahead of the hole. The bidirectional-cell assemblies were installed at 10 m through 20 m above the pile toes. The piles were instrumented with pairs of diametrically opposed vibrating wire strain-gages at three to four levels below and six to seven levels above the respective cell levels. After completed concreting, the shaft grouting was carried out throughout a 20 m length above the pile toe for the 1.5-m diameter pile and for one of the 2.0-m diameter piles. The static loading tests were performed about 34 through 44 days after the piles had been concreted. The analysis of strain-gage records indicated an average Young's modulus value of about 25 GPa for the nominal crosssections of the piles. The average unit grouted shaft resistances on the nominal pile diameters were about two to three times larger than the resistance along the non-grouted lengths. The measured load distribution of maximum mobilized shaft resistances corresponded to effective stress proportionality coefficients, ß, of about 0.2 through 0.3. The ultimate shaft resistance for the pile lengths below the bidirectional cells reached an ultimate value after about 8 to 10 mm movement, whereafter the load-movement was plastic. The pile toe stress-movement responses to toe stiffness were soft with no tendency toward an ultimate value.
Assessment of response bias in neurocognitive evaluations
Authors: Carone Dominic A. 
Published: July 2015

BACKGROUND: In clinical neuropsychological practice, assessment of response validity (e.g., effort, over-reporting, under-reporting) is an essential component of the assessment process. By contrast, other health care professionals, including those in neurorehabilitation settings, often omit assessment of this topic from their evaluations or only rely on subjective impressions. OBJECTIVE: To provide the first comprehensive review of response validity assessment in the neurorehabilitation literature, including why the topic is often avoided, what methods are commonly used, and how to decrease false positives. METHODS: A literature review and documentation of personal experience and perspectives was used to review this topic. RESULTS: There is a well-established literature on the necessity and utility of assessing response validity, particularly in patients who have external incentives to embellish their presentation or to under-report symptoms. There are many reasons why non-neuropsychologists typically avoid assessment of this topic. This poses a significant problem, particularly when patients exaggerate or malinger, because it can lead to misdiagnosis and it risks increasing the cost of healthcare by performing unnecessary tests and treatments, unfair distribution of disability/compensation resources, and a reduced access to these and other health resources by patients who genuinely need them. CONCLUSIONS: There is a significant need for non-neuropsychologists to develop and incorporate symptom and performance validity assessments in clinical evaluations, including those in neurorehabilitation settings.
Validity assessment and the neurological physical examination
Authors: Zasler Nathan D. 
Published: July 2015

BACKGROUND: The assessment of any patient or examinee with neurological impairment, whether acquired or congenital, provides a key set of data points in the context of developing accurate diagnostic impressions and implementing an appropriate neurorehabilitation program. As part of that assessment, the neurological physical exam is an extremely important component of the overall neurological assessment. PURPOSE: In the aforementioned context, clinicians often are confounded by unusual, atypical or unexplainable physical exam findings that bring into question the organicity, veracity, and/or underlying cause of the observed clinical presentation. The purpose of this review is to provide readers with general directions and specific caveats regarding validity assessment in the context of the neurological physical exam. CONCLUSIONS: It is of utmost importance for health care practitioners to be aware of assessment methodologies that may assist in determining the validity of the neurological physical exam and differentiating organic from non-organic/functional impairments. Maybe more importantly, the limitations of many commonly used strategies for assessment of non-organicity should be recognized and consider prior to labeling observed physical findings on neurological exam as non-organic or functional.
Examination of validity in spoken language evaluations: Adult onset stuttering following mild traumatic brain injury
Authors: Roth Carole R. , Cornis-Pop Micaela , Beach Woodford A. 
Published: July 2015

BACKGROUND: Reports of increased incidence of adult onset stuttering in veterans and service members with mild traumatic brain injury (mTBI) from combat operations in Iraq and Afghanistan lead to a reexamination of the neurogenic vs. psychogenic etiology of stuttering. OBJECTIVE: This article proposes to examine the merit of the dichotomy between neurogenic and psychogenic bases of stuttering, including symptom exaggeration, for the evaluation and treatment of the disorder. METHODS: Two case studies of adult onset stuttering in service members with mTBI from improvised explosive device blasts are presented in detail. Speech fluency was disrupted by abnormal pauses and speech hesitations, brief blocks, rapid repetitions, and occasional prolongations. There was also wide variability in the frequency of stuttering across topics and conversational situations. Treatment focused on reducing the frequency and severity of dysfluencies and included educational, psychological, environmental, and behavioral interventions. RESULTS: Stuttering characteristics as well as the absence of objective neurological findings ruled out neurogenic basis of stuttering in these two cases and pointed to psychogenic causes. However, the differential diagnosis had only limited value for developing the plan of care. CONCLUSIONS: The successful outcomes of the treatment serve to illustrate the complex interaction of neurological, psychological, emotional, and environmental factors of post-concussive symptoms and to underscore the notion that there are many facets to symptom presentation in post-combat health.
Assessment of validity and response bias in neuropsychiatric evaluations
Authors: Wygant Dustin B. , Granacher Robert P. 
Published: July 2015

BACKGROUND: Forensic neuropsychiatric assessment requires thorough consideration of malingering and response bias. Neuropsychiatric evaluations are complicated due to the multiple domains in which symptoms and impairment present. Moreover, symptom exaggeration in these evaluations can also present along various symptom domains (e.g., psychological, neurocognitive, somatic). Consequently, steps must be taken to ensure adequate coverage of response bias across all three domains of function. PURPOSE: The following article reviews the conceptualization of malingering in neuropsychiatric settings, as well as various approaches and measures that can be helpful in the assessment of malingering and response bias. CONCLUSIONS: Forensic neuropsychiatric assessment requires thorough consideration of malingering and response bias. These evaluations are complicated due to the multiple domains in which symptoms and impairment present. Performance and symptom validity measures should be routinely included in these evaluations. Collaboration between psychiatry and psychology can provide the optimal multi-method approach needed for thorough neuropsychiatric assessment in forensic cases. We illustrate our points with two case studies from forensic traumatic brain injury neuropsychiatric evaluations.
Pediatric validity assessment
Authors: Kirkwood Michael W. 
Published: July 2015

BACKGROUND: Youth have been assumed historically to be less capable of deception than adults, even though acts of deception in childhood are not uncommon. Relatively little attention has focused on how frequently they feign or exaggerate during healthcare evaluations. PURPOSE: The current article reviews the literature relevant to using validity tests in children and adolescents, as well as provides a case example of a young adolescent providing noncredible effort and exaggerated symptomatology during neuropsychological evaluation after a mild traumatic brain injury. CONCLUSION: Numerous case reports and case series have documented clearly that medical and neuropsychological noncredible presentations occur in children, likely more often than many practitioners believe. Thus far, research has found that the base rates of pediatric noncredible presentations are highest in children seen frequently by rehabilitation providers (i.e., children with persistent problems after mild traumatic brain injury and children from families seeking disability benefits on their behalf). Subjective clinical judgment is apt to be ineffective in consistently detecting noncredible presentations. Fortunately, recent research supports the use of several stand-alone validity tests in identifying noncredible pediatric data including the Test of Memory Malingering, Word Memory Test, and Medical Symptom Validity Test. If feigning and exaggeration are not considered in work-ups by rehabilitation practitioners, mismanagement and iatrogenic harm to the child can result.
Assessment of validity with polytrauma Veteran populations
Authors: Bush Shane S. , Bass Carmela 
Published: July 2015

BACKGROUND: Veterans with polytrauma have suffered injuries to multiple body parts and organs systems, including the brain. The injuries can generate a triad of physical, neurologic/cognitive, and emotional symptoms. Accurate diagnosis is essential for the treatment of these conditions and for fair allocation of benefits. To accurately diagnose polytrauma disorders and their related problems, clinicians take into account the validity of reported history and symptoms, as well as clinical presentations. OBJECTIVES: The purpose of this article is to describe the assessment of validity with polytrauma Veteran populations. METHODS: Review of scholarly and other relevant literature and clinical experience are utilized. RESULTS: A multimethod approach to validity assessment that includes objective, standardized measures increases the confidence that can be placed in the accuracy of self-reported symptoms and physical, cognitive, and emotional test results. CONCLUSIONS: Due to the multivariate nature of polytrauma and the multiple disciplines that play a role in diagnosis and treatment, an ideal model of validity assessment with polytrauma Veteran populations utilizes neurocognitive, neurological, neuropsychiatric, and behavioral measures of validity. An overview of these validity assessment approaches as applied to polytrauma Veteran populations is presented. Veterans, the VA, and society are best served when accurate diagnoses are made.
Invalid symptom reporting and performance: What are we missing?
Authors: Silver Jonathan M. 
Published: July 2015

BACKGROUND: In the evaluation of neurorehabilitation patients involved in compensation or litigation, it is often assumed that poor performance or exaggerated symptoms reflects an intentional attempt to game the system. PURPOSE: The purpose of this article is to review multiple issues that can contribute to invalid symptom reporting and performance. CONCLUSIONS: Multiple factors relevant to normal behavior, including observations from social psychology and behavioral economics, are important in the context of invalid symptom reporting and performance. These factors, which include pre-injury traits and beliefs (e.g., beliefs about prognosis and symptoms after TBI), factors at the time of initial treatment (e.g., expectations of recovery, nocebo effects, stereotype threat), and thoughts and feelings during evaluations (e.g., anger, resentment, injustice), may be important explanations. To best serve our patients, further research is needed to illuminate these relative effects on performance compared to “not trying.”
Dynamical Analysis of a Stage-Structured Model for Lyme Disease with Two Delays
Authors: Li Dan , Ma Wanbiao 
Published: July 2015

AbstractIn this paper, a nonlinear stage-structured model for Lyme disease is considered. The model is a system of diòerential equations with two time delays. We derive the basic reproductive rate R0(τ1, τ2). If (τ1, τ2) < 1, then the boundary equilibriumis globally asymptotically stable. If R0(τ1, τ2) > 1, then there exists a unique positive equilibrium whose local asymptotic stability and the existence of Hopf bifurcations are established by analyzing the distribution of the characteristic values. An explicit algorithm for determining the direction of Hopf bifurcations and the stability of the bifurcating periodic solutions is derived by using the normal form and the center manifold theory. Some numerical simulations are performed to confirm the correctness of theoretical analysis. Finally, some conclusions are given.
Positive Solutions for the Generalized Nonlinear Logistic Equations
Authors: Gasiński Leszek , Papageorgiou Nikolaos S. 
Published: July 2015

AbstractWe consider a nonlinear parametric elliptic equation driven by a nonhomogeneous differential operator with a logistic reaction of the superdiòusive type. Using variationalmethods coupled with suitable truncation and comparison techniques, we prove a bifurcation type result describing the set of positive solutions as the parameter varies.
The Effect of Human Resources Practices on Organizational Commitment: A Jordanian Study
Authors: Suifan Taghrid Saleh 
Published: July 2015

<p><strong>Abstract</strong></p><p>The effect of human resources practices on organizational commitment was examined in this study using a sample of 500 subjects randomly selected from employees working for public and private organization in various industries in Amman, the capital city of Jordan. Of the mailed questionnaires, 431 questionnaires were returned with a response rate of 86 percent. A bulk of scales was adopted from related works to measure constructs. Organizational commitment was measured by organizational commitment scale developed by Meyer and Allen (1997), training was measured using a scale developed by Yahya and Goh (2002), person-organization fit was measured by a scale developed by Netemeyer et al. (1997), and, finally, rewards construct was measured by a scale adopted from Sejjaaka and Kaawaase (2014). The results pointed out that all HR practices examined (training, person-organization fit, and rewards) were significantly and positively associated with organizational commitment. Research limitations and future research directions were brought out. </p>
Radar signatures of snowflake riming: A modeling study
Authors: Leinonen Jussi , Szyrmer Wanda 
Published: July 2015

The capability to detect the state of snowflake riming reliably from remote measurements would greatly expand the understanding of its global role in cloud‐precipitation processes. To investigate the ability of multifrequency radars to detect riming, a three‐dimensional model of snowflake growth was used to generate simulated aggregate and crystal snowflakes with various degrees of riming. Three different growth scenarios, representing different temporal relationships between aggregation and riming, were formulated. The discrete dipole approximation was then used to compute the radar backscattering properties of the snowflakes at frequencies of 9.7, 13.6, 35.6, and 94 GHz. In two of the three growth scenarios, the rimed snowflakes exhibit large differences between the backscattering cross sections of the detailed three‐dimensional models and the equivalent homogeneous spheroidal models, similarly to earlier results for unrimed snowflakes. When three frequencies are used simultaneously, riming appears to be detectable in a robust manner across all three scenarios. In spite of the differences in backscattering cross sections, the triple‐frequency signatures of heavily rimed particles resemble those of the homogeneous spheroids, thus explaining earlier observational results that were compatible with such spheroids.