bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Tractable and Expressive Class of Marginal Contribution Nets and Its Applications
Authors: Elkind Edith , Goldberg Leslie Ann , Goldberg Paul W. , Wooldridge Michael 
Published: July 2009

AbstractCoalitional games raise a number of important questions from the point of view of computer science, key among them being how to represent such games compactly, and how to efficiently compute solution concepts assuming such representations. Marginal contribution nets (MC‐nets), introduced by Ieong and Shoham, are one of the simplest and most influential representation schemes for coalitional games. MC‐nets are a rulebased formalism, in which rules take the form pattern → value, where “pattern ” is a Boolean condition over agents, and “value ” is a numeric value. Ieong and Shoham showed that, for a class of what we will call “basic” MC‐nets, where patterns are constrained to be a conjunction of literals, marginal contribution nets permit the easy computation of solution concepts such as the Shapley value. However, there are very natural classes of coalitional games that require an exponential number of such basic MC‐net rules. We present read‐once MC‐nets, a new class of MC‐nets that is provably more compact than basic MC‐nets, while retaining the attractive computational properties of basic MC‐nets. We show how the techniques we develop for read‐once MC‐nets can be applied to other domains, in particular, computing solution concepts in network flow games on series‐parallel networks (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Representing Utility Functions via Weighted Goals
Authors: Uckelman Joel , Chevaleyre Yann , Endriss Ulle , Lang Jérôme 
Published: July 2009

AbstractWe analyze the expressivity, succinctness, and complexity of a family of languages based on weighted propositional formulas for the representation of utility functions. The central idea underlying this form of preference modeling is to associate numerical weights with goals specified in terms of propositional formulas, and to compute the utility value of an alternative as the sum of the weights of the goals it satisfies. We define a large number of representation languages based on this idea, each characterized by a set of restrictions on the syntax of formulas and the range of weights. Our aims are threefold. First, for each language we try to identify the class of utility functions it can express. Second, when different languages can express the same class of utility functions, one may allow for a more succinct representation than another. Therefore, we analyze the relative succinctness of languages. Third, for each language we study the computational complexity of the problem of finding the most preferred alternative given a utility function expressed in that language (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Computational Complexity of Choice Sets
Authors: Brandt Felix , Fischer Felix , Harrenstein Paul 
Published: July 2009

AbstractSocial choice rules are often evaluated and compared by inquiring whether they satisfy certain desirable criteria such as the Condorcet criterion, which states that an alternative should always be chosen when more than half of the voters prefer it over any other alternative. Many of these criteria can be formulated in terms of choice sets that single out reasonable alternatives based on the preferences of the voters. In this paper, we consider choice sets whose definition merely relies on the pairwise majority relation. These sets include the Copeland set, the Smith set, the Schwartz set, von Neumann‐Morgenstern stable sets, the Banks set, and the Slater set. We investigate the relationships between these sets and completely characterize their computational complexity, which allows us to obtain hardness results for entire classes of social choice rules (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cervical dystonia affects aimed movements of nondystonic segments
Authors: Pelosin Elisa , Bove Marco , Marinelli Lucio , Abbruzzese Giovanni , Ghilardi M. Felice 
Published: July 2009

AbstractPatients with focal dystonia exhibit proprioception abnormalities that can lead to kinematic deficits. Proprioceptive abnormalities are present in both symptomatic and asymptomatic body parts of dystonic patients. To ascertain whether in patients with idiopathic cervical dystonia (CD) movements performed with nondystonic segments display kinematic abnormalities, we studied trajectory formation of out and back arm reaching movements in 10 patients with CD (before and 3 weeks after treatment with Botulinum toxin) and in 10 age‐matched controls. Before treatment, patients with CD showed significant trajectory abnormalities when compared with normal controls. Patients' trajectories were more curved with asymmetrical temporal velocity profiles as well as increased hand path areas, and had longer reversal lags between the out and back segments. Treatment with botulinum toxin improved all the kinematic parameters. These results suggest that in patients with CD, movements performed with nondystonic segments are abnormal. The kinematic abnormalities are likely to derive from long‐standing defective integration of the proprioceptive input, which, in turn, causes general changes in the internal models of limb dynamics. It is plausible that treatment with botulinum toxin partially restores proprioceptive processing and thus, such internal models. © 2009 Movement Disorder Society
Characterisation of histone variant distribution in human embryonic stem cells by transfection of in vitro transcribed mRNA
Authors: Shaw Margaret L. , Williams Evan J. , Hawes Susan , Saffery Richard 
Published: July 2009

AbstractRecent studies, primarily in mouse embryonic stem cells, have highlighted the unique chromatin state of pluripotent stem cells, including the incorporation of histone variants into specific genomic locations, and its role in facilitating faithful expression of genes during development. However, there is little information available on the expression and subcellular localisation of histone variants in human embryonic stem cells (hESCs). In this study, we confirmed the expression of a panel of histone variant genes in several hESC lines and demonstrated the utility of transfection of in vitro transcribed, epitope‐tagged mRNAs to characterise the subcellular localisation of these proteins. The subcellular localisations of variant histone H3 (CENP‐A, H3.3), H2A (MACROH2A, H2AX, H2AZ, H2ABBD) and H1 (H1A, HB, H1C, H1D) were examined, revealing distinct nuclear localisation profiles for each protein. These data highlight the differences between murine (m) ESCs and hESCs, including the presence of a MACROH2A‐enriched inactive X chromosome in undifferentiated XX hESC lines. We also provide the first evidence for MACROH2A accumulation on the Y‐chromosome in XY hESCs. Mol. Reprod. Dev. 76: 1128–1142, 2009. © 2009 Wiley‐Liss, Inc.
Adductor T reflex abnormalities in patients with decreased patellar reflexes
Authors: Tataroglu Cengiz , Deneri Ersin , Ozkul Ayca , Sair Ahmet , Yaycioglu Soner 
Published: July 2009

AbstractThe adductor reflex (AR) is a tendon reflex that has various features that differ from other tendon reflexes. This reflex was tested in different disorders presenting with diminished patellar reflexes such as diabetic lumbosacral radiculoplexus neuropathy (DLRPN), L2–L4 radiculopathy, and distal symmetric diabetic neuropathy (diabetic PNP). The AR and crossed‐AR (elicited by tapping the contralateral patellar tendon) were recorded using concentric needle electrodes. Additionally, the patellar T reflex (vm‐TR) and vastus medialis H reflex (vm‐HR) were recorded using surface electrodes. AR was recorded in only one out of eight patients with DLRPN, but it was recorded in 21 out of 22 patients with L2–L4 radiculopathy (95.5%). Of these reflexes, only AR showed prolonged latency in the L2–L4 radiculopathy group. The latencies of AR, vm‐TR, and vm‐HR were prolonged in patients with diabetic PNP. We conclude that AR can be useful in the differential diagnosis of some lower motor neuron disorders that present with patellar reflex disturbance. Muscle Nerve 40: 264–270, 2009
Actin sliding velocity on pure myosin isoforms from dystrophic mouse muscles
Authors: Canepari Monica , Rossi Rosetta , Pansarasa Orietta , Maffei Manuela , Bottinelli Roberto 
Published: July 2009

AbstractDuchenne muscular dystrophy (DMD) is a genetic disease characterized by skeletal muscle wasting and atrophy. Recent evidence suggests that the impaired skeletal muscle performance in DMD is not solely dependent on a loss of contractile muscle mass. In this study the myosin motor function of mdx and control (wildtype, WT) mice was compared using pure myosin isoforms in an “in vitro motility assay” (IVMA). Actin sliding velocity (Vf) on myosin 2B extracted from single muscle fibers of gastrocnemius muscles was significantly lower in mdx mice (3.48 ± 0.13 μm/s, n = 18) than in WT mice (4.02 ± 0.19 μm/s, n = 10). No difference in Vf was found between myosin 1 extracted from soleus muscles of mdx (0.84 ± 0.04 μm/s, n = 13) and of WT (0.89 ± 0.04 μm/s, n = 10). The results suggest that the dystrophic process alters myosin molecular function, and this contributes to the functional impairment in dystrophic muscles. Muscle Nerve 40: 249–256, 2009
Spinal angiography and epidural venography in juvenile muscular atrophy of the distal arm “Hirayama disease”
Authors: Elsheikh Bakri , Kissel John T. , Christoforidis Gregory , Wicklund Matthew , Kehagias Dimitri T. , Chiocca E. Antonio , Mendell Jerry R. 
Published: July 2009

AbstractWe studied two 16‐year‐old males with juvenile muscular atrophy of the distal arm, “Hirayama disease,” resulting in asymmetric atrophy and weakness of the distal upper extremities. Pathogenic theories include a compressive myelopathy with or without ischemia, and occasional cases are accounted for by genetic mutations. To specifically address the ischemia hypothesis we performed spinal angiography and epidural venography. Neck flexion during spinal angiography showed a forward shift of a nonoccluded anterior spinal artery without impedance to blood flow. Epidural venography demonstrated engorgement of the posterior epidural venous plexus without obstruction to venous flow. The findings do not support large vessel obstruction as a contributory factor. The Hirayama hypothesis continues to best explain the disease pathogenesis: neck flexion causes tightening of the dura and intramedullary microcirculatory compromise with resultant nerve cell damage. The age‐related factor can most likely be accounted for by a growth imbalance between the vertebral column and the cord/dural elements. Resolution of progression is associated with cessation of body growth, after which the symptoms plateau or modestly improve. Muscle Nerve 40: 206–212, 2009
Favorable response to rituximab in a patient with anti‐VGCC‐positive Lambert‐Eaton myasthenic syndrome and cerebellar dysfunction
Authors: Pellkofer Hannah L. , Voltz Raymond , Kuempfel Tania 
Published: July 2009

AbstractLambert‐Eaton myasthenic syndrome (LEMS) is an autoimmune disease that is characterized by impaired transmission across the neuromuscular junction due to autoantibodies directed against the presynaptic voltage‐gated calcium channels (VGCC‐ab). Clinical symptoms are usually characterized by proximal muscle weakness and mild dysautonomia. In some patients there are signs of cerebellar dysfunction as well, usually associated with cancer. Here we report the long‐term follow‐up of a patient with VGCC‐ab‐positive LEMS and a severe cerebellar syndrome but without evidence of cancer over 5 years. While conventional immunosuppressive therapy (steroids, azathioprine) failed, he improved with plasma exchange and consecutive treatment with rituximab. Muscle Nerve 40: 305–308, 2009
Distal‐symmetric focal inflammatory myopathy distinct from focal myositis and polymyositis
Authors: Melzer Nico , Wessig Carsten , Ulzheimer Jochenc. , Reiners Karlheinz , Toyka Klausv. , Bendszus Martin , Stoll Guido 
Published: July 2009

AbstractWe describe an inflammatory myopathy that was symmetrically restricted to both gastrocnemius muscles in a young man. Histopathological findings were typical for polymyositis, but there were neither signs of generalization nor muscle weakness and wasting. This condition was highly sensitive to steroids and has been kept in remission for more than a year using azathioprine. Our findings add another entity to the spectrum of spatially restricted inflammatory myopathies. Muscle Nerve 40: 309–312, 2009
CD73 is expressed on invading T lymphocytes in the inflamed peripheral nerve
Authors: Meyer Zu Hörste Gerd , Reiners Jens , Lehmann Helmar C. , Airas Laura , Kieseier Bernd C. 
Published: July 2009

AbstractCD73 is a cell surface enzyme that modulates immune and inflammatory responses by affecting adenosine‐receptor‐mediated signaling. We examined its expression and cellular distribution in the inflamed human peripheral nerve. CD4+ and CD8+ T lymphocytes stained positive for CD73, with no differences in numbers between acute and chronic inflammatory polyneuropathies. Endothelial cells in the peripheral nerve did not express CD73. Our findings support the concept that CD73 is involved in lymphocyte entry into the inflamed nervous system. Muscle Nerve 40: 287–289, 2009
Effects of prednisolone on skeletal muscle contractility in mdx mice
Authors: Baltgalvis Kristen A. , Call Jarrod A. , Nikas Jason B. , Lowe Dawn A. 
Published: July 2009

AbstractCurrent treatment for Duchenne muscular dystrophy (DMD) is chronic administration of the glucocorticoid prednisolone. Prednisolone improves muscle strength in boys with DMD, but the mechanism is unknown. The purpose of this study was to determine how prednisolone improves muscle strength by examining muscle contractility in dystrophic mice over time and in conjunction with eccentric injury. Mdx mice began receiving prednisolone (n = 23) or placebo (n = 16) at 5 weeks of age. Eight weeks of prednisolone increased specific force of the extensor digitorum longus muscle 26%, but other parameters of contractility were not affected. Prednisolone also improved the histological appearance of muscle by decreasing the number of centrally nucleated fibers. Prednisolone treatment did not affect force loss during eccentric contractions or recovery of force following injury. These data are of clinical relevance, because the increase in muscle strength in boys with DMD taking prednisolone does not appear to occur via the same mechanism in dystrophic mice. Muscle Nerve, 2009
Quantitative sensation and autonomic test abnormalities in transthyretin amyloidosis polyneuropathy
Authors: Kim Dong Hwee , Zeldenrust Steven R. , Low Phillip A. , Dyck Peter J. 
Published: July 2009

AbstractThis study assesses the value of standard quantitative autonomic (QAT) and sensation (QST) tests in detecting, characterizing, and quantitating the severity of transthyretin amyloid polyneuropathy (TTR‐A‐PN). This information is needed for prospective therapeutic trials, epidemiologic surveys, and medical practice. We reviewed 36 patients with TTR‐A‐PN who were evaluated between 1997 and 2007. They had neurologic, genetic, electrodiagnostic, and autonomic reflex screen evaluations and allowed their medical records and test results to be evaluated for research purposes. Of these, 22 patients had also been tested by quantitative sensation tests (QSTs). The median symptom duration was 4 years (range 1–30 years). Among quantitative nerve tests evaluated, composite scores of nerve conduction (Σ5 NC nds), a composite score of QSTs (Σ3 QST nds), and quantitative autonomic tests (QSART, HRdb, and CASS) gave high frequencies of abnormality. The results show that peripheral autonomic and small‐fiber sensory dysfunction was prominent and characteristic of most of the patients we studied. However, this involvement was not selective for small‐diameter sensory and autonomic nerve fibers; large motor and sensory fibers were also shown to be dysfunctional. Dysfunction of large fibers was approximately as frequent as that of small fibers. This study provides a rationale for the use of QAT, QST, and Σ5 NC nds as standard, objective, and quantitative measures for assessing the severity of TTR‐A‐PN in epidemiologic surveys, therapeutic trials, and medical practice. Muscle Nerve, 2009
Clinical utility of electrodiagnostic studies in the inpatient setting
Authors: Perry Daryl I. , Tarulli Andrew W. , Nardin Rachel A. , Rutkove Seward B. , Gautam Shiva , Narayanaswami Pushpa 
Published: July 2009

AbstractAlthough nerve conduction studies/electromyograms are often requested to evaluate hospitalized patients (inpatients) with suspected neuromuscular diseases, their clinical utility has not been studied. They can be technically challenging, especially in intensive care units. We studied the contribution of inpatient electromyograms (IP‐EMGs) to the management of patients with suspected neuromuscular disorders. A total of 103 IP‐EMGs in 98 patients were analyzed. IP‐EMGs confirmed the clinical diagnosis in 53.3% and provided a new, clinically relevant diagnosis in 12.6%. IP‐EMGs revealed only an incidental diagnosis in 14.5%, were inconclusive in 16.5%, and were normal in 3%. In over a quarter of patients, IP‐EMGs assisted in planning further diagnostic evaluation or treatment. Although IP‐EMGs most often only confirm already suspected diagnoses, in a substantial minority of patients they lead to the identification of clinically unsuspected, significant diagnoses that alter subsequent clinical care. Muscle Nerve 40: 195–199, 2009
Acetylcholine receptor‐α subunit expression in myasthenia gravis: A role for the autoantigen in pathogenesis?
Authors: Sheng Jian Rong , Li Liang Cheng , Prabhakar Bellur S. , Meriggioli Matthew N. 
Published: July 2009

AbstractPrevious studies have shown increased expression of acetylcholine receptor‐alpha (AChR‐α) subunit transcripts in myasthenia gravis (MG) and experimental MG (EAMG), but none examined the functional properties of this overexpression. In this study we examined the mRNA and protein expression of AChR‐α as well as the pattern of α‐bungarotoxin labeling in muscle tissue from EAMG mice with varying disease severity. AChR‐α expression was increased considerably in endplates from mice with severe EAMG, but it was distinct and greatly in excess of α‐bungarotoxin labeling. This “aberrant expression” occurred in mice with morphologic endplate damage, and the pattern of complement and immunoglobulin deposition in muscle from these mice appeared to mirror the pattern of AChR‐α expression. The loss of functional AChR in severe MG increases transcription of AChR‐α mRNA, but the expressed protein is “functionally inert,” failing to compensate for loss of AChR. This enhanced expression of AChR may play a role in driving the ongoing autoimmune response. Muscle Nerve 40: 279–286, 2009
Clinical and experimental aspects of Adreno‐muscarinic synergy in the bladder base and prostate
Authors: Roosen Alexander , Blake‐James Ben T. , Wood Daniel , Fry Christopher H. 
Published: July 2009

AbstractRecent clinical trials have shown that combination therapy using an alpha‐receptor antagonist and an antimuscarinic is more effective than either agent alone in improving quality of life and objective urodynamic variables in men with bladder outflow obstruction. There appear to be no negative effects on bladder function. The mode of action of this combination is unknown but presumed to be an antimuscarinic reduction in detrusor overactivity and the alpha‐receptor antagonist reduced outflow tract resistance. We have shown with in vitro experiments that in smooth muscles influencing outflow tract resistance (prostate, trigone) there is a profound contractile synergy between adrenergic and muscarinic pathways. We propose the hypothesis that both arms of the combination therapy reduce contractile tone of the outflow tract and that their simultaneous attenuation has a disproportionately large effect on outflow tract resistance. Our data from trigone muscle suggest that adrenergic and muscarinic receptor activation increase the intracellular [Ca2+] but the adrenergic pathway also operates through Ca2+‐sensitisation of the contractile apparatus, primarily through a PKC‐dependent pathway. Neurourol. Urodynam. 28:938–943, 2009. © 2009 Wiley‐Liss, Inc.
Intravaginal pressure generated during voluntary pelvic floor muscle contractions and during coughing: The effect of age and continence status
Authors: Madill Stéphanie J. , McLean Linda 
Published: July 2009

AbstractAimsThe purpose of this study was to determine if, compared to continent women, women with stress urinary incontinence (SUI) generate lower intravaginal pressure (IVP) during maximum voluntary pelvic floor muscle contractions (PFM MVCs) or coughing, slower contraction times or less ability to sustain IVP, and if there are reductions in the ability to generate IVP during these tasks associated with increasing age.MethodsEighty‐seven (35 continent, 35 with mild SUI and 17 with severe SUI) women participated. IVP data were acquired while participants performed PFM MVCs, maximum effort coughs and a sustained PFM contraction. The maximum IVP amplitudes measured during the MVCs and coughs, the time for IVP to reach a peak during coughing and the time for the IVP to drop by 50% during the sustained contraction were compared among the groups using separate analyses of covariance, with age included as a covariate.ResultsThere were no differences in maximum PFM MVC IVP or in endurance time among the groups. Women with SUI produced higher cough IVP amplitudes than continent women. Age was associated with a reduction in IVP and with longer contraction times during coughing.ConclusionsThe data suggest that PFM weakness may not be an important factor in the pathophysiology of SUI. Women with SUI may intuitively use their PFMs to compensate for urethral sphincter or fascial deficits. The IVP generated during coughing and the speed at which peak IVP is attained are, however, substantially reduced with increasing age, which might affect continence in older women. Neurourol. Urodynam. 29:437–442, 2010. © 2009 Wiley‐Liss, Inc.