Apples, oranges, and the lunate sulcus

Holloway (1984) used a method of direct tape-arc measurements on chimpanzee brain casts to reject the hypothesis that the lunate sulcus is located in an anterior position in the Taung endocast. However, Holloway neglected to measure the occipital pole-lunate sulcus (OP-LS) arc directly on the Taung endocast as he did on chimpanzee brain casts (a crucial part of his methodology); instead, he determined the relative position of Taung's lunate sulcus on the basis of a calculation that confounds direct measurements and measurements from photographs. When arc OP-LS is measured directly on Taung according to Holloway's methods, the feature that has been identified as the medial end of the lunate sulcus is shown to be located within the range that Holloway determined for chimpanzees. Thus Holloway's methodology and data support rather than refute the claim that the lunate sulcus is located in a pongid-like position in australopithecines.     

Allometric growth of the sulcus in Cynoscion spp. (Sciaenidae)

The sulcus of Cynoscion spp. exhibited strong positive allometric growth relative to the medial surface of the otolith, and the ratio between the area of the sulcus and the otolith (S:O) increased dramatically with size. The S:O ratios of larger specimens are the highest that have so far been reported.     

Replication study of the insulin receptor gene in migraine with aura

We performed the first replication study for the reported association of the insulin receptor gene (INSR) with migraine with aura (MA). Two of 35 SNPs (rs1052371 and rs2860174) reached borderline significance (best uncorrected allelic p value of 0.052 for rs2860174) in stage 1 of our study (270 MA patients, 280 controls). As rs2860174 was 1 of the 5 SNPs with prior evidence of association, we also genotyped this SNP in our stage 2 sample (679 MA patients, 368 controls), and it was nonsignificant (allelic p value 0.478). The combined analysis of our samples showed just a nonsignificant trend for rs2860174 (p = 0.1). However, the joint analysis of our study and the initial study reporting an association—including 1278 Caucasian MA patients and 1337 Caucasian controls altogether—displayed a significant allelic p value of 0.005. In conclusion, further association studies for rs2860174 with even larger numbers of individuals are required to exclude or confirm definitely a small effect of this SNP on migraine susceptibility.     

Hominoid visual brain structure volumes and the position of the lunate sulcus

It has been argued that changes in the relative sizes of visual system structures predated an increase in brain size and provide evidence of brain reorganization in hominins. However, data about the volume and anatomical limits of visual brain structures in the extant taxa phylogenetically closest to humans-the apes-remain scarce, thus complicating tests of hypotheses about evolutionary changes. Here, we analyze new volumetric data for the primary visual cortex and the lateral geniculate nucleus to determine whether or not the human brain departs from allometrically-expected patterns of brain organization. Primary visual cortex volumes were compared to lunate sulcus position in apes to investigate whether or not inferences about brain reorganization made from fossil hominin endocasts are reliable in this context. In contrast to previous studies, in which all species were relatively poorly sampled, the current study attempted to evaluate the degree of intraspecific variability by including numerous hominoid individuals (particularly Pan troglodytes and Homo sapiens). In addition, we present and compare volumetric data from three new hominoid species-Pan paniscus, Pongo pygmaeus, and Symphalangus syndactylus. These new data demonstrate that hominoid visual brain structure volumes vary more than previously appreciated. In addition, humans have relatively reduced primary visual cortex and lateral geniculate nucleus volumes as compared to allometric predictions from other hominoids. These results suggest that inferences about the position of the lunate sulcus on fossil endocasts may provide information about brain organization.     

Alcohol-triggered signs of migraine: An animal model

We describe an animal model where characteristics of migraine can be triggered by alcohol administration. In rats chronically implanted with a cannula overlying the transverse sinus, we applied potassium chloride (KCl) (or saline) to the meninges to sensitize trigeminovascular afferents. We assessed effects of repeated KCl application on animal behavior using conditioned place avoidance paradigm. In KCl-treated rats we discovered that alcohol injections (0.2?mg/kg), but not saline, resulted in the development of extracephalic allodynia and signs of ongoing pain.     

A numerical phytosociological study of the summits of the majella massive (Italy)

Summary A phytosociological study of Majella's summits by the use of multivariate methods has allowed to discover the following new associations:Gnaphalio-Plantaginetum atratae on humocarbonatic soils in snowy depressions,Leontopodio-Elynetum on rendzina in wind exposed and stony places,Saxifrago-Papaveretum julici andCrepidi-Leontodontetum montani on protorendzina with gravel.Gnaphalio-Plantaginetum atratae andLeontopodio-Elynetum might be classified inElyno-Seslerietea, although the former presents character species ofSalicetea herbaceae; Saxifrago-Papaveretum julici andCrepidi-Leontodontetum montani are classified inThlaspidion stylosi (foeder. nova) ofThlaspidietea.Comparisons between some clustering methods and between ordination methods based on the mathematics of principal component analysis are discussed. The efficiency of sum of squares agglomeration when the plant communities vary in a continuum and the importance of a linearizing transformation in principal component analysis are stressed.The research was supported by a grant from the Italian CNR to Prof. D. Lausi. We wish to thank also Prof. L. Orlóci, Dr. E. van der Maarel and Prof. S. Pignatti for reading and discussing the text, and Mr. A. Zampar, S. Sedmak and T. Ubaldini for technical assistance.     

A numerical study of the nonsteady transport of gases in the pulmonary capillaries

A mathematical model is formulated for simulating the unsteady transport of gases in the blood flowing through the pulmonary capillaries. The formulation takes into account the transport mechanisms of molecular diffusion, convection and facilitated diffusion of the species due to haemoglobin. A time dependent situation is created by allowing to vary suddenly the partial pressures of the gases either in the venous blood or in the alveolar air. A numerical technique is described to solve the resulting time-dependent system of nonlinear coupled partial differential equations with the physiologically relevant boundary, entrance and initial conditions. The time required by the gases to achieve equilibrium is computed. It is shown that the dissolved oxygen takes longest in reaching equilibration whereas the carbon dioxide is the fastest. The various physiologically relevant unsteady situations have been examined.     

Effectiveness of Petasites hybridus preparations in the prophylaxis of migraine: A systematic review

The objective of this review was to evaluate the strength of evidence of effectiveness for Petasites hybridus in the prophylaxis of migraine. Several databases and other sources were searched to identify randomised-controlled trials investigating P. hybridus preparations. Two trials totalling 293 patients (60 and 233 patients) were included in this review. Both trials investigated the proprietary Petasites root extract Petadolex^®. The trials were described in narrative way, taking into consideration methodological quality scores. Pooling of data was not carried out due to the heterogeneity of the results. The extract at higher dose (150 mg) showed a greater decreased frequency of migraine attacks and a greater number of responders (improvement >50%) after treatment over 3–4 months than the extract at lower dose (100 mg) and placebo. Moderate evidence of effectiveness is, thus, available for a higher than the recommended dose of the proprietary Petasites root extract Petadolex^® in the prophylaxis of migraine. Further rigorous studies are required to confirm effectiveness and safety in long-term use before treatment with Petasites root extract can be recommended as an alternative option in the treatment schedule for the prophylaxis of migraine.     

外源输入对大亚湾大鹏澳浮游生物影响的模拟研究

本文通过建立一个简单的浮游植物、浮游动物和营养盐动力学数值模型,根据大亚湾大鹏澳秋季一个月的连续观测资料,利用线性回归分析法来求得上述动力学数值模型的一些主要参数,结果表明,降雨及陆源输入是导致该海区营养盐增加的一个重要因子;根据上述参数进行的数值模拟结果与实测结果基本吻合,同时也表明,降雨及陆源输入对该海区浮游植物和浮游动物的分布规律影响较大。     

A numerical classification of European Spartina communities

Summary The classical syntaxonomical treatment of the European Spartina communities as published in the series Prodrome of the the European plant communities, is compared with the results of a numerical treatment, based on largely the same set of relevés. 576 relevés, selected from the total salt marsh data set were subjected to agglomerative clustering with relocation with the similarity ratio as similarity measure. The resulting numerical system was compared with the syntaxonomical hierarchy. The correlation between both systems is close. The numerical units are slightly more heterogeneous because no purification occurred, which implies relevés to be left out of consideration. One new syntaxon, Spartinetum townsendii asteretosum tripolii, could be suggested from the results of the numerical treatment. Perspectives for the development of a numerical syntaxonomy are stressed.Communication number 40.     

3D patient-specific numerical modeling of the soft palate considering adhesion from the tongue

Collapse of the soft palate in the upper airway contributes to obstructive sleeping apnea (OSA). In this study, we investigate the influence of the adhesion from the tongue on the soft palate global response. This is achieved using a cohesive zone finite element approach. A traction-separation law is determined to describe the adhesion effect from the surface tension of the lining liquid between the soft palate and the tongue. According to pull-off experimental tests of human lining liquid from the oral surface of the soft palate, the corresponding cohesive properties, including the critical normal traction stress and the failure separation displacement, are obtained. The 3D patient-specific soft palate geometry is accounted for, based on one specific patient’s computed tomography (CT) images. The calculation results show that influence of the adhesion from the tongue surface on the global response of the soft palate depends on the length ratio between the cohesive length and the soft palate length. When the length of the cohesive zone is smaller than half of the soft palate length, the adhesion’s influence is negligible. When the adhesion length is larger than 70 percent of soft palate length, the adhesion force contributes to preventing the soft palate from collapsing towards to the pharynx wall, i.e. the closing pressure is more negative than in the no adhesion case. These results may provide useful information to the clinical treatment of OSA patients.     

Modeling and numerical simulation of biotin carboxylase kinetics: implications for half-sites reactivity

Biotin carboxylase catalyzes the ATP-dependent carboxylation of biotin and is one component of the multienzyme complex acetyl-CoA carboxylase that catalyzes the first committed step in fatty acid synthesis in all organisms. In Escherichia coli, biotin carboxylase exists as a homodimer where each subunit contains a complete active site. In a previous study (Janiyani, K., Bordelon, T., Waldrop, G.L., Cronan Jr., J.E., 2001. J. Biol. Chem. 276, 29864-29870), hybrid dimers were constructed where one subunit was wild-type and the other contained an active site mutation that reduced activity at least 100-fold. The activity of the hybrid dimers was only slightly greater than the activity of the mutant homodimers and far less than the expected 50% activity for completely independent active sites. Thus, there is communication between the two subunits of biotin carboxylase. The dominant negative effect of the mutations on the wild-type active site was interpreted as alternating catalytic cycles of the active sites in the homodimer. In order to test the hypothesis of oscillating catalytic cycles, mathematical modeling and numerical simulations of the kinetics of wild-type, hybrid dimers, and mutant homodimers of biotin carboxylase were performed. Numerical simulations of biotin carboxylase kinetics were the most similar to the experimental data when an oscillating active site model was used. In contrast, alternative models where the active sites were independent did not agree with the experimental data. Thus, the numerical simulations of the proposed kinetic model support the hypothesis that the two active sites of biotin carboxylase alternate their catalytic cycles.     

A specification of numerical taxonomy: Thermodynamical taxonomy

Thermodynamic taxonomy (ThT) is established from both a theoretical and pragmatical point of view. An application of thermodynamic taxonomy is given.     

Palatal implant surgery effectiveness in treatment of obstructive sleep apnea: A numerical method with 3D patient-specific geometries

Obstructive sleep apnea (OSA) affects a large percentage of the population and is increasingly recognized as a major global health problem. One surgical procedure for OSA is to implant polyethylene (PET) material into the soft palate, but its efficacy remains to be discussed. In this study, we provide input to this topic based on numerical simulations. Three 3 dimensional (3D) soft palate finite element models including mouth-close and mouth-open cases were created based on three patient-specific computed tomography (CT) images. A simplified material modeling approach with the Neo-Hookean material model was applied, and nonlinear geometry was accounted for. Young’s modulus for the implant material was obtained from uniaxial tests, and the PET implant pillars were inserted to the 3D soft palate model. With the finite element model, we designed different surgical schemes and investigated their efficacy with respect to avoiding the soft palate collapse. Several pillar schemes were tested, including different placement directions, different placement positions, different settings for the radius and the array parameters of the implant pillars, and different Young’s moduli for the pillars. Based on our simulation results, the longitudinal-direction implant surgery improved the stiffness of the soft palate to a small degree, and implanting in the transverse direction was evaluated to be a good choice for improving the existing surgical scheme. In addition, the Young’s modulus of the polyethylene material implants has an influence on the reinforcement efficacy of the soft palate.     

Morphological changes in the central sulcus of children with isolated growth hormone deficiency versus idiopathic short stature

In this study, the morphological changes in the central sulcus between children with isolated growth hormone deficiency (IGHD) and those with idiopathic short stature (ISS) were analyzed. Thirty children with IGHD (peak growth hormone < 5 µg/L) and 30 children with ISS (peak growth hormone > 10.0 µg/L) were included. Morphological measurements of the central sulcus were obtained from T1‐weighted MRIs using BrainVISA, including the average sulcal width, maximum depth, average depth, top length, bottom length, and depth position‐based profiles (DPPs). The bilateral average width of the central sulci was significantly wider, while the left maximum depth and right average depth of the central sulcus were significantly smaller, in children with IGHD than in children with ISS. There were no significant differences in the right maximum depth, left average depth, or bilateral top length and bottom length of the central sulcus between groups. The DPPs of the middle part of both central sulci (corresponding to the hand motor activation area) and the inferior part of the right central sulcus (corresponding to the oral movement area) near the Sylvian fissure were significantly smaller in children with IGHD than in controls before false discovery rate (FDR) correction. However, all the above significant DPP sites disappeared after FDR correction. There were significant morphological changes in the three‐dimensional structure of the central sulcus in children with IGHD, which were the outcome of other more essential cortical or subcortical changes, resulting in their relatively slower development in motor, cognitive, and linguistic functional performance.     

A numerical algorithm for investigating the role of the motor-cargo linkage in molecular motor-driven transport

We extend the numerical algorithm developed by Wang et al. (2003. J. Theor. Biol. 221, 491-511) for studying biomolecular transport processes to include the linkage that connects molecular motors to their cargo. The new algorithm is used to investigate how the stiffness of the linkage affects the average velocity, effective diffusion coefficient, and randomness parameter. Three different models for molecular motors are considered: (1) a discrete stepping motor (2) a motor moving in a tilted-periodic potential and (3) a motor driven by a flashing potential. We demonstrate that a flexible motor-cargo linkage can make inferences on motor behavior based on measurements of the cargo's position difficult. We also show that even for the case of a tilted-periodic potential there exists an optimal stiffness of the linkage at which transport is maximized. The MATLAB code used in this paper is available at: http://www.unc.edu/approximatelytelston/code/.     

The role of purinergic signaling in the etiology of migraine and novel antimigraine treatment

Etiopathogenesis of migraine involves different structures of the central nervous system: the trigeminal nerve with nuclei located in the brain stem, vascular system, and the cerebral cortex as well as diverse mechanisms and pathological processes. The multidirectional action of purines in different cell types (blood vessels, neurons, and satellite glial cells) and through different types of purinergic receptors contributes to the etiopathogenesis of migraine pain. Adenosine triphosphate (ATP) and its derivatives are involved in initiation and propagation of migrenogenic signals in several ways: they participate in vasomotor mechanism, cortical spreading depression, and in fast transmission or cross-excitation based on the satellite glial cells in trigeminal ganglion. Contribution of purinergic signaling in the conduction of pain is realized through the activation of P1 and P2 receptors expressed widely in the central nervous system: on the neurons and glial cells as well as on the smooth muscles and endothelium in the vascular system. Therefore, the purinergic receptors can be an excellent target for pharmacologists constructing new antimigraine therapeutics. Moreover, the mechanisms facilitating ATP and adenosine degradation may prevent vasodilatation and thus avoid a secondary central sensitization during a migraine attack. Thus, agonists and antagonists of P receptors as well as ecto-enzymes metabolizing nucleotides/nucleosides could gain the growing attention as therapeutic agents.     

Isozymes inhibited by active site blocking: versatility of calcium indifferent hesperidin binding to phospholipase A2 and its significance

sPLA₂ is released under inflammatory conditions from neutrophils, basophils and T-cells. They cleave the cellular phospholipids leading to the release of arachidonic acid and there by provide intermediates for biosynthesis of inflammatory mediators. The focus of this study is on the interaction of hesperidin, a natural flavonoid with Group IB, IIA, and V and X isozymes of sPLA₂. Affinity of hesperidin towards PLA₂ isozymes was analyzed through enzymatic studies and molecular modeling. The experiments showed that hesperidin competitively inhibited PLA₂ with IC₅₀ of 5.1?µM. Molecular modeling studies revealed the association of hesperidin with the docking scores ?6.90, ?9.53, ?5.63 and ?8.29?kcal for isozymes Group IB, IIA, V and X of PLA₂ respectively. Their binding energy values were calculated as ?20.25, ?21.63, ?21.66 and ?33.43?kcal for the Group IB, IIA, V and X respectively. Structural model for Group V was made by homology modeling since no structural coordinates were available. Molecular dynamics studies were carried out to evaluate the structural stability of protein ligand complex. The analyses showed that hesperidin blocked the entry of the substrate to the active site of PLA₂ and it was indifferent to the differences of the isozymes. Hence, hesperidin might serve as lead for designing highly specific anti-inflammatory drugs directed to the PLA₂ isozyme specific to various diseases, with IC₅₀ value of therapeutic significance.     

A software tool for modeling and simulation of numerical P systems

A P system represents a distributed and parallel bio-inspired computing model in which basic data structures are multi-sets or strings. Numerical P systems have been recently introduced and they use numerical variables and local programs (or evolution rules), usually in a deterministic way. They may find interesting applications in areas such as computational biology, process control or robotics. The first simulator of numerical P systems (SNUPS) has been designed, implemented and made available to the scientific community by the authors of this paper. SNUPS allows a wide range of applications, from modeling and simulation of ordinary differential equations, to the use of membrane systems as computational blocks of cognitive architectures, and as controllers for autonomous mobile robots. This paper describes the functioning of a numerical P system and presents an overview of SNUPS capabilities together with an illustrative example. Availability: SNUPS is freely available to researchers as a standalone application and may be downloaded from a dedicated website, http://snups.ics.pub.ro/, which includes an user manual and sample membrane structures.