cssi/SciSciGPT-SciSciNet huggingface dataset:
WNT8 and BMP2B co-regulate non-axial mesoderm patterning during zebrafish gastrulation

During vertebrate mesoderm formation, fates are established according to position in the dorsoventral (D/V) axis of the embryo. Initially, maternal signaling divides nascent mesoderm into axial (dorsal) and non-axial (ventral) domains. Although the subsequent subdivision of non-axial mesoderm into multiple D/V fate domains is known to involve zygotic Wnt8 and BMP signaling as well as the Vent/Vox/Ved family of transcriptional repressors, how levels of signaling activity are translated into differential regulation of fates is not well understood. To address this question, we have analyzed zebrafish embryos lacking Wnt8 and BMP2b. Zebrafish wnt8; swr (bmp2b) double mutants display a progressive loss of non-axial mesoderm and a concomitant expansion of axial mesoderm during gastrulation. Mesoderm induction and specification of the axial domain occur normally in wnt8; swr mutants, but dorsal mesoderm genes eventually come to be expressed throughout the mesoderm, suggesting that the establishment of non-axial mesoderm identity requires continual repression of dorsal mesoderm factors, including repressors of ventral genes. Loss-of-function for Vent, Vox, and Ved phenocopies the wnt8; swr mutant phenotype, consistent with Wnt8 and BMP2b maintaining non-axial mesoderm identity during gastrulation through the regulation of these three transcriptional repressors. We postulate that timely differentiation of the mesoderm requires the maintenance of non-axial mesoderm identity by Wnt8 and BMP2b at the onset of gastrulation followed by subdivision of the non-axial mesoderm into different functional domains during gastrulation.
Multiband s-wave topological superconductors: Role of dimensionality and magnetic field response

We further investigate a class of time-reversal-invariant two-bands-wave topological superconductors introduced in Phys. Rev. Lett. 108, 036803 (2012). Provided that a sign reversal between the two superconducting pairing gaps is realized, the topological phase diagram can be determined exactly (within mean field) in one and two dimensions, as well as in three dimensions upon restricting to the excitation spectrum of time-reversal invariant momentum modes. We show how, in the presence of time-reversal symmetry, Z2 invariants that distinguish between trivial and non-trivial quantum phases can be constructed by considering only one of the Kramers’ sectors in which the Hamiltonian decouples into. We find that the main features identified in our original two-dimensional setting remain qualitatively unchanged, with non-trivial topological superconducting phases supporting an odd number of Kramers’ pairs of helical Majorana modes on each boundary, as long as the required phase dierence between gaps is maintained. We also analyze the consequences of time-reversal symmetry-breaking either due to the presence of an applied or impurity magnetic field or to a deviation from the intended phase matching between the superconducting gaps. We demonstrate how the relevant notion of topological invariance must be modified when time-reversal symmetry is broken, and how both the persistence of gapless Majorana modes and their robustness properties depend in general upon the way in which the original Hamiltonian is perturbed. Interestingly, a topological quantum phase transition between helical and chiral superconducting phases can be induced by suitably tuning a Zeeman field in conjunction with a phase mismatch between the gaps. Recent experiments in doped semiconducting crystals, of potential relevance to the proposed model, and possible candidate material realizations in superconductors with s pairing symmetry are discussed.
The Dynamical Theory of Nuclear Induction

Starting from the microscopic viewpoint, the dynamics of nuclear induction is derived by means of statistical methods. The only essential lack of generality lies in the assumption that the nuclei in the sample are independent of each other, so that the treatment does not account for features arising from spin-spin interaction. By considering the simultaneous action of an arbitrary external field and of the molecular surroundings upon a representative nucleus a system of linear differential equations of the first order is derived for the "distribution matrix." It is analogous to the classical Boltzmann equation for the distribution function and allows, upon integration, to determine the macroscopic average value of any spin function in its dependence upon time. This general result is particularly applied to the time dependence of the macroscopic nuclear polarization, and the conditions are investigated under which it satisfies the phenomenological differential equation originally proposed by one of the authors (F.B.). Besides the fact that this equation does not describe line structures caused by the interaction of neighboring spins its validity is found to be seriously restricted only for nuclei having a spin larger than unity and in cases where, in addition, quadrupole relaxation is essential. It demands in these cases that the molecular surroundings are isotropic, e.g., as in gaseous and liquid samples, and further, that their characteristic frequencies of interaction with the nuclei are large compared to the Larmor frequency so that there exists equality between the longitudinal and the transverse relaxation time.
The Comparative Influences of Transformational Leadership and Leader–Member Exchange on Follower Engagement

Scholars of transformational leadership and leader–member exchange (LMX) have argued that leaders are able to positively influence the job attitudes and behaviors of followers by different means. Whereas transformational leadership focuses on the leaders’ ability to transform followers through a global inspiring vision that encourages positive change among all employees, LMX highlights the importance of the leaders’ unique relationships with followers as the driver of positive attitudes and behaviors. Using field data gathered from 280 full-time employees, the current research compared the influence of these two leadership styles on follower engagement. The results suggested that rather than the influence derived from inspirational leadership behaviors, it is employees’ unique relationship with their leader that creates follower engagement. Additionally, the results indicated that follower engagement mediates the relationship between leadership and key employee outcomes (i.e., organizational citizenship behavior [OCB] and employee turnover intentions). Implications to theory and practice are discussed.
Testing Word Knowledge by Telephone To Estimate General Cognitive Aptitude Using an Adaptive Test.

Abstract A computerized adaptive test of word knowledge was administered over the telephone by reading items and response alternatives to 144 individuals who had recently enlisted in the U.S. Army and had completed the Armed Services Vocational Aptitude Battery (ASVAB). The ASVAB was developed to assess the trainability of potential recruits and ASVAB data are used to compute Armed Forces Qualification Test (AFQT) scores. Subject responses were entered into a computer by a telephone interviewer, thereby allowing the computerized adaptive test program to accurately estimate individual differences by presenting approximately 10 verbal items. The Telephone Test and the AFQT scores correlated .66 in this sample, and a population correlation of .81 was estimated based on the bivariate correction for range restriction. A confirmatory factor analysis supported a four factor solution with the Telephone Test loading at a very high level (.91) on a Verbal factor, which had a substantial loading (.72) on Psychometric g . The correlations, factor loadings and administration time (5 to 10 minutes) indicate that the procedure provides an excellent measure of crystallized verbal aptitude that could be incorporated into telephone interviews and used to estimate general cognitive aptitude.
A composite viscoelastic model for incorporating grain boundary sliding and transient diffusion creep; correlating creep and attenuation responses for materials with a fine grain size

A new viscoelastic creep function that incorporates both the effects of elastically-accommodated grain boundary sliding (GBS) and transient diffusion creep is proposed. It is demonstrated that this model can simultaneously describe both the transient microcreep curves and the shear attenuation/modulus dispersion in a fine-grained (d ∼ 5 µm) peridotite (olivine + 39 vol. % orthopyroxene) specimen. Low-frequency shear attenuation, , and modulus dispersion, G(ω), spectra were measured in a one-atmosphere reciprocating torsion apparatus at temperatures of 1200 ≤ T ≤ 1300°C and frequencies of 10−2.25 ≤ f ≤ 100 Hz. Reciprocating tests were complemented by a series of small stress (τ ∼ 90 kPa) microcreep experiments at the same temperatures. In contrast to previous models where the parameters of viscoelastic models are derived by fitting the Laplace transform of the creep function to measured attenuation spectra, the parameters are derived solely from the fit of the creep function to the experimental microcreep ...
Dopamine uptake inhibitory capacities of β-carboline and 3,4-dihydro-β-carboline analogs of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) oxidation products

Potentially endogenous β-carboline and 3,4-dihydro-β-carboline alkaloidal compounds were compared, generally as 2-methylated (quaternary) and normethylated pairs, to the neurotoxin, 1-methyl-4-phenyl-dihydropyridinium ion (MPP+), with respect to inhibition of [3H]dopamine uptake into rat striatal synaptosomal preparations. Although less potent than MPP+, several compounds displayed IC50 values for inhibition in the moderate range (12–24 μM). Notably, quaternization generally did not improve inhibitory potency, and the 3,4-dihydro-compounds often were more effective inhibitors than their heteroaromatic analogs. The partially competetive nature of inhibition by one of the more effective pairs, 2-methyl-harmine and harmine, was consistent with uptake of the beta-carbolines by the synaptosomal dopamine uptake system, as was the fact that the accumulation of 2-[14C]methyl-harmine was significantly reduced by low Na+ media and by nomifensine, a potent inhibitor of the dopamine transporter. When viewed with reports that certain 2-methyl-β-carbolines show MPP+-like toxicity in vitro and in vivo, these studies support the proposal that a mammalian β-carbolinium compound may be taken up by nigrostriatal neurons and provoke the neuronal degeneration underlying Parkinson's disease.
Evaluation of 3-[18F]Fluoro-α-fluoromethyl-p-tyrosine as a tracer for striatal tyrosine hydroxylase activity

Abstract 3-[ 18 F]Fluoro-α-fluoromethyl- p -tyrosine (3-F-FMPT) was evaluated as a tracer for CNS tyrosine hydroxylase (TH) activity in rodents and in a rhesus monkey. Results of in vitro experiments using rat striatal homogenates showed that the introduction of fluorine into the 3-phenyl position did not significantly alter the ability of FMPT to act as a TH-activated l -aromatic amino acid decarboxylase ( l -AAAD) inhibitor. These studies further showed that 3-F-FMPT-induced l -AAAD inhibition was dose-dependent. Furthermore, striatal homogenates prepared from rats pretreated with the potent TH inhibitor α-methyl- p -tyrosine was found to have diminished 3-F-FMPT-induced l -AAAD inhibition. However, despite these promising in vitro results, the biodistribution of this compound in mice showed low brain uptake and fast clearance through the kidneys. A PET study using a Rhesus monkey injected with 3-[ 18 F]F-FMPT confirmed the results obtained in mice, i.e. negligible brain uptake but high localization in the bladder. We conclude that 3-[ 18 F]F-FMPT would not be useful as a tracer for cerebral TH activity.
Metalorganic chemical vapor deposition growth and characterization of InGaP/GaAs superlattices

Lattice-matched In0.49Ga0.51P/GaAs superlattices were grown on (001) GaAs substrates using metalorganic chemical vapor deposition. The interface properties were characterized by photoluminescence, transmission electron microscopy, and x-ray diffraction. By varying the growth temperature, the precursor flow rates, and the growth interruption at the interfaces, we found that, while arsenic and phosphorus carry over have some effect on the formation of a low-bandgap InGaAsP quaternary layer at the interfaces, the In surface segregation seems to play an important role in the formation of the interface quaternary layer. Evidence of this indium segregation comes from x-ray and photoluminescence studies of samples grown at different temperatures. These studies show that the formation of an interfacial layer is more prominent when the growth temperature is higher. Growing a thin (∼1 monolayer thick) GaP intentional interfacial layer on top of the InGaP before the growth of the GaAs layer at the P→As transition effectively suppresses the formation of the low-bandgap unintentional interface layer. On the other hand, the growth of a thin GaAsP (or GaP) layer before the growth of the InGaP layer, at the As→P transition increases the formation of a low-bandgap interfacial layer. This nonequivalent effect of a GaP layer at the two interfaces on the PL properties is discussed.
Influence of Weld Mismatch on the Structural Integrity of Pipes for Reeling

Structural integrity analysis of tough materials based on Elastic-Plastic Fracture Mechanics (EPFM) has been successfully employed in the assessment of components. EPFM has originally been developed for homogeneous materials and its applicability to inhomogeneous materials has some peculiarities. In particular, Fitness for Service design of welded pipes requires to know the weld fracture toughness and to estimate accurately the J-integral applied on the actual structural member. In this work, finite element analyses of simulated welds have been carried out in order to qualify and quantify the lack of accuracy of experimental methodologies for measuring fracture toughness of welds and the influence of welds on the applied J-integral in a pipe under bending. Different weld widths and cracks positions are characterized for single edge notch specimens in tension (SE(T)) and pipes. It has been found that inhomogeneity affects elastic-plastic fracture parameters for cracks centered in welds of certain widths. Moreover, the applied J-integral on pipes with circumferential cracks depends significantly on the weld width and crack position.Copyright © 2008 by ASME
The mechanisms for adult-onset apraxia and developmental dyspraxia: an examination and comparison of error patterns.

OBJECTIVES The purpose of this study was to determine whether persons with developmental dyspraxia and apraxia make similar errors during the performance of four types of tasks. METHOD Three groups of subjects with dyspraxia or apraxia (i.e., children with learning disabilities and dyspraxia, young adults with learning disabilities and dyspraxia, older adults with left-hemisphere brain damage with apraxia) and three groups of age-matched control subjects (i.e., children, young adults, older adults) were observed performing transitive, intransitive, verbal command, and imitation tasks. Performance was scored on the basis of the types of errors made. Errors were classified as conceptual (nonrelated, unrecognizable, sequencing) or production (omission, perseveration, related, internal configuration, external configuration, incorrect movement, body part as object). RESULTS No significant difference was found between conceptual and production error patterns for any group. In addition, there was no significant difference between the dyspraxia and apraxia groups or among the control groups on the specific types of production errors made. However, the dyspraxia and apraxia groups differed in the type of conceptual error made on the intransitive task. The body-part-as-object error was the most frequently made error on the transitive, verbal command, and imitation tasks, whereas the movement error was the most frequently made error on the intransitive task. CONCLUSION Subjects with dyspraxia or apraxia make similar errors, suggesting that the praxis behaviors are similar.
Early Experience with Single-Incision Thoracoscopic Surgery in the Pediatric Population

Abstract Introduction: Single-incision pediatric endosurgery is gaining popularity in children. We have recently applied the single-incision approach for thoracoscopic procedures. We report our initial experience with single-incision thoracoscopic surgery in the pediatric population. Methods: A retrospective chart review of the first 10 single-incision thoracoscopic operations done at our institution was conducted. The patients' mean age and weight and the median operative time, postoperative length of stay, and time until discontinuation of chest tubes were determined. Results: The 10 procedures were performed in eight patients (two patients each had bilateral procedures). The procedures performed included wedge resection and mechanical pleurodesis for spontaneous pneumothorax (n = 7), wedge biopsies for lymphoma (n = 1) and chronic granulomatous disease (n = 1), and resection of an apical extrapulmonary neuroblastoma (n = 1). All of the procedures were completed without intraoperative complication or si...
Rainbow scattering at shadowing and blocking critical angles

Abstract We show that blocking and shadowing effects for energetic ions scattering from more than one atom are special cases of rainbow scattering. Even at keV energies and above, the cross section at the critical angle for scattering must be evaluated by quantum or semi-classical means to avoid the singularity in the classically calculated cross sections. Experimentally observed scattered distributions are averaged over a large range of atomic orientations because of lattice vibrations, so supernumerary rainbows are not observed. Practical considerations for numeric evaluation of the cross section are discussed.
No association of DAPK1 and ABCA2 SNPs on chromosome 9 with Alzheimer's disease

Abstract Recently genetic variation in the DAPK1 and ABCA2 genes has been reported to be associated with late- and early-onset Alzheimer's disease (AD), respectively. We examined the most significant two single-nucleotide polymorphisms (SNPs) in DAPK1 in a large case–control cohort of late-onset subjects and matched controls and one of the most significant SNPs in ABCA2 in a small set of early-onset subjects as well. We did not detect associations with AD for any variation.
Amide-Amide Hydrogen Bonding. Semirubin Amides

Semirubins are analogs for one-half of the bilirubin structure and capable of intramolecular hydrogen bonding. Semirubin amides of ammonia and primary amines are also capable of intramolecular hydrogen bonding. From a combination of spectroscopic methods (1H NMR, NOE, and VPO), the primary amide is found to engage very effectively in intramolecular hydrogen bonding. The secondary and tertiary amides engage in both intramolecular (i) and intermolecular (ii) hydrogen bonding: N-methyl (i, monomer + ii, dimer), N-tert-butyl (ii, dimer), N,N-diethyl (i, monomer + ii, dimer). With an oxo-group at C(10), all of the amides are monomeric and most engage in intramolecular hydrogen bonding.
Concepts in Social and Spatial Marginality

The purpose of this paper is to present a conceptual taxonomy of marginality resulting from two counterposed structural conditions within laissez-faire on the one hand and controlled markets on the other. Marginality is a complex condition of disadvantage that individuals and communities may experience because of vulnerabilities which may arise from unequal or inequitable environmental, ethnic, cultural, social, political and economic factors. A typology of marginality is based on two primary and two derivative forms. The primary forms are contingent and systemic. The derivative forms are collateral and lever-aged. Contingent marginality is a condition that results from competitive inequality in which individuals and communities are put at a disadvantage because of the dynamics of the free market whose uncertain and stochastic outcomes affect them adversely. Systemic marginality is a socioeconomic condition of disadvantage created by socially constructed inequitable non-market forces of bias. Collateral marginality is a condition experienced by individuals or communities who are marginalized solely on the basis of their social and/or geographic proximity to individuals or communities that experience either contingent or systemic marginality. Lever-aged marginality is a contingent or systemic disadvantage that people/communities are made to experience when their bargaining position in free markets is weakened by dominant stakeholders like transnational corporations which are able to leverage lucrative concessions by using the threat of alternative, often cheaper and marginalized (contingent or systemic) labour pools to which they can potentially take their business.
Separation of chiral molecules using polypeptide-modified poly(vinylidene fluoride) membranes

Abstract A membrane-based chiral separation system was developed by the modification of poly(vinylidene fluoride) (PVDF) ultrafiltration membranes with polyglutamate derivatives. Both physisorbed and chemisorbed poly(γ-benzyl- l -glutamates) (PBLG) were vapor-deposited on the membranes, and the resulting poly(amino acids) were modified through debenzylation or ester exchange reaction to produce poly( l -glutamic acid) (PLGA) and polyglutamates with triethylene glycol monomethyl ether side chains (PLTEG). The enantioselectivities for chiral α-amino acids (tryptophan (Trp), phenylalanine (Phe), and tyrosine (Tyr)) and chiral drugs (propranolol, atenolol, and ibuprofen) were determined by performing permeation cell experiments, with enantioselectivities ranging from 1.04 to 1.47. The selectivity of PLGA increased as its helical content increased, which occurred at high ethanol concentrations and at low pH. In addition, an increase in enantioselectivity was observed for chemically grafted polymers compared to physisorbed polypeptides. This may be attributed to an increase in molecular weight (MW) and density of the polymer chains, which may enhance the interaction between the chiral compounds and the surface-bound polypeptides.
Radiographic survey for extraluminal air following gastrointestinal tract fiberendoscopy

The frequency of pneumoperitoneum following fiberoptic endoscopy was evaluated in 124 patients who had standard abdominal radiographs taken following routine endoscopy. Three patients had intramural air (1 of 95 following peroral endoscopy, 2 of 21 following colonoscopy). None developed pneumoperitoneum, and none had pain.
An electron-microscopic study of methionine deficient Escherichia coli

The morphology of E. coli K-12 (mutant 58/161 of Reubner) grown in a simple salt and glucose solution containing various concentrations of L-methionine and also in nutrient broth has been determined by examining electron micrographs of thin sections of osmium-fixed bacteria. The morphology of the organisms grown in high concentrations of methionine and in broth was similar. Bacteria grown in methionine deficient media contained numerous round, apparently hollow vesicles of 600 A diameter in their cytoplasm. The relationship of these vesicles to previously described cytoplasmic structures has been discussed.
Insulin Resistance and Endothelial Dysfunction in Atherosclerosis: Implications and Interventions

Current research suggests that insulin resistance is associated with endothelial dysfunction, which is considered an early but significant step in the pathogenesis of atherosclerosis. Both insulin resistance and endothelial dysfunction appear to precede the development of overt hyperglycemia in patients with type 2 diabetes. Therefore, in patients with diabetes or insulin resistance, endothelial dysfunction may be a critical early target for preventing atherosclerosis and cardiovascular disease. Insulin-sensitizing agents - specifically, thiazolidinediones (TZDs) - may be useful for preventing or mitigating endothelial dysfunction. In vitro and clinical data show that TZDs can limit thrombotic, inflammatory, and oxidative changes that contribute to endothelial dysfunction. For example, TZDs have been shown to lower blood levels of plasminogen activator inhibitor-1, a prothrombotic substance, in patients with diabetes or insulin resistance. In obese patients, TZD treatment can improve vascular reactivity a...
Optimal Performance of Networked Control Systems with Nonclassical Information Structures

A discrete time stochastic feedback control system consisting of a nonlinear plant, a sensor, a controller, and a noisy communication channel between the sensor and the controller is considered. The sensor has limited memory and, at each time, it transmits an encoded symbol over the channel and updates its memory. The controller receives a noise-corrupted copy of the transmitted symbol. It generates a control action based on all its past observations and all its past actions. This control action is fed back to the plant. At each time instant the system incurs an instantaneous cost depending on the state of the plant and the control action. The objective is to choose encoding, memory update, and control strategies to minimize an expected total cost over a finite horizon, or an expected discounted cost over an infinite horizon, or an average cost per unit time over an infinite horizon. A solution methodology for obtaining a sequential decomposition of the global optimization problem is developed. This solution methodology is extended to the case when the sensor makes an imperfect observation of the state of the plant.
Cause and implications of rock varnish microchemical laminations

Rock varnish is a dark coating composed mostly of clays and manganese and iron oxides1 that accretes on rock surfaces in all terrestrial environments2. Perry and Adams3 first observed micron-scale manganese-rich and manganese-poor (relatively iron-rich) layers in varnish and proposed that these may be related to unspecified environmental changes. Electron microprobe analyses reported here suggest that Mn:Fe ratios vary systematically with depth in varnishes on K/Ar-dated volcanic rocks from the Coso and Cima volcanic fields, eastern California, and on talus flatirons in the Negev Desert, Israel. These microchemical laminations probably reflect past fluctuations in the level of aeolian alkalinity, and possibly climatic change. This new indicator of terrestrial environmental change may be of importance to research on geomorphology, archaeology, palaeoclimatology, and Quaternary studies in arid environments.
Scaling towards kilo-core processors with asymmetric high-radix topologies

In this paper, we explore the challenges in scaling on-chip networks towards kilo-core processors. Current low-radix topologies optimize for fast local communication, but do not scale well to kilo-core systems because of the large number of routers required. These increase both power and hop count. In contrast, symmetric high-radix topologies optimize for global communication with fewer hop counts, but degrade local communication with their large, slow routers. To address both local and global communication optimizations independently, we decouple the interconnect design using asymmetric high-radix topologies. By setting a design goal of matching rauter speed with wire speed, our praposed topologies use fast medium-radix rauters to optimize for local communication and a few slow high-radix rauters that reduce hop count to optimize for global communication. Our asymmetric high-radix designs are enabled by recently praposed SwizzleSwitches, which allow us to achieve peiformance scalability within realistic power budgets. We prapose and evaluate two asymmetric high-radix topologies: Super-Star (asymmetric folded Clos) and Super-StarX (asymmetric folded Clos with superimposed mesh). Our evaluations show that the best performing asymmetric high-radix topology improves average network latency over a mesh by 45% while reducing the power consumption by 40%. When compared to symmetric high-radix topologies network thraughput is improved by 2.9× while still praviding similar latency benefits and power ejficiency.
Optimization of reference library used in content-based medical image retrieval scheme

Building an optimal image reference library is a critical step in developing the interactive computer-aided detection and diagnosis (I-CAD) systems of medical images using content-based image retrieval (CBIR) schemes. In this study, the authors conducted two experiments to investigate (1) the relationship between I-CAD performance and size of reference library and (2) a new reference selection strategy to optimize the library and improve I-CAD performance. The authors assembled a reference library that includes 3153 regions of interest (ROI) depicting either malignant masses (1592) or CAD-cued false-positive regions (1561) and an independent testing data set including 200 masses and 200 false-positive regions. A CBIR scheme using a distance-weighted K-nearest neighbor algorithm is applied to retrieve references that are considered similar to the testing sample from the library. The area under receiver operating characteristic curve (A{sub z}) is used as an index to evaluate the I-CAD performance. In the first experiment, the authors systematically increased reference library size and tested I-CAD performance. The result indicates that scheme performance improves initially from A{sub z}=0.715 to 0.874 and then plateaus when the library size reaches approximately half of its maximum capacity. In the second experiment, based on the hypothesis that a ROI should bemore » removed if it performs poorly compared to a group of similar ROIs in a large and diverse reference library, the authors applied a new strategy to identify 'poorly effective' references. By removing 174 identified ROIs from the reference library, I-CAD performance significantly increases to A{sub z}=0.914 (p<0.01). The study demonstrates that increasing reference library size and removing poorly effective references can significantly improve I-CAD performance.« less
A retrospective study of advancement genioplasty using a special bone plate

This study evaluates skeletal stability and the remodeling process of the advanced genial segment when a single bone plate is used to stabilize the segment following osteotomy of the inferior border of the mandible. Thirty-nine patients with a minimum of 6 months follow-up who had advancement genioplasty stabilized with a Paulus chin plate were analyzed using cephalometrics and clinical examination. The results showed that stability of the result was excellent; pogonion maintained its immediate postsurgical horizontal position at longest follow-up. The remodeling pattern observed was similar to that reported in other studies using alternate forms of fixation in spite of the fact that the bone plate covered the areas where most remodeling occurs.
Benzene: a case study in parent chemical and metabolite interactions

Benzene, an important industrial solvent, is also present in unleaded gasoline and cigarette smoke. The hematotoxic effects of benzene in humans are well documented and include aplastic anemia and pancytopenia, and acute myelogenous leukemia. A combination of metabolites (hydroquinone and phenol for example) is apparently necessary to duplicate the hematotoxic effect of benzene, perhaps due in part to the synergistic effect of phenol on myeloperoxidase-mediated oxidation of hydroquinone to the reactive metabolite benzoquinone. Since benzene and its hydroxylated metabolites (phenol, hydroquinone and catechol) are substrates for the same cytochrome P450 enzymes, competitive interactions among the metabolites are possible. In vivo data on metabolite formation by mice exposed to various benzene concentrations are consistent with competitive inhibition of phenol oxidation by benzene. In vitro studies of the metabolic oxidation of benzene, phenol and hydroquinone are consistent with the mechanism of competitive interaction among the metabolites. The dosimetry of benzene and its metabolites in the target tissue, bone marrow, depends on the balance of activation processes such as enzymatic oxidation and deactivation processes such as conjugation and excretion. Phenol, the primary benzene metabolite, can undergo both oxidation and conjugation. Thus, the potential exists for competition among various enzymes for phenol. However, zonal localization of Phase I and Phase II enzymes in various regions of the liver acinus regulates this competition. Biologically-based dosimetry models that incorporate the important determinants of benzene flux, including interactions with other chemicals, will enable prediction of target tissue doses of benzene and metabolites at low exposure concentrations relevant for humans.
Genetic variability of resistance to Eimeria acervulina and E. tenella in chickens.

The genetic variability of 18 sire families of the Athens-Canadian randombred population infected with coccidiosis was assessed by examining the response variables of weight gain, packed red blood cell volume, mortality and coccidial lesions. A significant gain and PCV depression and high lesion scores for Eimeria tenella and E. acervulina were produced in the infected group compared to the noninfected group. Significant variation among the sire families was observed for all of the response variables except E. acervulina lesions and a significant sex x sire interaction was observed for weight gain. The heritability (h2) estimates for the response variables revealed that resistance to coccidiosis in chickens is moderately heritable. The h2 estimates for gain and PCV increased with the coccidial infections indicating that maximum progress in selecting for resistance should be made when the population was exposed to coccidial infection. Gain was positively correlated to the other measures of resistance and thus selecting for coccidial resistance should not reduce growth rates. PCV was similarly correlated but had higher positive correlation with E. tenella lesion. Percent mortality which is the selection parameter in most coccidial selection programs was correlated with resistance to coccidiosis. The phenotypic and genotypic correlations demonstrated that chickens susceptible to E. tenella were also susceptible to E. acervulina. Total lesion scores were moderately to highly correlated with the other variables and would be a suitable variable to use in coccidiosis experimentation including a genetic selection program for resistance. This study shows that progress could be made in selecting for resistance to coccidiosis in chickens using one or a combination of these response variables.
Reliability of Lift Alert ™ as a feedback device for detecting changes in body position

The Lift Alert™is a small battery-operated unit, usually worn on the back of a worker's collar that is designed to provide a form of biofeedback about changes in trunk position during lifting tasks. The purpose of this study was to determine how consistent the Lift Alert™was at each of five different sensitivity settings (A-E) in detecting changes in trunk flexion in a given individual during a controlled bending maneuver. The subjects were videotaped while performing a series of trials of bending maneuvers at each of the sensitivity settings according to a specific protocol. The videotapes were then converted onto a computer program where the still images were captured and marked for data analysis. The reliability of the Lift Alert™was determined by calculating a coefficient of agreement, that is, the percentage of trials that were within both 10 and 15 degrees for each of the trials at a given setting for a single individual. The coefficient of agreement for all trials at all five settings was 0.76 within 10 degrees and 0.92 within 15 degrees. The results of this study suggest that the Lift Alert™is a reliable device for detecting changes in trunk flexion during a controlled bending maneuver for a given individual.
Mirage models confront the LHC. II. Flux-stabilized type IIB string theory

We continue the study of a class of string-motivated effective supergravity theories in light of current data from the CERN Large Hadron Collider (LHC). In this installment we consider type IIB string theory compactified on a Calabi-Yau orientifold in the presence of fluxes, in the manner originally formulated by Kachru et al. We allow for a variety of potential uplift mechanisms and embeddings of the Standard Model field content into $D3$-and $D7$-brane configurations. We find that an uplift sector independent of the K\"ahler moduli, as is the case with anti-$D3$-branes, is inconsistent with data unless the matter and Higgs sectors are localized on $D7$ branes exclusively, or are confined to twisted sectors between $D3$-and $D7$-branes. We identify regions of parameter space for all possible $D$-brane configurations that remain consistent with Planck observations on the dark matter relic density and measurements of the $CP$-even Higgs mass at the LHC. Constraints arising from LHC searches at $\sqrt{s}=8\text{ }\text{ }\mathrm{TeV}$ and the LUX dark matter detection experiment are discussed. The discovery prospects for the remaining parameter space at dark matter direct-detection experiments are described, and signatures for detection of superpartners at the LHC with $\sqrt{s}=14\text{ }\text{ }\mathrm{TeV}$ are analyzed.
Recognition and Diagnosis of Apical Hypertrophic Cardiomyopathy

Recognition and diagnosis of nonobstructive apical hypertrophic cardiomyopathy is important to begin to understand the natural history and prognosis of such patients. Our experience with three patients indicates that a clue to the recognition of apical hypertrophic cardiomyopathy lies in the striking electrocardiographic repolarization changes consistent with subendocardial ischemia often prompting admission to the coronary care unit. The diagnosis of apical hypertrophic cardiomyopathy in two patients was confirmed by two-dimensional echocardiographic apical views, but due to a technically inadequate echocardiogram, the diagnosis in the third patient was made by left ventriculography. Two of the three patients underwent right and left cardiac catheterization and their rest and exercise hemodynamic data were consistent with restrictive cardiomyopathy.
Variations in latex protein profiles

Abstract Delayed hypersensitivity to natural latex is well documented, but there is an increasing number of reports of severe allergic reactions associated with exposure to latex products. Recent studies indicate that latex anaphylaxis is mediated by water soluble proteins in latex, but the specific antigen(s) responsible for the sensitization has not been definitively identified. Differences in the type and severity of the allergic reaction may be due to differences in an individual's sensitivity or variations in the constituent proteins found in latex. The purpose of this study was to assess the qualitative differences between the proteins present in a variety of latex sources. Proteins extracted from fresh and ammoniated latex and various latex products were separated by SDS-PAGE. Our results indicate that substantial variation exists in the constituent proteins obtained from various sources of raw latex, various latex products, as well as among the same product from various manufacturers. These qualitative differences in the proteins of various latex preparations may help explain, in part, variations in the reported identification of latex antigens.
Endoribonuclease activities of Trypanosoma brucei mitochondria.

Abstract RNA editing in kinetoplastids is a type of post-transcriptional processing that changes mitochondrial mRNA sequences by the addition or deletion of uridines. Multiple enzymatic activities, such as endoribonuclease and RNA ligase, are associated with this process and exist in a multienzyme complex. Endonuclease activities from Trypanosoma brucei mitochondrial extracts were fractionated by sequential ion exchange and gel filtration chromatography. The RNA editing specific endonuclease activity co-fractionated with in vitro editing while another endonuclease activity with a different substrate specificity, and the majority of mtRNase P activity fractionated away from the editing activity. The pH, salt, temperature, and Mg 2+ optima of all three endonucleases were determined. All three activities are sensitive to high temperature and protease digestion. In addition, treatment with micrococcal nuclease resulted in partial disruption of the editing complex and decreased pre-cleaved in vitro insertion editing activity, suggesting that both RNA(s) and protein(s) are necessary in the intact functional complex.
Putative oxidative metabolites of 1-methyl-6-hydroxy-1,2,3,4-tetrahydro-β-carboline of potential relevance to the addictive and neurodegenerative consequences of ethanol abuse

Ethanol is metabolized in the brain by catalase/H2O2 to yield acetaldehyde and by an ethanol-inducible form of cytochrome P450 (P450 IIE1) in a reaction that yields oxygen radicals. Within the cytoplasm of serotonergic axon terminals these metabolic pathways together provide conditions for the endogenous synthesis of 1-methyl-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline (1), by reaction of acetaldehyde with unbound 5-hydroxytryptamine (5-HT), and for the oxygen radical-mediated oxidation of this alkaloid. The major initial product of the hydroxyl radical (HO.)-mediated oxidation of 1 in the presence of free glutathione (GSH), a constituent of nerve terminals and axons, is 8-S-glutathionyl-1-methyl-1,2,3,4-tetrahydro-beta-carboline-5,6-dione (6). When administered into the brains of mice, 6 is a potent toxin (LD50 = 2.9 microg) and evokes episodes of hyperactivity and tremor. Compound 6 binds at the GABA(B) receptor and evokes elevated release and turnover of several neurotransmitters. Furthermore, the GABA(B) receptor antagonist phaclofen attenuates the behavioral response caused by intracerebral administration of 6. These observations suggest that 6 might be an inverse agonist at the GABA(B) receptor site. Accordingly, it is speculated that ethanol drinking might potentiate formation of 6 that contributes to elevated release of several neurotransmitters including dopamine (DA) and endogenous opioids in regions of the brain innervated by serotonergic axon terminals. Subsequent interactions of DA and opioids with their receptors might be related to the initial development of dependence on ethanol. Redox cycling of 6 (and of several putative secondary metabolites) in the presence of intraneuronal antioxidants and molecular oxygen to produce elevated fluxes of cytotoxic reduced oxygen species might contribute to the degeneration of serotonergic pathways. Low levels of 5-HT in certain brain regions of the rat predisposes these animals to drink or augments drinking. Accordingly, 6, formed as a result of ethanol metabolism in the cytoplasm of certain serotonergic axon terminals, might contribute to the initial development of dependence on ethanol, by mediating DA and opioid release, and long-term preference and addiction to the fluid as a result of the progressive degeneration of these neurons.
Nonlinear material design using principal stretches

The Finite Element Method is widely used for solid deformable object simulation in film, computer games, virtual reality and medicine. Previous applications of nonlinear solid elasticity employed materials from a few standard families such as linear corotational, nonlinear St.Venant-Kirchhoff, Neo-Hookean, Ogden or Mooney-Rivlin materials. However, the spaces of all nonlinear isotropic and anisotropic materials are infinite-dimensional and much broader than these standard materials. In this paper, we demonstrate how to intuitively explore the space of isotropic and anisotropic nonlinear materials, for design of animations in computer graphics and related fields. In order to do so, we first formulate the internal elastic forces and tangent stiffness matrices in the space of the principal stretches of the material. We then demonstrate how to design new isotropic materials by editing a single stress-strain curve, using a spline interface. Similarly, anisotropic (orthotropic) materials can be designed by editing three curves, one for each material direction. We demonstrate that modifying these curves using our proposed interface has an intuitive, visual, effect on the simulation. Our materials accelerate simulation design and enable visual effects that are difficult or impossible to achieve with standard nonlinear materials.
CED-10/Rac1 Mediates Axon Guidance by Regulating the Asymmetric Distribution of MIG-10/Lamellipodin

Summary Axon migrations are guided by extracellular cues that induce asymmetric outgrowth activity in the growth cone [1, 2]. Several intracellular signaling proteins have been implicated in the guidance response [3–10]. However, how these proteins interact to generate asymmetric outgrowth activity is unknown. Here, we present evidence that in C. elegans, the CED-10/Rac1 GTPase binds to and causes asymmetric localization of MIG-10/lamellipodin, a protein that regulates actin polymerization and has outgrowth-promoting activity in neurons [5, 11]. Genetic analysis indicates that mig-10 and ced-10 function together to orient axon outgrowth. The RAPH domain of MIG-10 binds to activated CED-10/Rac1, and ced-10 function is required for the asymmetric MIG-10 localization that occurs in response to the UNC-6/netrin guidance cue. We also show that asymmetric localization of MIG-10 in growth cones is associated with asymmetric concentrations of f-actin and microtubules. These results suggest that CED-10/Rac1 is asymmetrically activated in response to the UNC-6/netrin signal and thereby causes asymmetric recruitment of MIG-10/lamellipodin. We propose that the interaction between activated CED-10/Rac1 and MIG-10/lamellipodin triggers local cytoskeletal assembly and polarizes outgrowth activity in response to UNC-6/netrin.
A theoretical investigation of the effects of pi-donor substituents on the frontier molecular orbitals of carbene ligands

Abstract Ab-initio calculations were performed on methylaminophenylcarbene, methoxyphenylcarbene, methylphenylcarbene, and methylcyclohexenylcarbene at the minimal (STO-3G) basis set level. The results are used to compare the effects of substituent heteroatoms and pi-conjugation on the ligand behavior of the carbene moeity. In particular, sigma donor and pi acceptor properties of the carbene ligand are treated in the context of the frontier molecular orbital formalism.
An Investigation into the Harms Dead Time Correction Procedure for Pulse Height Analyzers Using Monte Carlo Modeling Techniques

An automatic dead time correction technique for multichannel pulse height analyzers that does not make use of the usual live time correction has recently been proposed by J. Harms. In order to study the validity of this new correction technique, a Monte Carlo code was written to simulate the response of multichannel pulse height analyzers, incorporating both the Harms and standard live time correction techniques, to a variety of pulse height spectra. Simulated pulse height spectra of the type one might encounter from nuclear radiation detectors under a variety of count rate conditions were generated by the code. It was found that the Harms correction technique gave valid results in all cases tested, whereas the standard live time correction technique did not work properly when the spectral shape changed drastically during the course of the measurement.