5,618 research outputs found
The Impact of Failing to Identify Suspect Effort in Patients Undergoing Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Assessment
This retrospective study examines how many adult patients would plausibly receive a diagnosis of attention-deficit/hyperactivity disorder (ADHD) if performance and symptom validity measures were not administered during neuropsychological evaluations. Five hundred fifty-four patients were extracted from an archival clinical dataset. A total of 102 were diagnosed with ADHD based on cognitive testing, behavior rating scales, effort testing, and clinical interview; 115 were identified as putting forth suspect effort in accordance with the Slick, Sherman, and Iverson (1999) criteria. From a clinical decision-making perspective, suspect effort and ADHD groups were nearly indistinguishable on ADHD behavior, executive function, and functional impairment rating scales, as well as on cognitive testing and key clinical interview questions. These results suggest that a significant percentage of those making a suspect effort will be diagnosed with ADHD using the most commonly employed assessment methods: an interview alone (71%); an interview and ADHD behavior rating scales combined (65%); and an interview, behavior rating scales, and most continuous performance tests combined (57%). This research makes clear that it is essential to evaluate task engagement and possible symptom amplification during clinical evaluations
String-Inspired Triplet See-Saw from Diagonal Embedding of SU(2)_L in SU(2)_A x SU(2)_B
Motivated by string constructions, we consider a variant on the Type II
see-saw mechanism involving the exchange of triplet representations of SU(2)_L
in which this group arises from a diagonal embedding into SU(2)_A x SU(2)_B. A
natural assignment of Standard Model lepton doublets to the two underlying
gauge groups results in a bimaximal pattern of neutrino mixings and an inverted
hierarchy in masses. Simple perturbations around this leading-order structure
can accommodate the observed pattern of neutrino masses and mixings.Comment: 8 pages; uses RevTe
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Serious Bacterial Infections Acquired During Treatment of Patients Given a Diagnosis of Chronic Lyme Disease - United States.
The term "chronic Lyme disease" is used by some health care providers as a diagnosis for various constitutional, musculoskeletal, and neuropsychiatric symptoms (1,2). Patients with a diagnosis of chronic Lyme disease have been provided a wide range of medications as treatment, including long courses of intravenous (IV) antibiotics (3,4). Studies have not shown that such treatments lead to substantial long-term improvement for patients, and they can be harmful (1,5). This report describes cases of septic shock, osteomyelitis, Clostridium difficile colitis, and paraspinal abscess resulting from treatments for chronic Lyme disease. Patients, clinicians, and public health practitioners should be aware that treatments for chronic Lyme disease can carry serious risks
Critical Success Factors for Inner City Businesses
We survey incumbent businesses in the Ouachita Enterprise Community primarily located in Monroe, Louisiana. We seek to discover what common factors are critical to the success of inner city businesses. Our results indicate that taxes are a strong negative factor while government regulation is a positive factor. The availability of information technology, good transportation links, and location are important positive factors. Internal factors such as good customer relations were important while production costs relatively unimportant. Internal factors were rated as more important than external factors suggesting training programs to be an effective economic development tool
Dynamical Arrest in Attractive Colloids: The Effect of Long-Range Repulsion
We study gelation in suspensions of model colloidal particles with
short-ranged attractive and long-ranged repulsive interactions by means of
three-dimensional fluorescence confocal microscopy. At low packing fractions,
particles form stable equilibrium clusters. Upon increasing the packing
fraction the clusters grow in size and become increasingly anisotropic until
finally associating into a fully connected network at gelation. We find a
surprising order in the gel structure. Analysis of spatial and orientational
correlations reveals that the gel is composed of dense chains of particles
constructed from face-sharing tetrahedral clusters. Our findings imply that
dynamical arrest occurs via cluster growth and association.Comment: Final version: Phys. Rev. Lett. 94, 208301 (2005
The social issues pedagogy vs. the traditional principles of economics: an empirical examination
Standardized test (TUCE) scores for students enrolled in a Social Issues course were compared to those of students in traditional Principles of Economics courses within the framework of a standard educational production function. The production function was estimated using Heckman's two-step procedure to correct for self-selection due to student attrition over the course of study. After controlling for student demographics, prior experiences, and academic aptitude, no significant test score differences were found between students in the Social Issues course and those in the Principles of Macroeconomics. However, Social Issues students were found to score significantly below students in the Principles of Microeconomics, ceteris paribus. The results also indicate that students had a higher probability of completion in the Social Issues course relative to a theory oriented Principles course
Communications Biophysics
Contains reports on five research projects.United States Air Force (Contract AF19(604)-4112)National Institute of Neurological Diseases and Blindness (B369 Physiology
The Regulation of Phosphoenolpyruvate Carboxylase in Stomatal Guard Cells of Commelina communis
A great deal of work has been done recently to investigate mechanisms which control plant metabolism. In the CAM and C4 systems, it was found that phosphoenolpyruvate carboxylase which catalyses the primary fixation of CO2 in these plants is controlled by a reversible phosphorylation mechanism, with the enzyme being more active in the phosphorylated form than the nonphosphorylated form. Stomatal guard cells exhibit a form of malate metabolism very similar to CAM, and require the pathway of malate synthesis to be active during stomatal opening, and inactive during closure. This pathway involves flux through phosphoenolpyruvate carboxylase. The main aim of the work described in this thesis was to investigate the regulation of phosphoenolpyruvate carboxylase in guard cells. In addition, signal transduction in stomatal guard cells has recently been investigated by many workers, and this system is often now regarded as a model for signal transduction in plants. An additional aim of this project, therefore, was to study aspects of the signalling process involved in regulation of guard cell phosphoenolpyruvate carboxylase. The first part of the work involved the definition of conditions that would reproducibly cause stomatal movements. Stomata in epidermal strips from the C3 plant Commelina communis were found to open when incubated in the light on a solution containing 25mM K2SO4 and which had air with a reduced concentradon of CO2 bubbled through it. When the epidermis was placed into darkness and normal air was bubbled through the medium, the stomata closed. Stomata were also found to open in response to the fungal toxin fusicoccin when incubated on 25mM K2SO4 in the dark. The possibility that guard cell phosphoenolpyruvate carboxylase is regulated by phosphorylation was investigated in several ways. The incubation of extracts of guard cell protoplasts with [gamma-32P] ATP, Mg2+ and cyclic AMP dependent protein kinase catalytic subunits showed that guard cell phosphoenolpyruvate carboxylase became phosphorylated in vitro. In the absence of added kinase, no phosphorylation of the enzyme was observed, even in the presence of 1mM free Ca2+. Incubation of intact guard cell protoplasts with [32P]-orthophosphate showed that the enzyme was also phosphorylated in vivo. The phosphorylation state of guard cell phosphoenolpyruvate carboxylase was increased when guard cell protoplasts were incubated with 50mM K+ in the light or with fusicoccin. The phosphorylation state of the enzyme did not increase when protoplasts were incubated in the presence of 50mM K+ in darkness or with either abscisic acid or okadaic acid, an inhibitor of protein phosphatases. Light stimulated phosphorylation of the enzyme was reversed when protoplasts were placed in darkness. Protein phosphatase 2A activity, known to be responsible for the dephosphorylation of phosphoenolpyruvate carboxylase in the CAM plant Bryophyllum fedtschenkoi, was detected in extracts of guard cell protoplasts. Fusicoccin-stimulated phosphorylation was prevented by the protein synthesis inhibitor cycloheximide, a phenomenon similar to observations made in the CAM and C4 systems. It was also found that cycloheximide appeared to retard the stomatal opening that occors in response to both light and fusicoccin. Assays were carried out to measure the activity and some of the kinetic parameters of guard cell phosphoenolpyruvate carboxylase. Enzyme activity was almost five fold higher at pH 8.0 than at pH 7.2, but the enzyme was relatively insensitive to the feedback inhibitor malate at higher pH. When measured at pH 7.8, increasing concentration of the inhibitor malate increased both apparent Km and apparent Vmax values and at malate concentrations higher than 5mM, the enzyme appeared to depart from Michaelis-Menten kinetics. When guard cell protoplasts were incubated in the presence of K2SO4 in the light and dark or with and without fusicoccin, no significant differences in Ki (malate) from protoplasts in different conditions were observed. Further attempts to change Ki (malate) by the incubation of guard cell extracts with protein phosphatases and kinases also produced no significant change. When enzyme assays were carried out at pH 7.0 in the presence of glucose 6- phosphate, the enzyme extracted from guard cell protoplasts which had been incubated in the light had a Km (PEP) of 4.7muM, whilst that from those incubated in the dark had a Km (PEP) of 10.7muM, with a probability of identity between the two of less than 7%. Extracts of fusicoccin-stimulated protoplasts contained phosphoenolpyruvate carboxylase with a Km (PEP) of 6.7muM, with a less than 18% probability of identity with the dark control. Ki (malate) was not found to change significantly when measured under these conditions, although Vmax was decreased in protoplasts which were incubated in the light or with fusicoccin compared to the dark control. These results provide strong evidence to suggest that guard cell phosphoenolpyruvate carboxylase is controlled by reversible phosphorylation, in a manner analagous to the CAM and C4 enzymes. In addition, consideration of these results leads to the suggestion that cytoplasmic K+ concentration is an important signalling factor in guard cells
Feasibility of self-structured current accessed bubble devices in spacecraft recording systems
The self-structured, current aperture approach to magnetic bubble memory is described. Key results include: (1) demonstration that self-structured bubbles (a lattice of strongly interacting bubbles) will slip by one another in a storage loop at spacings of 2.5 bubble diameters, (2) the ability of self-structured bubbles to move past international fabrication defects (missing apertures) in the propagation conductors (defeat tolerance), and (3) moving bubbles at mobility limited speeds. Milled barriers in the epitaxial garnet are discussed for containment of the bubble lattice. Experimental work on input/output tracks, storage loops, gates, generators, and magneto-resistive detectors for a prototype device are discussed. Potential final device architectures are described with modeling of power consumption, data rates, and access times. Appendices compare the self-structured bubble memory from the device and system perspectives with other non-volatile memory technologies
Characterizing the immune microenvironment of malignant peripheral nerve sheath tumor by PD-L1 expression and presence of CD8+ tumor infiltrating lymphocytes.
BackgroundMalignant peripheral nerve sheath tumor (MPNST) is an aggressive sarcoma with few treatment options. Tumor immune state has not been characterized in MPNST, and is important in determining response to immune checkpoint blockade. Our aim was to evaluate the expression of programmed death-ligand 1 (PD-L1), programmed cell death protein 1 (PD-1), and presence of CD8+ tumor infiltrating lymphocytes (TILs) in MPNST, and correlate these findings with clinical behavior and outcome.ResultsPD-L1 staining of at least 1% was seen in 0/20 nerves, 2/68 benign lesions and 9/53 MPNST. Two of 68 benign lesions and 7/53 (13%) MPNST had at least 5% PD-L1 staining. CD8 staining of at least 5% was seen in 1/20 (5%) nerves, 45/68 (66%) benign lesions and 30/53 (57%) MPNST. PD-L1 was statistically more prevalent in MPNST than both nerves and benign lesions (p=0.049 and p=0.008, respectively). Expression of PD-1 was absent in all tissue specimens. There was no correlation of PD-L1 or CD8 expression with disease state (primary versus metastatic) or patient survival.MethodsA comprehensive PNST tissue microarray was created from 141 surgical specimens including primary, recurrent, and metastatic MPNST (n=53), neurofibromas (n=57), schwannoma (n=11), and normal nerve (n=20). Cores were stained in triplicate for PD-L1, PD-1, and CD8, and expression compared between tumor types. These data were then examined for survival correlates in 35 patients with primary MPNST.ConclusionsMPNST is characterized by low PD-L1 and absent PD-1 expression with significant CD8+ TIL presence. MPNST immune microenvironment does not correlate with patient outcome
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