cssi/SciSciGPT-SciSciNet huggingface dataset:
Age-related changes in the neurophysiology of language in adults: Relationship to regional cortical thinning and white matter microstructure

Although reading skill remains relatively stable with advancing age in humans, neurophysiological measures suggest potential reductions in efficiency of lexical information processing. It is unclear whether these age-related changes are secondary to decreases in regional cortical thickness and/or microstructure of fiber tracts essential to language. Magnetoencephalography, volumetric MRI, and diffusion tensor imaging were performed in 10 young (18–33 years) and 10 middle-aged (42–64 years) human individuals to evaluate the spatiotemporal dynamics and structural correlates of age-related changes in lexical-semantic processing. Increasing age was associated with reduced activity in left temporal lobe regions from 250 to 350 ms and in left inferior prefrontal cortex from 350 to 450 ms (i.e., N400). Hierarchical regression indicated that age no longer predicted left inferior prefrontal activity after cortical thickness and fractional anisotropy (FA) of the uncinate fasciculus (UF) were considered. Interestingly, FA of the UF was a stronger predictor of the N400 response than cortical thickness. Age-related reductions in left-lateralization of language responses were observed between 250 and 350 ms, and were associated with left temporal thinning and frontotemporal FA reductions. N400 reductions were not associated with poorer task performance. Rather, increasing age was associated with reduction in the left prefrontal N400, which in turn was also associated with slower response time. These results reveal that changes in the neurophysiology of language occur by middle age and appear to be partially mediated by structural brain loss. These neurophysiological changes may reflect an adaptive process that ensues as communication between left perisylvian regions declines.
Comparisons between tail probabilities of sums of independent symmetric random variables

Abstract We show how estimates for the tail probabilities of sums of independent identically distributed random variables can be used to estimate the tail probabilities of sums of non-identically distributed independent symmetric random variables which are majorized by a single distribution in the sense of Gut's (1992) weak mean domination. As an application, we prove a weak one-sided extension of a law of large numbers of Chen (1978) to a non-identically distributed case and show how some of Gut's (1992) extensions of Hsu-Robbins type laws of large numbers follow from previously known identically distributed cases. We also extend some theorems of Klesov (1993) to the case of weak mean domination. One intermediate result of independent interest is that if X 1 ,…, X n and Y 1 ,…, Y n are two collections of independent symmetric random variables such that P (| X k | ≥ λ ) ≤ P (| Y k | ≥ λ ) for every λ and k , then P (| Y 1 + … + Y n | ≥ λ ) ≤ 2 P (| X 1 + … + X n | ≥ λ ) for all λ.
TUI or GUI--It's a Matter of Somatics

The author considers the advantages and possibilities for developing and implementing touch-based interfaces.
Interkingdom signaling: Deciphering the language of acyl homoserine lactones

Bacteria use small secreted chemicals or peptides as autoinducers to coordinately regulate gene expression within a population in a process called quorum sensing. Quorum sensing controls several important functions in different bacterial species, including the production of virulence factors and biofilm formation in Pseudomonas aeruginosa and bioluminescence in Vibrio fischeri. Many gram-negative bacterial species use acyl homoserine lactones as autoinducers that function as ligands for transcriptional regulatory proteins. Several recent reports indicate that bacterial acyl homoserine lactones can also affect gene expression in host cells. Direct signaling also appears to function in the opposite direction as some eukaryotic cell types produce mimics that interact with quorum sensing systems in bacteria. Here, we will describe the evidence to support the existence of bi-directional interkingdom signaling via acyl homoserine lactones and eukaryotic mimics and discuss the potential molecular mechanisms that mediate these responses. The functional consequences of interkingdom signaling will be discussed in relation to both pathogenic and non-pathogenic bacterial–host interactions.
Virtuosity with the Mallet and Gouge: The Brilliant Triumph of the “Modern” Mastoid Operation

The development of mastoid surgery can be traced through the past 4 centuries. Once used as a means of evacuating a postauricular abscess, it has evolved to become a method for gaining entry into the middle ear for diagnostic purposes, to control chronic ear disease, or for otologic and neuro-otologic procedures. Earlier works led the way to the Wilde postauricular incision, which gave rise to Schwartze mastoidectomy. Stacke's technique of mastoidectomy was practiced for some time before Bondy, Heath, and Bryant introduced the modified radical mastoidectomy. By the 1930s, the mastoidectomy had evolved into a generally accepted otologic procedure. Endowed with a rich history, the future of mastoid surgery promises to be equally momentous.
Unleashed platelets in aHUS

Lack of regulation of the complement system is associated with thrombosis. In this issue of Blood , Stahl and colleagues report that deficiency of factor H in patients with atypical hemolytic uremic syndrome activates platelets and generates platelet microparticles. Several membrane and plasma
Nonlinear fluid slosh coupled to the dynamics of a spacecraft

The dynamics of a linear spacecraft mode coupled to the nonlinear low-gravity slosh of a fluid in a cylindrical tank is investigated. Coupled, nonlinear equations of motion for the fluid-spacecraft system are derived through an assumed mode Lagrangian method. Unlike a linear model, this nonlinear model retains two fundamental slosh modes and three secondary slosh modes. An approximate perturbation solution of the equations of motion indicates that the nonlinear coupled system response involves fluid-spacecraft modal resonances not predicted by either a linear, or a nonlinear, uncoupled slosh analysis. An experiment was developed to verify and complement this analysis. Scale model fluid tanks were coupled to an electromechanical analog for the second-order oscillatory spacecraft mode. Moderate and low gravity were simulated in 1 g using capillary scale models, and zero gravity was simulated in parabolic flight tests on the NASA KC-135 Reduced Gravity Test Facility. The experimental results substantiated the analytical predictions. The dependence of the coupled nonlinear response on the coupled system parameters and the gravity level is illustrated and discussed.
Evaluating Age in the Field Triage of Injured Persons

Study objective We evaluate trauma undertriage by age group, the association between age and serious injury after accounting for other field triage criteria and confounders, and the potential effect of a mandatory age triage criterion for field triage. Methods This was a retrospective cohort study of injured children and adults transported by 48 emergency medical services (EMS) agencies to 105 hospitals in 6 regions of the western United States from 2006 through 2008. We used probabilistic linkage to match EMS records to hospital records, including trauma registries, state discharge databases, and emergency department databases. The primary outcome measure was serious injury, as measured by an Injury Severity Score greater than or equal to 16. We assessed undertriage (Injury Severity Score ≥16 and triage-negative or transport to a nontrauma center) by age decile and used multivariable logistic regression models to estimate the association (linear and nonlinear) between age and Injury Severity Score greater than or equal to 16, adjusted for important confounders. We also evaluated the potential influence of age on triage efficiency and trauma center volume. Results Injured patients (260,027) were evaluated and transported by EMS during the 3-year study period. Undertriage increased for patients older than 60 years, reaching approximately 60% for those older than 90 years. There was a strong nonlinear association between age and Injury Severity Score greater than or equal to 16. For patients not meeting other triage criteria, the probability of serious injury was most notable after 60 years. A mandatory age triage criterion would have decreased undertriage at the expense of overtriage, with 1 patient with Injury Severity Score greater than or equal to 16 identified for every 60 to 65 additional patients transported to major trauma centers. Conclusion Trauma undertriage increases in patients older than 60 years. Although the probability of serious injury increases among triage-negative patients with increasing age, the use of a mandatory age triage criterion appears inefficient for improving field triage.
Antibiotic Prophylaxis and Dermatologic Surgery-Reply

In Reply.— Although Dr Lycka does not question the use of antibiotic prophylaxis for procedures such as oral, gastrointestinal, or genitourinary surgery, he avoids the fact that there have never been controlled clinical trials that prove that antibiotic prophylaxis will decrease the risk for bacterial endocarditis associated with these procedures. In fact, it is not likely that such a study will ever be conducted. 1 Thus, the decision to administer antibiotic prophylaxis against possible bacterial endocarditis is a medical judgment that rests on the specific risk-to-benefit ratio. It is our opinion that patients at high risk for bacterial endocarditis who undergo dermatologic surgery should receive appropriate antibiotic prophylaxis. 2 Fine et al 3 have recently reported significant bacteremia following the incision and drainage of abscesses and have advised for appropriate bacterial endocarditis prophylaxis. Kaye 4 has also recommended antibiotic prophylaxis against bacterial endocarditis for the surgical management of abscesses in
Structural phase stability in nanocrystalline titanium to 161 GPa

Nanocrystalline titanium (nc-Ti) metal was investigated up to 161 GPa at room temperature using a diamond anvil cell. X-ray diffraction and electrical resistance techniques were used to investigate the compressibility and structural phase stability. nc-Ti is observed to undergo three structural phase transitions at high pressures, starting with at 10 GPa and followed by at 127 GPa and at 140 GPa. The observed structural phase transitions, as well as compressibility, are consistent with previously reported values for coarse grained Ti (c-Ti). The high pressure experiments on nc-Ti samples do no show any significant variation of the transition pressure under varying non-hydrostatic conditions. This is in sharp contrast to c-Ti, where a significant decrease in the transition pressure is observed under increasing non-hydrostatic conditions. This would indicate that the decrease in grain size in nano grained titanium makes the phase transition less sensitive to shear stresses as compared to bulk or c-Ti.
The Lenoir thesis revisited: Blumenbach and Kant

Abstract Timothy Lenoir launched the historical study of German life science at the end of the 18th century with the claim that J. F. Blumenbach’s approach was shaped by his reception of the philosophy of Immanuel Kant: a ‘teleomechanism’ that adopted a strictly ‘regulative’ approach to the character of organisms. It now appears that Lenoir was wrong about Blumenbach’s understanding of Kant, for Blumenbach’s Bildungstrieb entailed an actual empirical claim. Moreover, he had worked out the decisive contours of his theory and he had exerted his maximal influence on the so-called ‘Gottingen School’ before 1795, when Lenoir posits the main influence of Kant’s thought took hold. This has crucial significance for the historical reconstruction of the German life sciences in the period. The Lenoir thesis can no longer serve as the point of departure for that reconstruction.
Species differences in the eeg response to epinephrine, 5-hydroxytryptamine and nicotine in brainstem transected animals

Summary--Species differences have been observed in the EEG activation response to intravenous epinephrine, 5-hydroxytryptamine, and nicotine in rabbits, cats, dogs and monkeys. It was also found that a relatively high level of brainstem transection was required to induce a slow wave EEG pattern in the monkey. In midpontine** rabbits, cats and dogs and high pontine monkeys EEG activation was seen after 10-20/zg/kg of nicotine. Similar doses of nicotine also produced EEG activation in prepontine§ rabbits and cats but not in the preponzinc dog. Also, whereas 4-8/~g/kg of epinephrine and 30 t~g/kg 5-hydroxytryptamine produced EEG activation in the midpontine rabbit anti cat, no such response was observed following the administration of these agents in the midpontine dog or high pontine monkey.
Effects of projected cortical epileptiform discharges on unit activity in the cat cuneate nucleus.

Abstract Recordings of single cells in the cuneate nucleus were made during cortical epileptiform activity. Spontaneous and evoked spiking activity of relay cells was primarily inhibited by the corticofugal epileptiform discharge. Most interneurons were inhibited, but a large proportion also showed an early excitatory corticofugal input. The EPSPs and IPSPs induced by corticofugal discharges were seen in intracellular and quasi-intracellular recordings of cuneate neurons. The observation of IPSPs, and the effectiveness of corticofugal input in inhibiting unit injury discharges and glutamate-induced firing, showed that corticofugal inhibition in cuneate was at least partially postsynaptic. Most cuneate neurons studied during cortical ictal episodes discharged in a fashion consistent with their responses to cortical interictal activity; i.e., units that had been inhibited were inhibited during the ictus and those that had been excited fired during the cortical seizure. Some units were gradually recruited by corticofugal input during seizure, but since most such units were interneurons, cuneate did not provide a positive feedback to the cortical focus. The corticocuneate pathway appeared to provide a negative feedback circuit which may be used to modulate transmission of sensory input.
Comparison of massive vs. repeated resection leading to short bowel syndrome

Short bowel syndrome can result from either a single massive intestinal resection or repeated lesser resections, which might have prognostic implications. The aim of this study was to compare patient populations and outcome of short bowel syndrome caused by massive and repeated resection. The records of 95 adult patients with short bowel syndrome evaluated over a 20-year period were reviewed. Massive resection was performed in 72 patients (76%) and repeated lesser resections in 23 patients (24%). Patients undergoing massive resection were more likely to be more than 70 years of age (26% vs. 9%, P <0.05). Mesenteric vascular disease was more prevalent among patients undergoing massive resection (39% vs. 9%, P <0.05), whereas Crohn’s disease was less prevalent (1% vs. 35%, P <0.05). Distribution of remnant length, presence of the ileocecal junction, and presence of a stoma were similar. Patients undergoing massive resection were more likely to require parenteral nutrition after the first year (56% vs. 23%, P <0.05). Patients with very short remnants (<60 cm) were more likely to receive parenteral nutrition after massive resection (95% vs. 60%, P <0.05). Thirty-day mortality was higher after massive resection (24% vs. 4%, P <0.05). However, those surviving 30 days had similar survival rates at 1 year and 5 years after massive and repeated resections. Patients undergoing massive vs. repeated resections are different with respect to age, underlying condition, and nutritional support needs. These factors may influence overall outcome in short bowel syndrome. The better nutritional prognosis of patients undergoing repeated resection given similar intestinal remnants may be related in part to enhanced intestinal adaptation.
The polar electrojet.

Polar electrojet causing magnetic substorms in high latitudes flows westward along closed oval curve and is connected with auroral activity and outer radiation belt
Size effects in superfluid 3 He films

This paper addresses two related problems. One is the effect of small geometries on the superfluid phases of $^{3}\mathrm{He}$, and the other is the nature of the scattering of $^{3}\mathrm{He}$ quasiparticles at surfaces. We perform measurements on 300-nm-thick films of $^{3}\mathrm{He}$ created by confining the liquid between closely spaced Mylar sheets. The fluid is probed simultaneously by two methods. Nuclear magnetic resonance monitors the spin dynamics of the system, yielding information with which we identify the superfluid phase. In this case, the liquid signal must be separated from that of the adsorbed surface layer, with which it is averaged by spin exchange. The hydrodynamic response of the fluid is determined from the period and damping of a torsion pendulum, which generates oscillatory motion of the substrate. In the normal and superfluid phases alike, this response is strongly dependent on microscopic details of the quasiparticle interactions with the surface. We compare the superfluid measurements to the Ginzburg-Landau model in which the order parameter vanishes at the walls (the diffusive boundary condition). Results for the superfluid transition temperature, the superfluid density, and the NMR frequency shift are in good quantitative agreement with the theory. Also in accord with the theory, we find that the superfluid A phase is stabilized by the walls over a wide range of pressures and temperatures at which the B phase is stable in bulk. In contrast with the calculations, however, we do not observe the A-B phase boundary. The $^{3}\mathrm{substrate}$ interface is modified in these experiments by the introduction of small quantities of $^{4}\mathrm{He}$. $^{4}\mathrm{He}$ plates out preferentially on the surfaces at low temperatures, an effect that persists until a layer several atoms deep has been built up. The boundary condition on the order parameter is observed to vary continuously with the surface $^{4}\mathrm{He}$ coverage, spanning almost the full range between the limits corresponding to diffusive and specular quasiparticle scattering.
Studies of the chemical composition of cosmic rays withZ=3 30 at high and low energies

We have measured the chemical composition of cosmic rays withZ≥2 over an energy range from ∼100 MeV/nuc to >2 GeV/nuc using 2 new large area counter telescopes. One of these instruments was a 4 element dE/dx×E× Range telescope, the other a 4 element dE/dx×Cerenkov× ×Range telescope. Two balloon flights with these telescopes at Ft. Churchill in the summer of 1970 provided a total of nearly 1000 Fe nuclei with a charge resolution ranging from ∼0.10 charge unit at Carbon to ∼0.25 charge unit at Fe. A detailed charge spectrum is obtained at both high and low energies. Some important differences exist between the present results and those obtained earlier, due in part to the improved statistical accuracy and in part to the improved background rejection of the present data. In particular, the abundance of Cr and Mn are each found to be ∼0.10×Fe in contrast to the earlier ratio of ∼0.30 found by some workers for each of these nuclei. The abundance of these two nuclei, as well as others in the 15–25 range, shows no strong dependence on energy. We have extrapolated our composition data to the cosmic ray sources using a variety of interstellar path length distributions. The abundances ofall secondary nuclei withZ between 3–25 are consistent only with propagation models which have vacuum path length distributions which do not differ greatly from exponential. The source abundances of nuclei withZ=15, 17, 18, 19, 21, 22, 23, 24, and 25 are found to be <0.02×Fe. For the remaining nuclei, Na, Al, S, and Ca are found to have source abundances of 0.07, 0.11, 0.18 and 0.13 of Fe respectively. The source abundance of C and O relative to Fe is also much different than some earlier compilations. A comparison of solar and cosmic ray abundances reveals certain selective differences, rather than a systematic overabundance of heavy nuclei in cosmic rays, as has been suggested in the past. These differences are discussed in terms of a common nucleosynthesis origin of the two species of particles.
Secondary drug resistance in breast cancer: Failure to reverse with oral nifedipine

We tested the efficacy of nifedipine to reverse acquired resistance to chemotherapy regimens containing doxorubicin or vinblastine or both in 12 patients with metastatic breast cancer. All patients had been receiving one or both of these drugs, had had a prior partial response (median duration 5 months, range 2–10) and subsequently progressed. Immediately after drug resistance was documented by tumor progression, eligible patients with measurable or evaluable disease were treated with nifedipine beginning 3 days before restarting the same chemotherapy. The initial dose of nifedipine was 20 mg TID, escalating daily to 40 mg TID on day 3 if the patient had no serious side effects. Nifedipine was continued at the highest tolerable dose during and for 2 days after completion of the chemotherapy. Most patients had ≤2 prior chemotherapy regimens and a median Zubrod performance status of 1. Twelve patients received a total of 23 courses preceded by nifedipine. No objective tumor responses were observed. The expected toxic effects attributable to nifedipine occurred, but nifedipine did not increase the toxicity caused by the chemotherapy. Nifedipine, given in this dose and schedule, did not reverse acquired drug resistance in patients with breast cancer. Int. J. Cancer 73:184–186, 1997. © 1997 Wiley-Liss, Inc.
Susceptibility of stainless steel alloys to crevice corrosion in ClO2 bleach plants

Abstract Stainless steels, including duplex stainless steels, are extensively used for equipment in pulp bleaching plants. One serious corrosion problem in chlorine dioxide bleach plants is crevice corrosion of stainless steels, which is frequently the factor that limits their use in bleach plants. Crevice corrosion susceptibility of alloys depends on various environmental factors including temperature, chemical composition of environment and resulting oxidation potential of system. Upsets in the bleaching process can dramatically change the corrosivity of the bleaching solutions leading to temperatures and chemical concentrations higher than those normally observed in the bleach process. When the environmental limits are exceeded the process equipment made of stainless steel can be severely affected. Environmental limits for crevice corrosion susceptibility of eight stainless steel alloys with PRE numbers ranging from 27 to 55 were determined in chlorine dioxide environments. Alloys used in this study included austenitic, ferritic–austenitic (duplex), and superaustenitic stainless steels. The performance of the different stainless steel alloys mostly followed the PRE numbers for the respective alloys. The 654SMO alloy with the highest PRE number of 55 showed the highest resistance to crevice corrosion in this environment. Under the most aggressive chlorine dioxide bleach plant conditions tested, even alloys Nicr3127 and 654SMO with PRE numbers 51 and 55 respectively were susceptible to crevice corrosion attack. The two factors that seem to contribute the most to crevice corrosion and pitting in the investigated environments are temperature and potential.
Binding of α- and β-adrenergic ligands to cerebral cortical membranes: Effect of 6-hydroxydopamine treatment and relationship to the responsiveness of cyclic AMP-generating systems in two rat strains

Abstract The binding of an α-adrenergic antagonist, WB 4101 and of a β-adrenergic antagonist, dihydroalprenolol, to cerebral cortical membranes fromo two rat strains, Sprague-Dawley and F-344, was examined after intraventricular administration of 6-hydroxydopamine. Cyclic AMP-generating systems in cerebral cortical slices from Sprague-Dawley rats respond to norepinephrine with an accumulation of cyclic AMP which is increased twofold after 6-hydroxydopamine treatment, while the cyclic AMP systems in slices from F-344 rat respond to norepinephrine with a relatively large accumulation of cyclic AMP which is not further increased after 6-hyxdroxydopamine treatment. The binding of WB 4101 to cerebral cortical membranes was similar in both rat strains and was unchanged after 6-hydroxydopamine treatment. The binding of dihydroalprenolol to membranes was similar in both rat strains and increased about 25% in both strains after 6-hydroxydopamine. Thus, the number of binding sites for these ligands does not correlate well with the magnitude of responses of cyclic AMP-generating systems to norepinephrine. Activity of cyclic AMP-phosphdiesterases in cerebral cortical homogenates was similar in both rat strains and was unchanged after 6-hydroxydopamine. Fluoride-stimulated adenylate cyclase activity in cerebral cortical homogenates appeared to be slightly higher in F-344 rats compared to Sprague-Dawley rats before but not after 6-hydroxydopamine treatment suggesting that changes in responsiveness of the cyclic AMP system might not be dependent upon changes in receptor density but in a post-receptor alteration such as adenylate cyclase activity.
Topological gravity in two dimensions

Abstract We derive two-dimensional topological gravity, which previously has been discussed in a BRST framework, by gauge fixing of an underlying gauge invariant system. The underlying lagrangian is zero.
The Effects of the Interstate Commerce Act on Transport Costs: Evidence from Wheat Prices

There is significant debate over the effect of the Interstate Commerce Act (ICA) on the cost of rail transport to shippers. Taking price differences across locations as proxy for transport costs, we use data on wheat prices before and after the implementation of the ICA to see if the Act led to smaller differences in wheat prices across American cities relative to a control group of European cities. We find that the ICA had no effect on US transport costs; however, it reduced their volatility substantially. This evidence supports the view that the ICA helped stabilize cartel prices after a period of significant price wars.
The Quadratic Residues —1 and —3

Let p be an odd prime. Then -1 is a quadratic residue (mod p) if and only if p 1 (mod 4), and 3 is a quadratic residue (mod p) if and only if p = 1 (mod 6). These results are well known. The first follows immediately from Euler's criterion and it appears as a theorem in just about every book in which quadratic residues are discussed. The proof of the result about -3 usually requires a little more effort and the law of quadratic reciprocity. The purpose of this note is to show that the "if' part of both results follows from Lagrange's theorem in group theory and the theory of algebraic field extensions. Let Zp be the field of integers (mod p). Assume that -1 is not a square (quadratic residue) in Zp. The quadratic extension Zp( -1) has p2 elements. Thus its group of nonzero elements Zp( -)* has p2_ 1 elements and the subgroup Zp* (the group of nonzero elements in Zp) has p 1 elements. The group we want to examine is the factor group Zp( -1)*/Zp*, with p + 1 elements. A direct calculation shows that the coset represented by 1 + has order 4. Thus 4 divides p + 1, which means that p -1 (mod 4). To prove the result about -3, extend Zp to Zp( -3). The order of the coset represented by 3 + -3 in the factor group Zp(-30)*/Zp* is 6. So, again by Lagrange's theorem, p -1 (mod 6).
Observations on cerebral computed tomography in patients having carotid endarterectomy.

Abstract A review was undertaken of all patients seen in our institution between January 1978 and March 1987 in whom a cerebral CT scan was obtained in association with elective carotid endarterectomy. Three hundred fifty-nine such patients were identified. In a subgroup of 89 patients who were neurologically normal after carotid endarterectomy, scans were performed at least 48 hours after surgery to quantitate the incidence of silent postoperative infarction. These scans were interpreted by one neuroradiologist. Preoperative cerebral CT scans showed ipsilateral infarction in 146 of 359 patients (40.6%). Ipsilateral infarction was most common in patients with stroke (76%) but was also seen in 32.8% of patients with transient ischemic attacks, in 9 of 40 patients (22.5%) with nonhemispheric symptoms, and in 9 of 45 patients (20%) with asymptomatic hemodynamically significant carotid stenosis. The postoperative stroke rate was not significantly increased by the presence of infarct on preoperative cerebral CT scan (2.6% vs 1.9%). New infarcts were seen on cerebral CT scanning after carotid endarterectomy in 2 of 89 patients with no detectable neurologic abnormality (2.3%). This study demonstrates a high frequency of ipsilateral infarction in patients having elective carotid endarterectomy, even in those patients with clinical symptom complexes thought by many physicians to be relatively benign (i.e., transient cerebral ischemia, nonhemispheric ischemia, and asymptomatic carotid stenoses). Such patients are at significant risk for cerebral infarction and should have cerebral CT scans performed before a decision is made to treat them nonoperatively. The incidence of silent postoperative infarction is low, but this should be evaluated in any prospective study comparing surgical and medical treatment of patients who have cerebrovascular disease.
Indian policy and a couple of beers

Abstract Metaphor is a carrier. It conveys our knowledge of known things to the unknown The most pervasive methaphor in Indian affairs is the idea that the relationship of an Indian to the federal government is that of a ward to a guardian. The metaphor has bedeviled past Indian policy, dominates present thinking about Indian affairs and, worst of all, it molds our thinking about alternative prospects for the future of Indians in this country. The following dialogue between two people, Mike and John, is set in the hotel of the Western Social Science Association's National Conference in Albuquerque in April, 1989. The strength of the ward-guardian metaphor is apparent throughout their conversation about Indian policy. Ironically, while John deplores the influence of the metaphor “Indian as research subject,” in social science research, he is unable to transcend it, or the ward-guardian metaphor, in his own thinking about Indian policy.
Superpixel Clustering and Planar Fit Segmentation of 3D LIDAR Point Clouds

Terrestrial laser scanning (TLS, also called ground based Light Detection and Ranging, LIDAR) is an effective data acquisition method capable of high precision, detailed 3D models for surveying natural environments. However, despite the high density, and quality, of the data itself, the data acquired contains no direct intelligence necessary for further modeling and analysis - merely the 3D geometry (XYZ), 3-component color (RGB), and laser return signal strength (I) for each point. One common task for LIDAR data processing is the selection of an appropriate methodology for the extraction of geometric features from the irregularly distributed point clouds. Such recognition schemes must accomplish both segmentation and classification. Planar (or other geometrically primitive) feature extraction is a common method for point cloud segmentation, however, current algorithms are computationally expensive and often do not utilize color or intensity information. In this paper we present an efficient algorithm, that takes advantage of both colorimetric and geometric data as input and consists of three principal steps to accomplish a more flexible form of feature extraction. First, we employ a Simple Linear Iterative Clustering (SLIC) super pixel algorithm for clustering and dividing the colorimetric data. Second, we use a plane-fitting technique on each significantly smaller cluster to produce a set of normal vectors corresponding to each super pixel. Last, we utilize a Least Squares Multi-class Support Vector Machine (LSMSVM) to classify each cluster as either "ground", "wall", or "natural feature". Despite the challenging problems presented by the occlusion of features during data acquisition, our method effectively generates accurate (>85%) segmentation results by utilizing the color space information, in addition to the standard geometry, during segmentation.
Discrete-Event Simulation Models of Plasmodium falciparum Malaria.

We develop discrete-event simulation models using a single “timeline” variable to represent the Plasmodium falciparum lifecycle in individual hosts and vectors within interacting host and vector populations. Where they are comparable our conclusions regarding the relative importance of vector mortality and the durations of host immunity and parasite development are congruent with those of classic differential-equation models of malaria, epidemiology. However, our results also imply that in regions with intense perennial transmission, the influence of mosquito mortality on malaria prevalence in humans may be rivaled by that of the duration of host infectivity.
An axoplasmic component of the Schmidt-Lanterman deformation.

In three instances, peripheral nerves containing numerous Schmidt-Lanterman discontinuities of myelin revealed transverse, wedge-shaped, or arrowhead-shaped axoplasmic excrescences visible with axon stains. These were arranged with a frequency and length like that of the myelin clefts, but the axonal materials were located within the myelin masses bordering the clefts, not in the clefts themselves. These axoplasmic changes are not consistent with most assumptions concerning the physiologic functions of the clefts, and supports the concept that the clefts are artifactual, due possibly to mechanical factors acting on abnormal nerve fibers.
Xanthine analysis in biological fluids by capillary electrophoresis

Xanthine, a precursor of uric acid, is measured here in serum, urine, and cerebrospinal fluids by capillary electrophoresis (CE) after deproteinization with acetonitrile. The migration time is about 7.5 min with a minimum detection limit of 0.4 mg/l. Different purines and pyrimidines did not interfere with the determination. The method demonstrates the suitability of the CE for determination of small molecules present in a complex matrix at levels of ca. 1 mg/l. It also demonstrates that acetonitrile deproteinization is a simple and effective method for preparing samples for CE, allowing a large volume to be introduced into the capillary.
Site-Specific Prebiotic Oligomerization Reactions of Glycine on the Surface of Hectorite

Condensation reactions of the amino acid glycine on the surface of Cu(II)-exchanged hectorite are investigated using the technique of scanning force microscopy. Prebiotic conditions are simulated using alternate wetting and heating cycles. Concentration, immobilization, and subsequent polymerization resulting in glycine oligomers are seen to occur primarily at step edges or faults in the topmost layer. Condensation reactions also occur within tiny micropores or defects in the topmost layer. These reactions are facilitated by the availability of intergallery metal cations at the step edges or pores in the surface region.
CT versus MR in neonatal brain imaging at term.

Background Recent reports have highlighted the lifetime risk of malignancy from using ionizing radiation in pediatric imaging. Computed tomography (CT), which uses ionizing radiation, is employed extensively for neonatal brain imaging of term infants. Magnetic resonance (MR) provides an alternative that does not use ionizing radiation. Objective The purpose of this study was to assess the cross-modality agreement and interobserver agreement of CT and MR brain imaging of the term or near-term neonate. Materials and methods Brain CT and MR images of 48 neonates were retrospectively reviewed by two pediatric neuroradiologists. CT and MR examinations had been obtained within 72 h of one another in all patients. CT was obtained with 5 mm collimation (KV=120, mAs=340). MR consisted of T1-weighted imaging (TR/TE=300/14; 4-mm slice thickness/1-mm gap), T2-weighted imaging (TR/TE/etl= 3000/126/16; 4-mm slice thickness/1-mm gap), and line scan diffusion imaging (LSDI) (TR/TE/b factor=1258/63/750; nominal 4-mm slice thickness/3-mm gap). The brain was categorized as normal or abnormal on both CT and MR. Results Ischemic injury was the most common brain abnormality demonstrated. McNemar's test indicated no significant difference between CT and MR test results for reader 1 (P=0.22) or reader 2 (P=0.45). The readers agreed on the presence or absence of abnormality on CT in 40 patients (83.3%) and on MR in 45 patients (93.8%). For CT, the kappa coefficient indicated excellent interobserver agreement (kappa=0.68), although the lower limit of the 95% confidence interval extends to kappa=0.55, which indicates only good-to-moderate agreement. For MR, the kappa coefficient indicated almost perfect interobserver agreement (kappa=0.88) with the 95% confidence interval extending to a lower limit of kappa=0.76, which represents excellent agreement. CONCLUSION. Because MR demonstrates findings similar to CT and has greater interobserver agreement, it appears that MR is a superior test to CT in determining brain abnormalities in the term neonate. Furthermore, since MR eliminates the use of ionizing radiation, a putative cause of malignancy, it should be the standard in neonatal brain imaging. Future efforts should be directed to improving neonatal access to MR to avoid the routine use of CT in infants.
Responsive membranes for hydrophobic interaction chromatography

Abstract Poly N-vinylcaprolactam (PVCL) chains were grown from the surface of regenerated cellulose membranes using atom transfer radical polymerization (ATRP). Modified membranes were characterized using scanning electron microscopy, infrared spectroscopy, X-ray photoelectron spectroscopy and by measuring surface contact angles. The grafting degree of PVCL increases with increasing ATRP initiator immobilization time. PVCL is a thermo-responsive polymer with a lower critical solution temperature (LCST) that depends on the concentration of salt ions present in solution. The LCST decreases below room temperature in buffer containing 1.8 M (NH3)2SO4 where the polymer adopts a more hydrophobic/collapsed conformation. At low ionic strength, the LCST remains above room temperature. Contact angles for PVCL in 20 mM phosphate buffer with and without 1.8 M (NH3)2SO4 were determined. Contact angles in the buffer with high ionic strength were higher than those in low ionic strength. Adsorption and desorption of bovine serum albumin (BSA) and immunoglobulin G (IgG) have been investigated. Loading was conducted in high ionic strength buffer. Elution was conducted in low ionic strength buffer. By using a responsive ligand that changes its conformation during loading and elution, high protein recoveries were obtained. Ligands that respond to solution ionic strength show promise for high performance hydrophobic interaction chromatography.
Historical challenge of large lenses

To present a full account of the developments in the manufacture of large lenses one needs to address wider issues rather than just provide a catalogue of technological progress. The advances in glass manufacture and improvement in optical techniques have to be considered in relation to the cultural, social and economic factors that have determined where, how and why large lens manufacture developed in specific countries. The challenge facing historians trying to tackle this technological theme, is that it is often poorly documented and little is preserved in the historical records. Until relatively recent times, opticians have concealed their methods, trade secrecy being an important economic strategy. To provide an example, it should be noted that although William Herschel produced the best optics and telescopes of the day, he published practically nothing about his methods. What has been gleaned of his techniques has only been uncovered by careful study of surviving manuscript sources and measurement of his surviving optics. Such was William's personal knowledge, that his son John had to take instruction from his father to refurbish William Herschel's 20-foot telescope. This training gave John tacit knowledge of William's methods and allowed him to successfully undertake his cape observations in the Southern Hemisphere. In spite of the shortcomings of the historical record, historians can give a measured account of the developments of lens optics by studying surviving telescopes and their optics.
Wrinkles and Sagging Flesh: Exploring Transformations in Women's Sexual Body Image

In American society, the sexually desirable woman is young and thin. Changes associated with aging such as wrinkled skin or weight gain often bring women further from societal ideals of attractiveness. As physical appearance is very much related to desirability, we explore sexual body image and the way that it changes as women age. Based on in-depth interviews with 95 women aged 20-68, we find women's sexuality and feelings of desirability are influenced by physical appearance, media, as well as significant others and family. We also note that sexual body image is more often negative than positive for women of all ages and that women struggle to accept changes in their bodies as a result of the aging process and life experiences; however, women in their 50s and 60s are most likely to accept their bodies and not feel influenced by social pressures.
Neonatal castration and intermale aggression in mice.

Abstract Male mice were castrated or sham-operated at one of several times after birth. Castrates were sham-operated at 40 days of age and neonatally sham-operated animals were castrated at that time. All mice were isolated at weaning, treated with testosterone propionate as adults, and then grouped to assess relative aggressiveness. The first experiment utilized the C57BL/6J strain of mouse and assessed adult aggressiveness by wound counts after 3 days of grouping. The second experiment evaluated aggressiveness both by direct observation and by frequency of wounding among CF-1 male mice during a 2-hr interval. Regardless of strain and/or method of assessing aggressiveness, castration on either Days 0 or 2 of life markedly suppressed incidence of fighting and wounding when such mice were grouped as adults and compared to neonatally sham-operated or intact controls. Castration on Day 6 of life or later resulted in fighting of the same incidence and severity as seen among sham-operated controls. It may thus be concluded that the neonatal organization of androgen-dependent aggressive behavior normally terminates sometime between 2 and 6 days of age in male mice.
AsthmaGuru: a framework to improve adherence to asthma medication

Asthma is a widespread chronic disease. Poor management of Asthma results in a large number of hospitalizations each year, the majority of which are avoidable through strict adherence to medication. AsthmaGuru is a system which aims to provide personalized guidance to users on their health state, with an aim to improve their compliance to medication. To achieve this aim, AsthmaGuru aggregates three forms of data: (a) automated and unobtrusive measurement of medication adherence using a low-power portable electronic attachment to an inhaler, (b) lung function measurement based on portable spirometry and (c) local air quality metrics. We leverage a custom low-power hardware platform for augmenting the inhalers and spirometry and develop a custom Android API for delay-tolerant data collection.
The effect of "usual care" on cardiovascular risk factors in a clinical trial.

Abstract The use of referral to “usual care” (UC) for participants in randomized clinical trials satisfies the need for a control group who receive medical attention at the level of community standards. However, it has been suggested that this method, which may include follow-up with multiple examinations to collect trial information, may actually enhance quality of care. To determine the effect of this UC status, 64 UC men from the Multiple Risk Factor Intervention Trial (MRFIT) were matched on serum cholesterol (SC), diastolic blood pressure (DBP), and age with men who had similar characteristics at the initial recruitment screening but were not selected for the trial. Both groups were remeasured an average of 45 months after the initial recruitment. DBP at the second measurement was lower in both groups (11 mm Hg) and did not differ between groups. The percentage taking blood pressure medications was similar. SC was unchanged in either group. Reduction in risk observed in this MRFIT usual care group appears to be related to improved preventive practice in the community, specifically in blood pressure treatment. The additional effect of participation in a clinical trial as a control subject appears minimal for these risk characteristics.
Transactions costs and production in a legislative setting

In a recent contribution to the literature on public sector production, Crain, Leavens and Tollison [C-L-T, AER, September 1986] argue that production in a legislative setting may be characterized aptly by an Alchian/Demsetz type model of team production. They operationalize their model by arguing that more valuable inputs in the production process (more trustworthy congressmen) will be reimbursed accordingly (via faster and/or more frequent passage of sponsored bills than for less trustworthy House members). Lack of a specified residual claimant, such as the party or some other entrepreneurial political entity, aside, the basic point seems well taken: team production is part and parcel of the legislative process. In fact, however, it is not clear that legislative output results from team production. The logrolling model of legislative activity is an obvious, competitive alternative to the team production model. What does seem abudantly clear vis-t-vis any model of legislative activity is that transactions costs (in a variety of forms) play an important role in determining final results. The purpose of this paper is to provide additional evidence from the state legislatures that gives credence to the importance of transactions costs, in a team production or logrolling setting, in determining legislative outcomes. According to C-L-T, the team production model of legislative organization implies that more senior, more trustworthy members of the legislative body will secure passage of 'their' bills faster than less senior, less trustworthy members of the legislature. Across several specifications of the model, their empirical results support this implication, for the 96th Congress. If a single legislative period were the correct time unit of analysis for bills, the results would be convincing. However, bills may be (and frequently are) introduced into numerous legislative sessions prior to receiving final approval. Under the circumstances, the correct time period of analysis may extend across several legislative periods,
Emission quenching and charge separation in bridged donor-acceptor block copolymers

The optical properties of previously synthesized sulfone and methoxy substituted block co-polymers of poly-phenlyenevinylene (PPV) have been examined. An internal space charge field is formed which has been used to quench the luminescence intensity in these materials by separating optically generated excitons and electron-hole pairs. The absorption and emission spectra and the time dependence of the emission of donor and acceptor derivatized block co-polymers was measured and the quenching of the luminescence was observed and quantified. PPV materials with this internal field have potential applications as solar energy converters and photodetectors.