cssi/SciSciGPT-SciSciNet huggingface dataset:
Wavelet-based representations for the 1/f family of fractal processes

It is demonstrated that 1/f fractal processes are, in a broad sense, optimally represented in terms of orthonormal wavelet bases. Specifically, via a useful frequency-domain characterization for 1/f processes, the wavelet expansion's role as a Karhunen-Loeve-type expansion for 1/f processes is developed. As an illustration of potential, it is shown that wavelet-based representations naturally lead to highly efficient solutions to some fundamental detection and estimation problems involving 1/f processes. >
Aggressive preoperative use of intraaortic balloon pump in elderly patients undergoing coronary artery bypass grafting

Abstract Background . The use of the intraaortic balloon pump (IABP) in patients undergoing coronary artery bypass grafting has been traditionally associated with a high complication rate and adverse outcomes. However, recent reports show that many of these catastrophic outcomes can be avoided by preoperatively placing the IABP in high-risk patients. To further validate these reports, we defined a set of liberal criteria for preoperative IABP insertion and applied them to a series of elderly patients (70 years or older) undergoing isolated coronary artery bypass grafting. Methods . Two hundred six consecutive patients who underwent isolated coronary artery bypass grafting with cardiopulmonary bypass were retrospectively reviewed. A rapid recovery protocol emphasizing reduced cardiopulmonary bypass time, an anesthetic protocol for early extubation, perioperative administration of corticosteroids and thyroid hormone, and aggressive diuresis was applied to all patients. Patients who required an urgent operation because of failed percutaneous transluminal coronary angioplasty, a critical left main stenosis (70% or greater), pronounced left ventricular dysfunction (left ventricular ejection fraction 40% or less), or unstable angina refractory to medical therapy or who required an emergency reoperation received preoperative IABP support. Results . The 30-day mortality rate for the entire group was 4.4%. There were 97 patients (47%) who received a preoperative IABP (group II) in comparison with 109 patients (53%) who did not fulfill the preoperative insertion criteria (group I). Patients in group II had a lower left ventricular ejection fraction (mean, 46% versus 59%, p p p p Conclusions . Liberal preoperative insertion of the IABP can be performed safely in high-risk elderly patients undergoing coronary artery bypass grafting, with results comparable to those in lower risk patients.
Single-point sampling for assessment of constitutive, induced, and inhibited cytochrome P450 3A activity with alfentanil or midazolam

Introduction The clearances of oral and intravenous alfentanil are in vivo probes for assessing first-pass and hepatic cytochrome P450 (CYP) 3A activity. Clearance determinations require time-consuming and expensive serial blood samples and quantitative analysis. This investigation tested the hypothesis that a single concentration measurement can accurately predict alfentanil clearance and compared limited sampling results for alfentanil and midazolam. Methods Data were analyzed from 2 previous studies in healthy volunteers (n = 10 in each). By use of a dose-finding protocol, subjects received oral alfentanil (23, 30, 43, or 75 μg/kg). By use of a CYP3A modulation protocol, subjects received oral or intravenous alfentanil and midazolam after pretreatment with rifampin (INN, rifampicin) (CYP3A induction), troleandomycin (CYP3A inhibition), grapefruit juice (intestinal CYP3A inhibition), or nothing (control). Alfentanil and midazolam area under the concentration-time curve (AUC) was calculated by noncompartmental analysis. Correlations between AUC and plasma concentration at each time point were evaluated by unweighted and weighted (1/y, 1/y2) linear regression, and the optimal weight and sampling time were determined. Results Correlations between AUC and plasma concentration were best with 1/y2 weights. Optimal correlations were at 1.5 to 2 hours for each alfentanil dose and also in an all-dose composite analysis. With the CYP3A modulation protocol, correlations for the control, grapefruit juice, rifampin, and troleandomycin sessions were optimal at 2, 3, 1.5, and 12 hours, respectively, for oral alfentanil, at 2, 3, 0.5, and 9 hours, respectively, for intravenous alfentanil, at 5, 5, 1.5, and 13 hours, respectively, for oral midazolam, and at 3, 1.75, 1, and 13 hours, respectively, for intravenous midazolam. In a composite analysis of all treatments, correlations (oral and intravenous) were optimal at 4 to 5 hours for alfentanil and 5 to 6 hours for midazolam. AUC estimated by a single-point concentration was highly predictive of measured AUC (r2 = 0.91 and 0.93 for oral and intravenous alfentanil, respectively, and r2 = 0.90 and 0.87 for oral and intravenous midazolam, respectively). CYP3A induction or inhibition was detected equally well by single-point alfentanil concentrations and by formal AUC determinations. Conclusion A single plasma concentration can predict alfentanil AUC and hence clearance, independent of dose, and thus appears to be an effective and efficient strategy for assessing CYP3A modulation over a broad spectrum of enzyme activity. Clinical Pharmacology & Therapeutics (2005) 78, 529–539; doi: 10.1016/j.clpt.2005.08.004
A Tapping Test in Apraxia

An enigma in understanding the mechanism of motor apraxia is why patients with disease restricted to the left hemisphere cannot imitate motions with the left hand despite intact visual motor apparatus. Liepmann suggested that motor memories are stored in the left hemisphere and that in apraxia these engrams are either destroyed or separated from the right hemisphere. If Liepmann's hypothesis is correct, then, in addition to poor performance on commands and imitation, there should be poor performance in a motor task. To ascertain if there is a motor defect of the non-paretic hand of apraxic patients, twenty apraxic patients were given a rapid finger tapping test and their performance was compared with the left hand performance of aphasic right hemiparetic non-apraxic controls. The aptaxic group performed this task significantly slower than the control group, thereby giving support to Liepmann's hypothesis of apraxia.
A comparison of energy flow among the grazing animals of different societies

Domestic cattle serve a variety of purposes in human society. In most cultures they are used primarily as a source of food: either meat, milk, or both. However, in some societies products such as blood and manure are important and elsewhere cattle are important draft animals or symbols of status and prosperity. Comparisons of energy flow in Indian, Ugandan, and North American cattle reveal how these different human strategies shape the energetics of cattle herds. Despite allegations to the contrary, Indian cattle appear to be rather productive when all consumable and nonconsumable products are considered. North American range cattle are considerably more productive than Ugandan cattle; however, the latter are efficient at maintaining high biomass. Other aspects of cattle energetics demonstrate the divergence in grazing strategies used by different peoples and the ecological efficiencies of these diverse strategies.
PROTON MR SPECTROSCOPIC IMAGING OF THE STRIATUM IN PARKINSON'S DISEASE

Assess the feasibility of proton MR spectroscopic imaging (1H-MRSI) of the striatum (putamen and caudate nucleus) in patients with Parkinson's disease and evaluate striatal neuronal density. Proton MRSI of the striatum and thalamus with 2 cc spatial resolution was performed in 10 patients with Parkinson's disease, 1 patient with atypical parkinsonism, and 13 control subjects. Single voxel proton MR spectra with signals from choline metabolites (Cho), creatine metabolites (Cr), and the putative neuronal marker, N-acetyl-aspartate (NAA), were obtained from the putamen and thalamus, but not the caudate nucleus, of patients with parkinsonism and control subjects. Metabolite rations in controls and patients were: in putamen NAA/Cho 1.70 +/- 0.25 vrs 1.74 +/- 0.32, NAA/Cr 2.80 +/- 0.79 vrs 2.36 +/- 0.42, Cho/Cr 1.63 +/- 0.25 vrs 1.39 +/- 0.3; in thalamus, NAA/Cho 1.78 +/- 0.15 vrs 1.62 +/- 0.22, NAA/Cr 2.78 +/- 0.34 vrs 2.64 +/- 0.41, Cho/Cr 1.57 +/- 0.25 vrs 1.65 +/- 0.28. There were no statistically significant differences between patients and controls. The putaminal NAA/Cho ratio of the single subject with atypical parkinsonism was lower than that of 9 of the 10 patients with classic Parkinson's disease and 11 of the 13 control subjects. Likewise, the putaminal NAA/Cr ratio in the single subject with atypical parkinsonism was lower than that of 7of the patients with guided selection of spectra from very small brain volumes, is a technique that can be used to evaluate neuronal density in individual subcortical gray nuclei in the brains of patients with parkinsonism. Using this technique, we have shown that Parkinson's disease produces no change in relative levels of the neuronal marker, NAA, in the putamen.
Diagnosis of stenosis in a pulmonary valve-conduit using an angioplasty guide and probing catheter.

A 42-year-old man who had undergone previous Blalock-Taussig anastomoses and placement of a homograft aortic valve-root conduit for tetralogy of Fallot presented with dyspnea at rest. Previous catheterization had shown homograft stenosis at the level of the pulmonic valve. Repeat catheterization necessitated the use of angioplasty guide and probing catheters to cross the stenosis, and pullback documented stenoses both across the homografted valve and within the homograft aortic root-native pulmonary artery conduit. © 1993 Wiley-Liss, Inc.
Amyloid-like fibrils of ribonuclease A with three-dimensional domain-swapped and native-like structure

Amyloid or amyloid-like fibrils are elongated, insoluble protein aggregates, formed in vivo in association with neurodegenerative diseases or in vitro from soluble native proteins, respectively. The underlying structure of the fibrillar or 'cross-beta' state has presented long-standing, fundamental puzzles of protein structure. These include whether fibril-forming proteins have two structurally distinct stable states, native and fibrillar, and whether all or only part of the native protein refolds as it converts to the fibrillar state. Here we show that a designed amyloid-like fibril of the well-characterized enzyme RNase A contains native-like molecules capable of enzymatic activity. In addition, these functional molecular units are formed from a core RNase A domain and a swapped complementary domain. These findings are consistent with the zipper-spine model in which a cross-beta spine is decorated with three-dimensional domain-swapped functional units, retaining native-like structure.
Real-time continuous estimation of gas exchange by dual oximetry

We designed a ventilation-perfusion index (VQI) to estimate venous admixture (Qsp/Qt) in a real-time fashion by simultaneous pulse and pulmonary artery oximetry in 17 patients with acute respiratory failure. Changes in Qsp/Qt were produced by altering the level of continuous positive airway pressure. VQI correlated well with Qsp/Qt (r=0.78). This contrasts with the poor correlation found between Qsp/Qt and the commonly used oxygen tension based indices such as PaO2/FIO2 (r=-0.51), PaO2/PAO2 (r=-0.47), and PAO2-PaO2 (r=0.23). The use of dual oximetry to derive a VQI appears to be a reliable and accurate method for real-time assessment of pulmonary gas exchange in patients with acute respiratory failure.
Directional annealing of cold-rolled copper single crystals

The effects of annealing temperature, hot zone velocity and temperature gradient ahead of the hot zone on the microstructure of directionally-annealed, cold-rolled, high-purity copper single crystals were investigated. Columnar grains were observed at an optimum hot zone velocity that increased with increasing annealing temperature and decreasing temperature gradient. Equiaxed grains were formed both when the velocity of hot zone movement was low, and when it exceeded the maximum growth rate of grains. The number of twin boundaries per unit area decreased with increasing hot zone velocity, increasing temperature gradient and decreasing annealing temperature. The results are explained in terms of the effects of annealing temperature and temperature gradient on the grain boundary mobility and the nucleation of new grains and twins.
The Influence of Alkyl Chain Length on Extraction Equilibria of Ni(II) Complexes with 1‐Alkylimidazoles in Aqueous Solution/Organic Solvent Systems

Abstract Extraction process has been studied of Ni(II) complexes with 1‐alkylimidazoles (with alkyl = C4H9 through C14H29) from aqueous solutions at 25°C, at a fixed ionic strength (0.5; KNO3). Toluene, p‐xylene, dichloromethane and 2‐ethyl‐1‐hexanol were used as diluents. Stability constants of the complexes formed in the aqueous phase, βn, were determined as well as the composition and partition constants, Pc, of the extracted species. It was demonstrated that stability constants of the Ni(II) complexes with the 1‐alkylimidazoles as well as their partition constants increased with increasing chain length of the alkyl substituent. The larger stability constants were received for dichloromethane. The highest values of the partition constants of Ni(II) complexes were received for the system water/2‐ethyl‐1‐hexanol. On the basis of the UV‐VIS spectra it was found that during all experiments the basic structure of the coordination polyhedron of Ni(II) has been retained.
Acrolein inflicts axonal membrane disruption and conduction loss in isolated guinea-pig spinal cord.

We have examined the effect of acrolein, an aldehyde product of lipid peroxidation, on axons in isolated guinea-pig spinal cord white matter. We found that 200 μM acrolein, but not 50 μM, induced a time-dependent loss of compound action potential conduction. Such conduction loss was irreversible within 1 h after acrolein perfusion. Parallel anatomical assessment indicates membrane integrity breakdown based on a horseradish peroxidase-exclusion assay. This is the first report to suggest that acrolein inflicts severe axonal damage. Since axonal damage within white matter plays a key role in the pathology of traumatic spinal cord injury, we suggest that acrolein may be a critical factor in mediating secondary functional loss.
Material specific hemispheric activation

Abstract Attention is defined as consisting of three components—arousal, attentiveness and activation (preparation for action). The purpose of this study was to determine: (1) whether verbal and nonverbal stimuli differentially prepare the hemispheres for action; (2) how long this asymmetric activation persists; and (3) whether a response-linked decisional process is necessary for inducing these asymmetries. The findings indicated that: (1) although verbal warning stimuli (WS) reduced reaction times (RTs) of the right hand more than those of the left hand, visuospatial WS reduced RTs of both hands equally; (2) the asymmetries induced by the verbal WS were less robust at 15–20 sec after the WS and were not present during post-session testing; and (3) a response-linked decisional process was necessary for inducing activation asymmetries.
Amphiphilic particles with hydrophilic core/hydrophobic shell prepared via inverted emulsions

An aqueous solution of acrylamide, its crosslinker (N, N′-methylenebisacrylamide), and an oxidant (ammonium persulfate) was first used to prepare an inverted concentrated emulsion in hexane. Span 80, which is soluble in hexane, was employed as a dispersant. The polymerization of acrylamide in the concentrated emulsion was greatly accelerated by introducing an aqueous solution of a reductant (sodium metabisulfite); it started at room temperature and was completed in a few seconds, resulting in a pastelike product. The system thus obtained was subsequently diluted with hexane containing a hydrophobic monomer. When styrene was used as the hydrophobic monomer, cumene hydroperoxide (which, together with sodium metabisulfite present in the dispersed phase, constitutes the initiator for the polymerization of styrene) was dissolved in the continuous phase. When vinylidene chloride was employed as the hydrophobic monomer, no additional initiator besides sodium metabisulfite and ammonium persulfate already present in the hydrophilic phase had to be employed. The use of initiators which are present only in the hydrophilic phase, and hence also at the interface between this phase and hexane, ensured the polymerization of the hydrophobic monomer as shells that encapsulate the polyacrylamide latexes. Under the proper conditions, a porous outer shell can be generated, which makes the hydrophilic chains present inside accessible. Such hydrophilic core/hydrophobic porous shell particles can be dispersed in water, where 116they remain stable for a long time, and in hydrophobic liquids, where they remain stable for at least 24 h. For this reason, we call these kinds of particles amphiphilic particles. © 1996 John Wiley & Sons, Inc.
Copolymerization of vinylferrocene and N-vinylcarbazole. Conductivity studies of the trinitrofluorenone and mixed-valence [Fe(II), Fe(III)] complexes of these copolymers

Vinylferrocene (M1) has been copolymerized with N-vinylcarbazole (M2) using azobisisobutyronitrile as the initiator. In benzene at 70°C, the reactivity ratios r1 = 0.47 and r2 = 0.20 were obtained. Using an e value of −1.34 for N-vinylcarbazole, the calculated value e for vinylferrocene is about −2.8, in general agreement with the large negative e values vinylferrocene exhibits with other monomers which are electron rich. These copolymers were treated with trinitrofluororenone to give copolymers with carbazole–trinitrofluorenone charge–transfer complex sites (type B). The copolymers were oxidized with dichlorodicyanoquinone to give a series of copolymers with both ferrocenium and ferrocene sites in them (type C). In addition, type C copolymers were further treated with trinitrofluorenone to give a class of polymers having ferrocene, ferrocenium and carbazole–trinitrofluorenone charge–transfer sites (type D). Introducing ferrocene and ferrocenium sites into the poly(vinylcarbazole–trinitrofluorenone) polymers resulted in an increase in their conductivity, but the polymers were no longer photoconducting.
Pattern language and HCI: expectations and experiences

Pattern Language (PL) has been researched and developed in HCI research since the mid-80s. Our research was initiated by the question why something like PL can create such enthusiasm and interest over the years, while at the same time not be more widespread and successful? In this paper, we examine the experiences and expectations that HCI researchers who have been involved in PL research have had and still have when it comes to PL. Based on the literature review and interview studies, we provide some overall reflections and several possible directions on the use of PL in HCI.
Malignant epithelioid vascular tumors of the pleura: report of a series and literature review.

Primary malignant vascular tumors of the pleura are rare. The significance and difficulty of distinction between pleural epithelioid hemangioendothelioma (EHE) and angiosarcoma have not yet been addressed. A new series of pleural angiosarcoma is reported, and the relevant literature is reviewed. Five cases were identified from files of the authors' institutions and personal consultation cases (J.J.B.). Twenty-six cases of primary malignant vascular tumors of the pleura were identified in the literature. In a total of 31 cases, 22 were from the West and 9 from Japan. Patients were 22 to 79 years old (average, 57), and the male/female ratio was 9:1. Prior chronic pyothorax was identified only in cases reported from Japan. History of exposure to radiation or asbestos was noted in a few Western cases. The most common presentation was pleural thickening and effusion. Almost all of the patients died of disease shortly after diagnosis. A spectrum of histology ranging from characteristic high-grade epithelioid to relatively low-grade EHE-like features was observed in our cases and can be found in previous reports. Most cases showed variable spotty cytokeratin immunoreactivity. Endothelial markers (factor 8, CD34, or CD31) were invariably positive. Pleural angiosarcomas are often epithelioid and can be easily mistaken for mesothelioma or carcinoma clinically and histologically. Awareness of this rare tumor should prompt the use of endothelial markers when faced with a questionable mesothelioma. When cytokeratin is negative, or focal with strong vimentin reactivity, a vascular tumor should be suspected and confirmed with vascular markers. Because of their invariably aggressive behavior, all epithelioid vascular tumors of the pleura should be considered highly malignant regardless of the presence of EHE-like histological features.
Biosynthesis of heparin. Evidence for the transfer of radioactive sulfate to small-molecular-weight acceptors.

The incorporation of [35S]sulfate into the heparin fraction was studied in a high-speed supernatant from the Furth mass-cell tumor. The rate of incorporation was found to be linear over a 45-min period. Preincubation prior to the addition of carrier-free [35S]-sulfate caused a marked decrease in labeling of the heparin fraction. These results were interpreted to indicate that a dialyzable sulfate acceptor system was depleted during the preincubation period. The data support the hypothesis that sulfate is incorporated primarily into small-molecular-weight heparin precursors which are then polymerized to form heparin.
land conflicts in Amazonia

Persistent conflict between small-farmer migrants and the owners of large estates has characterized frontier expansion in the Brazilian Amazon region. These two groups respond to distinct government policy initiatives and hold antagonistic ideological perspectives regarding the appropriation, use, and function of land. To address land conflicts, government intervention has taken on an increasingly political and ideological cast. The evolution and polarization of ideological perspectives, and their relation to distinct material and political positions in land conflicts, are examined. It is argued that the dispute over access to land on the Amazon frontier is an expression of fundamental contradictions in Brazilian state and society. [Amazon, frontier, land conflicts, ideology, Brazil]
Clozapine overdose, a case report

Clozapine, an atypical antipsychotic agent with few of the extrapyramidal side effects of other antipsychotic agents, was approved for use in the United States in 1989. Because of drug-induced agranulocytosis, it is dispensed only under rigid guidelines. Overdose has been rare. Presented here is a case of clozapine overdose treated successfully with supportive care in which agranulocytosis did not develop.
Preferential depletion of host over donor T cells through in vivo decay of active rabbit-anti-thymocyte globulin levels during reduced intensity conditioning.

Inadequate T-cell chimerism following reduced-intensity conditioning transplantation may contribute to graft rejection and disease relapse. Anti-thymocyte globulin (ATG) enhances early donor T-cell chimerism, but may also deplete donor T cells, increasing risks of infection and relapse. We prospectively tested administration of rabbit ATG (rATG) ⩾14 days before the infusion of the graft, followed by in vivo decay of active rATG levels, to selectively deplete host T cells. Twenty-three patients received rATG total dose 4.5 mg/kg on days −16 and −15, fludarabine 30 mg/m2 per day on day −7 through −3, IV busulfan 130 mg/m2 per day on days −4 and −3 and cyclophosphamide 1500 mg/m2 on day −2. rATG levels were therapeutic in all patients on day −14, but were sub-therapeutic (<1 μg/mL) by day 0 in 82% of patients. Median donor T-cell chimerisms on days 30 and 180 were 100% (75–100%) and 100% (90–100%), respectively. Non-relapse mortality and relapse/progression at 48 months were 17 and 30%. Cumulative incidences of acute GvHD grades II–IV and III–IV were 39 and 9%. Median follow-up is 64 months (46–79 months). Survival and disease-free survival at 48 months were 70 and 52%. These data suggest that selective depletion of host T cells using this regimen is a feasible and effective strategy.
Resisting Abuse at What Cost? The Impact of Mandated Reporting Laws on the Process and Content of Therapy

Child abuse reporting is mandatory for family therapists. Little is written regarding the impact of mandated reporting and its impact on the family therapy systemic processes. This paper reviews literature on the impact on therapy of mandated reporting, and shares the results of a study designed to assess the impact of mandated reporting on family therapist's attention to systemic issues. The study demonstrates that MFTs shift their focus when the question of a mandated report arises to the detriment of systemic considerations. The institutional split between investigation and treatment of child abuse is discussed.
Inducible Control of Subcellular RNA Localization Using a Synthetic Protein-RNA Aptamer Interaction

Evidence is accumulating in support of the functional importance of subcellular RNA localization in diverse biological contexts. In different cell types, distinct RNA localization patterns are frequently observed, and the available data indicate that this is achieved through a series of highly coordinated events. Classically, cis–elements within the RNA to be localized are recognized by RNA-binding proteins (RBPs), which then direct specific localization of a target RNA. Until now, the precise control of the spatiotemporal parameters inherent to regulating RNA localization has not been experimentally possible. Here, we demonstrate the development and use of a chemically–inducible RNA–protein interaction to regulate subcellular RNA localization. Our system is composed primarily of two parts: (i) the Tet Repressor protein (TetR) genetically fused to proteins natively involved in localizing endogenous transcripts; and (ii) a target transcript containing genetically encoded TetR–binding RNA aptamers. TetR–fusion protein binding to the target RNA and subsequent localization of the latter are directly regulated by doxycycline. Using this platform, we demonstrate that enhanced and controlled subcellular localization of engineered transcripts are achievable. We also analyze rules for forward engineering this RNA localization system in an effort to facilitate its straightforward application to studying RNA localization more generally.
Temporal resolution of multiharmonic phase analysis of ECG-gated myocardial perfusion SPECT studies.

Background. Multiharmonic phase analysis (MHPA) was developed to assess left-ventricular dyssynchrony from gated myocardial perfusion single-photon emission computed tomography (GSPECT) studies. This study was intended to determine the temporal resolution of MHPA. Methods. A reference normal GSPECT study with 128 frames/cycle was simulated using NCAT, a nonuniform rational B-splines-based cardiac torso phantom. It was shifted in the time domain to insert phase delays. Realistic GSPECT studies (8 or 16 frames/cycle) were then obtained by down-sampling the reference and shifted studies. All GSPECT projections were generated with attenuation, scatter, collimator blurring, and Poisson noise. Seventeen regional phases were calculated from the GSPECT reconstructions (filtered back-projection without compensation for physical factors), using linear interpolation for the reference study, and MHPA for the realistic studies. Comparing the regional phases between the realistic studies without and with shifts determined whether MHPA could identify certain phase delays. Results. When there were enough counts/pixel (>10 counts/pixel), MHPA with either 1, 2, or 3 harmonics could resolve a phase difference of 5.6°, corresponding to 1/64 of the cardiac cycle. Conclusions. With clinically equivalent counts, the temporal resolution of MHPA is 1/64 of a cardiac cycle. Achieving this high temporal resolution from data with low temporal resolution demonstrates the benefit of replacing discrete points with continuous harmonic functions.
Solid-state 29Si NMR study of polycondensation during heat treatment of sol-gel-derived silicas

Abstract Solid-state magic angle spinning (MAS) and cross-polarization (CP)-MAS 29 Si NMR spectroscopy was used to monitor polycondensation in alkoxide-derived silica gels during thermal treatment from 25 to 800°C. Gels prepared from tetramethylorthosilicate under both neutral and basic conditions were studied and differences in the evolution of chemical structure during thermal treatment are readily observed by NMR. As thermal treatment proceeds the extent of condensation parallels the BET surface area. For uncatalyzed gels, the amount of cross-linking increases and the BET surface area decreases on each step of heating through 800°C. The base-catalyzed gel depolymerizes slightly on heating from 150 to 450°C, accompanied by a slight increase in BET area, then undergoes extensive cross-linking on heating from 450 to 800 °C, with a large decrease in surface area. After heating to 800°C both gels have similar degrees of cross-linking and surface area.
Recent chemical exposures and blood volatile organic compound levels in a large population-based sample.

Abstract Little is known about factors that influence blood levels of volatile organic compounds in nonoccupationally exposed populations. The authors examined the possible relationship between recent self-reported chemical exposures and elevated blood volatile organic compound levels among 982 adult participants in the Third National Health and Nutrition Examination Survey. A strong dose-response effect was indicated (p < .001) for increasing lifetime pack-years of cigarettes smoked for elevated levels of toluene, styrene, and benzene. A positive dose-response effect was indicated for daily alcohol consumption with respect to elevated blood levels of 2-butanone and acetone. For volatile organic compounds typically found in 10-75% of the population, the establishment of a link with specific environmental exposures is relatively easy because there is less effect of confounding in this group. Some volatile organic compounds, however, are seen in less than 10% of the general population; finding these compoun...
Medicare beneficiary knowledge of the Part D program and its relationship with voluntary enrollment.

Background: The 2003 Medicare Modernization Act established the Part D drug benefit in 2006. Because the benefit involves a voluntary enrollment process with numerous plan options, there has been concern about whether beneficiaries have adequate knowledge of the program, but research on this issue has been limited. Objectives: To examine Medicare beneficiary knowledge of the Part D program and estimate how knowledge affected voluntary enrollment decisions at the program’s outset. Methods: We linked data from the 2005 Medicare Current Beneficiary Survey with CMS administrative data regarding beneficiary 2006 drug coverage and market characteristics. We estimated a multivariate logistic regression model to explore the relationship between Part D knowledge and beneficiaries’ voluntary enrollment in a Part D plan. Results: At the inception of the Medicare Part D benefit, no single knowledge test question was correctly answered by more than three-fourths of beneficiaries. Correct responses to five knowledge test questions were positively associated with enrollment: “everyone has plan choices” (adjusted odds ratio = 1.4); “plans can change costs once per year” (aOR = 1.2); “beneficiaries must use plan pharmacies” (aOR = 1.5); “beneficiaries must pay a penalty if they enroll late” (aOR = 1.3); “assistance is available for low income beneficiaries” (aOR = 1.2). Conclusion: Beneficiary understanding of the Part D program in early 2006 was limited. Beneficiary knowledge of Part D program details was associated with enrollment in Medicare Part D. Efforts to educate Medicare beneficiaries about Part D may improve rates of prescription drug coverage.
Gene traps: tools for plant development and genomics.

Classical genetic approaches to gene identification rely on disruption of a gene leading to a recognizable phenotype. This approach continues to be an extremely successful one, yielding mutations that result in overt phenotypes reflecting the function of the corresponding gene. Not all genes,
Sperm–Egg Interactions: Sperm–Egg Binding in Mammals

Fertilization of the mammalian egg occurs through an ordered sequence of reactions in which the sperm adheres to, then penetrates, the zona pellucida. It then binds to and then fuses with the egg's plasma membrane, so that the gametes fuse to form the zygote. The zona pellucida and egg plasma membrane are then modified after fertilization to block polyspermic fertilization. The interactions between the sperm and egg involve specific molecules on both gametes that mediate the interactions; malfunction may cause infertility. Keywords: fertilization in mammals; zona pellucida; acrosomal reaction; acrosomal exocytosis; zonadhesins in sperm membrane; molecular basis of sperm–egg binding and fusion; blocks to polyspermy
Use it and/or lose it—experience effects on brain remodeling across time after stroke

The process of brain remodeling after stroke is time- and neural activity-dependent, and the latter makes it inherently sensitive to behavioral experiences. This generally supports targeting early dynamic periods of post-stroke neural remodeling with rehabilitative training (RT). However, the specific neural events that optimize RT effects are unclear and, as such, cannot be precisely targeted. Here we review evidence for, potential mechanisms of, and ongoing knowledge gaps surrounding time-sensitivities in RT efficacy, with a focus on findings from animal models of upper extremity RT. The reorganization of neural connectivity after stroke is a complex multiphasic process interacting with glial and vascular changes. Behavioral manipulations can impact numerous elements of this process to affect function. RT efficacy varies both with onset time and its timing relative to the development of compensatory strategies with the less-affected (nonparetic) hand. Earlier RT may not only capitalize on a dynamic period of brain remodeling but also counter a tendency for compensatory strategies to stamp-in suboptimal reorganization patterns. However, there is considerable variability across injuries and individuals in brain remodeling responses, and some early behavioral manipulations worsen function. The optimal timing of RT may remain unpredictable without clarification of the cellular events underlying time-sensitivities in its effects.
Software radio architecture: a mathematical perspective

As the software radio makes its transition from research to practice, it becomes increasingly important to establish provable properties of the software radio architecture on which product developers and service providers can base technology insertion decisions. Establishing provable properties requires a mathematical perspective on the software radio architecture. This paper contributes to that perspective by critically reviewing the fundamental concept of the software radio, using mathematical models to characterize this rapidly emerging technology in the context of similar technologies like programmable digital radios. The software radio delivers dynamically defined services through programmable processing capacity that has the mathematical structure of the Turing machine. The bounded recursive functions, a subset of the total recursive functions, are shown to be the largest class of Turing-computable functions for which software radios exhibit provable stability in plug-and-play scenarios. Understanding the topological properties of the software radio architecture promotes plug-and-play applications and cost-effective reuse. Analysis of these topological properties yields a layered distributed virtual machine reference model and a set of architecture design principles for the software radio. These criteria may be useful in defining interfaces among hardware, middleware, and higher level software components that are needed for cost-effective software reuse.
Raising Considerations: Public Opinion and the Fair Application of the Death Penalty*

Objectives. A major justification for capital punishment is its perceived public support, yet common measures of public opinion do not capture the complexity of death penalty attitudes. This research, first, examines the stability of attitudes regarding the fair application of the death penalty when those attitudes are expressed within the context of an enlarged pool of considerations about its administration and, second, evaluates the directional effect of the considerations on those attitudes. Methods. Data from a national telephone survey that capture the complexity of these attitudes are analyzed using ordered probit estimation. Results. These results indicate substantial instability in attitudes regarding the fair application of capital punishment given the context of more pertinent considerations. Furthermore, within this context respondents tend to indicate that the death penalty is less fairly applied. Conclusion. The justification for capital punishment may rest on oversimplified conceptions of attitudes toward the death penalty and its application.
Integrating CCSDS and MIL-STD-1553: What you should know

The use of the MIL-STD-1553B (1553) communications bus and the Consultative Committee for Space Data Systems (CCSDS) recommendations are increasingly common elements in the design of satellite command and data handling systems. However, the 1553 bus has some fundamental characteristics which are often not understood by those implementing the data protocol which will run on top of it. In addition to spacecraft-to-ground communications, various CCSDS data protocol units are being used as the format for the communication of commands, messages, and telemetry data between the spacecraft, instruments, and other subsystems. Experience has produced a list of "dos and don'ts" in implementing 1553 bus command and telemetry protocols using CCSDS.
The effect of whole ejaculate filtration on the morphology and the fertility of bovine semen.

Abstract A Sephadex G-15 filtration method was developed to remove abnormal and nonmotile bull sperm from an entire ejaculate. The efficiency of filtration was determined by adding freeze-killed sperm to the ejaculate or using ejaculates with elevated numbers of abnormal cells induced by scrotal insulation. A fertility trial, using split ejaculates, compared fertility of filtered and unfiltered semen. After filtration, samples with 0, 25, and 50% killed cells added contained 77 to 81% motile cells. Addition of 75% killed sperm resulted in significant decrease (52%) of motile cells following filtration. Morphologic examination of semen with elevated numbers of abnormal cells revealed higher percentages of sperm with normal shaped heads and normal or swollen acrosomes after filtration than in unfiltered samples. Percentage of pear-shaped heads, lifted acrosomes, and bent tails decreased after filtration. Six high fertility and six low fertility bulls were used to evaluate fertility of filtered semen. Filtering increased motile sperm from 51 to 57% and from 36 to 50% for the high and low fertility bulls, respectively. The 60- to 90-d nonreturn rates for high fertility bulls were not increased by filtering (73 vs. 72%). However, filtering significantly improved the nonreturn rates for the low fertility bulls (61 vs. 67%).
Head-disk dynamics in the flying, near contact, and contact regimes

To achieve an areal density approaching 50 Gb/in. 2 for the magnetic storage of data in hard disk drives requires reduced mechanical and magnetic spacing. Off-track jitter caused by airflow or contact can cause track misregistration on the order of 20-70 nm which may be excessive for adequate servo performance. The magnetic signal can be used to identify both the vertical spacing modulation due to the air bearing modes and off-track jitter due to suspension modes with nanometer resolution. We find that the off-track jitter in the flying regime is driven by airflow and is a strong function of the disk velocity and the suspension type. In the contact regime, the vertical spacing modulation and off-track jitter increase due to contact. Using a laser Doppler vibrometer we identified the leading contribution to the off-track jitter to be primarily the first torsional mode (T1) and to a lesser extent the first bending mode (B1) of the suspension.
A Comparative, Experimental Study of Model Suitability to Describe Vehicle Rollover Dynamics for Control Design

This work presents results of an initial investigation into models and control strategies suitable to prevent vehicle rollover due to untripped driving maneuvers. Outside of industry, the study of vehicle rollover inclusive of both experimental validation and practical controller design is limited. The researcher interested in initiating study on rollover dynamics and control is left with the challenging task of identifying suitable vehicle models from the literature, comparing these models with experimental results, and determining suitable parameters for the models. This work addresses these issues via experimental testing of published models. Parameter estimation data based on model fits is presented, with commentary given on the validity of different methods. Experimental results are then presented and compared to the output predicted by the various models in both the time and frequency domain in order to provide a foundation for future work.Copyright © 2005 by ASME
The Role of Neuroticism and Mastery in Spouse Caregivers' Assessment of and Response to a Contextual Stressor

Data from more than 300 spousal caregivers and their care recipients were analyzed to demonstrate the effects of caregivers' personality attributes--neuroticism and mastery--on their assessment of a contextual stressor (the care recipient's behavioral and functional impairment) and on their experience of distress associated with that stressor. Caregivers who were high in neuroticism and/or low in mastery reported higher levels of behavioral and functional impairment in their disabled spouse and experienced more strain and depressive symptoms associated with caregiving relative to caregivers with lower neuroticism or higher mastery scores. We further showed that the widely reported association between caregiver-assessed impairment of the care recipient and caregiver outcomes can in part be explained by caregivers' personality attributes, such as neuroticism and mastery. Our findings that caregivers' personality variables are related to their assessment of a given objective stressor and their response to a given level of stress have implications for interventions targeting caregivers and for the use of caregivers as proxy informants.
Redefining q: quaternary ammonium cross sectional area (XSA) as a general descriptor for transport-limiting PTC rate approximations

The relationships of several key molecular descriptors with the rate of the O'Donnell alkylation under phase transfer catalysis (PTC) have been investigated. The most common parameter used to predict PTC rates, the ammonium ion accessibility, q, is defined in such a way that limits its use to straight-chain tetraalkylammonium catalysts. To find a general descriptor of rate, eight linear, symmetrical tetraalkylammonium cations were examined to determine if a model containing broadly applicable descriptors could be found. The catalytic activity of these salts was determined under PTC conditions (operating under an interfacial, transport-rate limiting mechanism) and was compared with these molecular descriptors. Models could be generated from the ammonium ion accessibility parameter q and the amphiphilic cross sectional area descriptor (XSA), and each gave a correlative model predicting the rate of alkylation. However, a similar model cannot be generated from a descriptor that is a direct measure of ammonium ion accessibility, the solvent accessible ammonium surface area (NC4_SA). These models lead to the conclusion that q must approximate catalyst properties other than ammonium ion accessibility. Additionally, the relationship between XSA and rate demonstrates that XSA approximates the complex behavior of ammonium ions at the interfacial region of a biphasic system, allowing for its use as a general descriptor for transport-limiting PTC rate approximations.
Modeling of temperature effects on nano-CMOS devices with the predictive technologies

Predictive technology model (PTM) enables early device and circuit characterization by providing the research community the expected profiles of devices in the future technologies. The parameters that need particularly accurate estimation are the speed and the power consumption. Fluctuations in the die temperature affect the device characteristics thereby altering the performance of integrated circuits. Furthermore, increase in the doping concentration and the enhanced electric fields in scaled devices tend to affect the rate of change of device parameter variations when the temperature fluctuates. For precise characterization of the MOSFETs at various temperatures, the parameters that model the temperature effects have to be accurately extracted. With the PTMs, however, the model parameters that characterize the temperature effects are typically transferred from an older technology generation without any change. This inappropriate transfer of parameters across different generations of predictive CMOS technologies may lead to gross errors during the characterization of CMOS circuits at various die temperatures. In this paper, the principle factors that determine the device characteristics when the temperature fluctuates are presented. The impact of technology scaling on the temperature fluctuation induced variation of the device parameters is illustrated. The parameters that model the temperature effects of the predictive technologies are compared. The study indicates that the device and circuit characterization with the PTMs may not be reliable at temperatures other than a single nominal temperature where the critical model parameters are extracted.
Multicast scheduling for list requests

Advances in wireless and optical communication, as well as in Internet multicast protocols, make broadcast and multicast methods an effective solution to disseminate data. In particular, repetitive server-initiated broadcast is an effective technique in wireless systems and is a scalable solution to relieve Internet hot spots. A critical issue for the performance of multicast data dissemination is the multicast schedule. Previous work focused on a model where each data item is requested by clients with a certain probability that is independent of past accesses. We consider the more complex scenario where a client accesses pages in blocks (e.g., a HTML file and all its embedded images), thereby introducing dependencies in the pattern of accesses to data. We present a sequence of heuristics that exploit page access dependencies. We measured the resulting client-perceived delay on multiple Web server traces, and observed an average speed-up over previous methods ranging from 8% to 91%. We conclude that scheduling for multi-item requests is a critical factor for the performance of repetitive broadcast.