cssi/SciSciGPT-SciSciNet huggingface dataset:
New view of lipid bilayer dynamics from 2H and 13C NMR relaxation time measurements

Abstract Natural abundance 13C spin-lattice (T1) relaxation time measurements are reported for unilamellar vesicles of 1,2-dipalmitoylphosphatidylcholine (1,2-dipalmitoyl-sn-glycero-3-phosphocholine), in the liquid crystalline phase, at magnetic field strengths of 1.40, 1.87, 2.35, 4.23, 7.05, 8.45, and 11.7 tesla (resonance frequencies of 15.0, 20.0, 25.1, 45.3, 75.5, 90.5, and 126 MHz, respectively), and the results are compared to previous 2H T1 studies of multilamellar dispersions. For both the 13C and 2H T1 studies, a dramatic frequency dependence of the relaxation was observed. At superconducting magnetic field strengths (4.23-11.7 tesla), plots of the 13C T1(-1) relaxation rates as a function of acyl chain segment position clearly reveal the characteristic "plateau" signature of the liquid crystalline phase, as found previously from 2H NMR studies. The dependence of T1(1) on ordering, determined previously from 2H NMR, and the T1(-1) dependence on frequency, determined from both 13C and 2H NMR studies, suggest that a unified picture of the bilayer molecular dynamics can be provided by a simple relaxation law of the form T1(-1) approximately equal to A tau f + BS2C-H omega -1/2(0). In the above expression, A and B are constants, SC-H (= SC-D) is the bond segmental order parameter, and omega 0 is the nuclear Larmor frequency. The first (A) term includes contributions from fast, local segmental motions characterized by the effective correlation time tau f, whereas the second (B) term describes slower, collective fluctuations in the local ordering. The value of tau f approximately equal to 10(-11) sec, obtained by extrapolating T1(-1) to infinite frequency, suggests that the segmental microviscosity of the bilayer hydrocarbon region does not differ appreciably from that of the equivalent n-paraffinic liquids of similar chain length.
Measurement of d-amphetamine-induced effects on the binding of dopamine D-2/D-3 receptor radioligand, 18F-fallypride in extrastriatal brain regions in non-human primates using PET.

Abstract The ability to measure amphetamine-induced dopamine release in extrastriatal brain regions in the non-human primates was evaluated by using the dopamine D-2/D-3 receptor radioligand, 18F-fallypride. These regions included the thalamus, amygdala, pituitary, temporal cortex and frontal cortex as well as putamen, caudate and ventral striatum. The positron emission tomography (PET) studies involved control studies, which extended to 3 h, and the amphetamine-challenge studies, which involved administration of d-amphetamine (approx. 0.5–1 mg/kg, i.v.). PET data analysis employed the distribution volume ratio method (DVR) in which the cerebellum was used as a reference region. Our results show a substantial decrease in the binding potential of 18F-fallypride in extrastriatal regions: thalamus (−20%), amygdala (−39%) and pituitary (−14%). Putamen, caudate and ventral striatum also exhibited significant decreases (−20%). The decrease in 18F-fallypride binding in the extrastriatal regions points to the importance of dopaminergic neurotransmission in these brain regions. Furthermore, our findings support the use of 18F-fallypride to measure extrastriatal dopamine release.
Variation in jump force production within an instar of the grasshopper Schistocerca americana

Jumping ability varies by two-fold within an instar during the moult cycle in the grasshopper, Schistocerca americana (Acrididae: Cyrtacanthacridinae). Changes in jump distance could result from deviations in jump angle away from the optimum during development, a change in jump energy and/or a change in body mass. Body mass has already been shown to vary by over two- fold within an instar (Queathem, 1991). In the present study, jump angle remained near the optimum of 43° during the time course of maximal jumps throughout the instar. Jump energy was correlated with ground reaction force production because energy lost to backward rotation and drag was small. Ground reaction force production varied by nearly four-fold over the period of the instar. Within instar six, force production and body mass accounted for 85% of the variation in jump distance. Their patterns of change relative to one another explain the four functional stages we define for within instar performance. Jump distance increased early within instar six (Stage I, days 0–2) because force production increased. In Stage II (days 3–8), jump distance remained at its peak because an increase in body mass was offset by an equal increase in force production. Jump distance decreased in Stage III (days 8–11) because body mass continued to increase while force production levelled off. Force production decreased to a greater extent than body mass during Stage IV (days 11–13), resulting in a further decline in jump distance during the three days preceding the moult to adulthood. Our results suggest that further examination of the musculo-skeletal system could provide a causal explanation for this change in jumping ability within an instar. The present study illustrates the remarkable physiological and mechanical changes that affect locomotion within a single instar, and highlights developmental differences between arthropods and vertebrates. Arthropod development is by its very nature a discontinuous process separated by periods of continuous, parabolic changes, and this pattern of growth is reflected in locomotor performance through ontogeny.
Electronic structural changes of the electrochemically Li-ion deintercalated LiNi0.8Co0.15Al0.05O2 cathode material investigated by X-ray absorption spectroscopy

Abstract In situ hard X-ray absorption spectroscopy (XAS) at metal K-edges and soft XAS at O K-edge and metal L-edges have been carried out during the first charging process for the layered Li1−xNi0.8Co0.15Al0.05O2 cathode material. The metal K-edge XAS results show that the major charge compensation at the metal site during Li-ion deintercalation is achieved by the oxidation of Ni ions, while the cobalt ions remain mostly unchanged in the Co3+ state. Ni LII,III-edge and O K-edge XAS results in both the fluorescence yield (FY) and partial electron yield (PEY) modes show that substantial amount of Ni ions at the surface of LiNi0.8Co0.15Al0.05O2 powders exist as Ni2+, whereas most of Ni ions in the bulk are in the form of Ni3+. Therefore, if the PEY mode, which is a surface-sensitive technique, is used alone, the interpretation of the results is limited to the surface structures only. In order to get the full picture of both the surface and the bulk, the FY mode and PEY mode should be used simultaneously.
Distinct subtypes of myelitis in systemic lupus erythematosus

Objective Myelitis causes pain, weakness, and sphincteric deficits, and is 1,000-fold more prevalent in patients with systemic lupus erythematosus (SLE) than in the general population. For the last century, descriptions of SLE myelitis have been primarily limited to case reports. In contrast, larger-scale cohort studies have revealed that myelitis occurring in the idiopathic demyelinating diseases (i.e., multiple sclerosis versus neuromyelitis optica) represents distinct syndromes. This study was undertaken to determine whether SLE myelitis similarly encapsulates distinct syndromes. Methods We analyzed a cohort of 22 patients with SLE and myelitis. Patients were assessed for neurologic variables related to myelitis and for clinical and serologic features of SLE. Magnetic resonance images of the spine, cerebrospinal fluid profiles, and autoantibody profiles were obtained. Results Eleven patients presented with signs of gray matter dysfunction (i.e., flaccidity and hyporeflexia), whereas 11 patients presented with signs of white matter dysfunction (i.e., spasticity and hyperreflexia). Patients with gray matter dysfunction were more likely to have irreversible paraplegia (P < 0.01), despite presenting with a monophasic versus polyphasic course (P = 0.01), higher levels of SLE activity (mean SLE Disease Activity Index 9.8 versus 2.0; P = 0.01), and a cerebrospinal fluid profile indistinguishable from bacterial meningitis. Prior to irreversible paraplegia, these patients presented with prodromes of fever and urinary retention, but were misdiagnosed by physicians of different specialties as having urinary tract infections. Patients with white matter dysfunction were more likely to meet criteria for neuromyelitis optica (P = 0.04) and were also more likely to have antiphospholipid antibodies (lupus anticoagulant) (P = 0.01). Conclusion Our findings indicate that SLE myelitis encapsulates 2 distinct and previously unrecognized syndromes that can be distinguished clinically by gray matter versus white matter findings. Recognition of fever and urinary retention as prodromes of irreversible paraplegia may allow earlier diagnosis and treatment in SLE patients presenting with gray matter findings.
430. Transductional mechanisms and gene expression in melancholia

We have shown that melancholic depressives have a reduction in the exogenous phosphorylation activity of protein kinase A (PKA) relative to normal volunteers using cultured skin fibroblasts. In this study we contrasted melancholics and normals with regard to three factors: (1) The binding of [H] cyclic AMP to PKA; (2) The phosphorylation of endogenous CREB; and (3) The alteration of the expression of a CREB/CRE-dependent transfected luciferase reporter gene. Methods: Fibroblasts were cultured from drug-free subjects with DSM-IV major depression (melancholic type) and normal volunteers. [H] cyclic AMP binding (7 nM) was determined in the 48,000 3 g supernatant fraction. Cultures were incubated with 1 mM isoproterenol for 10 minutes after which CREB/CREB-P were assayed by subjecting nuclear lysates to gel electrophoresis followed by immunoblotting using polyclonal anti-CREB/CREB-P. Fibroblasts were also stably transfected with the luciferase reporter plasmid pAD neo2-C 12-BGL to evaluate any alteration in cAMP-PKA-CREB-dependent gene expression. Results: [H] cyclic AMP binding was significantly reduced in melancholics (p , 0.02): 902 6 73 vs. 631 6 51 fmol/mg protein. Isoproterenol-stimulated CREB-P and luciferase gene expression are also reduced in fibroblasts from melancholics. Both of these effects were blocked by the beta-2 antagonist ICI 118551. Conclusions: The previous finding of an abnormality of PKA activity in melancholia are now extended to suggest a reduction in CREB-P formation and an alteration in the expression of a specific CREB-CREdependent genes. We also will present newer data regarding differential expression of endogenous genes by differential display.
Postmarketing surveillance of abuse liability of sibutramine

Abstract The abuse liability of medications is a growing concern as the number of newly approved psychoactive medications increases. Postmarketing surveillance can assist in determining abuse liability, but strategies are not well-defined for medications believed to be at low abuse risk. Using a newly approved medication (sibutramine—an anorectic drug), a novel approach to postmarketing abuse surveillance was introduced. A one-page anonymous questionnaire covering sibutramine, a scheduled anorectic drug (phentermine), and a fabricated name was added to the intake process of 58 treatment programs. From the 8780 completed questionnaires, 8.8% had heard of sibutramine and phentermine. For continued use to get high (a proxy for abuse), the rate for sibutramine was lower than for phentermine (0.6 vs. 2.2%, McNemar's χ 2 =110.45, P χ 2 =11.86, P
Genetic structure in the coral, Montastraea cavernosa: assessing genetic differentiation among and within Mesophotic reefs.

Mesophotic coral reefs (30–150 m) have recently received increased attention as a potential source of larvae (e.g., the refugia hypothesis) to repopulate a select subset of the shallow water (<30 m) coral fauna. To test the refugia hypothesis we used highly polymorphic Amplified Fragment Length Polymorphism (AFLP) markers as a means to assess small-scale genetic heterogeneity between geographic locations and across depth clines in the Caribbean coral, Montastraea cavernosa. Zooxanthellae-free DNA extracts of coral samples (N = 105) were analyzed from four depths, shallow (3–10 m), medium (15–25 m), deep (30–50 m) and very deep (60–90 m) from Little Cayman Island (LCI), Lee Stocking Island (LSI), Bahamas and San Salvador (SS), Bahamas which range in distance from 170 to 1,600 km apart. Using AMOVA analysis there were significant differences in ΦST values in pair wise comparisons between LCI and LSI. Among depths at LCI, there was significant genetic differentiation between shallow and medium versus deep and very deep depths in contrast there were no significant differences in ΦST values among depths at LSI. The assignment program AFLPOP, however, correctly assigned 95.7% of the LCI and LSI samples to the depths from which they were collected, differentiating among populations as little as 10 to 20 m in depth from one another. Discriminant function analysis of the data showed significant differentiation among samples when categorized by collection site as well as collection depth. FST outlier analyses identified 2 loci under positive selection and 3 under balancing selection at LCI. At LSI 2 loci were identified, both showing balancing selection. This data shows that adult populations of M. cavernosa separated by depths of tens of meters exhibits significant genetic structure, indicative of low population connectivity among and within sites and are not supplying successful recruits to adjacent coral reefs less than 30 m in depth.
NMDA antagonists exacerbate neuronal death caused by proteasome inhibition in cultured cortical and striatal neurons.

The proteasome is involved in multiple cellular processes including control of the cell cycle, apoptosis and intracellular signalling; loss of proteasome function has been postulated to participate in the pathogenesis of triplet repeat diseases. We examined the vulnerability of central neurons to proteasome inhibition and tested the ability of anti-excitotoxic and anti-apoptotic treatments to attenuate proteasome inhibition-induced neuronal death. Exposure of murine neocortical cultures to proteasome inhibitors (0.1-10 microm clasto-lactacystin beta-lactone or MG-132) for 48 h resulted in widespread neuronal death associated with a reduction in intracellular free calcium; higher inhibitor concentrations killed astrocytes. Cultured striatal neurons were more vulnerable than cortical neurons. Within each population, the NADPH diaphorase-positive neuronal subpopulation was more vulnerable than the general neuronal population. Enhancing calcium entry with S(-)BayK8644 or kainate, or blocking apoptosis with cycloheximide, actinomycin D or Z-VAD.FMK attenuated neuronal death, whereas, reducing calcium entry with NMDA antagonists or R(+)BayK8644 potentiated neuronal death. These findings suggest that proteasome inhibition can induce selective neuronal apoptosis associated with intracellular calcium starvation, and point to manipulation of intracellular calcium as a specific therapeutic strategy. In particular, concern is raised that glutamate receptor antagonists might exacerbate, rather than attenuate, proteasome inhibition-induced neuronal death.
Will sex selection reduce fertility

This paper investigates both theoretically and numerically the impact of sex selection on fertility. A static quantity-quality model of fertility is employed to compare fertility choices in two regimes: one in which parents cannot choose the gender of children and another in which parents can fully choose the gender of children. The static theory shows that whether sex selection reduces fertility depends on the second and third derivatives of the utility function and the child expenditure function. A numerical dynamic analysis is also presented. Using empirical dynamic models of fertility and Monte Carlo integration technique, the simulation shows that sex selection on the firstborn child among the Chinese in Malaysia could reduce fertility by about 3%.
Lateral and anterior plating of intra-articular distal femoral fractures treated via an anterior approach.

Thirty-five patients with 36 displaced distal femoral fractures (16 AO-type C2 and 19 AO-type C3) were treated with an anterior approach and double plating and followed for an average of 7 (3–44) months. Bone grafting with allograft and demineralized bone matrix was used. Postoperative therapy included immediate ROM and non-weight bearing for 12 weeks. Two patients died during hospitalization and one was lost to follow-up. Reductions were near anatomic in all but three patients. Uneventful healing by 16 weeks occurred in 24/36 fractures. Double plating via the anterolateral approach minimized stripping of the medial side and improved controlled access to the distal femur.
Incorporating circulation data in relevancy rankings for search algorithms in library collections

This paper demonstrates a series of analyses to calculate new clusters of shared subject headings among items in a library collection. The paper establishes a method of reconstituting anonymous circulation data from a library catalog into separate user transactions. The transaction data is incorporated into subject analyses that use supercomputing resources to generate predictive network analyses and visualizations of subject areas searched by library users. The paper develops several methods for ranking these subject headings, and shows how the analyses will be extended on supercomputing resources for information retrieval research.
Mucosa-associated lymphoid tissue lymphoma with initial supradiaphragmatic presentation: natural history and patterns of disease progression.

Abstract Purpose: Mucosa-associated lymphoid tissue (MALT) lymphoma commonly presents in the gastrointestinal (GI) tract. Supradiaphragmatic MALT lymphoma is less common and its natural history is not well defined. This study was conducted to understand the natural history, to determine the frequency of synchronous disease in the GI tract, and to understand the patterns of disease progression after treatment for supradiaphragmatic MALT lymphoma. Patients and Methods: We retrospectively reviewed the medical records of 39 patients who presented with supradiaphragmatic MALT lymphoma between 1991 and 1997. Results: The median age of patients was 58 years (range, 25–90 years) with 16 male and 23 female patients. The most common primary site was salivary gland followed by ocular adnexa, lung, oral cavity, and others. Sixteen patients underwent esophagogastroduodenoscopy and biopsy (EGD + Bx) and 4 were found to have gastric involvement. Ann Arbor stages were the following: IEA, 17; IIEA, 5, IIEB, 1; and IVA, 16. The initial treatments were: involved field radiation therapy ( n = 10), chemotherapy ( n = 14), combination of radiation therapy and chemotherapy ( n = 9), observation after biopsy ( n = 4), antibiotics only ( n = 1), and patient refusal of further intervention ( n = 1). Seven patients received antibiotics as a part of the initial treatment. Every patient except for 1 was alive at a median follow-up of 39.5 months (range, 3–83 months). Thirty-six patients achieved complete response (CR) to the initial treatment. The actuarial 5-year progression-free survival rate was 83%. Progression of the disease occurred in 4 patients, with 2 in the stomach. Salvage attempts were made to 4 and were successful in 3. Of the 2 patients who relapsed in the stomach, 1 had negative EGD + Bx at the time of initial diagnosis. An EGD + Bx was not done in the second patient. Conclusion: Supradiaphragmatic MALT lymphoma appears to have a favorable prognosis. However, routine evaluation of the stomach is recommended for patients who present with supradiaphragmatic MALT lymphoma at the time of initial evaluation and at the time of relapse. Patients who failed initial therapy can be successfully salvaged with further treatment.
Modification of the Cary Model 14 recording spectrophotometer for low-temperature spectroscopy.

Abstract Low-temperature spectroscopy possesses several advantages over room-temperature spectroscopy, especially for the spectral study of complex or particulate systems. An apparatus is described for automatically recording absorption spectra at liquid-nitrogen temperature with the Cary Model 14 spectrophotometer. Excellent resolution of cytochrome absorption bands in particulate systems is observed, as is typical of the low-temperature method. The technique is also applicable to soluble systems.
Cellular and Molecular Guidance of GABAergic Neuronal Migration from an Extracortical Origin to the Neocortex

Formation of the normal mammalian cerebral cortex requires the migration of GABAergic inhibitory interneurons from an extracortical origin, the lateral ganglionic eminence (LGE). Mechanisms guiding the migratory direction of these neurons, or other neurons in the neocortex, are not well understood. We have used an explant assay to study GABAergic neuronal migration and found that the ventricular zone (VZ) of the LGE is repulsive to GABAergic neurons. Furthermore, the secreted protein Slit is a chemorepellent guiding the migratory direction of GABAergic neurons, and blockade of endogenous Slit signaling inhibits the repulsive activity in the VZ. These results have revealed a cellular source of guidance for GABAergic neurons, demonstrated a molecular cue important for cortical development, and suggested a guidance mechanism for the migration of extracortical neurons into the neocortex.
INTERVIEWING IN SINOLOGY: OBSERVATIONS ON METHODS AND FUNDAMENTAL CONCEPTS

Observations, experientially and analytically based, are offered to maximize the contribution that the interview, as a research instrument, can make to sinology. Four major aspects of the interview...
The Cauchy Theorem

Runge’s Theorem can be used to prove Cauchy’s Theorem. This will require the elements of integration theory described in Chapter 2. Recall that for a rectifiable curve γ: [0,1] → ℂ, we let ‖γ‖ denote its length, i.e. ‖γ‖ = 1 |γ′(t)|dt, so that $$ \left| {\int_{\gamma } {f(z)dz} } \right| \leqslant \left\| \gamma \right\| \cdot \left\| f \right\| $$ where ‖f‖ = sup{| f(z) |: z ∈ γ}. The reader is reminded that γ^ denotes the “physical curve”, that is the image of γ.
Enhancing the Alkaline Hydrogen Evolution Reaction Activity through the Bifunctionality of Ni(OH)2/Metal Catalysts

Active in alkaline environment: The activity of nickel, silver, and copper catalysts for the electrochemical transformation of water to molecular hydrogen in alkaline solutions was enhanced by modification of the metal surfaces by Ni(OH)(2) (see picture; I = current density and η = overpotential). The hydrogen evolution reaction rate on a Ni electrode modified by Ni(OH)(2) nanoclusters is about four times higher than on a bare Ni surface.
In Defense of Formal Rulemaking

For both administrative law amateurs and cognoscenti alike, when one thinks of rulemaking, informal rulemaking, with its notice-and-comment procedures, comes to mind. This association is natural; in modern administrative law, informal rulemaking is ubiquitous. This Article, however, addresses a different type of rulemaking — one that, if not forgotten altogether, is usually brushed aside quickly as an unwanted relic of the past: formal rulemaking. In marked contrast to its informal counterpart, formal rulemaking uses procedures akin to a trial, including hearing officers, pre-trial conferences, burdens of proof and persuasion, proposed findings, cross-examination, and a closed record. Although the APA provides for formal rulemaking, however, the Supreme Court largely put an end to it decades ago in United States v. Florida East Coast Railway Co. There, following the winds of scholarly opinion that had turned against formal rulemaking as unduly cumbersome, the Court held that unless an agency’s organic statute uses magic words like “on the record after opportunity for an agency hearing” no formal rulemaking is required. Because so few statutes use those magic words, formal rulemaking has largely disappeared.Since Florida East Coast Railway, few have risen to formal rulemaking’s defense. Indeed, no scholar in over thirty years has seriously considered formal rulemaking’s virtues. This Article fills the void. While formal rulemaking’s robust procedural protections admittedly can be a misfit in some contexts, it may be a mistake to categorically dismiss them in all contexts, especially because formal rulemaking has the potential to facilitate better rules of greater legitimacy. In today’s world where a handful of technically complex rules can impose billions of dollars of costs on the nation’s economy, the time has come to ask whether formal rulemaking might yet play a limited but crucial role in the future of administrative law.
A comparative study of surface reconstruction of wurtzite GaN on (0 0 0 1) sapphire by RF plasma-assisted molecular beam epitaxy

We present a comprehensive study of the electrical, optical, and structural properties of wurtzite GaN films grown under various initial growth conditions The GaN films were grown directly on sapphire substrates using GaN nucleation layers by a Riber 3200 system with a radio-frequency plasma source. In situ reflection high-energy electron diffraction (RHEED) reveals a strong correlation between nucleation conditions, including the nitridation step, and the final surface reconstruction of the GaN thin film. Well-defined reconstruction patterns, primarily (2 � 2) and(4 � 4), are observed for some of the nucleation conditions. Hall mobility, photoluminescence (PL), X-ray rocking curve data, and transmission electron microscopy (TEM) measurements are usedto interpret the observedrelationship. The results show that for the conditions investigated, an unreconstructed (1 � 1) surface after growth correlates with improved electrical, optical, andstructural properties. The surface reconstructedthin film exhibits a strong columnar growth with inversion domains (IDs). We attribute the degraded characteristics to the presence of a mixture of both polarities in the films with reconstruction. r 2001 Publishedby Elsevier Science B.V.
Undertreatment of Tobacco Use Relative to Other Chronic Conditions

Objectives. We compared the likelihood that a tobacco user would receive treatment with the likelihood that an adult with another common chronic condition would receive treatment for that condition at an office visit.Methods. We analyzed data from the 2005–2007 National Ambulatory Medical Care Survey to compare the proportion of US office visits at which tobacco users and individuals with hypertension, hyperlipidemia, diabetes, asthma, or depression received condition-specific treatment. We calculated the odds that a visit for a comparison condition would result in treatment relative to a visit for tobacco dependence.Results. From 2005 to 2007, 38 004 patient visits involved at least 1 study condition. Tobacco users received medication at fewer visits (4.4%) than individuals with hypertension (57.4%), diabetes (46.2%), hyperlipidemia (47.1%), asthma (42.6%), and depression (53.3%). In multivariate analyses, the odds for pharmacological treatment of these disorders relative to tobacco use were, for hyperte...
Evolutionary spectral co-clustering

Co-clustering is the problem of deriving sub-matrices from the larger data matrix by simultaneously clustering rows and columns of the data matrix. Traditional co-clustering techniques are inapplicable to problems where the relationship between the instances (rows) and features (columns) evolve over time. Not only is it important for the clustering algorithm to adapt to the recent changes in the evolving data, but it also needs to take the historical relationship between the instances and features into consideration. We present ESCC, a general framework for evolutionary spectral co-clustering. We are able to efficiently co-cluster evolving data by incorporation of historical clustering results. Under the proposed framework, we present two approaches, Respect To the Current (RTC), and Respect To Historical (RTH). The two approaches differ in the way the historical cost is computed. In RTC, the present clustering quality is of most importance and historical cost is calculated with only one previous time-step. RTH, on the other hand, attempts to keep instances and features tied to the same clusters between time-steps. Extensive experiments performed on synthetic and real world data, demonstrate the effectiveness of the approach.
Acquired immunodeficiency syndrome in urban Brazil.

Since 1983 when the 1st verified case was reported there the number of AIDS victims has grown rapidly enough to place Brazil high on the list of countries with the largest number of confirmed cases. This article draws on the authors research on Brazilian sexual culture and suggests its relevance for understanding the transmission of AIDS in Brazil. It calls for a more active and culturally appropriate response to the disease in Brazil as well as for an increasingly sophisticated understanding of cultural differences that influence the AIDS epidemic nationally. From November 1983 to March 1984 the author interviewed formally and informally the men and women he met through social networks related to the Brazilian carnival. The informants included most or all of the sexual life in Brazil generally: male and female prostitutes and their clients; self-identified lesbians and male homosexuals; both single and married heterosexuals with and without children. Most were between the ages of 18 and 40 years of age. The research was qualitative rather than quantitative. The flexible structure of both homosexual practices and the homosexual subculture in Brazil make the categorization of homosexuals as a distinct high risk group rather questionable. Anal intercourse is central to same-sex interactions in Brazil regardless of the specific sexual identities of the participants. Anal intercourse is also a common practice between males and female prostitutes and is also a part of the sexual life of many heterosexual couples. Because anal intercourse is a major vehicle for transmission of AIDS these cultural and behavioral data gain particular importance for the epidemiology of AIDS in Brazil.
Staircase Model for New Practice Implementation

Implementation of new ideas and new practices are essential for an organization to remain competitive in a changing business environment. The absence of these new ideas will eventually lead to stagnation, but the challenge to organizations remains how to overcome the many barriers that appear during an implementation process and successfully convert these ideas into sustainable practices. Within the capital facility industry, this challenge is amplified based on long-held industry practices, corporate culture, and a necessary focus on minimizing risk. However, even the capital facility industry is being forced to recognize the need to adapt to changing business conditions through the implementation of best practices. Specifically, organizations require an implementation plan that provides enough detail that all parties impacted by the process understand the process roadmap that is going to be followed during implementation. This paper introduces the development of the staircase implementation model and how it addresses the need for an implementation roadmap that is applicable to all implementation initiatives. The paper introduces the model components, the proposed application of the model, and the initial testing of the model that led to specific implementation considerations. This paper has significant relevance to industry as it gives a practical introduction to the important focus of implementing new practices.
Minimizing Required Energy Storage in Off-Line LED Drivers Based on Series-Input Converter Modules

This paper introduces techniques to reduce energy storage in off-line light-emitting diode (LED) drivers. Rather than targeting the ideals of unity input power factor (PF) and constant LED current, a topology is selected to minimize the required energy storage with the more practical targets of 0.9 PF and a selectable LED current ripple. The objectives are accomplished using a combination of the following: first, constant-input-current regulation, which results in 0.9 PF and 34% less required energy storage than when using unity power factor, and is achieved with a simple reference signal that does not require input voltage sensing; second, a two-stage approach that isolates the LED from the capacitor to allow full use of the stored energy; third, a bidirectional second stage (LED string is between the two stages) that processes only the necessary energy storage; and fourth, a selectable regulation band on the LED current ripple to pass through the maximum allowed double-line-frequency ripple. The topology is applied to the series-input modular architecture to utilize low-voltage high-frequency circuits and low-profile components in off-line applications. Experimental results are presented for a series-input system with three modules each driving eight LEDs with 30% double-line-frequency current ripple using small filter capacitors.
Sequential Discreteness and Clopen-$I$-Boolean Classes

Kantorovich and Livenson [6] initiated the study of infinitary Boolean operations applied to the subsets of the Baire space and related spaces. It turns out that a number of interesting collections of subsets of the Baire space, such as the collection of Borel sets of a given type (e.g. the F σ sets) or the collection of analytic sets, can be expressed as the range of an ω -ary Boolean operation applied to all possible ω -sequences of clopen sets. (Such collections are called clopen- ω -Boolean.) More recently, the ranges of I -ary Boolean operations for uncountable I have been considered; specific questions include whether the collection of Borel sets, or the collection of sets at finite levels in the Borel hierarchy, is clopen- I -Boolean. The main purpose of this paper is to give a characterization of those collections of subsets of the Baire space (or similar spaces) that are clopen- I -Boolean for some I . The Baire space version can be stated as follows: a collection of subsets of the Baire space is clopen- I -Boolean for some I iff it is nonempty and closed downward and σ -directed upward under Wadge reducibility, and in this case we may take I = ω 2. The basic method of proof is to use discrete subsets of spaces of the form K 2 to put a number of smaller clopen- I -Boolean classes together to form a large one. The final section of the paper gives converse results indicating that, at least in some cases, ω 2 cannot be replaced by a smaller index set.
The unusual reaction of Ga(C5Me5)3 with a nucleophilic carbene

Abstract Treatment of Ga(C5Me5)3 with tetramethylimidazol-2-ylidene affords the carbene complex, Ga(C5Me5)2H·carbene (1). The structure of 1 was determined by X-ray crystallography. Possible mechanisms for the formation of 1 are discussed.
The articulation of values and principles involved in health care reform

The Ethics Working Group of Clinton's Health Care Task Force developed a list of principles and values that should govern health care reform. These principles and values are compatible with central moral and political traditions, as well as with more rigorous theoretical accounts of justice and health care, but they are "freestanding" points of agreement, not presupposing any particular theoretical background. Though imprecise and not ranked by priorities, the principles guide thinking about the fairness of alternative reform proposals. Their use is illustrated by comparing alternatives on universality of access, phase-in period, the creation of unequal tiers, and the provision for wise allocation and rationing.
Limits of the Local: Expanding Perspectives on Literacy as a Social Practice

This essay reflects on how the social practice model of literacy, an approach that defines reading and writing as situated, social practices, under-theorizes certain aspects of literacy, making it hard to account fully for its workings in local contexts. We trace this theoretical blind spot to the ways that the social practice model was formulated as a challenge to the “Great Divide” or “autonomous” models of literacy. We suggest that in rejecting a conception of literacy as a deterministic force, the revisionists critique veers too far in a reactive direction. By exaggerating the power of local contexts to define the meaning and forms that literacy takes and by under-theorizing the potentials of the technology of literacy, methodological bias and conceptual impasses are created. To open new directions for literacy research we suggest more attention be paid to the material dimensions of literacy. Drawing on the work of Bruno LaTour (1993, 1996), we seek to theorize the transcontextualized and transcontext...
Popular responses and cultural differences; an analysis based on frequencies in a group of American Indian subjects.

(1945). “Popular” Responses and Cultural Differences: An Analysis Based on Frequencies in a Group of American Indian Subjects. Rorschach Research Exchange: Vol. 9, No. 4, pp. 153-168.
How natural habitat patchiness affects the distribution of diversity in Californian serpentine chaparral

Components of diversity in the woody plant community were compared among three sets of sites in the Coast Ranges of Northern California: 24 small patches (0.5–3 ha) of serpentine soil, found in four sets of 5–7 patches; 24 equivalently spaced sampling sites within four large (6–55 km2) continuous areas of serpentine; and 24 sites on the nonserpentine soils adjacent to the small patches. On patchy compared with continuous serpentine, alpha diversity (local) was 32% lower, gamma diversity (total) was 17% higher, and beta diversity (differentiation in species composition among sites) was 72% higher. Of the increased beta diversity on patches, most (62%) occurred at the “local” scale of patches 50–3200 m apart, and only 10% occurred at the scale of clusters of patches 16–45 km apart. Complementarity, an alternative measure of beta diversity, showed the same patterns. Woody plants on nonserpentine soils showed diversity patterns similar to those on patchy serpentine, i.e., lower alpha and higher beta and gamma diversity relative to continuous serpentine. Nonserpentine plants showed a stronger response to environmental gradients than did serpentine plants. For the woody plant community. on serpentine soils, the natural large-scale patchiness of the habitat leads to lower local diversity but higher differentiation and regional diversity. The increased regional diversity appears to be almost entirely the result of edge effects, rather than of “patchy coexistence” as described by metacommunity models.
Measurement Validation of Navigation During the Pivot-Shift Test

Computer-assisted surgery systems have been used for both clinical and research applications. Specifically for anterior cruciate ligament (ACL) reconstruction procedures, newer applications have focused on kinematic analysis rather than tunnel placement or isometry profiles. The surgeon, during a manual physical examination, lacks the ability to reliably quantify knee kinematics and laxity before, during, or after ACL reconstruction. A navigated knee laxity examination could potentially close the computed-assisted surgery treatment loop by providing quantitative feedback about various ACL reconstruction procedures. Recent iterations of navigated laxity examination include complex physical examinations, such as the pivot shift examination. This article explains measurement validation of knee laxity examinations with a navigation system.
Male infertility, genetic analysis of the DAZ genes on the human Y chromosome and genetic analysis of DNA repair

Many genes that are required for fertility have been identified in model organisms (Castrillon et al., 1993; Chubb et al., 1993; Mello et al., 1996). Mutations in these genes cause infertility due to defects in development of the germ cell lineage, but the organism is otherwise healthy. Although human reproduction is undoubtedly as complex as that of other organisms, very few fertility loci have been mapped (Reijo et al., 1995; Vogt et al., 1996; Aittomaki et al., 1995). This is in spite of the prevalence of human infertility, the lack of effective treatments to remedy germ cell defects, and the cost to couples and society of assisted reproductive techniques. Fifteen percent of couples are infertile and half of all cases can be traced to the male partner. Aside from defects in sperm production, most infertile men are otherwise healthy. This review is divided into two distinct parts to discuss work that: (i) led to the identification of several genes on the Y chromosome that likely function in sperm production; and (ii) implicates DNA repair in male infertility via increased frequency of mutations in DNA from men with meiotic arrest.
An unexpected role for brain-type sodium channels in coupling of cell surface depolarization to contraction in the heart

Voltage-gated sodium channels composed of pore-forming α and auxiliary β subunits are responsible for the rising phase of the action potential in cardiac muscle, but the functional roles of distinct sodium channel subtypes have not been clearly defined. Immunocytochemical studies show that the principal cardiac pore-forming α subunit isoform Nav1.5 is preferentially localized in intercalated disks, whereas the brain α subunit isoforms Nav1.1, Nav1.3, and Nav1.6 are localized in the transverse tubules. Sodium currents due to the highly tetrodotoxin (TTX)-sensitive brain isoforms in the transverse tubules are small and are detectable only after activation with β scorpion toxin. Nevertheless, they play an important role in coupling depolarization of the cell surface membrane to contraction, because low TTX concentrations reduce left ventricular function. Our results suggest that the principal cardiac isoform in the intercalated disks is primarily responsible for action potential conduction between cells and reveal an unexpected role for brain sodium channel isoforms in the transverse tubules in coupling electrical excitation to contraction in cardiac muscle.
WOLF SPIDERS SHOW GRADED ANTIPREDATOR BEHAVIOR IN THE PRESENCE OF CHEMICAL CUES FROM DIFFERENT SIZED PREDATORS

The wolf spider, Pardosa milvina, displays effective antipredator behavior (reduced activity) in the presence of silk and excreta cues from adults of another cooccurring wolf spider, Hogna helluo. However, Pardosa and Hogna engage in size-structured intraguild predation, where Pardosa may be either the prey or predator of Hogna. We tested the ability of adult female Pardosa to vary antipredator responses toward kairomones produced by Hogna that vary in size. Hogna were maintained on filter paper for 24 hr. We then presented the paper to adult female Pardosa simultaneously paired with a blank sheet of paper. One treatment had two sheets of blank paper to serve as a control. The Hogna stimulus treatments were as follows (N = 15/treatment): (1) 1 Hogna half the mass of Pardosa; (2) 1 Hogna of equal mass of a Pardosa; (3) 1 adult Hogna, 30 times the mass of Pardosa; and (4) 8 Hogna each 0.25 the mass of Pardosa. Pardosa decreased activity in the presence of kairomones from Hogna of equal or larger size, but showed no change in activity in the presence of a blank control or from a single Hogna smaller than itself. Pardosa showed a reduction in activity in the presence of cues from eight small Hogna. Pardosa avoided substrates with adult Hogna cues, but showed no avoidance response to any other treatment. These results suggest that Pardosa is showing graded antipredator behavior relative to the quantity of predator kairomones present rather than directly discriminating among the different sizes of the predator.
Cellular lesions in intestinal mucosa of gnotobiotic calves experimentally infected with a new unclassified bovine virus (Breda virus).

Four gnotobiotic calves were inoculated intranasally with Breda virus within two hours after cesarean section. Three calves developed diarrhea between 48 and 60 hours after inoculation; one calf was killed at 36 hours. Consistent microscopic findings in the intestinal mucosae of calves with diarrhea were cytopathologic changes in enterocytes of the lower small intestine, large intestine, and dome epithelial cells and an acute inflammatory response with cellular infiltration and subtle changes in capillaries. Virions with average dimensions of 35 × 80 nm were seen in rounded cells that had severe cell swelling, dilatation of the cytocavitary network, and hydropic degeneration. Virions were most often in multiple, large autophagolysosomes. There was a good correlation in detection of virus in cells with electron microscopy and indirect immunofluorescence. No lesions were detectable in two control calves killed five days after inoculation.
Polarimetric remote sensing of aerosols

In this paper we summarize the capabilities of multi-angle, multi-spectral polarimetric remote sensing using passive solar reflectance measurements. The approaches required to retrieve aerosol properties over ocean and land are described together with the types of cloud property retrieval that are possible.
An overview of level set methods for etching, deposition, and lithography development

The range of surface evolution problems in etching, deposition, and lithography development offers significant challenge for numerical methods in front tracking. Level set methods for evolving interfaces are specifically designed for profiles which can develop sharp corners, change topology, and undergo orders of magnitude changes in speed. They are based on solving a Hamilton-Jacobi type equation for a level set function, using techniques borrowed from hyperbolic conservation laws. Over the past few years, a body of level set methods have been developed with application to microfabrication problems. In this paper, we give an overview of these techniques, describe the implementation in etching, deposition, and lithography simulations, and present a collection of fast level set methods, each aimed at a particular application. In the case of photoresist development and isotropic etching/deposition, the fast marching level set method, introduced by Sethian (1996), can track the three-dimensional photoresist process through a 200/spl times/200/spl times/200 rate function grid in under 55 s on a Sparc10. In the case of more complex etching and deposition, the narrow band level set method, introduced in Adalsteinsson and Sethian (1995), can be used to handle problems in which the speed of the interface delicately depends on the orientation of the interface versus an incoming beam, the effects of visibility, surface tension, reflection and re-emission, and complex three-dimensional effects. Our applications include photoresist development, etching/deposition problems under the effects of masking, visibility, complex flux integrations over sources, nonconvex sputter deposition problems, and simultaneous deposition and etch phenomena.
SPATIAL AND TEMPORAL INTEGRATION OF SIGNALS IN FOVEAL LINE ORIENTATION

Westheimer, Gerald and Eric J. Ley. Spatial and temporal integration of signals in foveal line orientation. J. Neurophysiol. 77: 2677–2684, 1997. The discrimination of the orientation of a line imp...
Conjectures, Proofs, and Counterexamples

The collection of integers is defined to be the set of numbers $$ \left\{\dots, - 3, - 2, - 1,\ 0,\ 1,\ 2,\ 3,\dots \right\} $$ where the dots indicate that the pattern continues indefinitely in each direction. The integers are also sometimes called the whole numbers. We will use these terms interchangeably. In this chapter we will introduce definitions of the terms even, odd, divides and prime. Then we will develop the skills needed to prove statements about the integers relating to these terms. Direct proofs, indirect proofs, and proofs by contradiction are included.