cssi/SciSciGPT-SciSciNet huggingface dataset:
Computer-aided measurement of liver volumes in CT by means of geodesic active contour segmentation coupled with level-set algorithms

Purpose: Computerized liver extraction from hepatic CT images is challenging because the liver often abuts other organs of a similar density. The purpose of this study was to develop a computer-aided measurement of liver volumes in hepatic CT. Methods: The authors developed a computerized liver extraction scheme based on geodesic active contour segmentation coupled with level-set contour evolution. First, an anisotropic diffusion filter was applied to portal-venous-phase CT images for noise reduction while preserving the liver structure, followed by a scale-specific gradient magnitude filter to enhance the liver boundaries. Then, a nonlinear grayscale converter enhanced the contrast of the liver parenchyma. By using the liver-parenchyma-enhanced image as a speed function, a fast-marching level-set algorithm generated an initial contour that roughly estimated the liver shape. A geodesic active contour segmentation algorithm coupled with level-set contour evolution refined the initial contour to define the liver boundaries more precisely. The liver volume was then calculated using these refined boundaries. Hepatic CT scans of 15 prospective liver donors were obtained under a liver transplant protocol with a multidetector CT system. The liver volumes extracted by the computerized scheme were compared to those traced manually by a radiologist, used as ''gold standard.''Results: The mean livermore » volume obtained with our scheme was 1504 cc, whereas the mean gold standard manual volume was 1457 cc, resulting in a mean absolute difference of 105 cc (7.2%). The computer-estimated liver volumetrics agreed excellently with the gold-standard manual volumetrics (intraclass correlation coefficient was 0.95) with no statistically significant difference (F=0.77; p(F{<=}f)=0.32). The average accuracy, sensitivity, specificity, and percent volume error were 98.4%, 91.1%, 99.1%, and 7.2%, respectively. Computerized CT liver volumetry would require substantially less completion time (compared to an average of 39 min per case by manual segmentation). Conclusions: The computerized liver extraction scheme provides an efficient and accurate way of measuring liver volumes in CT.« less
Hafnium carbide strengthening in a tungsten-rhenium matrix at ultrahigh temperatures

Tungsten--rhenium--hafnium carbide (W---Re---HfC) alloy is the strongest metallic material at temperatures greater than 2000 K. In the this paper, the mechanical properties of tungsten and a W--3.6Re--0.26HfC alloy were determined from 1700 to 2980 K in a vacuum below 10[sup [minus]5] Pa. hfC particles had an exceptional strengthening effect n the tungsten-rhenium matrix at temperatures up to 2700 K. The strengthening was attributed to the high thermodynamic stability of HfC particles at ultrahigh temperatures. The growth behavior of HfC particles in the tungsten-rhenium matrix is examined. Carbon is found to be the rate-limiting element in the growth process of HfC particles. The strengthening mechanisms in a W--3.6Re--0.26HfC were discussed. It was concluded that the strength of a dispersion-strengthened material was proportional to the square root of the volume fraction of the particles. The calculation of a W--3.6Re--0.26HfC alloy's yield strength, calculated based on the dislocation pinning and the particle statistical distribution, was in good agreement with the experimental data over the entire temperature range.
Localized and Sustained Delivery of Silencing RNA from Macroscopic Biopolymer Hydrogels

The ability to silence the expression of specific genes at a particular location of the body would provide a powerful new therapeutic tool for treatment of diseases such as cancer or for use in regenerative medicine. RNA interference (RNAi) is a gene silencing mechanism where specific mRNA molecules that are complementary to short interfering RNA (siRNA) are degraded, thus inhibiting gene expression at the post-transcriptional level. However, the use of siRNA has not yet realized its full clinical potential due to degradation in vivo, the difficulty retaining siRNA at the site of interest, and the relatively short-term effect it has on rapidly dividing cells. In this work a new paradigm is presented that will allow for the localized delivery of siRNA that is controlled and sustained over time, thus allowing cells at the site of interest to be directly exposed to a gradual release of bioactive siRNA. To accomplish this, three different types of macroscopic, degradable biomaterial hydrogel scaffolds were em...
Concomitant Cervical and Lumbar Stenosis: Strategies for Treatment and Outcomes

Concomitant cervical and lumbar spinal stenosis is an infrequently reported condition that may affect approximately 5% of patients presenting with cervical or lumbar spinal stenosis. The diagnosis is difficult, and reliance must be placed on history and physical examination when deciding whether the stenosis should be treated surgically at either region in isolation or concomitantly. Surgical treatment is usually directed at the most symptomatic level, although there are some circumstances when the cervical spine should be decompressed first regardless of symptoms. Consideration can be given to decompression of both the cervical spine and lumbar spine during the same surgery, although these patients must be carefully chosen.
Matrix methods in synthetic seismograms

Summary. Some methods are examined for the matrix problems arising in the computation of seismograms in a stratified medium. In particular, the Thomson-Haskell and Kennett algorithms are placed in a common setting, and their connections with standard methods in numerical analysis are given. Finally, a new formulation is presented which has advantages both for physical insight and for numerical accuracy.
Biologic Complexity in Sickle Cell Disease: Implications for Developing Targeted Therapeutics

Current therapy for sickle cell disease (SCD) is limited to supportive treatment of complications, red blood cell transfusions, hydroxyurea, and stem cell transplantation. Difficulty in the translation of mechanistically based therapies may be the result of a reductionist approach focused on individual pathways, without having demonstrated their relative contribution to SCD complications. Many pathophysiologic processes in SCD are likely to interact simultaneously to contribute to acute vaso-occlusion or chronic vasculopathy. Applying concepts of systems biology and network medicine, models were developed to show relationships between the primary defect of sickle hemoglobin (Hb S) polymerization and the outcomes of acute pain and chronic vasculopathy. Pathophysiologic processes such as inflammation and oxidative stress are downstream by-products of Hb S polymerization, transduced through secondary pathways of hemolysis and vaso-occlusion. Pain, a common clinical trials endpoint, is also complex and may be influenced by factors outside of sickle cell polymerization and vascular occlusion. Future sickle cell research needs to better address the biologic complexity of both sickle cell disease and pain. The relevance of individual pathways to important sickle cell outcomes needs to be demonstrated in vivo before investing in expensive and labor-intensive clinical trials.
Control of Camless Intake Process—Part II

A model-based control scheme is designed to regulate the cylinder air charge of a camless multicylinder engine for unthrottled operation. The controller consists of a feedforward and an adaptive feedback scheme based on a control-oriented model of the breathing process of an engine equipped with electro-hydraulic springless valvetrain. The nonlinear control scheme is designed to achieve cylinder-to-cylinder balancing, fast cycle-to-cycle response, and minimization of pumping losses. The algorithm uses conventional sensor measurements of intake manifold pressure and mass air flow to the intake manifold, and intake valve duration measurement. Closed-loop simulation results are shown for a four-cylinder engine.
Prostate cancer: PSA velocity in prostate cancer screening—the debate continues

Prostate cancer screening in the PSA era is controversial and the most appropriate measures for diagnosis are widely debated. Vickers and colleagues recently suggested that using PSA velocity in screening offers little benefit compared with traditional markers; however, elimination of this test from practice or guidelines may be premature.
Disciplinary fragmentation, peer review, and the publication process

Publication productivity among academics is notoriously low?and lower among social, than among natural, scientists (Ladd and Lipset 1975; Wanner, Lewis and Gregorio 1981). In fact, a third of social scientists have published nary a word over the course of their careers (Ladd and Lipset 1977; Porter, Chubin, Rossimi, Boeckmann and Connolly 1982). At the same time, rejection rates among social science journals are high, averaging about 80 percent (see Hargens 1988). Does low publication productivity owe to discouragement with the publication process, as Dwight Dean argues? Do high rejection rates?and a "sadomasochis tic" review process?drive off would-be authors? What we know about publica tion productivity (Fox 1983; Fox 1985a) suggests not. Low publication produc tivity reflects a low rate of research productivity1?research agendas gone dry after dissertation projects, which represent the end rather than the beginning of productive scholarship for many academics (Fox 1985b). Research productivity results from complex factors, characteristics of both individuals and their environments (Fox 1983). Reinforcement?the feedback of success with publication and citation?figures into the process2 (see Cole and Zuckerman 1984; Reskin 1977). Yet with the numbers of publications available, authors are not short-circuited in publishing outlets; they can and do submit their articles to a sequence of journals until accepted3 (Bankanic, McPhail and Simon 1987; Garvey, Lin and Nelson 1970). Further, the high rejection rates in social sciences and in sociology in particular, do not derive from a shortage of journal pages, as Dean suggests. Lowell Hargens's longitudinal data (1967-1983) on rejection rates of 30 scholarly journals show
A NEW APPROACH TO SOLVING ETHICAL PROBLEMS IN MEDICINE. 229

New medical, scientific and technological advances, ever present fiscal restrictions and changes in the practice such as managed care by insurance companies and increased restrictions of government force physicians to examine each change in light of their moral and ethical values. “Ethics is the highest possible level of moral thought and action” and every pediatrician who is a member of the American Academy of Pediatrics has accepted an advocacy role for children. Irrespective of our multiple races, religions and languages, all can find basic values and standards of accepted conduct which are held universally. Thought does not extend beyond language and this is also true for medical ethics. There is a need for a basic cluster of words or definitions which we can follow in making ethical decisions.
Subtype-selective electroporation of cortical interneurons.

The study of central nervous system (CNS) maturation relies on genetic targeting of neuronal populations. However, the task of restricting the expression of genes of interest to specific neuronal subtypes has proven remarkably challenging due to the relative scarcity of specific promoter elements. GABAergic interneurons constitute a neuronal population with extensive genetic and morphological diversity. Indeed, more than 11 different subtypes of GABAergic interneurons have been characterized in the mouse cortex1. Here we present an adapted protocol for selective targeting of GABAergic populations. We achieved subtype selective targeting of GABAergic interneurons by using the enhancer element of the homeobox transcription factors Dlx5 and Dlx6, homologues of the Drosophila distal-less (Dll) gene2,3, to drive the expression of specific genes through in utero electroporation.
A semiclassical inversion procedure for the dipole-moment function for diatomic molecules

A simple formalism is presented to deduce the dipole moment as a function of internuclear distance from experimental vibrational intensity data. This method, like the RKR method for obtaining the potential‐energy function, is based on the semiclassical WKB formalism and no particular functional form need be assumed for the dipole moment. The method is applied to the experimental data of Sileo and Cool for HF.
Endometrial carcinoma in previously ovariectomized patients

Abstract Endometrial adenocarcinoma occurred in three patients, each of whom had undergone bilateral oophorectomy more than 30 years previously. None had used hormones during that time. Endocrine studies were performed pre- and postoperatively on one patient and her tumor was subjected to estrogen receptor analysis.
Perceptual expertise enhances the resolution but not the number of representations in working memory.

Despite its central role in cognition, capacity in visual working memory is restricted to about three or four items. Curby and Gauthier (2007) examined whether perceptual expertise can help to overcome this limit by enabling more efficient coding of visual information. In line with this, they observed higher capacity estimates for upright than for inverted faces, suggesting that perceptual expertise enhances visual working memory. In the present work, we examined whether the improved capacity estimates for upright faces indicates an increased number of “slots” in working memory, or improved resolution within the existing slots. Our results suggest that perceptual expertise enhances the resolution but not the number of representations that can be held in working memory. These results clarify the effects of perceptual expertise in working memory and support recent suggestions that number and resolution represent distinct facets of working memory ability.
IN VITROSTUDIES AND ADRENAL STER01D0GENESLS BY THE GOLDEN HAMSTER1,2

No detectable amounts of steroid hormones can be recovered by direct extraction of hamster adrenal tissue or after incubation of adrenal slices in Krebs-Ringer Bicarbonate medium. Adrenal slices or cell-free homogenate preparations can. however, readily convert various steroid precursors to hydrocortisone (Cpd. F), cortisone (Cpd. E), corticosterone (Cpd. B), dehydrocorticosterone (Cpd. A) 17-hydroxy-ll-desoxycorticosterone (Subst. S) and at least three other unknown alpha ketols. It was demonstrated that hamster adrenal glands contain the 3β-ol dehydrogenease system, the C-llβ, C-17 and C-21 hydroxylase enzyme systems. Sodium acetate was not converted to adrenal corticoids either by incubation with adrenal slices or by incubation with cell-free homogenate preparations. On the other hand, sodium acetate-1-C14 was readily converted to radioactive Cpd. F in vivo, thus demonstrating that the hamster can incorporate acetate into corticoids. A cell-free homogenate preparation with added cofactors was able to c...
Evidence for interstrand quadruplex formation in the dimerization of human immunodeficiency virus 1 genomic RNA

Abstract Retroviruses package two homologous single-stranded RNA genomes within a gag protein-RNA complex. In mature virion particles, the two RNA strands are thought to associate primarily through direct RNA-RNA interactions, although the structural basis for this stable association is unknown. We now report that a 127-nucleotide (nt) HIV-1NL4-3 RNA fragment (positions 732-858) encompassing the 5' end of the gag gene dimerizes spontaneously under high ionic strength conditions in the absence of any protein cofactor. The HIV-1 RNA dimer is dramatically and specifically stabilized by the monovalent cation potassium. Thermal dissociation of the dimer occurs at 80 degrees C in 100 mM K+ (5 mM Mg2+) but at significantly lower temperatures in the presence of either smaller or larger monovalent cations (100 mM Li+, 40 degrees C; 100 mM Na+, 55 degrees C; 100 mM Cs+, 30 degrees C). Deletion analyses of the 3' end of the 127-nt fragment reveal that an HIV-1 RNA fragment as short as 94 nt (732-825) can dimerize spontaneously, but a further 9-base deletion of the purine-rich sequence, GGGGGAGAA from positions 817 through 825, eliminates dimerization. These experimental results support a model in which HIV-1 RNA dimerizes by forming an interstrand quadruple helix stabilized by guanine (and/or purine)-base tetrads in analogy to the well-known dimerization of telomeric DNA. We speculate that this structure may also mediate the association of genomic HIV-1 RNA in vivo, revealing how RNA itself can achieve the self-recognition required for subsequent genetic recombination.
Book Review Walking the tightrope. Informal livelihoods and social networks in a West African city By Iida Lourenco-Lidell (2002)

Stockholm, Almqvist and Wiksell. 275 pp ISBN 91-22-01968-5 African Sociological Review 2004, 8(2): 183-185
Racial boundary formation at the dawn of Jim Crow: the determinants and effects of black/mulatto occupational differences in the United States, 1880.

This article examines variation in the social position of mixed‐race populations by exploiting county‐level variation in the degree of occupational differentiation between blacks and mulattoes in the 1880 U.S. census. The role of the mixed‐race category as either a “buffer class” or a status threat depended on the class composition of whites. Black/mulatto occupational differentiation was greatest where whites had high occupational prestige and thus little to fear from a mulatto group. Furthermore, differentiation increased the risk of lynching where whites had relatively low status and decreased the risk of lynching where whites had relatively high status.
Actinin-associated LIM Protein: Identification of a Domain Interaction between PDZ and Spectrin-like Repeat Motifs

PDZ motifs are protein–protein interaction domains that often bind to COOH-terminal peptide sequences. The two PDZ proteins characterized in skeletal muscle, syntrophin and neuronal nitric oxide synthase, occur in the dystrophin complex, suggesting a role for PDZ proteins in muscular dystrophy. Here, we identify actinin-associated LIM protein (ALP), a novel protein in skeletal muscle that contains an NH2-terminal PDZ domain and a COOH-terminal LIM motif. ALP is expressed at high levels only in differentiated skeletal muscle, while an alternatively spliced form occurs at low levels in the heart. ALP is not a component of the dystrophin complex, but occurs in association with α-actinin-2 at the Z lines of myofibers. Biochemical and yeast two-hybrid analyses demonstrate that the PDZ domain of ALP binds to the spectrin-like motifs of α-actinin-2, defining a new mode for PDZ domain interactions. Fine genetic mapping studies demonstrate that ALP occurs on chromosome 4q35, near the heterochromatic locus that is mutated in fascioscapulohumeral muscular dystrophy.
Stall-Time Fair Memory Access Scheduling for Chip Multiprocessors

DRAM memory is a major resource shared among cores in a chip multiprocessor (CMP) system. Memory requests from different threads can interfere with each other. Existing memory access scheduling techniques try to optimize the overall data throughput obtained from the DRAM and thus do not take into account inter-thread interference. Therefore, different threads running together on the same chip can ex- perience extremely different memory system performance: one thread can experience a severe slowdown or starvation while another is un- fairly prioritized by the memory scheduler. This paper proposes a new memory access scheduler, called the Stall-Time Fair Memory scheduler (STFM), that provides quality of service to different threads sharing the DRAM memory system. The goal of the proposed scheduler is to "equalize" the DRAM-related slowdown experienced by each thread due to interference from other threads, without hurting overall system performance. As such, STFM takes into account inherent memory characteristics of each thread and does not unfairly penalize threads that use the DRAM system without interfering with other threads. We show that STFM significantly reduces the unfairness in the DRAM system while also improving system throughput (i.e., weighted speedup of threads) on a wide variety of workloads and systems. For example, averaged over 32 different workloads running on an 8-core CMP, the ratio between the highest DRAM-related slowdown and the lowest DRAM-related slowdown reduces from 5.26X to 1.4X, while the average system throughput improves by 7.6%. We qualitatively and quantitatively compare STFM to one new and three previously- proposed memory access scheduling algorithms, including network fair queueing. Our results show that STFM provides the best fairness, system throughput, and scalability.
On the existence of the entropic solution for the transonic flow problem

RESULTS contained in the presented paper are the further development of the paper by Kloueek and Netas [l]. The spirit of the analysis for the psuedo-time-dependent approach is taken from the paper of Friedman and Netas [2]. The “nearest” mathematical model bringing the problem of transonic flow within the framework of well-established theory, is the so-called unsteady transonic flow problem. The analysis of the existence and eventually the uniqueness of the solutions of the resulting nonlinear second order hyperbolic equation is still an open problem. Most of the numerical methods for the calculating of transonic flow can be rewritten in a form, from which a successive iteration could be derived, using an artificial time coordinate (see, e.g. Jameson [3,4], Hafez et al. [5]). Typically, one ends up with
Relationship Between the K-ABC and WISC-R for Students Referred for Severe Learning Disabilities:

This study examined the relationship between performance on the K-ABC and the WISC-R for 67 students referred for evaluation as a result of serious academic or academic/behavioral problems. Of the 67 students referred, 32 were identified as having severe learning disabilities. The correlational results of the study documented strong relationships among all of the global standard scores on both instruments (r = .65 to .95). Individual performance patterns reflected a preponderance of Simultaneous > Sequential processing and Performance IQ > Verbal IQ patterns for the students with severe learning disabilities, but not for the students without severe learning disabilities. The results of t tests also confirmed Simultaneous > Sequential, Mental Processing Composite > Achievement, and Performance IQ > Verbal IQ differences for the students with severe learning disabilities.
Brief report: An extension of the sequential alternating treatment design using reversals with subjects not available concurrently

This brief report proposes an extension of the traditional Alternating Treatments Design that would be acceptable to use in hospital and residential settings where subjects are often not concurrently available. Concerns about the inability of traditional designs to work in these special situations and the emergence of a “scientist–practitioner split” are discussed. An example of how the Extended Alternating Treatments Design might be used is provided.
Quantitative Evaluation of Collagen Crosslinks and Corresponding Tensile Mechanical Properties in Mouse Cervical Tissue during Normal Pregnancy

The changes in the mechanical integrity of the cervix during pregnancy have implications for a successful delivery. Cervical collagens are known to remodel extensively in mice with progressing gestation leading to a soft cervix at term. During this process, mature crosslinked collagens are hypothesized to be replaced with immature less crosslinked collagens to facilitate cervical softening and ripening. To determine the mechanical role of collagen crosslinks during normal mouse cervical remodeling, tensile load-to-break tests were conducted for the following time points: nonpregnant (NP), gestation day (d) 6, 12, 15, 18 and 24 hr postpartum (PP) of the 19-day gestation period. Immature crosslinks (HLNL and DHLNL) and mature crosslinks (DPD and PYD) were measured using ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). There were no significant changes in the total immature crosslink density (HLNL+DHLNL mol per collagen mol) throughout normal mouse gestation (range: 0.31-0.49). Total mature crosslink density (PYD+DPD mol per collagen mol) decreased significantly in early softening from d6 to d15 (d6: 0.17, d12: 0.097, d15: 0.026) and did not decrease with further gestation. The maturity ratio (total mature to total immature crosslinks) significantly decreased in early softening from d6 to d15 (d6: 0.2, d15: 0.074). All of the measured crosslinks correlated significantly with a measure of tissue stiffness and strength, with the exception of the immature crosslink HLNL. This data provides quantitative evidence to support the hypothesis that as mature crosslinked collagens decline, they are replaced by immature collagens to facilitate increased tissue compliance in the early softening period from d6 to d15.
A semi-supervised efficient learning approach to extract biological relationships from web-based biomedical digital library

Many biological results are published only in plain --text documents and these documents or their abstracts are collected in web-based digital libraries such as PubMed and BioMed Central. To expedite the progress of functional bioinformatics, it is important to efficiently process large amounts of these documents, to extract these results into a structured format, and to store them in a database so that these results can be retrieved and analyzed by biologists and medical researchers. Automated discovery and extraction of the biological knowledge from biomedical web documents has become essential because of the enormous amount of biomedical literature published each year. In this paper we present a semi-supervised efficient learning approach to automatically extract biological knowledge from the web-based digital libraries. Our method integrates ontology-based semantic tagging as well as information extraction and data mining together. Our method automatically learns the patterns based on a few user seed tuples and then extracts new tuples from the biomedical web documents based on the discovered patterns. A novel system, SPIE Scalable and Portable Information Extraction, is implemented and tested on the PuBMed to find the chromatin protein --protein interaction. The experimental results indicate our approach is very effective in extracting biological knowledge from a huge collection of biomedical web documents.
ATR spectroscopic study of PMMA/PDMS graft copolymers using a barrier layer method

The use of an intermediate barrier layer to vary the penetration depth in an ATR experiment is investigated. Both theoretical and experimental results suggest that this method may be useful in probing concentration profiles away from the interface, particularly in the case of thin films, where variable-angle methods have limitations. Application of this technique in the study of poly(methylmethacrylate)/poly(dimethylsiloxane) (PMMA/PDMS) graft copolymers deposited onto a copper oxide surface indicates a preferential presence of the siloxane component at the oxide interface, a concentration which tends to decrease with increasing distance into the bulk of the sample film.
Is there a space–time continuum in olfaction?

The coding of olfactory stimuli across a wide range of organisms may rely on fundamentally similar mechanisms in which a complement of specific odorant receptors on olfactory sensory neurons respond differentially to airborne chemicals to initiate the process by which specific odors are perceived. The question that we address in this review is the role of specific neurons in mediating this sensory system—an identity code—relative to the role that temporally specific responses across many neurons play in producing an olfactory perception—a temporal code. While information coded in specific neurons may be converted into a temporal code, it is also possible that temporal codes exist in the absence of response specificity for any particular neuron or subset of neurons. We review the data supporting these ideas, and we discuss the research perspectives that could help to reveal the mechanisms by which odorants become perceptions.
Fractionation of antibodies to human chorionic somatomammotropin: application to radioimmunoassay.

ABSTRACT A column of Sepharose coupled to human chorionic somatomammotropin (HCS) has been used to adsorb and fractionate anti-HCS by gradient elution with 0.01– 6m guanidine-HC1 at pH 3.0. Up to 3m guanidine, the antibody fractions had progressively increasing affinity constants for HCS over a 170-fold range (0.014 to 2.4×10111/mole). Among the fractions, there was an 8-fold range in the degree of crossreaction with human growth hormone, not strictly related to the affinity for HCS. Compared to the unfractionated antiserum, certain fractions improved the sensitivity and specificity of the radioimmunoassay of HCS. These methods are generally applicable to the immunoassay of proteins and other antigens.
Development of Building Automation and Control Systems

In this paper, we proposed a design flow for BAC systems that enables integrating heterogeneous input models, conducts automatic design space exploration, and performs software synthesis on distributed platforms while guaranteeing correctness and reducing communication load. We believe these capabilities can enable the building designers to better adopt model-based design methodologies, and facilitate them to improve design productivity, optimize system performance, and reduce cost.
Can They Afford the Rent? Resident Cost Burden in Low Income Housing Tax Credit Developments

Although the Low Income Housing Tax Credit (LIHTC) is the primary vehicle through which subsidized rental housing is developed in the United States, we know little about whether residents in LIHTC units can actually afford their rent. This article examines affordability as defined by the cost burden measure for nearly 38,000 Florida LIHTC households. Results indi- cate that the majority of LIHTC residents are cost burdened, and a smaller proportion are severely cost burdened. Results are presented based on race, ethnicity, and income, with separate analyses for LIHTC tenants who do not participate in the Housing Choice Voucher program and those who do. Findings indicate that Whites typically do not fare better than minorities in terms of cost burden in LIHTC developments. Further, participation in the Housing Choice Voucher program does not necessarily prevent cost burden. LIHTC residents with household incomes between 50% and 60% of area median fare best in avoiding cost burden.
Comparison of the nutrient ecology of coastal Banksia grandis elfinwood (windswept shrub-like form) and low trees, Cape Leeuwin-Naturaliste National Park, Western Australia

Trees growing along windy coasts often have canopies that are greatly reduced in size by the sculpting effects of wind and salt spray. Trees with environmentally reduced stature are called elfinwood (windswept shrub-form or krummholz) and are ecologically important because they represent outposts growing at the limit of tree success. The purpose of this study was to assess if Banksia grandis elfinwood growing at Cape Leeuwin had a different nutrient status than normal low-form (LF) trees growing nearby, and if nutrient deficiencies, toxicities and/ or imbalances were among the limiting factors imposed on elfinwood. The concentrations of N, P, K, Ca, Mg, Na, Cl-, Fe, Mn, Zn, Cu, Mo and B were analysed for mature green foliage, immature foliage, foliage litter, flowers and soil. When the elfinwood and LF trees were compared, the foliar nutrient status was generally similar, except that elfinwood foliage had significantly higher mean concentrations of N, Zn and Cu, while LF trees had higher Fe and Mn contents. Many nutrients were conserved before leaves were shed in both elfinwood and LF trees, including N, P, K, Na, Cl - , Mn and Cu (LF trees also conserved Ca and Mg). However, elfinwood and LF tree-litter contained significantly higher Fe concentrations than green foliage (elfinwood litter also had higher levels of Mg and B). It is tempting to suggest that the translocation of Fe into leaves before they were shed is a regulation mechanism to prevent Fe toxicity, or imbalance in the Fe : Mn ratio. Proteoid roots strongly acidify the soil to mobilize P, which also chemically reduces Fe +3 to plant-available Fe +2 . The increased supply of Fe +2 in the rhizosphere, caused by the action of proteoid roots, might tend to defeat self-regulation of Fe uptake. It is possible that excess Fe accumulation in the plant might be regulated, in part, by exporting Fe into the leaves before they are shed. The nutrient status of B.grandis elfinwood is compared with mountain elfinwood of North America. The extreme habitat of coastal elfinwood provides many theoretical pathways for nutrient limitation, but B. grandis elfinwood at Cape Leeuwin does not appear to be nutrient deficient.
The Influence of Musculoskeletal Conditions, Behavioral Health Diagnoses, and Demographic Factors on Injury-Related Outcome in a High-Demand Population

Background: The extent to which musculoskeletal injuries and sociodemographic factors impact long-term outcome remains unknown. The purpose of this study was to provide a prognostic analysis of the influence of musculoskeletal conditions, behavioral health diagnoses, and patient-based characteristics on outcomes among a longitudinal cohort. Methods: This is a longitudinal observational study of the population of an Army brigade deployed to Iraq from 2006 to 2007. The 4087 soldiers who survived the deployment were followed for forty-eight months and were observed for the development of chronic musculoskeletal conditions, behavioral health disorders, and inability to remain in active service as indicated by the findings of the Physical Evaluation Board. The influence of demographic factors, behavioral health conditions, and deployment-related musculoskeletal injuries on the capacity to remain in the military was assessed using Poisson multivariate analysis and receiver operating characteristic curves. Results: The mean age of the cohort was twenty-seven years (range, eighteen to fifty-two years). One hundred and sixty-three soldiers sustained combat-related musculoskeletal trauma, and 587 soldiers had musculoskeletal injuries not related to battle. Three hundred and seventy-four soldiers (9%) were found to be unfit by the Physical Evaluation Board, with 236 soldiers (63%) referred for at least one musculoskeletal condition. Of these 236 soldiers, 116 (49%) also had a behavioral health diagnosis. Multivariate regression analysis revealed that junior enlisted rank (incidence rate ratio, 9.7 [95% confidence interval, 3.1 to 30.3]), senior enlisted rank (incidence rate ratio, 5.6 [95% confidence interval, 1.8 to 17.7]), behavioral health diagnosis (incidence rate ratio, 7.4 [95% confidence interval, 5.6 to 9.6]), age of eighteen to twenty-three years (incidence rate ratio, 1.6 [95% confidence interval, 1.2 to 2.3]), and male sex (incidence rate ratio, 2.5 [95% confidence interval, 1.2 to 5.0]) were significant predictors of referral to the Physical Evaluation Board for a musculoskeletal condition. A prognostic model developed using receiver operating characteristic curves and the risk factors of musculoskeletal injury, presence of a psychiatric condition, and lower rank explained 78% (95% confidence interval, 77% to 80%) of the risk of being found unfit by the Physical Evaluation Board. Conclusions: Musculoskeletal conditions, psychological diagnoses, and lower rank (socioeconomic status) were identified as potent predictors of inferior outcome in this study. Targeting at-risk patients within populations may improve results. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Activation of central melanocortin pathways by fenfluramine

D-fenfluramine (d-FEN) was once widely prescribed and was among the most effective weight loss drugs, but was withdrawn from clinical use because of reports of cardiac complications in a subset of patients. Discerning the neurobiology underlying the anorexic action of d-FEN may facilitate the development of new drugs to prevent and treat obesity. Through a combination of functional neuroanatomy, feeding, and electrophysiology studies in rodents, we show that d-FEN-induced anorexia requires activation of central nervous system melanocortin pathways. These results provide a mechanistic explanation of d-FEN's anorexic actions and indicate that drugs targeting these downstream melanocortin pathways may prove to be effective and more selective anti-obesity treatments.
Disinhibition of perifornical hypothalamic neurones activates noradrenergic neurones and blocks pontine carbachol-induced REM sleep-like episodes in rats.

Studies in behaving animals suggest that neurones located in the perifornical (PF) region of the posterior hypothalamus promote wakefulness and suppress sleep. Among such cells are those that synthesize the excitatory peptides, orexins (ORX). Lack of ORX, or their receptors, is associated with narcolepsy/cataplexy, a disorder characterized by an increased pressure for rapid eye movement (REM) sleep. We used anaesthetized rats in which pontine microinjections of a cholinergic agonist, carbachol, can repeatedly elicit REM sleep-like episodes to test whether activation of PF cells induced by antagonism of endogenous, GABAA receptor-mediated, inhibition suppresses the ability of the brainstem to generate REM sleep-like state. Microinjections of the GABAA receptor antagonist, bicuculline (20 nl, 1 mm), into the PF region elicited cortical and hippocampal activation, increased the respiratory rate and hypoglossal nerve activity, induced c-fos expression in ORX and other PF neurones, and increased c-fos expression in pontine A7 and other noradrenergic neurones. The ability of pontine carbachol to elicit any cortical, hippocampal or brainstem component of the REM sleep-like response was abolished during the period of bicuculline-induced activation. The activating and REM sleep-suppressing effect of PF bicuculline was not attenuated by systemic administration of the ORX type 1 receptor antagonist, SB334867. Thus, activation of PF neurones that are endogenously inhibited by GABAA receptors is sufficient to turn off the brainstem REM sleep-generating network; the effect is, at least in part, due to activation of pontine noradrenergic neurones, but is not mediated by ORX type 1 receptors. A malfunction of the pathway that originates in GABAA receptor-expressing PF neurones may cause narcolepsy/cataplexy.
An efficient retargetable framework for instruction-set simulation

Instruction-set architecture (ISA) simulators are an integral part of today's processor and software design process. While increasing complexity of the architectures demands high performance simulation, the increasing variety of available architectures makes retargetability a critical feature of an instruction-set simulator. Retargetability requires generic models while high performance demands target specific customizations. To address these contradictory requirements, we have developed a generic instruction model and a generic decode algorithm that facilitates easy and efficient retargetability of the ISA-simulator for a wide range of processor architectures such as RISC, CISC, VLIW and variable length instruction set processors. The instruction model is used to generate compact and easy to debug instruction descriptions that are very similar to that of architecture manual. These descriptions are used to generate high performance simulators. The generation of the simulator is completely separate from the simulation engine. Hence, we can incorporate any fast simulation technique in our retargetable framework without loosing performance. We illustrate the retargetability of our approach using two popular, yet different realistic architectures: the Sparc and the ARM.
Extraordinary Macroscale Wear Resistance of One Atom Thick Graphene Layer

During the last few years, graphene's unusual friction and wear properties have been demonstrated at nano to micro scales but its industrial tribological potential has not been fully realized. The macroscopic wear resistance of one atom thick graphene coating is reported by subjecting it to pin-on-disc type wear testing against most commonly used steel against steel tribo-pair. It is shown that when tested in hydrogen, a single layer of graphene on steel can last for 6400 sliding cycles, while few-layer graphene (3–4 layers) lasts for 47 000 cycles. Furthermore, these graphene layers are shown to completely cease wear despite the severe sliding conditions including high contact pressures (≈0.5 GPa) observed typically in macroscale wear tests. The computational simulations show that the extraordinary wear performance originates from hydrogen passivation of the dangling bonds in a ruptured graphene, leading to significant stability and longer lifetime of the graphene protection layer. Also, the electronic properties of these graphene sheets are theoretically evaluated and the improved wear resistance is demonstrated to preserve the electronic properties of graphene and to have significant potential for flexible electronics. The findings demonstrate that tuning the atomistic scale chemical interactions holds the promise of realizing extraordinary tribological properties of monolayer graphene coatings.
One-step synthesis of ordered mesocomposites with non-ionic amphiphilic block copolymers: implications of isoelectric point, hydrolysis rate and fluoride

Highly ordered hexagonal silica/block copolymer mesostructured composites have been prepared using syntheses with fluoride over a wide range of pH conditions (pH 0–9), by controlling the rates of hydrolysis and condensation of the tetramethoxysilane silica source.
The President's Comments

Last year Dr. Calbert initiated the practice of frequent brief comments in the Journal of Dairy Science about subjects of concern to ADSA members. I found his remarks interesting and informative. Therefore, when appropriate, I plan to do likewise. The sequential scheduling of our annual meeting with that of the American Society of Animal Science provided our first opportunity for evaluation of this type of arrangement. A number of advantages, as well as problems, became apparent. At the annual business meeting of the ADSA, those present reacted favorably to a combined meeting but expressed a preference for concurrent rather than sequential scheduling. Additionally, the time preference was early summer (June). Since meetings of both the ADSA and ASAS are scheduled several years in advance, future combined meetings, ever if deemed desirable, cannot be arranged for some time. If we strongly favor such combined meetings, however, and if the ASAS concurs, steps should be taken soon to implement the arrangement for the future. Therefore, I urge you, while memory of the 1972 meeting is still fresh in your minds, to convey to the officers of the ADSA your views on this matter. Attendance at the 1972 annual meetings of the American Dairy Science Association and the American Society of Animal Science was as follows: ADSA ASAS Members 749 942 Nonmembers 99. 94 Students 208 312 Wives 354 381 Children 263 346 Total 1666 2075
MATRIX TRAINING OF PRELITERACY SKILLS WITH PRESCHOOLERS WITH AUTISM

Matrix training is a generative approach to instruction in which words are arranged in a matrix so that some multiword phrases are taught and others emerge without direct teaching. We taught 4 preschoolers with autism to follow instructions to perform action–picture combinations (e.g., circle the pepper, underline the deer). Each matrix contained 6 actions on 1 axis and 6 pictures on the other axis. We used most-to-least prompting to train the instructions along the diagonal of each matrix and probed the untrained combinations. For 2 participants, untrained responding emerged after the minimum amount of training. The other 2 participants required further training before untrained combinations emerged. At the end of the study, 3 of the 4 participants performed the trained actions with previously known pictures, letters, and numbers. This study demonstrated that matrix training is an efficient approach to teaching language and literacy skills to children with autism.
Genetic basis for clarithromycin resistance among isolates of Mycobacterium chelonae and Mycobacterium abscessus

Resistance to clarithromycin among isolates of Mycobacterium chelonae and M. abscessus was observed in 18 of 800 (2.3%) patients tested between 1990 and 1995. Patients whose isolates were resistant had either disseminated disease or chronic lung disease, and the resistant isolates were recovered after clarithromycin monotherapy. Sequencing of the gene coding for the 23S rRNA peptidyltransferase region revealed a point mutation involving adenine at position 2058 (38%) or adenine at position 2059 (62%) in 20 of 20 relapse isolates from the first 13 patients identified. By pulsed-field gel electrophoresis or random amplified polymorphic DNA PCR, initial and relapse isolates were shown to have identical DNA patterns. M. chelonae and M. abscessus isolates were found to have only a single chromosomal copy of the rRNA operon, thus making them susceptible to single-step mutations. Thus, clarithromycin resistance in these species of rapidly growing mycobacteria relates to a point mutation in the gene coding for 23S rRNA and occurs in limited clinical situations, but was identified in almost 5% of isolates tested in 1995.
Info-communism? Ownership and freedom in the digital economy

This paper takes a new look at the debate over commons and property in information and communications. It warns against recreating the old communist-capitalist ideological divide by framing the movement for informational commons as "info-communist." The spectre of communism haunts the movement because of an unresolved ideological tension in its ethical and philosophical foundations. The case for free software and open information contains both deontological appeals to the virtues of sharing, and consequentialist arguments against the growing intrusiveness of the institutional and technological mechanisms used to enforce exclusivity in the digital economy. The paper argues that the deontological case is a dead end that leads to info-communism. The strongest case for open access and freedom in information and communications is grounded in a liberalism that takes maximizing individual freedom as its objective and relies on creative complementarities between property and commons regimes as means to that end.
A termite from the Late Oligocene of northern Ethiopia

Termites of the family Stolotermitidae are a relict lineage of primitive Isoptera. The fossil record of Stolotermitidae is exceptionally poor, with only two Miocene (Neogene) species documented to date. Herein, a new genus and species of Paleogene termites is described and figured from the Late Oligocene (28-27 Ma, Early Chattian) of northwestern Ethiopia (Amhara Region, Chilga Woreda). Chilgatermes diamatensis gen. et sp. nov., is most similar to genera of the Stolotermitidae, Archotermopsidae, and Termopsidae but can be distinguished on the basis of forewing venational details. The genus is tentatively placed in the Stolotermitidae: Porotermitinae. Chilgatermes diamatensis is the first fossil termite from Ethiopia and, indeed, the first from the entire African continent.