cssi/SciSciGPT-SciSciNet huggingface dataset:
Thinking in deaf adolescents: Language and formal operations

Abstract Seven deaf adolescent boys, poor in written and oral English, but above average in tested intelligence were observed on six tasks of formal thinking. No subject clearly succeeded on all tasks but five subjects succeeded on at least one. The results were discussed within the framework of Piaget's theory and supported the hypothesis that propositional thinking can develop at least to its primary formation without the support of linguistic competence. Educational implications, particularly for language-handicapped children, are presented.
Canine kidney preservation using a new perfusate.

Abstract A new renal perfusate, which closely resembles intracellular electrolyte composition and is made hyperosmolar with mannitol, was successfully used without additives to preserve canine kidneys for up to 72 hours after initial perfusion and hypothermic storage. The technique allows renal viability for periods that compare favourably with those previously obtained with constant perfusion and hypothermia. The new perfusate was also successful in protecting the ischaemic canine kidney from the otherwise irreversibly damaging effects of 2 and 3 hours' normothermic exposure " in vivo ", and was successfully used to protect the ischaemic kidney for 3 hours without continuous cooling during " workbench " surgery.
A public HLA antigen associated with HLA-A9, Aw32, and Bw4.

TheHLA complex codes for three distinct 44000 dalton molecules associated withΒ 2 microglobulin — HLA-A, B and C —each with its own multiallelic series of private antigens. The HLA-B molecule is exceptional in that it also carries a diallelic system,Bw4 andBw6. One of these,Bw4, is often associated with the A- locus specificity A9. This finding has usually been ascribed to linkage disequilibrium between A-and B-locus antigens. We have shown, however, that an epitope called LHe is actually shared by A-locus and B-locus molecules. This epitope is found on all HLA-B molecules bearing the Bw4 determinant and is also found on all HLA-A molecules carrying the A9 (Aw23 and Aw24) or Aw32 specificities. We consider this a “public” HLA antigen; the possible molecular basis for both subtypic and public antigens on a single glycoprotein is discussed.
A note on the dispensability of proline for weanling pigs

A proline-free, chemically defined amino acid basal diet was compared with this same diet fortified with 4g L-proline per kg when given to 5-kg pigs. During a 28-day feeding period, daily gain, food intake, and gain: food ratio of pigs given the proline-free diet were not different (P > 0·05) from those of pigs given the proline-supplemented diet. Young pigs can apparently synthesize adequate quantities of proline endogenously to meet their needs for both growth and maintenance.
Rapid preoperative bowel preparation for patients undergoing radical cystectomy.

Abstract Rapid whole-gut irrigation, performed by instilling 6 L of Ringer's lactate solution through, a small nasogastric tube over a three-hour period, combined with antibiotic prophylaxis (oral neomycin and erythromycin base) was used for preoperative bowel preparation in 42 patients undergoing single-stage radical cystectomy and ileal conduit diversion. The procedure was well tolerated, rapid, effective, and proved cost-effective.
THE SHELF LIFE OF BIRD EGGS: TESTING EGG VIABILITY USING A TROPICAL CLIMATE GRADIENT

Avian parents influence the onset of development, hatching synchrony, and likelihood of brood reduction through the onset of incubation. Studies testing adaptive functions of brood reduction assume that eggs are protected by their shells and waiting for parents to initiate incubation in a manner that creates optimal hatching patterns, but the viability of early laid eggs may diminish over time due to putative effects of ambient temperature. We tested effects of exposure to ambient temperature on the viability of un- incubated bird eggs using an altitudinal climate gradient in Puerto Rico: daily maximum temperatures nearly always exceed developmental zero in the lowland forest, whereas tem- peratures rarely exceed developmental zero in the cloud forest and at intermediate altitudes. We removed 382 freshly laid Pearly-eyed Thrasher (Margarops fuscatus) eggs, placed them in holding boxes at three sites for 1-7 days, and returned them to nests to be incubated. Additional control eggs (n 5 39) tested effects of both handling and movement on hatching success, and unmanipulated eggs (n 5 139) provided a measure of natural hatching success. Hatching success of control eggs (82.0%) and unmanipulated eggs (84.9%) did not differ, indicating no impacts of handling on hatchability. Hatching success of experimental eggs exposed for one day (78.6%) was high but declined very strongly after exposure for three days (41.9%), five days (11.5%) and seven days (2.1%). Hatchability of eggs held at the cloud forest did not differ from eggs held at the lowland site but was lower for eggs exposed at mid-elevation. Hatching success was positively related to minimum temperature and marginally related to mean temperature and proportion of time above developmental zero. Exposure duration, treatment site, and maximum temperature were the only significant effects identified by stepwise logistic regression. Eggs held at the lowland site had shorter developmental periods than eggs held at other sites. Most embryo mortality (80.8%) oc- curred at very early stages. Our results demonstrate that viability of unincubated eggs exposed to moist tropical conditions declines strongly but suggest that ambient temperature is not the sole cause. We compare rates of egg viability decline among species, examine alternative mechanisms for the loss of viability, and discuss the significance of egg viability on avian life histories.
Distribution of the Eastern Woodrat (Neotoma Floridana Campestris) in Southern Nebraska

The eastern woodrat (Neotoma floridana) occurs throughout eastern and central parts of the United States. In Nebraska, 3 of 9 subspecies inhabit the state, including N. f. campestris, N. f. attwateri, and N. f. baileyi. We determined distributional limits of N. f. campestris along 2 river systems in southern Nebraska. As observed with other mammalian species in the Great Plains, we suspected that the distribution of woodrats likely had expanded, reflecting continued regulation of rivers and the concomitant increase in forests along them. We documented N. f. campestris at 7 sites in 5 counties, including a recent (since the 1960s) eastward expansion along the Republican River. We observed lit- tle movement along the Platte River. The greatest concentration of houses constructed by woodrats occurred in a shel- terbelt near the Republican River; otherwise, abundances of houses tended to be greater along the Platte River. We sus- pect that the distribution of woodrats will continue to change in Nebraska unless breaks exist or are established in ripar- ian forests along the Platte and Republican rivers.
Le cadavre à l’intersection du théâtre et du cinéma dans Lilies et Being at home with Claude

Le cadavre offre une analogie evocatrice des rapports entre la scene et l’ecran. En effet, le cadavre incarne a la fois la nature imaginaire du cinema et le caractere paradoxal du jeu theâtral. L’auteur analyse deux adaptations cinematographiques de pieces quebecoises, Lilies (1996) de John Greyson et Being at home with Claude (1992) de Jean Beaudin, dans lesquelles le cadavre personnifie la convergence du theâtre et du cinema. L’article etudie les choix qu’ont fait les cineastes pour representer le corps mort ou mourant et souligne comment ces choix demontrent l’aptitude de ces cineastes a porter un regard perspicace sur le processus de traduction mediatique, et ce, tout en reussissant a communiquer les themes principaux des oeuvres originales.
EFFECTIVENESS OF ENVIRONMENTAL TREATIES: TREND ANALYSIS OF TREATY-BASED ENVIRONMENTAL INDICATORS

The literature on environmental regime effectiveness has shown a predilection for behaviour modification studies, whereby effectiveness is associated with a change in the behaviour of relevant actors. There has not been a systematic endeavour to link the implementation of international environmental agreements (IEAs) with improvement in environmental conditions. This article shifts away from the paradigm of behavioural analysis and focuses instead on linking IEA effectiveness with positive environmental changes in treaty-based environmental effectiveness indicators. Thirty-four treaty texts have been analysed to determine potential environmental indicators, and treaty secretariats have been contacted to collect time-series data on the selected indicators. Based on data gathered, trend lines are established for the environmental indicators to depict changes in related global environmental conditions. The results of this exercise show that viewing IEA effectiveness from the environmental modification perspe...
Do investors still benefit from international diversification with investment constraints

Abstract This paper empirically investigates the potential benefits of international diversification for the U.S. investor with various investment constraints from both long-term and time-rolling perspectives. While the addition of portfolio bounds makes asset allocation more feasible, our findings suggest that adding short-selling and over-weighting constraints reduce but do not completely eliminate the diversification benefits of international investment. The over-time analyses show that diversifying portfolios internationally is still beneficial even though financial markets are becoming more integrated. The out-of-sample test suggests that the Markowitz model does not necessarily realize improved mean–variance efficiency but demonstrates risk reduction. The significant time variation in optimal asset allocation implies the necessity for the fund manager to rebalance international portfolio dynamically.
OmniCon: a Mobile IP-based vertical handoff system for wireless LAN and GPRS links

Wi-Fi based hotspots offer mobile users broadband wireless Internet connectivity in public work spaces and corporatesuniversity campuses. Despite the aggressive deployment of these hotspots in recent years, high-speed wireless Internet access remains restricted to small geographical areas due to the limited physical coverage of wireless LANs. On the other hand, despite their lower throughput, cellular networks have a significantly wider coverage and are thus much more available. Recognizing that 2.5G or 3G cellular networks can effectively complement wireless LANs, we set out to develop a vertical handoff system that allows mobile users to seamlessly fall back to such cellular networks as the general packet radio service (GPRS) or 3G whenever wireless LAN connectivity is not available. The resulting handoff mechanism allows a network connection of a mobile node to operate over multiple wireless access networks in a way that is transparent to end user applications. In this paper, we present the design, implementation, and evaluation of a fully operational vertical handoff system, called OmniCon, which enables mobile nodes to automatically switch between wireless LAN and GPRS, based on wireless LAN availability, by introducing a simple extension to the existing Mobile IP implementation. We discuss the design issues in the proposed vertical handoff system for heterogeneous networks, including connection setup problems due to network address translation, and the disparity in link characteristics between wireless LANs and GPRS. A detailed performance evaluation study of the OmniCon prototype demonstrates its ability to migrate active network connections between these two wireless technologies with low handoff latency and close to zero packet loss. Copyright © 2006 John Wiley & Sons, Ltd.
Two-scale asymptotic analysis for modeling activation of periodic cardiac strand

This work explores the applicability of two-scale asymptotic analysis to model the excitable cardiac strand with periodic discontinuities. The strand is composed of 60 cells connected by junctions. The membrane excitability is modeled using Ebihara-Johnson equations. The problem is described by a non-linear parabolic equation with one parameter, intracellular conductivity, changing periodically in space. Using two-scale asymptotic analysis, the transmembrane potential is given as a two-scale expansion in powers of the period length. The series converges rapidly, and the solution containing only zero- and first-order terms has a negligible error. Each term of the expansion is found by solving the differential equation derived by decomposing the original problem. The periodic, first-order term is given by a linear elliptic equation and has a closed-form solution. The aperiodic, zero-order term is the solution of a non-linear parabolic equation corresponding to the cardiac strand with homogenized intracellular conductivity; this equation is solved numerically using the Crank-Nicolson method modified to account for the presence of the periodic term. The use of the two-scale asymptotic analysis permits a substantial saving in computer resources over the solution from a purely numerical approach: the problem can be solved with a three times coarser discretization step, requires ten times less memory, and uses about half the computation time.
Variational description of a quasihole excitation in a quantum antiferromagnet.

An accurate variational ansatz is proposed for a single quasihole excitation in a two-dimensional quantum antiferromagnet. The trial state includes spin-hole and spin-hole-spin correlations, in addition to background antiferromagnetic spin-spin correlations. Background spin-spin correlations are induced by the Heisenberg antiferromagnetic exchange interaction and describe the zero-point motion of spin waves around the Ne\ifmmode\acute\else\textasciiacute\fi{}el state. Spin-hole and spin-hole correlations describe ``strings'' of spins displaced by one lattice site along the hole path. This is a generalization of the Brinkman-Rice approach to include quantum spin fluctuations. We have used the Monte Carlo method to compute the variational energy and the spectral weight of the quasihole state in the t-J model on the square lattice, with the proposed ansatz. Comparison with exact results for the 4\ifmmode\times\else\texttimes\fi{}4 lattice shows very good agreement for both energy and spectral weight, at k=(\ensuremath{\pi}/2,\ensuremath{\pi}/2) in the range 0\ensuremath{\le}t/J\ensuremath{\le}5. We report results for lattices of several sizes up to 16\ifmmode\times\else\texttimes\fi{}16 in the above range of t/J and for the two values of k where the hole energy band attains its minimum [k=(\ensuremath{\pi}/2,\ensuremath{\pi}/2)] and maximum [k=(0,0)].
Further discussion of Fiedler's contingency model of leadership effectiveness

Abstract Fiedler's claim that his model is empirically valid was refuted on methodological and empirical grounds. The analysis of cumulative results, using Fisher's method of combining correlations, indicated that the model failed the validity test in six of the eight situational octants. Further analysis indicated, contrary to Fiedler's claim, that the model and its related research have serious theoretical and methodological flaws.
Age-differences in odor preference following an odor-illness pairing

An ambient maple odor was paired with illness in rats ranging in age from weaning to old age. The animals then were tested for an aversion to a maple-odored solution. The results indicated no aversion to the odored solution at any age level and, hence, support previous research indicating that odor is a weak cue for illness. However, both young-adult and old-age rats made ill after drinking water in the absence of odor preferred the maple-odored solution to plain water. This finding suggests that, whereas odor may be a weak cue for illness in adult rats, it may be an effective safety signal. In contrast, weanling rats made ill in the presence of the odor preferred the odored solution. This paradoxical preference was explained in terms of olfactory imprinting and the effect punishment has on imprinted responses.
Prof. R. E. Kalman - A Deeply Inspiring Mentor [Historical Perspectives]

In a letter dated March 23, 1978, Prof. R.E. Kalman wrote Dear Mr. Khargonekar: I am very happy to inform you that you have been admitted to the Graduate School of the University of Florida and been awarded financial aid to pursue your studies here. I had just finished my undergraduate studies at the Indian Institute of Technology, Bombay, India. I had taken some advanced courses in control and estimation and had read some of his papers. Looking back, this admission letter from Prof. Kalman is perhaps the most important event that has shaped my professional career. I recall my great excitement at being able to pursue my doctorate under the world-famous master!
Anisotropy, disorder, and commensurability in superconducting networks

We report on recent experiments on electron beam lithographically prepared superconducting wire networks. In square networks we have found that along with the dips in the T c vs. φ/φ 0 phase boundary at rational fields, there is an even more pronounced effect of rationality on the width of the resistive transition. We have disordered several types of networks, fit the phase boundary excellently with the J 2 model and shown that there is no critical field or amount of disorder above which the phase boundary loses periodic structure. We have introduced anisotropy into the square lattice by varying the thickness of the horizontal and vertical wires. This produces an anisotropic “phase boundary”, dependent on the direction inn which the anisotropy is probed, that is in good agreement with calculations for anisotropic tight binding bands in a strong field. We have found a unique way to disorder a quasi-crystalline network and used it to demonstrate that commensurate states are directly related to the inflation properties of the network.
Serum neuroleptic concentrations and clinical response: a radioreceptor assay investigation of acutely psychotic patients.

Twenty-two acutely psychotic patients were rigorously assessed for psychopathology at baseline and after 14 days of neuroleptic treatment. The neuroleptic radioreceptor assay (NRRA) was used to determine serum neuroleptic concentrations. Serum neuroleptic concentration was significantly, nonlinearly related to changes in BPRS Total Score, and BPRS Factor Scores for Thought Disturbance and Anxiety-Depression. Clinical improvement was associated with intermediate (11–50, 51–126 ng/ml haloperidol equivalents) while poor clinical outcome was related to both low (less than or equal to 10 ng/ml) or high (greater than 125 ng/ml) serum levels. The results are discussed in terms of a possible “therapeutic window” for the neuroleptics and the implications this might have for clinical practice.
Imaging and diffusion of individual iridium adatoms on Ir(111)

Abstract Field ion images of single iridium adatoms on Ir(111) are triangular, with an orientation indicative of the type of site at which the adatom is bound. For an iridium adatom at a surface site (local hcp geometry) the apex of the triangular image points along [2 11 ]; at a bulk site (local fcc geometry) the triangle points away from [2 11 ]. The orientation of the image spot is found to afford a reliable indication of the binding site, and has been successfully used to explore the elementary step in diffusion of an iridium adatom on Ir(111).
The Trust Game in neuroscience: A short review

The Trust Game has been increasingly used in the emerging field of neuroeconomics to study brain mechanisms underlying decision-making in social interactions with financial outcomes. In this review, we attempt to concisely describe main neuroscience findings in the context of this game, with a special emphasis on the parameters potentially influencing the results. Factors modulating trust when the subject plays the part of the Investor are clustered into a few major categories: the Trustee, the administration of the game (single-shot or repeated interactions), the impact of hormones and genetics, inter-individual differences, time and other experimental settings. The few studies focusing on the Trustee are then briefly summarized, drawing again the attention of the future experimenter on possible pitfalls as well as offering some interpretation keys to the reader facing divergent results.
Cardiovascular effects following clonidine microinjection into the nucleus tractus solitarii of the rat

Abstract Clonidine microinjection into the mediocaudal region of the nucleus tractus solitarii (NTS) of the rat elicited dose-related (1.25–40.0 nmol) hypotension and bradycardia following NTS application. Cardiovascular effects produced by NTS injection of 5 nmol clonidine could be abolished by NTS pretreatment with the α 2 -adrenoceptor blocker, yohimbine (10 nmol). Dorsal medullary areas surrounding the NTS responded to clonidine microinjection with blood pressure falls similar to that seen after NTS microinjection. Bradycardic responses, however, were elicited more selectively from areas within anatomic boundaries of the NTS. These data suggest that, while blood pressure decreases can be demonstrated following direct application of clonidine into the medio-caudal NTS, the major interaction of clonidine with the NTS in the rat is to produce a decrease in heart rate.
The shape of the ear canal

It is proved that the measurement of the acoustic pressure on the ear membrane allows one to determine the shape of the ear canal uniquely.
Suitability Assessment for New Minia City, Egypt: A GIS Approach to Engineering Geology

Urban development is a high priority in Egypt. New Minia City, located on the eastern bank of the Nile River, approximately 250 km south of Cairo, is one of 16 new development communities. Urban development in New Minia City may encounter several geo-environmental problems. Karst conditions and structural features in the local heterogeneous bedrock limit its suitability for constructional purposes. In this research, suitability of the area for urban development was assessed using a geographic information systems (GIS)-based approach. A weighted GIS model that incorporated land use/cover, types of soil, karst feature distribution, fracture densities, slopes, distances to major faults and streams, road network, and city boundaries was established to create a map of site suitability for the city. Model weights were developed using the analytical hierarchy process (AHP) approach. Current urban land use within New Minia City falls into four classes of suitability. Approximately 7 percent of the area built by 2002 is in the low suitability class, which suggests that the map of site suitability can serve as a reliable base for planning sustainable development in New Minia City. The developed map of site suitability is effective for assessing and revealing ratings of suitability for urban development. Furthermore, the map of suitability provides the foundation for informed decision making in the development of New Minia City.
Parametric Trends in the Combustion Stability Characteristics of a Single-Element Gas-Gas Rocket Engine

Abstract : Combustion instability continues to be a challenge in the design of rocket engines. The use of computational fluid dynamics (CFD) simulations screen potential designs offers the ability to reduce the number of costly tests and improve understanding of the underlying instability mechanism. In this study a series of axisymmetric CFD simulations are used to investigate the instability sensitivity to four design changes. The design changes are selected in an attempt to reduce the level of instability. The parameters considered are the combustor wall temperature, the effect of adding swirl to the fuel injector and two geometric changes, namely, fuel injector area reduction and the introduction of a chamfer in the injector face. The simulations show that both the wall temperature and swirl are able to significantly lower the amplitude by 70%. The results of the geometric changes are mixed with both decreases and increases in the instability amplitude. The parametric study has enhanced the understanding of the instability mechanisms by demonstrating that the when a continuous fuel supply to the combustor is maintained the instability amplitude is decreased.
Empirical likelihood inferences for the semiparametric additive isotonic regression

We consider the (profile) empirical likelihood inferences for the regression parameter (and its any sub-component) in the semiparametric additive isotonic regression model where each additive nonparametric component is assumed to be a monotone function. In theory, we show that the empirical log-likelihood ratio for the regression parameters weakly converges to a standard chi-squared distribution. In addition, our simulation studies demonstrate the empirical advantages of the proposed empirical likelihood method over the normal approximation method in Cheng (2009) [4] in terms of more accurate coverage probability when the sample size is small. It is worthy pointing out that we can construct the empirical likelihood based confidence region without the hassle of tuning any smoothing parameter due to the shape constraints assumed in this paper.
Contingent Phosphorylation/Dephosphorylation Provides a Mechanism of Molecular Memory in WASP.

Cells can retain information about previous stimuli to produce distinct future responses. The biochemical mechanisms by which this is achieved are not well understood. The Wiskott-Aldrich syndrome protein (WASP) is an effector of the Rho-family GTPase Cdc42, whose activation leads to stimulation of the actin nucleating assembly, Arp2/3 complex. We demonstrate that efficient phosphorylation and dephosphorylation of WASP at Y291 are both contingent on binding to activated Cdc42. Y291 phosphorylation increases the basal activity of WASP toward Arp2/3 complex and enables WASP activation by new stimuli, SH2 domains of Src-family kinases. The requirement for contingency in both phosphorylation and dephosphorylation enables long-term storage of information by WASP following decay of GTPase signals. This biochemical circuitry allows WASP to respond to the levels and timing of GTPase and kinase signals. It provides mechanisms to specifically achieve transient or persistent actin remodeling, as well as long-lasting potentiation of actin-based responses to kinases.
Statistical generalization: theory and applications

In this paper, we discuss a new approach to generalize heuristic methods (HMs) to new test cases of an application, and conditions under which such generalization is possible. Generalization is difficult when performance values of HMs are characterized by multiple statistical distributions across subsets of test cases of an application. We define a new measure called probability of win and propose three methods to evaluate it: interval analysis, maximum likelihood estimate, and Bayesian analysis. We show experimental results on new HMs found for blind equalization and branch-and-bound search.
Design of a distal teacher recursive estimator for airplane flight controllers

Aircraft controllers in general have particular flight limitations in which the aircraft is controllable. It may be difficult, if not impossible to control an aircraft using a classical controller if the dynamics of the aircraft were to change or if the flight limitations are exceeded. This is because classical controllers for airplanes are designed according to specific dynamics of the system. This paper addresses the design of an estimation system for the purpose of aircraft control using artificial intelligence techniques. The method proposed for the design of the estimation system is the distal teacher recursive estimator. Intelligent decision-making techniques have emerged to overcome some of the deficiencies in conventional techniques when dealing with complex systems. These problems include knowledge adaptation, learning, and expert knowledge incorporation. Both neural networks and fuzzy systems have unique advantages. Neural networks have the advantage in learning while fuzzy systems have the advantage in inferencing. Neural networks and fuzzy systems have been used to implement intelligent failure detection and accommodation systems that should be able to learn and take actions in a way similar to humans. It should also be able to incorporate fuzziness and imprecision which exist in real-world systems.
Structures and visco-elastic properties of potassium tellurite: glass versus melt

The structure and visco-elastic properties of K2Te4O9 have been examined as a function of temperature, using neutron scattering and Brillouin light scattering, respectively. The neutron scattering data indicate that the coordination of tellurium by oxygen changes notably once the material is heated above the glass transition temperature. This and the associated decrease in elastic modulus are consistent with converting network building blocks from trigonal bipyramids to trigonal pyramids. The latter form chain-like structures that constitute a liquid characterized by a single relaxation mechanism. Structural relaxation in the liquid results in further decrease of its elastic storage capacity and in a maximum of dissipative losses due to viscous processes. The break-up of the glassy network, which is attributed to a frictionless transformation of building blocks, is distinct from the viscous relaxation of the liquid; their visco-elastic signatures can be observed in separate temperature intervals.
Effect of relative humidity on the curing and dielectric properties of polyurethane-based composites

Isocyanate groups present in the precure mix of polyurethane-based composites are highly moisture sensitive. Binding of water with isocyanate groups occurs at the expense of cross-linking in the cure process. Consequently, the dielectric properties of the resulting material may alter due to i) the presence of bound water in the material and ii) changes in the dielectric properties of the polymer due to reduced cross-linking. In this work, polyurethane-based composite samples were cured in various controlled relative-humidity environments, created using saturated salt solutions. The dielectric constant of the materials was measured as a function of cure time, in the frequency range of 0.5 to 18 GHz. In this way the relationship between relative humidity during cure, and dielectric properties of the resulting composites, is demonstrated.
Mode-coupling analysis of depolarization effects in a multimode optical fiber

A method of analyzing depolarization effects in a multimode fiber has been developed. A new expression for degree of polarization (DOP) in terms of fiber parameters, incident polarization condition, and mode coupling coefficients has been derived. The numerical results for DOP for various fiber lengths, coupling coefficients, and normalized angular spacings 'q' have been obtained. >
On Adding Link Dimensional Dynamism to CSMA/CA Based MAC Protocols

Though the popular IEEE 802.11 DCF is designed primarily for wireless LAN (WLAN) environments, today it is being widely used for wide area wireless mesh networking. The protocol parameters of IEEE 802.11 such as timeout values, interframe spaces, and slot durations, which are sufficient for a general WLAN environment need to be modified in order to efficiently operate in wide area wireless mesh networks. The current wide area wireless mesh network deployments use manual configuration of these parameters to the upper limit which essentially makes the networks operate at lower system efficiency. In this paper, we propose d802.11 (dynamic 802.11) which dynamically adapts the protocol parameters in order to operate at varying link distances. We present three strategies, (i) multiplicative timer back-off (MTB), (ii) additive timer back-off (ATB), and (iii) link RTT memorization (LRM), to adapt the ACK_TIMEOUT in d802.11 in order to provide better adaptation for varying link dimensions. Through extensive simulation experiments we observed significant performance improvement for the proposed strategies. We also theoretically modeled the maximum throughput as a function of the link dimension for the proposed system. Our results show that the LRM technique provides the best adaptation compared to all other schemes.
A Genome Search Identifies Major Quantitative Trait Loci on Human Chromosomes 3 and 4 That Influence Cholesterol Concentrations in Small LDL Particles

Abstract —Small, dense LDL particles are associated with increased risk of cardiovascular disease. To identify the genes that influence LDL size variation, we performed a genome-wide screen for cholesterol concentrations in 4 LDL size fractions. Samples from 470 members of randomly ascertained families were typed for 331 microsatellite markers spaced at ≈15 cM intervals. Plasma LDLs were resolved by using nondenaturing gradient gel electrophoresis into 4 fraction sizes (LDL-1, 26.4 to 29.0 nm; LDL-2, 25.5 to 26.4 nm; LDL-3, 24.2 to 25.5 nm; and LDL-4, 21.0 to 24.2 nm) and cholesterol concentrations were estimated by staining with Sudan Black B. Linkage analyses used variance component methods that exploited all of the genotypic and phenotypic information in the large extended pedigrees. In multipoint linkage analyses with quantitative trait loci for the 4 fraction sizes, only LDL-3, a fraction containing small LDL particles, gave peak multipoint log10 odds in favor of linkage (LOD) scores that exceeded 3.0, a nominal criterion for evidence of significant linkage. The highest LOD scores for LDL-3 were found on chromosomes 3 (LOD=4.1), 4 (LOD=4.1), and 6 (LOD=2.9). In oligogenic analyses, the 2-locus LOD score (for chromosomes 3 and 4) increased significantly ( P =0.0012) to 6.1, but including the third locus on chromosome 6 did not significantly improve the LOD score ( P =0.064). Thus, we have localized 2 major quantitative trait loci that influence variation in cholesterol concentrations of small LDL particles. The 2 quantitative trait loci on chromosomes 3 and 4 are located in regions that contain the genes for apoD and the large subunit of the microsomal triglyceride transfer protein, respectively.
Determining particulate–solid interphase strength using shear-induced anisotropy

The resistance to shear deformation developed by a granular material layer in contact with a topographically rough natural or manufactured solid material surface is critical to the stability of a variety of composite systems. By using discrete-element method numerical simulations, we show that evolution of fabric and contact force anisotropy at the boundary between the surface and the granular media controls shear behavior. Full mobilization of granular material strength occurs when the contact force anisotropy developed at the interface is equal to the maximum contact force anisotropy of the granular media.
Focused Cardiac Ultrasound as an Outpatient Tool To Assess Volume Status

Introduction: Accurate assessment of volume status is critical in the management of patients with congestive heart failure (CHF). We studied the utility of a pocket sized ultrasound device (Vscan; GE) in an outpatient cardiology clinic as a tool to guide volume assessment and reduce CHF admissions. Hypothesis: Use of pocket ultrasound to assess IVC parameters will help clinicians titrate diuretic medications and decrease hospital admissions. Methods: Inferior vena cava (IVC) maximum size and collapsibility were assessed in 95 patients by two internal medicine residents briefly trained in focused cardiac ultrasound (FCU). Both visual estimation and quantification of IVC size and collapsibility were performed during passive respiration and inspiratory sniff. Patients with IVC size O2cm and collapsibility !50% were deemed volume overloaded. Cardiologist assessment of volume status (blinded to imaging data) and changes in diuretic medication were also recorded. Patients were followed by means of chart review and telephone inquiry for occurrence of 30 day events (ER visit or hospital admission). Results: There was a 95% success rate of obtaining IVC size and collapsibility. Agreement between the visual and calculated IVC assessments of collapsibility and size were excellent, kappa 0.96 (95% CI: 0.89-1.00) and 0.87 (95% CI: 0.745-0.99), respectively, resulting in a 93% concordance for volume status assessment. Comparison of visual IVC and clinician ability to detect volume overload yielded a kappa statistic of 0.25 (95% CI: -0.01 0.51). Most patients were euvolemic by both IVC and clinician assessment (83%); only 2% were overloaded by both techniques. In 14% of patients there was discordance in volume status between visual IVC and clinician assessment, most of whom (11/ 12) were volume overloaded by IVC. In these 11 patients, 10 did not have their diuretic dose increased. At 30 days, 14 events occurred, with volume assessment discordant in 4. Two events were CHF-related and volume assessment was not discordant in either case. Of the other 12 events, half were cardiovascular and half were non-cardiovascular. Conclusion: Assessment of volume status in an outpatient cardiology clinic using FCU imaging of the IVC is feasible in a high percentage of patients. The strong agreement between visually assessed and measured IVC parameters validates FCU as a quick subjective bedside tool. Most patients in this outpatient cohort were euvolemic by both IVC and clinician. A group of patients was identified as volume overloaded by IVC yet euvolemic by clinician, suggesting that FCU in an outpatient setting may be a valuable adjunct to the physical exam. Whether FCU can help prevent hospital admission warrants further study in a larger patient population.
Altered mechanics and histomorphometry of canine tibial cartilage following joint immobilization

Abstract Joint immobilization is associated with altered cartilage biosynthesis and catabolism that may affect cartilage mechanics and joint function. In this study, the mechanical behavior of articular cartilage was studied in an experimental model of joint immobilization, in which the canine knee was cast-immobilized at 90° of flexion for 4 weeks. Articular cartilage from the medial tibial plateau was tested in compression and in shear. Biochemical assays for water and glycosaminoglycan content and histomorphometric grading were performed on site-matched samples. Significant decreases in the equilibrium and dynamic shear moduli, but not compressive moduli, were observed in cartilage after 4 weeks of joint immobilization as compared to cartilage from a separate control population. Importantly, there was also evidence of a decrease in the compressive and shear moduli of tibial cartilage from the contralateral knee joints compared to control joints that were not immobilized. No significant effect of immobilization on the biochemical parameters or histomorphometric scores was detected, expect for a significant loss of proteoglycan staining following immobilization. These findings for changes in the tibial cartilage following cast immobilization are consistent with a mild form of cartilage degeneration.
Attracting young minority women to engineering and science: necessary characteristics for exemplary programs

A national educational imperative has been issued to reverse the trend of declining numbers of students choosing to study engineering and science. Minority women are particularly underrepresented in engineering and science, but in order to reach this pool of talent, the special concerns that affect young minority women must be recognized and programs that deal with these concerns must be developed. One such program offered at The George Washington University (GW) and funded by the National Science Foundation (NSF) from 1989 through 1993, utilizes computer technology and cooperative learning in a university setting to interest young minority women in engineering and science careers. As a result of the success of the GW/NSF program, a two-day working conference of experts was convened to determine the characteristics of exemplary programs that focus on this population. Outcomes from the conference included a criteria checklist, a program planning and self-evaluation guide, and suggestions for a national clearinghouse of information about exemplary programs designed to attract young minority women to engineering and science. >
Symposium introduction: metabolic syndrome and the onset of cancer

Diabetes, obesity, and related metabolic disorders are among the most pressing of today's health care concerns. Recent evidence from epidemiologic and basic research studies, as well as translational, clinical, and intervention studies, supports the emerging hypothesis that metabolic syndrome may be an important etiologic factor for the onset of cancer. On March 15-16, 2006, The Harvard Medical School Division of Nutrition hosted the symposium "Metabolic Syndrome and the Onset of Cancer" as a platform to systematically evaluate the evidence in support of this hypothesis. This symposium, which gathered leaders in the fields of metabolism, nutrition, and cancer, will stimulate further research investigating the etiologic role of metabolic syndrome in cancer. Furthermore, it will help to guide the development of effective cancer prevention strategies via nutritional and lifestyle modifications to alleviate metabolic syndrome.
Symbolic Computation of Strongly Connected Components Using Saturation

Finding strongly connected components (SCCs) in the state-space of discrete-state models is a critical task in formal verification of LTL and fair CTL properties, but the potentially huge number of reachable states and SCCs constitutes a formidable challenge. This paper is concerned with computing the sets of states in SCCs or terminal SCCs of asynchronous systems. Because of its advantages in many applications, we employ saturation on two previously proposed approaches: the Xie-Beerel algorithm and transitive closure. First, saturation speeds up state-space exploration when computing each SCC in the Xie-Beerel algorithm. Then, our main contribution is a novel algorithm to compute the transitive closure using saturation. Experimental results indicate that our improved algorithms achieve a clear speedup over previous algorithms in some cases. With the help of the new transitive closure computation algorithm, up to 10(exp 150) SCCs can be explored within a few seconds.
A 40 GS/s SiGe track-and-hold amplifier

An ultra-high-speed SiGe track-and-hold amplifier (THA) using a switched-emitter-follower (SEF) configuration is presented. Operating off a +5.5 V power supply, this THA exhibits -32.4 dBc of total harmonic distortion (THD) when sampling a 10 GHz input signal at the rate of 40 GS/s, and reaches -50.5 dBc of THD when sampling a 2 GHz input at 12 GS/s. Compared to the THAs published in the literature with an operational range from 10 GS/s to 20 GS/s, the present THA demonstrates a THD comparable to the best one achieved to date to our knowledge for Si technology, with much improved high-frequency characteristics. On the other hand, in the operational range of 30 GS/s and above, the present SiGe THA still exhibits robust characteristics compared to the fastest THAs in terms of linearity, power consumption, and sampling rate.
False-positive mammography and depressed mood in a screening population: findings from the New Hampshire Mammography Network

Background False positives occur in approximately 11% of screening mammographies in the USA and may be associated with psychologic sequelae. Methods We sought to examine the association of false-positive mammography with depressed mood among women in a screening population. Using data from a state-based mammography registry, women who completed a standardized questionnaire between 7 May 2001 and 2 June 2003, a follow-up questionnaire between 19 June 2003 and 8 October 2004 and who received at least one screening mammogram during this interval were identified. False positives were examined in relation to depressed mood. Results Eligibility criteria were met by 13 491 women with a median age of 63.9 (SD ¼ 9.6). In the study population, 2107 (15.62%) experienced at least one false positive mammogram and 450 (3.34%) met criteria for depressed mood. Depressed mood was not significantly associated with false positives in the overall population [OR ¼ 0.96; 95% confidence interval (CI) ¼ 0.72‐1.28], but this association was seen among Non-White women (OR ¼ 3.23; 95% CI ¼ 1.32‐7.91).
The effect of changes in surface wettability on two-phase saturated flow in horizontal replicas of single natural fractures.

Abstract By using translucent epoxy replicas of natural single fractures, it is possible to optically measure aperture distribution and directly observe NAPL flow. However, detailed characterization of epoxy reveals that it is not a sufficiently good analogue to natural rock for many two-phase flow studies. The surface properties of epoxy, which is hydrophobic, are quite unlike those of natural rock, which is generally assumed to be hydrophilic. Different surface wettabilities result in dramatically different two-phase flow behavior and residual distributions. In hydrophobic replicas, the NAPL flows in well-developed channels, displacing water and filling all of the pore space. In hydrophilic replicas, the invading NAPL is confined to the largest aperture pathways and flow frequently occurs in pulses, with no limited or no stable channel development, resulting in isolated blobs with limited accessible surface area. The pulsing and channel abandonment behaviors described are significantly different from the piston-flow frequently assumed in current modeling practice. In addition, NAPL never achieved total saturation in hydrophilic models, indicating that significantly more than a monolayer of water was bound to the model surface. Despite typically only 60–80% NAPL saturation, there was generally good agreement between theoretically calculated Young–Laplace aperture invasion boundaries and the observed minimum apertures invaded. The key to determining whether surface wettability is negligible, or not, lies in accurate characterization of the contaminant-geologic media system under study. As long as the triple-point contact angle of the system is low (
Draft Genome of Phaeobacter gallaeciensis ANG1, a Dominant Member of the Accessory Nidamental Gland of Euprymna scolopes

Phaeobacter gallaeciensis strain ANG1 represents the dominant member of the bacterial consortium within the reproductive accessory nidamental gland (ANG) of the squid Euprymna scolopes. We present a 4.59-Mb assembly of its genome, which may provide clues as to how it benefits its host.
Geochemical characterization of an oil seep from the Bagua Basin, north-central Peru

Abstract Oil hosted in a rock taken from a seep exposed by a road cut in north-central Peru was studied by geochemical means. The oil is classified as heavy paraffinic (waxy) by liquid chromatography. The oil appears to be highly mature, showing evidence of chemical and/or biological degradation. This is further supported by relatively high yields of polar fractions (resins and asphaltenes), partial depletion of n-alkanes below C16, and a relative enrichment of isoprenoid hydrocarbons. The n-alkane distribution obtained by whole-oil gas chromatography (GC) also points to mature, waxy oil. Pristane/phytane and isoprenoid ratios suggest that Type II kerogen deposited in low-oxygen (dystrophic) environment was likely the source of the oil. Biomarker fingerprints of the saturate fraction obtained by gas chromatography–mass spectrometry (GC–MS) and other characteristic ratios indicate the high level of thermal maturation of the oil and suggest that the oil was derived from a clay-rich source rock rich in bacterial-derived organic matter deposited in suboxic conditions. Aromatic biomarker data confirm the high level of thermal maturity of the oil and point to a mixed shale/carbonate source rock deposited in a sulfate-poor marine environment. The parent oil most likely has a pre-Cretaceous source due to the absence of 18 α (H) oleanane and the fact that the C28 αββ/C29 αββ steranes and the C28 αββ/C29 αββ sterane vs. C27 αββ/C29 αββ sterane ratios are both comparable to values reported for oils derived from the Jurassic Pucara Formation source rock in the nearby Maranon Basin.