cssi/SciSciGPT-SciSciNet huggingface dataset:
Preparation and Characterization of (HAp/SiO2)/Ti Biocomposites

(HAp/SiO2)/Ti biocomposites were prepared by the powder metallurgy method. The phase compositions and the in vitro bioactivity of such biocomposites were systematically characterized. The XRD result shows that the phase compositions of (HAp/SiO2)/Ti composites are mainly composed of Ca4O(PO4)2 (TTCP), Ti, TiO2 and CaO. The synthesized (HAp/SiO2)/Ti biocomposites exhibit a good bioactivity, for example, after the samples are immersed in SBF solution only for 24 hours, the bone-like layer consisting of spherical apatite crystal clusters has deposited on the surface of the samples. The density and thickness of the apatite layer increases with increasing immersion time. The formation process and mechanisms of bone-like apatite layer are also discussed.
Regulation of the Bacillus subtilis bcrC Bacitracin Resistance Gene by Two Extracytoplasmic Function σ Factors

Bacitracin resistance is normally conferred by either of two major mechanisms, the BcrABC transporter, which pumps out bacitracin, or BacA, an undecaprenol kinase that provides C(55)-isoprenyl phosphate by de novo synthesis. We demonstrate that the Bacillus subtilis bcrC (ywoA) gene, encoding a putative bacitracin transport permease, is an important bacitracin resistance determinant. A bcrC mutant strain had an eightfold-higher sensitivity to bacitracin. Expression of bcrC initiated from a single promoter site that could be recognized by either of two extracytoplasmic function (ECF) sigma factors, sigma(X) or sigma(M). Bacitracin induced expression of bcrC, and this induction was dependent on sigma(M) but not on sigma(X). Under inducing conditions, expression was primarily dependent on sigma(M). As a consequence, a sigM mutant was fourfold more sensitive to bacitracin, while the sigX mutant was only slightly sensitive. A sigX sigM double mutant was similar to a bcrC mutant in sensitivity. These results support the suggestion that one function of B. subtilis ECF sigma factors is to coordinate antibiotic stress responses.
Premodern Orientalist Science Fictions

Where and how does "the Orient" figure in Western imaginations of the fixture? In a 2005 Foreign Policy article titled "The Once and Future China: What of China's Past Could Be a Harbinger For Its Future?," China scholar Jonathan D. Spence writes: "the prospect of China's rise has become a source of endless speculation and debate. To speak of China's 'rise' is to suggest its reemergence. It can also imply a recovery from some kind of slump or period of quietude. But 'rise' can also mean that a change is being made at someone else's expense" (4). Spence's implication is clear: China's "rise" poses a serious challenge to the dominance of the West, or, more specifically, the dominance of the United States. Such a prospect has stoked much American apprehension and fear in recent years, the expres sions of which can be heard regularly on programs such as CNN's Lou Dobbs Tonight. This current strain of "Sinophobia," of course, is more familiar than most realize: it is an updated version of not only the ram pant Japanophobia that plagued the US in the 1980s when Japan became a formidable competitor on the US and global economic stages, but also the periodic waves of anti-Chinese sentiments that held sway in the US over the last century. Pervasive expressions of what David Morley and Kevin Robins call "Japan Panic" through the eighties consolidated around that favored techno-orientalist trope?the robot. Toshiya Ueno cites the miming of android-like gestures of Japanese businessmen by German
Structure and function of the S1 nuclease-sensitive site in the adenovirus late promoter

Abstract We analyzed an S1 nuclease-sensitive site present in supercolled, but not linear, recombinant plasmids containing the adenovirus late promoter. S1 nicking was detected on both strands, primarily in the TATA box. Analysis of deletion mutants showed that sequences upstream of −47 and downstream of −12 are not required for S1 cutting. However, a number of different base substitution mutations in stretches of G residues upstream and/or downstream of the TATA box were sufficient to eliminate S1 cutting. When the transcriptional activities of these mutant promoters were assayed in vivo, six of seven mutants lacking the ability to form the S1-sensitive structure showed no reduction in transcriptional potential. In fact, several showed increased promoter activities. These data show that the S1 nuclease cutting site in the adenovirus late promoter has precise nucleotide sequence requirements for its formation. However, the ability of recombinant plasmids to adapt this conformation in vitro is not necessary for such plasmids to serve as templates for transcription in vivo.
Linking individual diet variation and fecundity in an omnivorous marine consumer

Individual diet variation is a common feature of populations. This variation may be particularly common in near-shore marine benthic habitats where omnivory is prevalent and prey availability is spatially variable. Accurately predicting population responses to anthropogenic change that is occurring rapidly in these systems requires a quantitative link between individual diet variation and fecundity. Here I develop this quantitative link for the European green crab Carcinus maenas, specifically focusing on variation in the relative amounts of plant and animal material included in the diet. I demonstrate both short- and long-term diet variation between crabs as well as large individual variation in fecundity. I then quantitatively link variation in diet and fecundity using a laboratory feeding experiment. Fecundity increased by approximately 5,200 eggs when daily consumption of animal tissue increased by 1 % of body weight, but was not influenced by the most commonly consumed algal species. Results presented here have important implications for understanding population dynamics in general, and also provide information necessary for accurately predicting population growth of this widespread invader.
What's driving hard disk storage cost?

Advances in hard disk magnetic recording technology are accelerating the increase in areal density. With the advent of MR heads and PRML channels, the drive industry is doubling the capacity of high performance drivers every twelve months. As a result, the cost of storage will reach $DLR .10/MB in 1997.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Schoolwide screening and programs of positive behavior support: Informing universal interventions

Researchers have suggested that screening, identification, and treatment are important components of comprehensive systems of positive behavior support. The authors highlight a procedure for using multiple data sources to develop strategies at the universal intervention level. Examples of schoolwide assessments include interviews, observations, focus groups, archival data, systematic screening for behavior disorders, and office disciplinary referrals. A descriptive summary of data collected in an elementary school illustrates an interpretive process that school teams could use before selecting universal interventions. A comparison of subjective and objective data collection methods suggests that varied data sources have differing implications for intervention planning. The authors underscore the benefits of integrating data before selecting universal interventions and include implications for research and practice.
Transport and recombination via thermally activated random walks

Abstract Thermally activated nearest-neighbor random walks (TANNRW) in a band of trap states are used to model carrier transport and monomolecular recombination in disordered solids. Dispersive transport (μ( t ) ∝ t α-1 , where a = T / T 0 and T 0 is the measure of the band width) and carrier thermalization (〈E( t )〉 ∝ - T ln( t )) appear exactly as in the non-local multiple trapping model. The carrier population shows algebraic decay, t −α d , with α d = T / T 0 for T / T 0 ≲ 0.6. with α d = 1 at higher temperature.
Apoptosis Evasion: The Role of Survival Pathways in Prostate Cancer Progression and Therapeutic Resistance

The ability of a tumor cell population to grow exponentially represents an imbalance between cellular proliferation and cellular attrition. There is an overwhelming body of evidence suggesting the ability of tumor cells to avoid programmed cellular attrition, or apoptosis, is a major molecular force driving the progression of human tumors. Apoptotic evasion represents one of the true hallmarks of cancer and appears to be a vital component in the immunogenic, chemotherapeutic, and radiotherapeutic resistance that characterizes the most aggressive of human cancers [Hanahan and Weinberg, 2000]. The challenges in the development of effective treatment modalities for advanced prostate cancer represent a classic paradigm of the functional significance of anti-apoptotic pathways in the development of therapeutic resistance.
"small" Accelerator, Radionuclide and Radiopharmaceutical Production

The scope of this discussion is limited to the proton/deuteron accelerators capable of producing the positron emitting isotopes carbon-11, nitrogen-13, oxygen-15, and fluorine-18. Attention is focussed on the production process from the selection of the target gas to the synthesis of the desired radiopharamaceutical. (GHT)
Do not drown the patient: appropriate fluid management in critical illness

Administering intravenous fluids to support the circulation in critically ill patients has been a mainstay of emergency medicine and critical care for decades, especially (but not exclusively) in patients with distributive or hypovolemic shock. However, in recent years, this automatic use of large fluid volumes is beginning to be questioned. Analysis from several large trials in severe sepsis and/or acute respiratory distress syndrome have shown independent links between volumes of fluid administered and outcome; conservative fluid strategies have also been associated with lower mortality in trauma patients. In addition, it is becoming ever more clear that central venous pressure, which is often used to guide fluid administration, is a completely unreliable parameter of volume status or fluid responsiveness. Furthermore, 2 recently published large multicenter trials (ARISE and ProCESS) have discredited the "early goal-directed therapy" approach, which used prespecified targets of central venous pressure and venous saturation to guide fluid and vasopressor administration. This article discusses the risks of "iatrogenic submersion" and strategies to avoid this risk while still giving our patients the fluids they need. The key lies in combining good clinical judgement, awareness of the potential harm from excessive fluid use, restraint in reflexive administration of fluids, and use of data from sophisticated monitoring tools such as echocardiography and transpulmonary thermodilution. Use of smaller volumes to perform fluid challenges, monitoring of extravascular lung water, earlier use of norepinephrine, and other strategies can help further reduce morbidity and mortality from severe sepsis.
Clicking thiourea into a salen scaffold: Structures and cytotoxicity of cobalt(II) and nickel(II) complexes

Abstract A thiourea moiety has been introduced into the known salen-type ligand scaffold to give a new unsymmetric ligand (L) by using a simple CLICK chemistry. The cobalt(II) and nickel(II) complexes of this ligand were prepared by a one-pot procedure and structurally characterized. X-ray structural analysis confirmed that the two complexes are isomorphic and exhibit a tetra-coordinate metal center in a near square planar N2OS coordination environment. The cocrystallized methanol molecules that act as both hydrogen bonding donors and acceptors are hydrogen bonded to the complexes with both the coordinated O atoms and uncoordinated NH groups to generate a novel one-dimensional supramolecular helical chain. Both P-helix and M-helix were present in the crystal, which resulted in an overall racemic mixture of the chiral helix. Both complexes display cytotoxicity towards rat pheochromocytoma (PC12) and human embryonic kidney (HEK293) cells with the cobalt(II) complex slightly more toxic than the nickel(II) one.
Is mechanical deformation of the suboccipital vertebral artery during cervical spine rotation responsible for vertebrobasilar insufficiency

Background and Purpose. The atlanto-axial region of the vertebral artery (VA) has traditionally been considered at risk for injury during cervical spine rotation, leading to compromised blood fl ow to the hindbrain and vertebrobasilar insufficiency or ischaemia (VBI). The anatomical relationships of the suboccipital VA (VA3) and related haemodynamic changes associated with cervical spine movements have been neglected, however. The present review aims to provide a new perspective on possible causes of reduced blood flow to the hindbrain, with particular reference to the functional anatomy of VA3 and related biomechanics of cervical spine rotation, to inform evidence-based practice. Method. To support the hypothesis that it is VA3, not the VA in the atlanto-axial region, that is compressed or stretched during cervical spine rotation, current studies of blood flow changes in the VA distal to the region of rotation and possible arterial deformation were retrieved, using AMED, CINAHL, Embase, Pedro and PubMed, and reviewed. Results. Possible sites for VA3 deformation, based on a re-examination of its anatomy and biomechanics, are described. However, no research reports of VA3 blood flow measurements associated with cervical spine rotation have been published to date. Five studies on blood flow changes in the intracranial VA after cervical spine rotation were reviewed. The subjects for four of these reports were young, healthy individuals, and the fifth included older patients and young non-patients. The analysis of these studies demonstrated that more rigorous control of variables is necessary before meaningful conclusions can be made. Conclusion. The paucity of studies of VA3 emphasises the need for research based on informed understanding of the anatomy and biomechanics of this area. This view on mechanical deformation of VA3 associated with cervical spine rotation as a possible cause of compromised blood flow to the hindbrain and VBI provides further argument for avoiding full-range or sustained cervical spine rotation in clinical practice. Copyright © 2008 John Wiley & Sons, Ltd.
A Meta-Analysis Finds Periodontal Treatment Provides a Non-Significant Improvement in Glycemic Control

Article Title and Bibliographic Information Does periodontal treatment improve glycemic control in diabetic patients? A meta-analysis of intervention studies. Janket SJ. Wightman A. Baird AE. Van Dyke TE. Jones JA. Journal of Dental Research 2005;84(12):1154-9. Level of Evidence 1a Purpose To quantitatively summarize existing evidence on the impact of periodontal treatment on glycemic control, using hemoglobin A1c (HbA1c) as the outcome, in people with diabetes. Source of Funding VA HSR & D grant #DII99.206-1 and NIH grant DE13191 Type of Study/Design Systematic review with meta-analysis
The Effects of citizenship dissimilarity and national pride on attitudes toward immigrants: Investigating mediators and moderators of intergroup contact

Abstract Building on research from organizational sociology and the contact hypothesis, we incorporated community characteristics to examine how coworker citizenship dissimilarity influences employees’ attitudes towards immigrants. We also proposed that the nature of this relationship would depend on national pride. Results from a national survey (N = 559) indicated living with more immigrants in one's neighborhood corresponded in heightened citizenship dissimilarity at the workplace. It, in turn, corresponded in employees holding more favorable views of immigrants. This effect was the most pronounced for people with high levels of national pride because of the presumably increased opportunities to dispel their previously held negative stereotypes about out-group members.
Management Briefs: Effect of Storage Time and Temperature on Selected Walleye Electrophoretic Phenotypes

Abstract Samples of white muscle and liver tissue from walleyes Stizostedion vitreum were Subjected to various storage regimes to determine the effect of Storage temperature on the biochemical integrity of three proteins commonly assayed in electrophoretic analyses (white muscle malate dehydrogenase, white muscle myogen, and liver isocitrate dehydrogenase). Samples stored on wet ice (0°C) for 24 h, followed by Storage for up to 306 d in a Standard freezer (–15°C), provided electrophoretic results similar to those for samples that were stored in liquid nitrogen (–195°C) immediately after death of the Subject fish. Tissue samples Stored in an ultracold freezer (–70°C) for longer than 3 years Showed no protein degradation.
Compared with control subjects, the systemic sympathetic nervous system is activated in patients with mitral regurgitation

Abstract Background Whether the systemic sympathetic nervous system is activated as a compensatory mechanism in response to mitral regurgitation (MR) in humans is unknown. We tested the hypotheses that the systemic sympathetic nervous system would be activated in patients with MR in comparison with control subjects and that this activation would occur early in the disease process as a compensatory mechanism for chronic left ventricular (LV) volume overload. Methods We studied 37 patients with MR who underwent right heart catheterization and biplane cineventriculography to obtain LV end-diastolic and end-systolic volumes, ejection fractions, and regurgitant volumes. In these 37 patients with MR and in 23 control subjects, an [ 3 H]-norepinephrine ([ 3 H]-NE) infusion and multiple arterial blood samples provided data for a 2-compartment modeling analysis to calculate extravascular NE release rates (NE 2 ). Results The mean NE 2 (2.05 ± 0.76 μg/min/m 2 ) in the patients with MR was greater than that in the control subjects (1.48 ± 0.75 μg/min/m 2 , P = .007). Furthermore, the mean NE 2 values were also greater in the patients with MR who were in clinical class I ( P = .05), with a pulmonary capillary wedge pressure P = .05) or a LV ejection fraction ≥0.60 ( P = .06) compared with the control subjects. The mean NE 2 values were increased further in patients with MR who had a LV ejection fraction P = .02). Conclusions The systemic sympathetic nervous system is activated in patients with MR in comparison with control subjects, and this activation appears to occur early in the disease process as a compensatory mechanism for LV volume overload.
New precoding for intersymbol interference cancellation using nonmaximally decimated multirate filterbanks with ideal FIR equalizers

In this paper, we propose a new precoding method for intersymbol interference (ISI) cancellation by using non-maximally decimated multirate filterbanks. Unlike the existing preceding methods, such as the TH and trellis precodings, the new preceding (i) may be independent of the ISI channel; (ii) is linear and does not have to implement any modulo operation; (iii) gives the ideal FIR equalization at the receiver for any FIR ISI channel including spectral-null channels; (iv) expands the transmission bandwidth in a minimum amount. The precoding is built on non-maximally decimated multirate filterbanks. Based on multirate filterbank theory, we present a necessary and sufficient condition on an FIR ISI transfer function in terms of its zero set such that there is a linear FIR N/spl times/M precoder so that an ideal FIR equalizer exists, where the integers K and N are arbitrarily fixed. The condition is easy to check. As a consequence of the condition, for any given FIR ISI transfer function (not identically 0), there always exist such linear FIR precoders. Moreover, for almost all given FIR ISI transfer functions, there exist linear FIR precoders with size N/spl times/(N-1), i,e., the bandwidth is expanded by 1/N. In addition to the conditions on the ISI transfer functions, a method for the design of the linear FIR precoders and the ideal FIR equalizers is also given. Numerical examples are presented to illustrate the theory.
Video retrieval using speech and image information

Video contains multiple types of audio and visual information, which are difficult to extract, combine or trade-off in general video information retrieval. This paper provides an evaluation on the effects of different types of information used for video retrieval from a video collection. A number of different sources of information are present in most typical broadcast video collections and can be exploited for information retrieval. We will discuss the contributions of automatically recognized speech transcripts, image similarity matching, face detection and video OCR in the contexts of experiments performed as part of 2001 TREC Video Retrieval Track evaluation performed by the National Institute of Standards and Technology. For the queries used in this evaluation, image matching and video OCR proved to be the deciding aspects of video information retrieval.
Troubling the Waters: Black–Jewish Relations in the American Century Cheryl Lynn Greenberg

Cheryl Lynn Greenberg's Troubling the Waters: Black-Jewish Relations in the American Century reopens the question of whether there was a “golden age” of cooperation between Black and Jewish groups ...
Experimental Results Of A High Q Quasi-Optical Reflection Cavity

A quasi-optical reflection cavity has been designed, constructed, and tested and consists of three elements in cascade: a high Q folded Fabry-Perot resonator, a lower Q Fabry-Perot resonator, and a diffraction grating. The resonator exhibits a Q of 6700 and 1.6 dB of loss at 63 GHz. The design can be scaled to 1 THz to serve as the resonator for high frequency quantum well resonant tunneling device oscillators.
Imaging of lipid species by MALDI mass spectrometry

Recent developments in MALDI have enabled direct detection of lipids as intact molecular species present within cellular membranes. Abundant lipid-related ions are produced from the direct analysis of thin tissue slices when sequential spectra are acquired across a tissue surface that has been coated with a MALDI matrix. The lipid-derived ions can often be distinguished from other biomolecules because of the significant mass defect that these ions present due to the large number of covalently bound hydrogen atoms in hydrophobic molecules such as lipids. Collisional activation of the molecular ions can be used to determine the lipid family and often structurally define the molecular species. Specific examples in the detection of phospholipids, sphingolipids, and glycerolipids are presented with images of mouse brain and kidney tissue slices. Regional distribution of many different lipid molecular species and Na+ and K+ attachment ions often define anatomical regions within the tissues.
Group Members’ Decision Rule Orientations and Consensus

Recent speculation and research concerning the achievement of unanimous agreement in small groups underscores the importance of consensus, implicit or explicit, regarding the criteria for selecting an option from the pool of alternative decisions. Moreover, an emerging stream of research indicates that individuals vary in their tendency to make choices that are indicative of specific decision rule orientations. Although many individuals do not demonstrate consistent orientations, many others display tendencies to select options congruent with assumptions underlying maximax, maximin, and maximum expected utility decision rules. In the present study, participants were assigned to groups composed of members who were either identical (matched) or different (mixed) with respect to decision rule orientation. The results indicated that, for interacting groups, consensus was more likely in matched than in mixed groups. However, the hypothesis did not hold for noninteracting groups. Implications for group consensus and the decision rule orientation construct arc discussed.
The Case for Routine Parathyroid Hormone Monitoring

Parathyroid hormone (PTH) is a uremic toxin with multiple systemic effects including bone disorders (renal osteodystrophy), myopathy, neurologic abnormalities, anemia, pruritus, and cardiomyopathy. Hyperparathyroidism is common in CKD and results in significant morbidity and mortality if left untreated. Clinical practice guidelines from the Kidney Disease Improving Global Outcomes initiative broadened the optimal PTH range to >2 and <9 times the upper limit of normal for the assay measured. Furthermore, the guidelines recommend following trends in PTH to determine the appropriate therapy. These guidelines overcome issues with the assay variability and help clinicians make judgments when treating individual patients. They also require frequent measurement in order to determine trends and implement appropriate treatments.
Effects of RelA on Key Virulence Properties of Planktonic and Biofilm Populations of Streptococcus mutans

Streptococcus mutans is a biofilm-forming bacterium that is adapted to tolerate rapid and dramatic fluctuations in nutrient availability, carbohydrate source, and pH in its natural environment, the human oral cavity. Dissecting the pathways used to form stable biofilms and to tolerate environmental stress is central to understanding the virulence of this organism. Here, we investigated the role of the S. mutans relA gene, which codes for a guanosine tetraphosphate and guanosine pentaphosphate [(p)ppGpp] synthetase/hydrolase, in biofilm formation and acid tolerance. Two mutants in which relA was insertionally inactivated or replaced by an antibiotic resistance determinant were constructed. Under normal growth and stress conditions, the mutants grew slower than the wild-type strain, although the final yields were similar. The mutants, which were still able to accumulate (p)ppGpp after the induction of a stringent response, showed significant reductions in biofilm formation on microtiter plates or hydroxylapatite disks. There was no difference in the sensitivities to acid killing of the parent and relA strains grown in planktonic cultures. However, when cells were grown in biofilms, the mutants became more acid resistant and could lower the pH through glycolysis faster and to a greater extent than the wild-type strain. Differences in acid resistance were not correlated with increases in F-ATPase activity, although bacterial sugar:phosphotransferase activity was elevated in the mutants. Expression of the luxS gene was increased as much as fivefold in the relA mutants, suggesting a link between AI-2 quorum sensing and the stringent response.
Injecting a Kapchinskij-Vladimirskij distribution into a proton synchrotron

Recently it has been suggested that the Kapchinskij-Vladimirskij (KV) distribution (1959) may be of practical interest for high intensity machines in that it may provide the maximum space charge limit for such a machine. One can make a plausible argument that the maximum beam intensity is obtained for a distribution for which all particles have the same tune, at least when the resonance is approached. Therefore, the following steps should be taken: first, reduce the chromaticity of the accelerator ring as much as possible, and second, make the betatron frequencies independent of amplitude, i.e., make the focusing forces linear. One way to make the focusing forces linear is to start with external focusing forces which are linear, and then make the space charge forces also linear by using a KV distribution. The authors describe two injection scenarios which produce a KV distribution (if we neglect beam-beam interactions during the injection process.) Simulations of these injection scenarios verify that the resulting distribution produces a uniform circular beam in xy-space. A simulation code was written which also includes the space charge interactions between the 500 injected turns in the proposed scenarios; the results are given. The space charge forces have a substantial effect on the resulting distribution.
Therapeutic abortion: Some dilemmas associated with increased application

A 23-fold increase in the ratio of therapeutic abortion to live births per year occurred subsequent to a change in hospital bylaws but in the absence of any change in state law. A limited number of physicians contributed to this change; four of the 63 staff obstetricians performed 53% of 528 abortions and five of the 158 physician consultants accounted for 49% of the patient consultations. This uneven distribution among physicians is also reflected in polarization of the paramedical personnel of the hospital as well as the practice of the clinic resident. We do not believe that in this community the predominant restraints to the unabated application of therapeutic abortion are restrictive state laws. Rather, it is the attitudes of the medical personnel and the hospital based aspect of the therapeutic act that are the critical factors.
Gesturing with an injured brain: How gesture helps children with early brain injury learn linguistic constructions

Children with pre/perinatal unilateral brain lesions (PL) show remarkable plasticity for language development. Is this plasticity characterized by the same developmental trajectory that characterizes typically developing (TD) children, with gesture leading the way into speech ? We explored this question, comparing eleven children with PL – matched to thirty TD children on expressive vocabulary – in the second year of life. Children with PL showed similarities to TD children for simple but not complex sentence types. Children with PL produced simple sentences across gesture and speech several months before producing them entirely in speech, exhibiting parallel delays in both gesture+speech and speech-alone. However, unlike TD children, children with PL produced complex sentence types first in speech-alone. Overall, the gesture–speech system appears to be a robust feature of language learning for simple – but not complex – sentence constructions, acting as a harbinger of change in language development even when that language is developing in an injured brain.
Challengers, Democratic Contestation, and Electoral Accountability

In most models of electoral accountability, the “challenger” is simply a passive replacement. We develop a model in which the challenger can actively criticize the incumbent’s policy choices, and we use this model to analyze whether voters can use the challenger’s critiques to enhance the incumbent’s incentives to choose correct policies. If the challenger’s information is soft, then challenger critiques are irrelevant, but if the challenger can obtain hard information the voter can use this information to discipline the incumbent. We extend our model to analyze selection concerns, the incumbency advantage, and incumbents’decisions about whether to focus on making policy or on generating public justi…cations for their policy choices.
Link-Level Network Topology Generation

Internet topology generation involves producing synthetic network topologies that imitate the characteristics of the Internet. Although the accuracy of newly developed network protocols or algorithms do not considerably depend on the underlying topology, the performance generally depends on the topology. As a result, synthetic topologies are widely utilized by network researchers to analyze performance of their design in simulation or emulation environments. Previous studies on the Internet topology generation have ignored the major building block of the networks, i.e., subnetworks. Generated topologies are composed of point to point links. These networks do not ref ect some crucial characteristics of the Internet such as the clustering of the Internet backbone. In this study, we propose subnet based Internet topology generation to better ref ect the underlying building blocks of the Internet. Subnet based synthetic topologies capture both the degree distribution and the subnet distribution characteristics of sample Internet topologies.
Iron supplementation improves endurance after training in iron-depleted, nonanemic women.

Our objective was to investigate the effects of iron depletion on adaptation to aerobic exercise, assessed by time to complete a 15-km cycle ergometer test. Forty-two iron-depleted (serum ferritin ...
Flying robots: modeling, control and decision making

This paper presents a flight management system (FMS) implemented as on-board intelligence for rotorcraft-based unmanned aerial vehicles (RUAV's), in order to gradually refine given abstract mission commands into real-time control signals for each vehicle. A strategy planner uses the probabilistic decision making algorithms to determine suboptimal action at each time step. A graphical interface on ground station enables human intervention. We derive nonlinear dynamics model upon which we design a tracking control layer using nonlinear model predictive control and integrate with a trajectory generator for logistical action planning. The proposed structure has been implemented on Berkeley RUAVs and validated in probabilistic pursuit-evasion games to show the possibility of intelligent flying robots.
Psychiatric disorders and impairment in the children of opiate addicts: prevalances and distribution by ethnicity.

This study examined rates of psychiatric disorders and impairment in 283 children, aged 6 to 17, of 69 Caucasian, 45 African-American, and 47 Hispanic-American methadone maintenance patients. Children were evaluated by direct and/or parental interview with the K-SADS-E. Final DS M-III-R diagnoses and Global Assessment Scale (C-GAS) were assigned by best estimate. Substantial lifetime prevalences of mood (21%), anxiety (24%) and disruptive disorders (30%), school problems (37%), and global impairment (C-GAS<61) (25%) were observed in the children of opiate-dependent patients. There were few differences between ethnic groups. Effects of proband gender and major depression and their interactions with ethnicity on risk for childhood psychopathology were also examined. The results suggest children of patients in treatment for opiate dependence from diverse ethnic groups are at risk for psychopathology. Programs for early detection and intervention should be devised and evaluated.
Sources of Archaeological Obsidian in the Southwest : An Archaeological, Petrological, and Geochemical Study

Comprehensive geochemical studies of archaeological obsidian sources in the Southwest typically have lagged behind other regions of North American and Mesoamerica. Current archaeological and petrological research indicates four previously unreported sources in Arizona, Sonora, and western New Mexico. This initial semiquantitative X-ray fluorescence (XRF) examination of archaeological silicic-glass sources in this region focuses on current technical problems in southwestern obsidian studies. The chemical variability within some regional obsidian sources appears to be relatively extensive and new data from the San Francisco volcanic field in northern Arizona modifies the results of earlier researchers.
Cultivating Engagement and Enjoyment in Exergames Using Feedback, Challenge, and Rewards.

Objective: This article reviews theoretical and empirical evidence related to three mechanisms for encouraging enjoyment during exergame play: Feedback, challenge, and rewards. Materials and Methods: A literature search and narrative review were conducted. Results: Feedback is found in nearly all exergames, and richer, more in-depth feedback is associated with increased activity. Challenge is a vital component of any videogame, and exergames include physical as well as cognitive challenges. Flow states have traditionally been conceptualized as occurring when an optimal match between player skills and game challenge occurs. However, failure and retrial are necessary for feelings of overall satisfaction and fun, despite not necessarily being ideally fun or satisfying themselves. Rewards are a more complicated issue, with significant theoretical and empirical evidence suggesting positive and negative effects of reward systems. How rewards are integrated into the mechanics and storyline of the game likely impacts how they are perceived and, thus, their effectiveness. Finally, integration of these mechanisms into exergames requires specific attention to both cognitive and physical implementations. Movements that are not themselves enjoyable or engaging may lead to cheating and lower energy expenditure. Conclusions: Feedback, challenge, and rewards are promising mechanisms by which exergames could become more enjoyable. How these concepts are operationalized can affect physical and psychological reactions to exergames. Attention to these concepts in future exergame development and implementation would benefit theory, research, and practice.
Silica Morphogenesis by Lysine-Leucine Peptides with Hydrophobic Periodicity

The use of biomimetic approaches in the production of inorganic nanostructures is of great interest to the scientific and industrial community due to the relatively moderate physical conditions needed. In this vein, taking cues from silaffin proteins used by unicellular diatoms, several studies have identified peptide candidates for the production of silica nanostructures. In the current article, we study intensively one such silica-precipitating peptide, LKα14 (Ac-LKKLLKLLKKLLKL-c), an amphiphilic lysine/leucine repeat peptide that self-organizes into an α-helical secondary structure under appropriate concentration and buffer conditions. The suggested mechanism of precipitation is that the sequestration of hydrophilic lysines on one side of this helix allows interaction with the negatively charged surface of silica nanoparticles, which in turn can aggregate further into larger structures. To investigate the process, we carry out 1D and 2D solid-state NMR (ssNMR) studies on samples with one or two uniform...
Spectra and structure of organophosphorus compounds

Abstract The infrared spectra (3200 to 80 cm −1 ) of gaseous and solid isopropyldichlorophosphine, (CH 3 ) 2 CHPCl 2 , and its deuterated analog (CD 3 ) 2 CDPCl 2 , as well as the Raman spectra of the liquids and solids (3200 to 10 cm −1 ) have been recorded. Qualitative depolarization values have been obtained for the liquids. Both gauche and trans rotational isomers have been observed in the fluid phases. From variable temperature studies of the Raman spectrum of the liquid the gauche conformer has been found to be 129 ± 23 cm −1 (369 ± 67 cal mol −1 ) more stable than the trans rotamer. An assignment of the normal modes of vibration is proposed based on isotopic shifts, band contours, depolarization values, and group frequencies. The results are compared to similar data for some corresponding molecules.
Governor Sir Thomas Brisbane's experiment in press freedom: A quantitative evaluation through media system dependency

ABSTRACTThe relatively isolated circumstances of colonial Australia provide a natural laboratory for examining the establishment of press freedom there in 1824. A quantitative content analysis of newspapers from 1821 to 1825, guided by media system dependency (MSD) theory, suggests publishers were more concerned with exploiting the end of their dependence on the government as censor than with addressing their remaining dependence on the government as a well-funded advertiser. Findings also reveal considerable variation among publications and between colonies. The analysis also demonstrates the value of MSD theory in historical research.
Effects of xanthine derivatives on lipolysis and on adenosine 3',5'-monophosphate phosphodiesterase activity.

The lipolytic potencies of 64 compounds, mostly xanthine derivatives, were determined in epididymal fat cells. Nine of the compounds of widely varying lipolytic potency were examined as inhibitors of cyclic AMP phosphodiesterase activity. Substantial lipolytic effects were seen at concentrations producing less than 20% inhibition of phosphodiesterase activity. The most active compound, 1-methyl-3-isobutylxanthine, was about 15 times more potent than theophylline in both systems. Over a 20-fold range of concentrations, there was close agreement between the lipolytic activities of the compounds and their activities as inhibitors of phosphodiesterase. The close correlation between these two activities strongly indicates that the lipolytic activity of the xanthine derivatives is a result of inhibition of cyclic AMP phosphodiesterase.
Distributed beamforming using mobile robots

We consider the case where a team of unmanned vehicles are tasked with distributed beamforming in order to cooperatively transmit a message to a remote station. We propose a joint motion and communication optimization framework where the robots move in order to find locations that satisfy the given reception quality requirement while minimizing the overall motion energy consumption. For the case where the channel is perfectly known, we show that this problem can be posed as a knapsack problem and show the underlying trends of the optimum solution. We then extend our approach to the case where the channel is not known over the space. We show how the previously proposed channel prediction framework can be integrated with path planning for distributed robotic beamforming under motion energy constraints. Finally, we present extensive simulation results in realistic communication environments.
An Experimental Study for Identifying Features of Legible Manipulator Paths

This work performs an experimental study on the legibility of paths executed by a manipulation arm available on a Baxter robot. In this context, legibility is defined as the ability of people to effectively predict the target of the arm’s motion. Paths that are legible can improve the collaboration of robots with humans since they allow people to intuitively understand the robot’s intentions. Each experimental trial in this study reproduces manipulator motions to one of many targets in front of the robot. An appropriate experimental setup was developed in order to collect the responses of people in terms of the perceived robot’s target during the execution of a trajectory by Baxter. The objective of the experimental setup was to minimize the cognitive load of the human subjects during the collection of data. The extensive experimental data provide insights into the features of motion that make certain paths more legible for humans than other paths. For instance, motions where the end-effector is oriented towards the intended target appear to be better in terms of legibility than alternatives.
Immersion at scale: Researcher's guide to ecologically valid mobile experiments

While there have been hundreds of psychological studies using virtual reality (VR) over the past few decades, those studies have almost exclusively been conducted in laboratory settings using small samples of college students with little demographic variance. Hence, the generalizability of the results is limited, as not all findings will apply outside the college demographic. In this paper, we present our mobile VR project (Immersion at Scale) where we conduct VR experiment sessions in naturalistic settings (e.g., local events, museums, etc.). On average, we were able to collect data from 20–25 people for each 4-hour data collection session of Immersion at Scale. We discovered a number of obstacles and opportunities based on bringing VR out into the field. Thus, we do not focus on experimental stimuli and results, but methodological guidelines based on our iterative design improvements from pilot testing.
Recombination Rate Variation, Hitchhiking, and Demographic History Shape Deleterious Load in Poplar

Deleterious alleles are expected to be purged by purifying selection or maintained at low frequency. However, many additional evolutionary forces may shape the pattern of deleterious mutations across the genome and among populations, including selection, hitchhiking, recombination, and demographic history. We used exome capture data to estimate the genome-wide distribution of deleterious alleles across natural populations of the model tree black cottonwood (Populus trichocarpa). Although deleterious alleles were on average present at low frequency suggesting purifying selection, they were preferentially enriched both within genomic regions of low-recombination and in regions showing evidence of positive selection. The demographic history of this species also appeared to play a role in the distribution of deleterious alleles among populations, with peripheral populations having higher rates of deleterious homozygosity. This be due to less efficient selection arising from smaller effective population sizes at the edges of the range, and possibly also due to recent bottlenecks associated with postglacial recolonization. Finally, correlations between deleterious homozygosity and plant growth suggest a significant effect of deleterious load on fitness. Our results show that both genomic context and historical demography play a role in shaping the distribution of deleterious alleles across the genome and range of P. trichocarpa.
Arbitrarily Accessible 3D Microfluidic Device for Combinatorial High-Throughput Drug Screening

Microfluidics-based drug-screening systems have enabled efficient and high-throughput drug screening, but their routine uses in ordinary labs are limited due to the complexity involved in device fabrication and system setup. In this work, we report an easy-to-use and low-cost arbitrarily accessible 3D microfluidic device that can be easily adopted by various labs to perform combinatorial assays for high-throughput drug screening. The device is capable of precisely performing automatic and simultaneous reagent loading and aliquoting tasks and performing multistep assays with arbitrary sequences. The device is not intended to compete with other microfluidic technologies regarding ultra-low reaction volume. Instead, its freedom from tubing or pumping systems and easy operation makes it an ideal platform for routine high-throughput drug screening outside traditional microfluidic labs. The functionality and quantitative reliability of the 3D microfluidic device were demonstrated with a histone acetyltransferase-based drug-screening assay using the recombinant Plasmodium falciparum GCN5 enzyme, benchmarked with a traditional microtiter plate-based method. This arbitrarily accessible, multistep capable, low-cost, and easy-to-use device can be widely adopted in various combinatorial assays beyond high-throughput drug screening.
Stability monitoring tests using a nuclear-coupled boiling channel model

A new test platform for stability studies is presented that can be used to generate a power time series, which in turn may be used to validate the capability of boiling water reactor stability-monitoring algorithms. The thermal hydraulics for boiling channels are modeled and coupled with neutron kinetics to analyze the nonlinear dynamics of the closed-loop system, The model uses point kinetics to study core-wide oscillations, and it couples two time-domain calculations, for the fundamental and first harmonic modes, to study out-of-phase oscillations. The channel coolant flow dynamics is dominant in the power fluctuations observed by in-core nuclear instrumentation, and additive white noise is added to the solution for the channel flow in the thermal-hydraulic model to generate a noisy power time series. Autoregressive analysis performed with the computer-generated series agrees with the stability properties of the boiling channel. The operating conditions of the channel can be modified to accommodate a wide range of stability conditions.