cssi/SciSciGPT-SciSciNet huggingface dataset:
Contributions of the mechanical properties of major structural polysaccharides to the stiffness of a cell wall network model

 Premise of the study: The molecular mechanisms regulating the expansive growth of the plant cell wall have yet to be fully understood. The recent development of a computational cell wall model allows quantitative examinations of hypothesized cell wall loosening mechanisms.  Methods: Computational cell wall network (CWN) models were generated using cellulose microfi brils (CMFs), hemicelluloses (HCs), and their interactions (CMF-HC). For each component, a range of stiffness values, representing various situations hypothesized as potential cell-wall-loosening mechanisms, were used in the calculation of the overall stiffness of the computational CWN model. Thus, a critical mechanism of the loosening of the primary cell wall was investigated using a computational approach by modeling the molecular structure.  Key results: The increase in the stiffness equivalent of the CMF-HC interaction results in an increase in the Young’s modulus of the CWN. In the major growth direction, the CWN stiffness is most sensitive to the CMF-HC interaction (75%). HC stiffness contributes moderately (24%) to the change in the CWN stiffness, whereas the CMF contribution is marginal (1%). Minor growth direction exhibited a similar trend except that the contributions of CMFs and HCs are higher than for the major growth direction.  Conclusions: The stiffness of the CMF-HC interaction is the most critical mechanical component in altering stiffness of the CWN model, which supports the hypothesized mechanism of expansin’s role in effi cient loosening of the plant cell wall by disrupting HC binding to CMFs. The comparison to experiments suggests additional load-bearing mechanisms in CMF–HC interactions.
Participatory Democracy and Criminal Justice

This essay asks if there is a role for an active public in ratcheting down the harsh politics of crime control in the United States and the United Kingdom that has led to increased use of the criminal law and greater severity in punishment. It considers two opposing answers offered by political and legal theorists and then begins to develop a participatory democratic framework for institutional reform.
Operating systems with POPSS

It is often difficult to select relevant and reasonable laboratory assignments in an introductory operating systems course. The students are seldom prepared to code intricate portions of an operating system, even if suitable hardware were available for such extensive use. Nevertheless, it is essential that the students gain a quantitative insight into the components and interactions of simple and complex operating systems. An operating system simulator that allows an evaluation of the performances of various operating system configutations without requiring the student to write complicated code would help to solve the dilemma. An operating systems simulator named POPSS is a fine tool for such such use.
Rejection Sensitivity and the Rejection–Hostility Link in Romantic Relationships

Rejection sensitivity is the disposition to anxiously expect, readily perceive, and intensely react to rejection. In response to perceived social exclusion, highly rejection sensitive people react with increased hostile feelings toward others and are more likely to show reactive aggression than less rejection sensitive people in the same situation. This paper summarizes work on rejection sensitivity that has provided evidence for the link between anxious expectations of rejection and hostility after rejection. We review evidence that rejection sensitivity functions as a defensive motivational system. Thus, we link rejection sensitivity to attentional and perceptual processes that underlie the processing of social information. A range of experimental and diary studies shows that perceiving rejection triggers hostility and aggressive behavior in rejection sensitive people. We review studies that show that this hostility and reactive aggression can perpetuate a vicious cycle by eliciting rejection from those who rejection sensitive people value most. Finally, we summarize recent work suggesting that this cycle can be interrupted with generalized self-regulatory skills and the experience of positive, supportive relationships.
Charged particles and neutral kaons in photoproduced jets at HERA

Charged particles ( $h^\pm$ ) and $K^0$ mesons have been studied in photoproduced events containing at least one jet of $E_T > 8$ GeV in a pseudorapidity interval (–0.5, 0.5) in the ZEUS laboratory frame. Distributions are presented in terms of transverse momentum, pseudorapidity and distance of the particle from the axis of a jet. The properties of $h^\pm$ within the jet are described well using the standard settings of PYTHIA, but the use of the multiparton interaction option improves the description outside the jets. A reasonable overall description of the $K^0$ behaviour is possible with PYTHIA using a reduced value of the strangeness suppression parameter. The numbers of $h^\pm$ and $K^0$ within a jet as defined above are measured to be $3.25\pm0.02\pm0.28$ and $0.431\pm0.013\pm0.088$ respectively. Fragmentation functions are presented for $h^\pm$ and $K^0$ in photoproduced jets; agreement is found with calculations of Binnewies et al. and, at higher momenta, with $p\bar p$ scattering and with standard PYTHIA. Fragmentation functions in direct photoproduced events are extracted, and at higher momenta give good agreement with data from related processes in $e^+e^-$ annihilation and deep inelastic $ep$ scattering.
Humanitarianism, Violence, and the Camp in Northern Uganda

This article shows how international humanitarianism and state violence developed a sustained relation of mutual support during the civil war in northern Uganda. This collaboration was anchored in the archipelago of forced displacement camps, which at the peak of the war contained about a million people, and which were only able to exist because of, first, the violence of the Ugandan state in forcing people into them, preventing people from leaving, and repressing political organisation in the camps; and, second, the intervention of international humanitarian aid agencies, which fed, managed, and sustained the camps for over a decade. The consequence was that state violence and international humanitarianism each depended on the other for its own viability.
Psychiatric teaching and consultation in a primary care clinic

Abstract Basing their report on an 11-month experience as members of a primary care team in an outpatient municipal hospital setting, the authors identify six major presenting problems in consultation requests: functional complaints, noncompliance, depression, chronic psychosis, alcoholism, and physician role conflicts. The primary care physician's multiple roles, the content of general medical practice, and the ambulatory setting all colored these consultation requests and shaped the ways in which psychiatrists could be most helpful as consultants. Consulting psychiatrists should have special expertise in several specific clinical areas that are common in primary care practice. They can help primary physicians become more effective clinically by encouraging them to heighten their personal and interpersonal sensitivities and to think through their own values and beliefs about medical practice.
A pulse radiolysis and flash photolysis study of the radicals SO-2, SO-3, SO-4 and SO-5

Pulse radiolysis and laser-flash photolysis have been used to generate the radicals SO-2, SO-3, SO-4 and SO-5. Optical absorption spectra for these radicals and rate constants for their self-reactions have been derived. The decay of SO-2, SO-3, and SO-4 follow simple second-order kinetics; the decay of SO-5 is slower and does not follow a second-order rate law when the radical is generated by the pulse radiolysis of an oxygenated sulfite or bisulfite solution, but is second-order when generated by the flash photolysis of an oxygenated dithionate solution. SO-2 reacts rapidly with O2 and a rate constant of 2.4 × 109 M-1 s-1 was derived. SO-3 also reacts rapidly with O2 and a rate constant of 1.1 × 109 M-1 was derived for this reaction. The rate constant for the reaction of H with SO2 was determined to be 2.9 × 109 M-1 s-1.
60GHz high speed wireless link - technology and design challenges

The recent success of millimeter wave integrated circuit designs in silicon has triggered a wave of interest and activity in a wide range of high speed wireless applications at 60 GHz. In this paper, we will review the latest developments in design and technology for 60 GHz multi-gigabit-per-second wireless communications. We will address the requirements and challenges for device performance, modeling and circuit design at millimeter wave frequencies, with a discussion of the advantages and disadvantages of SiGe BiCMOS and RFCMOS technology. Packaging, antenna design and integration will also be discussed.
High-throughput solution-based medicinal library screening against human serum albumin.

High-throughput screening of combinatorial libraries has evolved from studying large diverse libraries to analyzing small, structurally similar, focused libraries. This paradigm shift has generated a need for rapid screening technologies to screen both diverse and focused libraries in a simple, efficient, and inexpensive manner. We have proactively addressed these needs by developing a high-throughput, solution-based method combining size exclusion (SEC), two-dimensional liquid chromatography (2-D LC), and mass spectrometry (MS) for determining the relative binding of drug candidates in small, focused medicinal libraries against human serum albumin (HSA). Two types of libraries were used to evaluate the performance of the system. The first consisted of five diverse ligands with a wide range of hydrophobicities and whose association constants to HSA cover 3 orders of magnitude. A β-lactam library composed of structurally similar compounds was used to further confirm the validity of the methodology. The abi...
The Effect of Aggregation on Prediction in the Autoregressive Model

Abstract The article shows that if the original variable follows a pth order autoregressive system then the non-overlapping moving sum follows a pth order autoregression with at most a pth order moving-average of an independent sequence regardless of the length of the summation. From such an aggregate model we derive the optimal predictor of the aggregate variable and show that it performs remarkably well compared to the optimal disaggregate predictor. The article contains both theoretical and numerical analysis.
Activated Complement Component 3 (C3) Is Required for Ultraviolet Induction of Immunosuppression and Antigenic Tolerance

Complement component 3 (C3), a critical regulator of innate immunity, may also play a role in the regulation of cognate immunity, such as contact sensitivity responses. Because ultraviolet (UV) radiation also activates C3 in the skin, we determined whether the immunosuppressed state that results when a contact sensitizer is applied through UVB-exposed skin requires the presence and activation of C3. This question was addressed through the use of C3-deficient mice, blockade of C3 cleavage to C3b, and accelerated degradation of iC3b by soluble complement receptor 1 (sCR1). Both C3-modulated systems totally reversed the failure to induce a contact sensitivity response to dinitrofluorobenzene (DNFB) upon primary sensitization at the UV-exposed site, as well as immunologic tolerance to a second DNFB immunization through normal skin. Treatment with sCR1 reduced the infiltration of CD11b+ leukocytes into the epidermis and dermis of UV-irradiated skin but did not reverse the UV-induced depletion of epidermal class II MHC+CD11blo Langerhans cells. These data, taken together with previous results showing abrogation of locally induced UV immunosuppression by in vivo anti-CD11b treatment, suggest a novel mechanism by which ligation of the leukocyte β2 integrin, CD11b, by iC3b molecules formed from C3 activation in UV-exposed skin, modifies cutaneous CD11b+ cells such that skin antigen-presenting cells are unable to sensitize in a primary immune response, but actively induce antigenic tolerance.
Looking back on Lindau

The Nobel Laureate Meetings held on the German island of Lindau bring together some of the world's brightest young minds with those individuals who have reached a pinnacle of scientific achievement. The impact of this unique event on all the delegates — especially the young researchers — is far-reaching.
The effect of copper on the structural characteristics of carbon filaments produced from iron catalyzed decomposition of ethylene

Abstract Carbon filaments were produced by the decomposition of ethylene over unsupported iron-copper powders in the presence of varying amounts of hydrogen at temperatures ranging from 500°C to 800°C. The structure and properties of the carbon filaments were found to be dependent on a number of parameters including the composition of the catalyst, the temperature and the percent of hydrogen in the reactant gas mixture. Temperature programmed oxidation in CO 2 of demineralized samples of carbon filaments indicated that the most stable structures were those produced from a bimetallic catalyst containing a large fraction of iron. The addition of hydrogen to the system also caused changes in the structure of the carbon filaments and this aspect was manifested by variations in the graphitic nature of the material. High resolution transmission electron microscopy examination indicated the presence of two distinct morphologies: one in which the filaments appeared to have smooth surfaces and where the graphite platelets were preferentially oriented at an angle with respect to the fiber axis; and a second type consisting of a tubular structure in which the graphite platelets were aligned in a direction parallel to the axis of the fiber. Surface areas of the carbon filaments, as determined by nitrogen adsorption at −196°C, were also found to be dependent on the catalyst composition, the reaction temperature and the fraction of hydrogen in the feed gas.
Effect of agitation on removal of acetic acid from pretreated hydrolysate by activated carbon.

The effect of agitation on the adsorption of acetic acid by activated carbon was tested utilizing an external mass transfer-diffusion model. Simulated pretreated biomass was contacted with activated carbon under prescribed conditions of temperature and agitation. Adsorption isotherm studies are presented as well as batch kinetic rate studies. Use of these data enabled the determination of isotherm constants, an external mass transfer coefficient, and an effective diffusivity for each agitation rate studied. The external film coefficient results ranged from 33.62 µm/s to a complete absence of external mass transfer resistance, and the diffusivity results ranged from 0.8625 to 10.70 µm2/s. The optimum combination of no external film resistance, and highest diffusivity, 10.70 µm2/s, occurred at 250 rpm and 25°C. The results of these models and the experimental parameters suggested an efficacious method and conditions for the removal of this undesirable chemical.
Studies on the nucleotide arrangement in deoxyribonucleic acids VI. Pyrimidine nucleotide clusters: Frequency and distribution in several species of the AT-type

The pyrimidine oligonucleotide clusters released by the hydrolysis of DNA specimens from calf thymus, rye germ, and wheat germ have been studied. Sequences of the general structure (pyrimidine deoxyriboside)n(phosphorric acid residue)n+1 with n of 1–8, have been separated quantitatively and their distribution in the three DNA preparations has been compared. Clusters of 9 or more pyrimidines in a row account for 6–8 % of the pyrimidines. In all cases, the results deviate considerably from what would be expected from a random arrangement of clusters. Almost all oligonucleotide units, comprised in the fractions with n of 1–4, have been separated, characterized, and estimated. Whereas the totol abundance of the various oligonucleotide classes was rather similar in the three DNA specimens, which were all of the AT-type, calf-thymus DNA differed widely from the specimens from rye and wheat germ in the amounts of individual oligonucleotides isolated. Some pyrimidine oligonucleotides which could have been expected were not encountered, conspicuously those consisting of 4 or 5 cytosine units in a row, whereas the corresponding thymine oligonucleotides were observed invariably. Previous observations showing that in the plant nucleic acid 5-methylcytosine and cytosine do not share the same pattern of arrangement within the polymer have been confirmed. The bearing of some of the findings on the general problem of DNA structure is considered.
The Effects of Temporal and Semantic Conditions on the Occurrence of the Error Response of Perseveration in Adult Aphasics

This study sought to determine whether the incidence of perseveration in the responses of adult aphasics could be affected by altering stimulus factors such as semantic difficulty and the rate of p...
Venting vs Ventilating: A Danger of Manual Resuscitation Bags

A pressure relief valve, a standard safety feature on many hand held resuscitator bags, prevented the bag from developing sufficient pressure for ventilation during resuscitation of a patient. Many conditions for which cardiopulmonary resuscitation is needed require ventilation pressures higher than the pressure relief valve setting. Despite this, the venting of the “safety” valve is often unrecognized. Knowledge of this problem and of simple methods for overriding the valve need to be disseminated and the equipment designed for safer use.
Biomimetic cardiac microsystems for pathophysiological studies and drug screens

Microfabricated organs-on-chips consist of tissue-engineered 3D in vitro models, which rely on engineering design and provide the physiological context of human organs. Recently, significant effort has been devoted to the creation of a biomimetic cardiac system by using microfabrication techniques. By applying allometric scaling laws, microengineered cardiac systems simulating arterial flow, pulse properties, and architectural environments have been implemented, allowing high-throughput pathophysiological experiments and drug screens. In this review, we illustrate the recent trends in cardiac microsystems with emphasis on cardiac pumping and valving functions. We report problems and solutions brought to light by existing organs-on-chip models and discuss future directions of the field. We also describe the needs and desired design features that will enable the control of mechanical, electrical, and chemical environments to generate functional in vitro cardiac disease models.
An optimization-based approach to dynamic data content selection in intelligent multimedia interfaces

We are building a multimedia conversation system to facilitate information seeking in large and complex data spaces. To provide tailored responses to diverse user queries introduced during a conversation, we automate the generation of a system response. Here we focus on the problem of determining the data content of a response. Specifically, we develop an optimization-based approach to content selection. Compared to existing rule-based or plan-based approaches, our work offers three unique contributions. First, our approach provides a general framework that effectively addresses content selection for various interaction situations by balancing a comprehensive set of constraints (e.g., content quality and quantity constraints). Second, our method is easily extensible, since it uses feature-based metrics to systematically model selection constraints. Third, our method improves selection results by incorporating content organization and media allocation effects, which otherwise are treated separately. Preliminary studies show that our method can handle most of the user situations identified in a Wizard-of-Oz study, and achieves results similar to those produced by human designers.
D-n quivers from branes

D-branes can end on orbifold planes if the action of the orbifold group includes (-1) (FL). We consider configurations of D-branes ending on such orbifolds and study the low-energy theory on their worldvolume. We apply our results to gauge theories with eight supercharges in three and four dimensions. We explain how mirror symmetry for N = 4 d = 3 gauge theories with gauge group Sp(k) and matter in the antisymmetric tensor and fundamental representations follows from S-duality of IIB string theory. We argue that some of these theories have hidden Fayet-Iliopoulos deformations, not visible classically. We also study a class of finite N = 2 d = 4 theories (so-called D-n quiver theories) and find their exact solution. The integrable model corresponding to the exact solution is a Hitchin system on an orbifold Riemann surface. We also give a simple derivation of the S-duality group of these theories based on their relationship to SO(2n) instantons on R-2 x T-2.
Three-dimensional solutions for general anisotropy

The Stroh formalism is extended to provide a new class of three-dimensional solutions for the generally anisotropic elastic material that have polynomial dependence on x3, but which have quite general form in x1;x2. The solutions are obtained by a sequence of partial integrations with respect to x3, starting from Stroh’s two-dimensional solution. At each stage, certain special functions have to be introduced in order to satisfy the equilibrium equation. The method provides a general analytical technique for the solution of the problem of the prismatic bar with tractions or displacements prescribed on its lateral surfaces. It also provides a particularly efficient solution for threedimensional boundary-value problems for the half-space. The method is illustrated by the example of a half-space loaded by a linearly varying line force. r 2007 Elsevier Ltd. All rights reserved.
Tunable many-body effects in triple quantum dots

Exchange energies and charge densities for a few electrons in electrically tunable triangular and collinear triple quantum dot (TQD) systems are investigated by using the variational Monte Carlo method in the presence of magnetic fields. For $N=2$ electrons we observe a discontinuity in the $J$ derivative with detuning voltage $(dJ/d{V}_{\text{T}})$ in triangular triple QDs at $B=0\text{ }\text{T}$ as crossing of the eigenenergy levels leads to abrupt spatial symmetry change in the singlet and the triplet densities (density rotation) and relocalization. For $B\ensuremath{\ne}0\text{ }\text{T}$, the angular momentum provided to the electrons quenches this effect. The density rotation is absent in the collinear TQD for all magnetic fields as the lowest excited state remains the ${p}_{x}$ state and as such, no change in symmetry is possible. By varying the triangular TQD configuration, we show the discontinuity in $dJ/d{V}_{\text{T}}$ persists for the top angle comprised between $\ensuremath{\sim}20\ifmmode^\circ\else\textdegree\fi{}$ and $\ensuremath{\sim}70\ifmmode^\circ\else\textdegree\fi{}$. For three electrons in the symmetric triangular TQD, the monotonicity of the quadruplet-doublet energy difference from $B=0$ to 4 T remains intact for decoupled QDs but not for coupled QDs. Finally, addition energy for the triangular TQD system is computed for up to $N=3$ electrons.
Self-Consistent Klystron Simulations

A numerical analysis of large-signal klystron behavior based on general wave-particle interaction theory is presented. The computer code presented is tailored for the minimum amount of complexity needed in klystron simulation. The code includes self-consistent electron motion, space-charge fields, and intermediate and output fields. It also includes use of time periodicity to simplify the problem, accurate representation of the space-charge fields, accurate representation of the cavity standing-wave fields, and a sophisticated particle-pushing routine. In the paper, examples are given that show the effects of cavity detunings, of varying the magnetic field profile, of electron beam asymmetries from the gun, and of variations in external load impedance.
Circadian variations in the oxygen-consumption of anterior segments of earthworms

The oxygen-consumption of anterior segments (prostomium plus the first six segments) of earthworms, Lumbricus terrestris L., was measured around midday and in the evening on 25 days of late winter and early spring. The preparations were cut from animals which had lived in complete darkness for at least several days prior to their being studied. Data for 1) anterior pieces with intact suprapharyngeal ganglia (brain), for 2) pieces from which those ganglia had been removed about an hour before the segments were placed in the respirometers, for 3) pieces in which the circumpharyngeal connectives had been severed approximately an hour before measurements were made and for 4) pieces from which the ganglia had been removed 42 hours before recording, are presented in Tables 1 and 2. The average oxygen-consumption of preparations of the first three groups was 22 to 25% greater (p<0.05) in the evening than at noon, i. e., the circadian variation was found whether or not the central nervous system had been manipulated shortly before respiratory rates were determined. However, for the preparations of type 4), the differences between midday and evening rates were less, averaged only 16%, and were not statistically significant. Those findings may indicate that the longterm maintenance of the circadian variation in oxygen-consumption does depend upon nervous mediation or synchronization.
Introduction to the Special Section on Energy-Harvesting/Scavenging Circuits and Systems

The ten papers in this special section focus on energy harvesting/scavenging circuits and systems.
Mouse lactoferrin gene: a marker for estrogen and epidermal growth factor.

Abstract Lactoferrin mRNA in the 21-day-old mouse uterus can be increased several hundredfold by estrogen. The physiological role of lactoferrin in mouse uterus is unclear; however, it can be a useful marker for the estrogen action in the uterus. The structural organization and the chromosome location of the lactoferrin gene are similar to members of the transferrin gene family. At the 5' flanking region of the lactoferrin gene, we have characterized two modules that respond to estrogen and growth factor stimulation. Each module is composed of either overlapping or multiple transcription factor-binding elements. The well-characterized estrogen and growth factor response modules in the mouse lactoferrin gene could serve as the foundation to understand the intricate molecular mechanisms of estrogen action and its relationship to growth factors.
Acquiring library materials as efficiently, inexpensively, and quickly as possible: Exploring possibilities within “the impossible dream”

AbstractApproval plans, like all other methods of acquiring materials for libraries, have both strong and weak points. After careful consideration, the author concludes that approval plans’ strengths outweigh their weaknesses. He then proceeds to similarly consider possible arrangements with local bookstores, with stores specializing in the sales of review copies of books, and with other sources outside the mainstream of library acquisitions. The overall conclusion is that, while it is impossible to always acquire all library materials as efficiently, inexpensively, and quickly as one would like, it is possible — through judicious deliberation and application of the various methods noted — to procure materials in a fashion which, more than occasionally, approaches the ideal.
Leverage and Superleverage in Nonlinear Regression

Abstract Several measures of the leverage of an observation in a nonlinear regression model are defined and developed. In contrast to the upper bound on the leverage in a linear model, it is found that in a nonlinear model the leverage of an observation may exceed 1. Such a case is said to exhibit superleverage. Relationships between the leverage measures are explored, and several examples are developed to illustrate the proposed methodology.
Wetting reaction of Sn-Ag based solder systems on Cu substrates plated with Au and/or Pd layer

The wetting behavior of SnAg based Pb-free solders on Cu and Cu substrates plated with Au, Pd, and Au/Pd thin films have been studied. The wetting angle and kinetics of interfacial reaction were measured. The Au-plated substrates exhibit better wetting than the Pd-plated substrates. In the case of SnAg on Pd-plated Cu, SEM observation revealed that the solder cap was surrounded by an innerring of Cu−Sn compound and an outer ring of Pd−Sn compound. This implies that the molten SnAg solder had removed the Pd and wetted the Cu directly in the equilibrium state. The effects of pre-doping Cu in the SnAg solder on wetting behavior were also investigated. We found that wettability decreases with increasing Cu content in the solder. We also observed that the SnAgCu solders have a lower Cu consumption rate than the SnAg solder.
RNAi in mouse oocytes and preimplantation embryos: effectiveness of hairpin dsRNA.

RNA interference (RNAi), the targeted mRNA degradation by double-stranded RNA (dsRNA), is a useful tool for studying gene function in several organisms. Here we report results of experiments with mammalian dsRNA expression vectors that are suitable to study gene function in mouse oocytes and preimplantation embryos. The plasmid vectors were constructed to contain the SV40 small intron, EGFP coding sequence to permit detection of expression, and an inverted repeat to mos mRNA that would form a hairpin dsRNA. Results of the experiments indicated that (i) hairpin dsRNA was just as effective as dsRNA (i.e., annealed sense and antisense RNA) in promoting the destruction of targeted mRNA, (ii) the EGFP marker could be expressed from the construct, and (iii) the distance of the SV40 intron from the inverted repeat was critical for the transcribed RNA to function in RNAi.
Process of Site Selection for Handbook on Benefits of Regional Transportation Collaboration

Five University of Virginia Systems Engineering students worked in partnership with Science Applications International Corporation (SAIC) and the Federal Highway Administration (FHWA) to develop a handbook detailing agency benefits from regional transportation collaboration. The UVa students were responsible for devising site selection metrics and tangible benefits metrics, applying the metrics to rank and select a list of sites, interviewing these sites, and finally presenting the data for the eventual incorporation into a handbook. This report details the methodology used in selecting the interview sites and the creation of the tangible benefits and preliminary interview strategy.
Aluminum-26 in meteorites. VII - Ureilites, their unique radiation history.

Cosmogenic Al-26 activities have been measured by gamma-gamma coincidence counting in the three ureilites which had not previously been studied. The values in dpm/kg are: Dingo Pup Donga, 38.4 plus or minus 2.4; North Haig, 39.3 plus or minus 4.8; Dyalpur, 55.8 plus or minus 4.8. Five of the six known ureilites thus have lower Al-26 contents, 63 per cent to 77 per cent, than the calculated saturation values, in marked contrast to most other stony meteorites. This cannot be attributed to short cosmic ray exposure ages. The most likely explanation is that the ureilites had much smaller or much larger orbits than all other stony meteorites.
Developmental changes in environmentally induced analgesia

Previous studies have shown that exposure to inescapable, front-paw shock produces an opioid-mediated analgesia. Additionally, research has revealed that the majority of opioid receptors in the central nervous system are formed between birth and adulthood. The purpose of the present experiment was to examine the relationship between the development of the opioid receptors and the function of the endogenous opioid pain-inhibitory system activated by shock. Ten-day-old, 28-day-old and 5-7-month-old rats were exposed to 90 s of front-paw shock (1.6 mA). Results revealed that 10-day-old rats displayed lower levels of shock-induced analgesia than 28-day-old and 5-7-month-old rats. This age-related difference in shock-induced analgesia confirms a parallel in the development of opioid receptors and the function of an endogenous pain-inhibitory system. In addition, injection of naloxone produced an increased analgesia in the 10-day-old rats. In the 28-day-old rats naloxone completely blocked the shock-induced analgesia while in the 5-7-month-old rats naloxone only partially attenuated analgesia. This age-related difference (28-day-old vs 5-7-month-old) in the effectiveness of naloxone in blocking shock-induced analgesia suggests the involvement of a non-opioid analgesia system in the 5-7-month-old rats that is not present in the 28-day-old rats. This last difference led to the speculation that the non-opioid analgesia system develops more slowly than the opioid system.
Factors affecting androgen sex reversal of Tilapia aurea

Abstract Tilapia aurea were fed a single level of androgen-treated feed (ethynyltestosterone at 60 mg/kg of feed — ET-60) under a variety of conditions to determine the effect on sex reversal. Sex ratios were significantly altered in favor of males in 16- and 19-day treatments at 21 and 30° C; all-male populations were produced in 21- and 28-days at 21° C, but a few females persisted in the groups at 30° C. Feeding regimes of 12% body weight/day and satiation had variable impacts on growth but did not adversely affect success of sex reversal, except at higher temperatures. Because of higher metabolic rate at 30° C and the concomitant increase in appetite, a fixed level of feeding at 12% of body weight was considered to be limiting and was later increased to 15%. High stocking density (2600 fry/m2 of surface) reduced growth rate but did not affect sex reversal. A 21-day treatment with ET-60 fed at 15% body weight/day at water temperatures between 21 and 30° C should consistently produce all-male populations of T. aurea at stocking densities up to 2600 fry/m2.
Animal models for the study of myocardial protection against ischemia

Research efforts have focused on ways to attenuate deleterious consequences of coronary occlusion in humans. However, clinical research is hampered by the inability to measure morphological, biochemical and molecular changes produced by interventions. Accordingly, a variety of experimental models have been used. However, selection of the particular model is influenced by many considerations: species, physiologic parameter to be measured, perfusate (blood or cell-free), whole organ or isolated cardiomyocyte, among others. This review highlights these considerations.
FAMILIAL SPINOCEREBELLAR ATAXIA AND EMPTY SELLA TURCICA

Pituitary anomaly associated with familial spinocerebellar ataxia (FSCA) is a rare occurrence. This is a report of a child with FSCA who had an empty sella turcica and growth hormone deficiency. Growth hormone therapy accelerated growth velocity and improved muscular strength. Endocrinopathy associated with FSCA is reviewed.
Compact and Anonymous Role-Based Authorization Chain

We introduce a decentralized delegation model called anonymous role-based cascaded delegation. In this model, a delegator can issue authorizations on behalf of her role without revealing her identity. This type of delegation protects the sensitive membership information of a delegator and hides the internal structure of an organization. To provide an efficient storage and transmission mechanism for credentials used in anonymous role-based cascaded delegation, we present a new digital signature scheme that supports both signer anonymity and signature aggregation. Our scheme has compact role signatures that make it especially suitable for ubiquitous computing environments, where users may have mobile computing devices with narrow communication bandwidth and small storage units.
The relationships between sensory processing sensitivity, alexithymia, autism, depression, and anxiety

Abstract The goal of the current investigation was to better understand the relationships between the three recently-developed factors of sensory processing sensitivity (ease of excitation – EOE, low sensory threshold – LST, and aesthetic sensitivity – AES) and alexithymia, autism symptoms, anxiety, and depression. Two hundred and one college students completed the highly sensitive person scale, as well as measures of anxiety, depression, alexithymia, and autism symptoms. EOE and LST were related to autism symptoms, alexithymia, anxiety, and depression. AES was related to attention to details (a symptom of autism) and anxiety but not to depression. It was also negatively related to externally-oriented thinking (a symptom of alexithymia). Results indicate that AES is conceptually distinct from LST and EOE. Furthermore, EOE interacted with difficulty identifying feelings in predicting anxiety, indicating that being both easily excited by stimuli and unable to identify one’s feelings is particularly anxiety provoking.
A thermodynamic approach to ion flotation. II. Metal ion selectivity in the SDS–Cu–Ca and SDS–Cu–Pb systems

Abstract Two thermodynamically based, theoretical models are developed to predict the selectivity coefficients for Ca 2+ /Cu 2+ and Pb 2+ /Cu 2+ in ion flotation with sodium dodecylsulfate (SDS) as the collector. Pseudo selectivity coefficients predicted from surface tension measurements are 1.12 and 1.69 for Ca 2+ /Cu 2+ and Pb 2+ /Cu 2+ . This agrees rather poorly with experimentally measured selectivity coefficients of 1.44 and 2.14, but does predict the order of selectivity Cu 2+ 2+ 2+ . The selectivity coefficients estimated by the dehydration model are 1.55 and 2.07 for Ca 2+ /Cu 2+ and Pb 2+ /Cu 2+ , respectively, which agrees well with the experimentally measured values.
The Hairy–Downy Game: A model of interspecific social dominance mimicry

Abstract The evolution of many forms of mimicry are well understood, but the evolution of mimicry in the absence of aposematic models or third party participants remains poorly understood. This paper presents a model of the evolution of interspecific social dominance mimicry (ISDM), that does not rely on third-party observers, in the context of the Hairy–Downy game. Members of a socially dominant species contest a resource by playing the hawk–dove game. Nonmimic members of a subordinate species surrender the resource whenever encountering a member of the dominant species, and split the resource whenever interacting among themselves. Mimicry allows members of the subordinate species to pose as members of the dominant species who play dove, splitting the resource when facing other dominant doves while continuing to surrender the resource to dominant hawks. We characterize the evolutionary dynamics and equilibrium behavior of this game, developing conditions under which evolution will select for mimicry, and under which the subordinate species will consist (almost or even literally) entirely of mimics.
Indoor Radon Progeny Aerosol Size Measurements in Urban, Suburban, and Rural Regions

By using direct and indirect methods, we conducted size distribution measurements of radon progeny particles in a variety of indoor environments in urban, suburban, and rural areas. The radon progeny particle size distribution owing to indoor activities has two definable source categories: (1) gas combustion from stoves and kerosene heaters–particles were found to be smaller than 0.1 μm in diameter, mostly in the range 0.02–0.08 μm; and (2) cigarette smoking and food frying—particles were found to be larger, in the size range 0.1–0.2 μm. The radon progeny particle size distribution, without significant indoor activities, such as cooking, was found to be larger in rural areas than in urban or suburban areas. The modal diameters of the size spectra in the rural areas were two to three times larger than those in urban or suburban areas, around 0.3–0.4 vs. 0.1–0.2 μm. Results obtained by applying the attachment theory to the measured number-weighted size spectra from an electrical aerosol size analyzer suppor...
“Loop-at-a-Time” Design of Dynamic Surface Controllers for Nonlinear Systems

The use of multiple surface sliding controllers for robust control of nonlinear systems with mismatched uncertainties has produced a number of impressive applications, but also raised a few theoretical questions. Among the latter are the use of numerical differencing to obtain derivatives of desired trajectories, robustness to uncertainties in the gain terms and the common practice of filtering desired trajectories for implementation. This paper seeks to address these issues through the concept of a Dynamic Surface Controller, in which filters form an integral part of the structure. This filtering removes the need for numerical differencing and guarantees a certain smoothness, enabling other assumptions of smoothness to be relaxed. In this paper, the Dynamic Surface Controller is coupled with a sequential design procedure that carves a system workspace out of the state space. Within this bounded region, bounded tracking performance can be rigorously guaranteed in the presence of uncertainties and constraints such as rate limits and saturation can be systematically avoided. The design of Dynamic Surface Controller and the advantages of the workspace concept are demonstrated in the context of engine speed control.
Some cautionary remarks about smoothed particle hydrodynamics

Potential difficulties with smoothed particle hydrodynamics are discussed. In particular, empirical tests are used to demonstrate that the errors resulting from the use of variable smoothing can be much larger than commonly believed. Fortunately, however, these errors, which are normally small, do not appear to promote instability on small scales, such as fragmentation in self-gravitating fluids. Still, while SPH remains a useful tool for many problems of astrophysical interest, a rigorous formulation of it, which is adaptive but still satisfies conservation properties, is clearly wanting.
The effect of removing various endocrine glands on the hair cycles of black rats.

The manner in which Norway rats grow their fur and replace it throughout life has been described in a previous paper (Dieke, 1947). It was shown there that in this species the hair follicles near the midventer are the first to become active, then those on the sides and finally those on the head and the rump, so that a complete new coat is acquired in a wave-like fashion, with only the follicles in certain circumscribed areas being active at any given time. Each complete wave of hair growth is called a hair cycle. In black rats the pigment which will color the hair can be seen in the skin just before the hair shafts emerge, which makes it easy to recognize and follow the active phase of each cycle. In rats of this laboratory the first hair cycle begins several days after birth and is complete at about three weeks of age;
Cooperative application of holography and finite element modeling in determining critical vibration behavior of printed wiring boards

A PWB (printed wiring board) with dimensions of 6.5"/spl times/5.5" and attached with several bolts along the perimeter as constraints was acoustically vibrated and studied using CAH (computer-aided holometry). The frequency and shape of the first (primary) and second resonant modes, revealing the full field displacements and strains of the PWBs, were recorded automatically. Zero-displacement regions were also recorded for possible locations of strategic components. Finite element (FE) modeling using eigenvalue calculations was applied to correlate with the CAH results. Adjusting the boundary conditions in the modeling effort so as to match the experimental results proved to be the tricky task in the FE analysis since the mode shapes were extremely sensitive to boundary constraints. >
Finite element analyses of repaired articular surfaces.

The response to a compressive load of a repaired cartilage surface, consisting of full-thickness repair tissue adjacent to normal cartilage, was predicted by the u-p finite element method and compa...
Regional cooperation and multilateral agreements in the provision of public safety

Although much has been written about interlocal agreements for the delivery of services, few studies have examined the factors that influence the establishment of different types of multilateral ag...
Reliability of 0.35 μm Devices: Impact of Ultra-Shallow LDD-Source/Drains

Deep submicron MOSFETs with ultra shallow LDD junctions display a new mode of degradation previously not observed. The evolution of the substrate current with hot carrier stress is identified as a sensitive parameter for the degradation of ultra-shallow LDD devices. The cause for this new degradation mode is due to the fact that the oxide damage created during stress affects the field and current distribution over the entire shallow LDD junction. The substrate current degradation appears to be the result of positive charge build-up in a first stage followed by negative oxide charge formation in the drain-gate region, which explains the slower than expected degradation rate of sub-0.5μm MOSFETs with ultra-shallow LDD junctions.
Study of the Unsteady Flow Features on a Stalled Wing

The occurrence of large scale structures in the post stall flow over a rectangular wing at high angles of attack was investigated in a small-scale subsonic wind tunnel. Mean and time dependent measurements within the separated flow field suggest the existence of two distinct angle of attack regimes beyond wing stall. The shallow stall regime occurs over a narrow range of incidence angles (2-3 deg.) immediately following the inception of leading edge separation. In this regime, the principal mean flow structures, termed stall cells, are manifested as a distinct spanwise periodicity in the chordwise extent of the separated region on the model surface with possible lateral mobility not previously reported. Within the stall cells and on the wing surface, large amplitude pressure fluctuations occur with a frequency much lower than anticipated for bluff body shedding, and with minimum effect in the far wake. In the deep stall regime, stall cells are not observed and the separated region near the model is relatively free of large amplitude pressure disturbances.
Staphylococcal Hyaluronate Lyase: Purification and Characterization Studies

Staphylococcal hyaluronate lyase (hyaluronidase) derived from a pathogenic strain of staphylococcus was purified by means of salt fractionation with ammonium sulfate and gel filtration through Sephadex G-100. Most of the enzyme activity from concentrated culture supernatant fluids of staphylococci was obtained in a fraction precipitated by 90 to 100% saturation with ammonium sulfate. A small amount of enzyme was also precipitated by 80 to 90% saturation with the salt. The hyaluronidase-rich fractions did not contain other staphylococcal enzymes, such as coagulase, protease, lipase, and staphylokinase. These enzymes were present in the original concentrates. Molecular sieving chromatography of the partially purified enzyme by filtration through Sephadex G-100 resulted in a further increase in specific enzyme activity. However, more than one active peak was obtained after gel filtration, thus suggesting that there may be more than one molecular form of the enzyme. Immunodiffusion in agar gel of the chromatographically purified enzyme fraction, with immune serum from rabbits injected with concentrated staphylococcal culture supernatant fluids, indicated that there was one major antigen. A similar antigen, giving reactions of identity with the purified material, was present in the original culture supernatant fluid.