cssi/SciSciGPT-SciSciNet huggingface dataset:
FM noise in a Gunn-effect oscillator

FM noise in a cavity-controlled Gunn oscillator is investigated both theoretically and experimentally. The susceptance of a GaAs Gunn diode fluctuates following velocity fluctuations of high field domains. This results in FM noise. The fluctuations of the velocity are considered to be due mainly to those of carrier concentration fluctuations. Measured FM noise is in good agreement with the model, verifying that fluctuations of carrier concentration result in FM noise in the oscillator. When the quality factor Q ex of the resonant cavity used becomes large, the FM noise characteristic deviates from the theoretical one based on the fluctuations of carrier concentration. The fluctuations of the voltage across the diode in the resonant cavity also influence the domain dynamics and hence the diode susceptance. These seem to be causes of the deviation.
Spending patterns of lone‐parent and two‐parent Canadian families

Data on 214 lone-parent families and 1,133 two-parent families were drawn from the Canadian 1990 Survey of Family Expenditures to examine their expenditure patterns. Tobit analysis was used to estimate marginal propensities to consume and income elasticities of 14 expenditure categories. Statistically significant differences between lone-parent families and two-parent families were found for the marginal propensities to consume and the income elasticities for expenditures on food at home, household operations and personal care.
Inhalation analgesics in obstetrics

Abstract 1. 1. The pains associated with the first stage of labor are probably more practically controlled in other ways than by the use of inhalation agents. 2. 2. In the second stage inhalation analgesia works more satisfactorily, and is better controlled. 3. 3. While any of the anesthetic agents in general use may produce analgesia, the gases, nitrous oxide, ethylene and cyclopropane, are safer and more flexible than ether or chloroform. 4. 4. Ethylene and cyclopropane will produce better analgesia than nitrous oxide. 5. 5. With skilled anesthetists available, continuous analgesia is very practical, and the consumption of the anesthetic agent is reduced to a minimum. 6. 6. The functions of the anesthetist in a labor case are many. He must keep up the morale of the patient; produce real analgesia and not a mere camouflage; cause her to work when work is indicated, and to slow down when that is deemed best; be ready and able to produce any stage of anesthesia necessary in the safest known way. Last, but not least, keep up with all that is known about infant resuscitation and be prepared to execute it.
Neonatal chronic lung disease

Chronic lung disease (CLD), formerly known as bronchopulmonary dysplasia, is presently defined as the need for oxygen therapy either at 28 days of age or greater than 36 weeks postmenstrual age. Clinical signs and symptoms include tachypnea, retractions, apnea, and radiographic findings of poorly inflated lungs with reticulogranular opacities. The disease develops as a result of chronic pulmonary inflammation and continuous lung injury induced by oxygen, positive pressure ventilation, and other causes. Fifty to sixty-five percent of neonates with CLD are rehospitalized with respiratory problems, and 21% of very low birth weight neonates are diagnosed with asthma or other respiratory disorders by the age of five. These infants are at risk of adverse neurodevelopmental sequelae as they have a more complicated neonatal course. Many studies have explored various preventive therapies including α-proteinase inhibitors, superoxide dismutase, antioxidants, and ventilatory management. Although the results from these trials are promising, further studies are needed to define which patients are most likely to benefit from preventive therapy. Two preventive treatment approaches that have shown a decrease in morbidity and an improvement in mortality are antenatal steroids and surfactant therapy. Postnatal corticosteroid therapy continues to be the mainstay of treatment for CLD, however, there are a number of detrimental side effects associated with this treatment. Due to the increased incidence in periventricular leukomalacia, early treatment of steroid therapy cannot be recommended. The optimal time to start steroid therapy appears to be after the first week of life. In addition, the lowest dose and shortest duration of treatment needs to be implemented in order to minimize potential complications. Although bronchodilators and diuretics continue to be used extensively in infants with CLD, there are surprisingly few well-controlled studies that have evaluated the clinical impact of this therapy. Further trials are needed in order to support the routine use of these therapies in CLD. Unfortunately, inhaled steroids have not shown an improvement in long-term outcomes of CLD, however, they have shown a decrease in systemic steroid usage. CLD is a complex disease with many unanswered questions. Further studies are needed to evaluate the effects of various treatment modalities with particular focus on the long-term outcomes such as oxygen and ventilator dependency as well as the incidence of CLD.
Treatment of spontaneous and chemically induced EEG paroxysms in the Fischer-344 rat with traditional antiepileptic drugs or AED+CGP 35348 polytherapy

Abstract Twenty-four Fischer-344 rats implanted with cortical electroencephalograph (EEG) electrodes were evaluated for frequency, duration, and mean duration (duration/frequency) of both spontaneous and chemically induced spike-and-wave discharges (SWDs) during earlier and later adulthood. Fischer-344 rats, exhibiting a low level of spontaneous SWDs during earlier adulthood, progressed to exhibit a significantly larger number and duration of SWDs during later adulthood. The convulsant trimethylolpropane phosphate (TMPP), known to antagonize the GABAA inhibitory system through blockade of the chloride channel, induced or increased SWDs in every rat tested. Spontaneous or chemically induced SWDs in Fischer-344 rats were eliminated or reduced by several drugs used to control human absence seizures. The gamma-aminobutyric acid (GABA)B antagonist CGP 35348 reduced spontaneous EEG paroxysms; CGP 35348 as a polytherapy with several traditional antiabsence treatments improved control of TMPP-induced seizures. It would appear that the Fischer-344 rat provides an excellent research alternative to use of genetically selected rodent strains for investigation of progression of absencelike epilepsy with aging, induction of SWDs by toxicant exposures, and treatment of spontaneous and chemically induced paroxysms.
Single-Measurement Excitation/Emission Matrix Spectrofluorometer for Determination of Hydrocarbons in Ocean Water. 1. Instrumentation and Background Correction

A spectrofluorometer capable of dispersed-spectrum, simultaneous, multiwavelength UV excitation and collection of luminescence has been constructed for the purpose of qualitatively and quantitatively determining aromatic hydrocarbon pollutants dissolved in ocean water. Hydrocarbon fluorescence data produced by this instrument were in the form of excitation/emission matrices, which provide more spectral information about these complex mixtures than is available from conventional excitation or emission fluorescence profiles. Second-order statistical methods were applied to these data to determine low part-per-billion concentrations of two primary fluorescent compounds, naphthalene and styrene, found in ocean water exposed to gasoline despite the presence of uncalibrated interference from similar aromatic compounds, the ocean water matrix, and the instrumental background.
Workspace Synthesis for Flexible Fixturing of Stampings

Fixtures are used to position and hold parts for a series of assembly operations. In automotive body assembly, these fixtures conventionally have been dedicated, therefore they must be replaced whenever there are model changes in an auto body assembly plant. In recent years, however, the automotive industry has been changing from high volume to small-to-medium volume production per model with an increasing number of models because customer tastes are diversifying. To cope with this change, auto companies need to be capable of producing a variety of models in small-to-medium volume, and they rely on flexible assembly lines and flexible fixtures. These flexible fixtures use robots as programmable fixture elements so that they can be reprogrammed for different stamped sheet metal parts. When designing flexible fixtures, fixture designers need to be concerned with fixture workspaces for a set of different stampings. However, existing fixture design methods address the fixturing of one stamping only. This paper presents a system that fixture designers can use to synthesize flexible fixture workspaces for a set of different stampings. Based on circular workspaces for flexible fixture robots, this system finds optimal workspace sizes and centers on a fixture base plate with a graphical display for visual checking. This system is simple to use and produces results quickly.
Multiband tissue differentiation in ultrasonic transmission tomography

In diagnostic ultrasound, tissue differentiation is essential to detect lesions or cancerous tissues from normal tissue. The attenuation characteristics of various tissues will be different at different frequencies, since the propagating ultrasonic pulse undergoes frequency-dependent attenuation, that is characteristic of the material it traverses. These vectors of attenuation values at different frequency bands represent multi-band characteristics of individual pixels (termed “multispectral”) that can be used for tissue differentiation akin to color. In this study, we have developed tissue differentiation methods that utilize the multispectral signatures of different materials in multi-band images produced by a newly built high-resolution ultrasonic transmission tomography (HUTT) system. The HUTT system obtains 3-D multi-band sinograms through FFT analysis of the first arriving pulse (snippet). A filtered backprojection algorithm is utilized to reconstruct a stack of multi-band attenuation images that contain multispectral signatures for each pixel and represent a multispectral augmentation of the 2-D conventional tomographic slice. To differentiate each tissue type according to its characteristic multispectral signature, we adopt the methods of spectral unmixing and spectral target detection. We demonstrate the feasibility of tissue differentiation using multi-band/multispectral signatures of different tissue objects in initial data collected from soft animal tissue phantoms.
Postanal repair for fecal incontinence--is it worthwhile?

PURPOSE: Patients with idiopathic or neurogenic incontinence without an isolated sphincter defect may be suitable candidates for a postanal repiar. The aim of this study was to assess the results of postanal repair in patients with idiopathic or neurogenic fecal incontinence and to evaluate the role of various parameters, including preoperative physiologic testing on outcome. METHODS: Postanal repair was offered by a single surgeon to patients meeting the following criteria: incontinence score of at least 12 of 20, absence of an isolated anterior external anal sphincter defect, and failed conservative, medical, and biofeedback management. Physiologic investigation and clinical findings of female patients who had postanal repair for fecal incontinence between 1992 and 1998 were reviewed. Physiologic investigation included anorectal manometry, pudendal nerve terminal motor latency, concentric needle electromyography, and endoanal ultrasonography. Follow-up was obtained by telephone questionnaire; moreover, patients were asked to grade the outcome of their surgery as excellent or good (success) or as fair or poor (failure). RESULTS: Twenty-one patients of median age 68 (range, 40–80) years had a mean duration of fecal incontinence before postanal repair of 6.8 (range, 0.5–22) years. Twenty patients (95 percent) were available for at least one year of follow-up. Seventeen patients (80.9 percent) had at least one prior vaginal delivery, and prior sphincteroplasty had been performed in 10 patients (47.6 percent). The morbidity and mortality rates were 5 and 0 percent, respectively. After a mean follow-up period of three (range, 1–7.5) years, seven patients (35 percent) considered surgery to be successful and had a statistically significant decrease in their incontinence score. Neither prolongation of pudendal nerve terminal motor latency nor external sphincter damage as noted on electromyography or any of the preoperative manometric parameters correlated with outcome. Furthermore, patients' ages at surgery did not correlate with the degree of postoperative improvement in continence scores nor did the duration of the patients' symptoms, number of vaginal deliveries, or a history of previous surgery for fecal incontinence. CONCLUSION: None of the factors assessed was demonstrated to be predictive of outcome after postanal repair; moreover, the currently available preoperative testing has not altered the success rate, which remains low (35 percent). Despite the low success rate, the absence of any mortality and the low morbidity suggest that postanal repair may be a valid therapeutic approach. However, it should be offered only to selected patients with persistent, severe fecal incontinence despite an anatomically intact external anal sphincter who are not candidates for or refuse all other operative modalities.
Elimination of field size dependence of enhanced dynamic wedge factors.

Enhanced dynamic wedge factors (EDWF) are characterized by a strong field size dependence. In contrast to physical wedge factors, the EDWF decrease as the field size is increased: for 6 MV 60° wedge, the EDWF decreases by 50% when the field size is increased from 4×4 cm2 to 20×20 cm2. A method that eliminates the field size dependence of EDWF was developed and investigated in this work. In this method, the wedged field shape is determined by a multileaf collimator. The initial position of the moving Y jaw is determined by the field size and the stationary Y jaw is kept fixed at 10 cm for field sizes ≤20 cm in the wedged direction. For all other fields, the stationary Y jaw setting is determined by the field size. The modified method results in EDWF that are independent of field size, with no change in the wedge dose distribution when compared with the conventional use of EDW.
Urban and Small Town Comparison of Citizen Demand for Police Services

Little is known about the similarities and differences that exist between urban and small town police agencies with regard to citizen calls for service. The research about citizen demand for policing services in the USA has focused overwhelmingly on city police agencies and the research methodologies used made direct comparisons with smaller agencies impossible. The present research involved a comparison of calls for service from three urban municipal police departments and three small town departments for the same two-week period of time using identical coding schemes. The findings suggest that urban agencies receive proportionately more order maintenance calls, small town agencies receive proportionately more service calls, and both types of agencies receive similar proportions of law enforcement-related calls. The urban agencies, however, dealt with larger proportions of more serious crimes.
Determination of thiols by capillary electrophoresis with amperometric detection at a coenzyme pyrroloquinoline quinone modified electrode.

A chemically modified electrode has been developed as a detector for the sensitive and selective determination of thiol-containing compounds following capillary electrophoresis separation. Electrodes were constructed by entrapment of the coenzyme pyrroloquinoline quinone (PQQ) into a polypyrrole (PPy) matrix on a 245-μm graphite electrode during electropolymerization of pyrrole in the presence of PQQ. PQQ serves as an efficient biocatalyst to mediate the oxidation of thiols at a substantially reduced overpotential relative to an unmodified electrode. Furthermore, this design takes advantage of the pH-dependent reversible electrochemical properties of PQQ, which facilitates optimization of separation and detection conditions. The PQQ/PPy-modified electrode was incorporated as an end-column detector, and a separation of homocysteine, cysteine, N-acetylcysteine, and glutathione was developed. Detection limits for these four thiols were determined to be 11, 23, 104, and 134 nM, respectively, with mass detecti...
Consumer and worker perceptions of key child welfare competencies

Abstract Understanding key competencies in child welfare practice is a necessary prerequisite to improving practice technology and service delivery. Findings are reported from a series of focus groups which were held in Missouri. Two sets of focus groups were held, five groups consisting of consumers of child welfare services and four groups consisting of child welfare workers. Results show a high degree of agreement between workers and consumers regarding essential competencies. The relevance of findings to practice, policy and social work education are discussed.
Chromosome Mapping of Dragline Silk Genes in the Genomes of Widow Spiders (Araneae, Theridiidae)

With its incredible strength and toughness, spider dragline silk is widely lauded for its impressive material properties. Dragline silk is composed of two structural proteins, MaSp1 and MaSp2, which are encoded by members of the spidroin gene family. While previous studies have characterized the genes that encode the constituent proteins of spider silks, nothing is known about the physical location of these genes. We determined karyotypes and sex chromosome organization for the widow spiders, Latrodectus hesperus and L. geometricus (Araneae, Theridiidae). We then used fluorescence in situ hybridization to map the genomic locations of the genes for the silk proteins that compose the remarkable spider dragline. These genes included three loci for the MaSp1 protein and the single locus for the MaSp2 protein. In addition, we mapped a MaSp1 pseudogene. All the MaSp1 gene copies and pseudogene localized to a single chromosomal region while MaSp2 was located on a different chromosome of L. hesperus. Using probes derived from L. hesperus, we comparatively mapped all three MaSp1 loci to a single region of a L. geometricus chromosome. As with L. hesperus, MaSp2 was found on a separate L. geometricus chromosome, thus again unlinked to the MaSp1 loci. These results indicate orthology of the corresponding chromosomal regions in the two widow genomes. Moreover, the occurrence of multiple MaSp1 loci in a conserved gene cluster across species suggests that MaSp1 proliferated by tandem duplication in a common ancestor of L. geometricus and L. hesperus. Unequal crossover events during recombination could have given rise to the gene copies and could also maintain sequence similarity among gene copies over time. Further comparative mapping with taxa of increasing divergence from Latrodectus will pinpoint when the MaSp1 duplication events occurred and the phylogenetic distribution of silk gene linkage patterns.
Linear wave-vector dependence of an optical phonon frequency in Bi12GeO20 in the vicinity of the Brillouin zone center

Abstract A Raman spectroscopic study of a zone center optical phonon of Bi 12 GeO 20 which exhibits simultaneously a LO-TO and a linear wave-vector dependent splitting is presented. These are separated experimentally by studying the Raman line with a piezoelectrically scanned Fabry-Perot interferometer and the sample with and without an applied uniaxial stress.
Differential sensitivity to midazolam discriminative-stimulus effects following self-administered versus response-independent midazolam

Interactions between the discriminative and reinforcing effects of midazolam were studied in two baboons trained to discriminate midazolam (0.32 mg/kg, IV) from saline. The midazolam generalization gradient determined after the baboons were permitted to self-administer midazolam (IV) was shifted to the left of that determined before self-administration. In contrast, the midazolam generalization gradient determined after the same doses of midazolam were delivered response-independently, but in the same order and with the same temporal pattern as during self-administration, was shifted to the right of that determined just before the response-independent phase. These data suggest that sensitivity to the discriminative-stimulus effects of a drug can be modulated by behavioral experience with that drug.
Temperature-Dependent Development of Immature Stages of the Western Corn Rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae)

Larval and pupal development of western corn rootworm was studied at eight constant temperatures ranging from 15 to 33°C. Development from hatch to adult stage occurred at 15–31.5°C; no larvae completed the second stage at 33°C. Adult survival decreased and wing deformities increased significantly at 15 and 31.5°C. Optimum development and survival occurred within the temperature range of 21–30°C. Males developed faster than females in all stages at temperatures from 18–30°C, but the sexes have a similar lower thermal threshold of development estimated to be near 9°C. The relationship between developmental rate and temperature was described for both sexes in all stages using linear and nonlinear equations. The information presented will facilitate the development of phenological models for this important pest species.
Regulation of chronic stress-induced changes in hypothalamic-pituitary-adrenal activity by the basolateral amygdala.

Little is known about the role of the basolateral amygdala (BLA) in regulating hypothalamic-pituitary-adrenal (HPA) activity, particularly chronic stress-induced HPA activity. In the current studies, we examined the effects of manipulations of the BLA on HPA responses to the eighth restraint, to novel restraint after repeated cold, or to acute novel restraint alone. Excito- toxic lesions of the BLA, in general, inhibited HPA activity in both acute and chronically stressed animals.To examine the role of the BLA in chronic stress without affecting the response to the first stress, we injected the GABA agonist muscimol to temporarily inactivate the BLA prior to restraint in the same three groups of animals. In contrast to the lesion data, muscimol enhanced the HPA response to acute restraint and to novel restraint after repeated cold, but it did not affect responses to the eighth restraint. These data suggest that the BLA inhibits HPA responses to novel stress but is not important in animals repeatedly exposed to the same stressor. Future studies will focus on the neuro- anatomical substrates of BLA's effects on HPA activity including whether inputs from the pPVTh are important.
An adaptive optimal combustion control strategy

Abstract A strategy for optimizing the performance of a laboratory-scale combustor with respect to volumetric heat release (maximize) and pressure fluctuations (minimize) has been developed. This strategy utilizes (1) actuation techniques that simultaneously control volumetric heat release and pressure fluctuations; (2) sensing techniques that measure combustor performance; and (3) an adaptive optimal control strategy. Actuation techniques were chosen for their ability to alter the unsteady flow associated with the shear layer and recirculating flow regions of the combustor. Periodic spanwise forcing of the inlet boundary layer is used to reduce combustion-induced pressure fluctuations. Crossflow jets upstream of the inlet are used to control volumetric heat release. Sensing techniques were selected to measure or estimate the two performance parameters to be controlled. A fast-response piezoelectric pressure transducer measures the magnitude of the pressure fluctuations. A streamwise array of photodiodes measures light emission from the flame and enables estimation of volumetric heat release. Combustor performance is explicitly defined in terms of a cost function that is a weighted combination of rms pressure fluctuations and mean volumetric heat release. The control strategy performs an on-line minimization of the cost function by continuously seeking the optimal combination of actuator settings and subsequently maintaining the cost at a minimum when the combustor is subject to unknown inlet condition changes, such as flow disturbances. The strategy has been tested with large flow disturbances and found capable of indirectly sensing a change in combustor inlet conditions and finding the new optimal actuator settings.
Preservice Teachers and Religion: Serious Gaps in Religious Knowledge and the First Amendment

Recognizing the influence of religion on people's worldview and daily lives, we wondered if elementary and secondary social studies preservice teachers knew enough about religions not only to be culturally responsive in a classroom but also whether they knew enough to teach about these religions within the appropriate curriculum. We used questions from previously tested surveys to ascertain the students’ knowledge about world religions, the First Amendment's religion clauses, and the application of religion in schools. Our findings suggest that preservice teachers’ knowledge about all religions, including their own, and about the First Amendment's intent, is lacking.
Solubility measurements and modeling of molecules of biological and pharmaceutical interest with supercritical CO2

Abstract The tunable nature of the solubility of various compounds, including molecules of pharmaceutical and biological interest, in supercritical fluids (SCFs) makes SCF extraction technology attractive for many separation and purification processes. Exploring new applications requires fundamental understanding of phase behavior. Here we explore the use of supercritical CO2 to dissolve molecules of potential interest to the pharmaceutical industry. We present experimental measurements and modeling of the solubility of caffeine, uracil, and erythromycin in supercritical CO2 at temperatures between 40 and 60 °C and pressures up to 300 bar. The solubilities are between 10−6 and 10−3 mole fraction. The solubility behavior is modeled with the Peng-Robinson equation of state (EOS), which correlates the experimental solubility data of caffeine and uracil quite accurately. However, for erythromycin larger deviations are found. Different property estimation techniques are investigated and their influence on the ability to correlate the data with the Peng-Robinson EOS is explored. The combination of computational and experimental tools used here allows the verification of the integrity of the experimental technique and the evaluation of supercritical fluid extraction as an alternative method of purification.
The Formation Control Testbed Celestial Sensor: Overview, Modelling, and Calibrated Performance

The formation control testbed (FCT) is a ground based multiple robot testbed for simulating the dynamic interaction of spacecraft formations in a representative 6-DOF environment. Linear and spherical air bearings are used to mimic the drag free space environment. Each robot is fully autonomous with a self contained supply of float gas, integrated batter)' power, and a complete suite of onboard avionics including IMU (3-axis gyro), wireless interspacecraft and ground communication links, cold-gas thrusters, and reaction wheels. For attitude determination each robot uses an analog camera to image 1R beacons fixed to the walls and ceiling of the test facility. These navigation beacons act as an artificial star field. Due to the close proximity of these beacons, the camera direction measurements are coupled to both translation and attitude maneuvers of the robot. This allows unique determination of each quantity, provided enough beacons are in the camera FOV. We have come to refer to this sensing scheme as the "celestial sensor". In this paper, each subsystem of the celestial sensor is discussed with emphasis given to the filtering algorithms. The celestial sensor software processes sequential frame based bearing measurements on a peripheral CPU specifically designed for this application. A frame preprocessor is used to normalize each bearing measurement and apply a number of accept/reject rules. The accepted set of measurements is then passed to an extended Kalman Filter (EKF) that is tuned to track the motion of the robot within the room. A detailed sensor model is described in this paper that is used to predict the performance of the integrated system. Frame based simulations using this sensor model are presented that predict 1-sigma errors on the order of 3.0 arc minutes in attitude (per axis) and 4.0 millimeters in position (per cartesian coordinate). Preliminary results from the production system are given that demonstrate similar resolution statistics and decoupling of the attitude and position estimates
Tunneling between optima: partition crossover for the traveling salesman problem

A new recombination operator is introduced for the Traveling Salesman Problem called partition crossover. Theoretical and empirical results indicate that when two local optima are recombined using partition crossover, two offspring are produced that are highly likely to also be local optima. Thus, the operator is capable of jumping or tunneling from two local optima to two new and distinct local optima without searching intermediate solutions. The operator is respectful and it transmits alleles which means that 1) all common edges from the two parents are inherited and 2) the offspring are constructed using only edges inherited from the two parents. Partition crossover is not always feasible: sometimes two new Hamiltonian circuits cannot be constructed by the operator using only edges inherited from the two parents. But empirical results indicate that partition crossover is feasible 95 percent of the time when recombining randomly selected local optima. Furthermore, from a sample of local optima that are within a short random walk of the global optimum, partition crossover typically relocates the global optimum in a single move when crossover is feasible.
Elevated insulin-like growth factor 2 expression may contribute to the hypermuscular phenotype of myostatin null mice.

Abstract Objectives Myostatin ( Mstn ) inhibits while insulin-like growth factors 1 and 2 ( Igf1 and Igf2 ) increase skeletal muscle growth. However, there is little known regarding Mstn regulation of Igf1 and Igf2 expression. Therefore, the objective of this study was to quantify the expression of IGF family members in skeletal muscle and liver throughout the growth phase of Mstn null (MN) mice. Further, differences between male and female mice were investigated. Methods Male and female wild type (WT) and MN mice were euthanized at birth (0d), 7days (7d), weaning (21d), sexual maturity (42d), and 70d. For the neonatal periods, 0d and 7d, all muscles from the hind limbs were compiled for RNA extraction. At 21d, 42d, and 70d, biceps femoris (BF), tibialis anterior, triceps brachii (TB), and gastrocnemius–soleus complex were collected. Results As expected, muscle weights were up to 90% greater in MN mice compared with WT mice at 21d, 42d and 70d. However, Igf1 expression was reduced ( P ≤0.04) at 7d and 21d in MN mice compared to WT mice. Expression of Igf2 did not differ between genotypes at 0d and 7d, but, at 21d, 42d and 70d in BF and TB muscles, Igf2 expression was 1.9–2.9 fold greater ( P Igf1 and Igf2 levels were minimally affected by genotype; with the exception of a 1.4-fold reduction ( P =0.04) in Igf1 expression in 21d MN mice compared with WT mice. Though male mice were heavier than females starting at 21d of age, expression differences in Igf1 , Igf2 , their receptors and binding proteins do not account for growth differences. In every case, when expression was different between sexes, female expression was increased despite increased growth in male mice. Conclusion This study is the first to provide evidence that Mstn may negatively regulate Igf2 expression to control postnatal skeletal muscle growth, however differences in growth between male and female mice are not readily explained by changes in expression of Igf family members.
Interoperating with DIF data

Most computerized data is not under the purview of traditional database management systems, but, rather, it is stored in files. Data Interchange Formats (DIFs) are the basis of an important class of such files, containing massive volumes of data, and serving a large user community. Initially designed for data exchange, DIFs are increasingly being used for data storage. Collections of DIF files have become de facto databases, and the software tools surrounding them have evolved to become ad hoc data management systems. But these systems are primitive compared with traditional database management technology. They lack flexibility, and are unlikely to scale as DIF data volumes grow. An acute need exists to provide more robust DBMS style support for data in such files, and to support interoperability in heterogeneous environments that include this data. We suggest that object oriented database techniques can be used to provide effective data management support for individual DIFs and provide a platform for interoperating with heterogeneous DIF data, both in a scalable fashion. We present architectures for implementing this support, and outline the research issues they engender. We present initial results of an experimental evaluation of one such approach.
Thinking and Modeling at Multiple Levels: the Potential Contribution of Multilevel Modeling to Communication Theory and Research

In this introduction to the special issue on applications of multilevel modeling (MLM) to communication research, we provide a conceptual overview of the benefits of MLM-the ability to simultaneously analyze data collected at multiple levels, the ease with which it can be used to assess trends and change over time, and its incorporation of the nested structure of data in the estimation process. We highlight ways in which MLM can be used to further theory and research in communication. In addition, we comment on the applications of MLM highlighted in this special issue and echo past calls for more multilevel theorizing and analysis in the field of communication.
Structure-driven optimizations for amorphous data-parallel programs

Irregular algorithms are organized around pointer-based data structures such as graphs and trees, and they are ubiquitous in applications. Recent work by the Galois project has provided a systematic approach for parallelizing irregular applications based on the idea of optimistic or speculative execution of programs. However, the overhead of optimistic parallel execution can be substantial. In this paper, we show that many irregular algorithms have structure that can be exploited and present three key optimizations that take advantage of algorithmic structure to reduce speculative overheads. We describe the implementation of these optimizations in the Galois system and present experimental results to demonstrate their benefits. To the best of our knowledge, this is the first system to exploit algorithmic structure to optimize the execution of irregular programs.
Spatial patterns of bacterial signature biomarkers in marine sediments of the Gulf of Mexico

Abstract Sediment cores near a cold methane seep and gas hydrates in the Gulf of Mexico were analyzed for bacterial membrane phospholipid fatty acids (PLFA) and isoprenoid quinones. Nearby non-seep marine sediments were also analyzed for the purpose of comparison. Our goal was to use these biomarkers as proxies for microbial community structure and redox indicators. Total PLFA varied from core to core and were significantly less abundant in non-seep marine sediments than those near the cold seep or gas hydrates. In general, saturated straight chain, terminal branched and mid-chain branched, and monounsaturated fatty acids contributed > 98% of the total PLFA. The branched fatty acids (i.e., a C15:0, i C15:0, Me10C16:0) could be largely attributed to sulfate-reducing bacteria and the monounsaturated fatty acid (i.e., 16:1ω7c and 18:1ω7c) could be attributed to sulfide-oxidizing bacteria ( Beggiatoa / Thioploca ). Principal component analysis of PLFA data revealed that microbial communities were consistent with the spatial distributions of gas hydrates and Beggiatoa mats and with the variation in geochemical conditions. Isoprenoid quinone profiles indicated that aerobic respiration was the dominant metabolic process in the top-most sediment layers while the anaerobic respiration dominated the deeper intervals in the marine sediments. Significant amount of cyclopropyl fatty acids at all sites indicated the stress adaptation of the bacteria in the extreme environment. The consistency between the distribution of PLFA and respiratory quinones and the variation in geochemical conditions suggested that analyses of PLFA and quinone could help us to locate the existence of the coupled sulfide-oxidization and sulfate-reduction processes.
US fiscal policy in a (brief?) era of surpluses

Abstract This paper has several objectives. First, it reviews the recent improvement in the US fiscal picture and discusses the sources of this trend. It then considers the implications for the future, taking into account the past performance of budget forecasts as well as the changing composition of the federal budget. Next, it provides some estimates of the long-term fiscal imbalance still faced by the US. Finally, it briefly discusses the various policy options available to address this imbalance, and suggests how the budget measurement and forecasting procedures should be changed to accommodate the current budget situation, in which the long-term problems are not adequately conveyed by short-term measures.
TENSEGRITY: THE ARCHITECTURAL BASIS OF CELLULAR MECHANOTRANSDUCTION

Physical forces of gravity, hemodynamic stresses, and movement play a critical role in tissue development. Yet, little is known about how cells convert these mechanical signals into a chemical response. This review attempts to place the potential molecular mediators of mechanotransduction (e.g. stretch-sensitive ion channels, signaling molecules, cytoskeleton, integrins) within the context of the structural complexity of living cells. The model presented relies on recent experimental findings, which suggests that cells use tensegrity architecture for their organization. Tensegrity predicts that cells are hard-wired to respond immediately to mechanical stresses transmitted over cell surface receptors that physically couple the cytoskeleton to extracellular matrix (e.g. integrins) or to other cells (cadherins, selectins, CAMs). Many signal transducing molecules that are activated by cell binding to growth factors and extracellular matrix associate with cytoskeletal scaffolds within focal adhesion complexes. Mechanical signals, therefore, may be integrated with other environmental signals and transduced into a biochemical response through force-dependent changes in scaffold geometry or molecular mechanics. Tensegrity also provides a mechanism to focus mechanical energy on molecular transducers and to orchestrate and tune the cellular response.
A comparison of the radio data and model calculations of Jupiter's synchrotron radiation. I - The high energy electron distribution in Jupiter's inner magnetosphere. II - East-west asymmetry in the radiation belts as a function of Jovian longitude

A comparison has been made between detailed model calculations of Jupiter's synchrotron radiation and the radio data at wavelengths of 6, 21, and 50 cm. The calculations were performed for a Jovian longitude of 200 deg and were based on the multipole field configurations as derived from the Pioneer data. The electron distribution in the inner magnetosphere was derived as a function of energy, pitch angle, and spatial coordinates. In addition, the hot region or east-west asymmetry in the radiation belts is investigated. It is suggested that this asymmetry is due to the combined effect of an overabundance of electrons at jovicentric longitudes of 240-360 deg and the existence of a dusk-to-dawn directed electric field over the inner magnetosphere generated by the wind system in the upper atmosphere.
New compact broadband high-efficiency mode converters for high power microwave tubes with TE/sub 0n/ or TM/sub 0n/ mode outputs

Shorter, broader bandwidth designs are discussed for TE/sub 03/-TE/sub 02/ and TE/sub 02/-TE/sub 01/ varying-radius mode converters and TE/sub 01/-TE/sub 11/ serpentine mode converters for a 2.779-cm-diameter circular waveguide for 60- and 140-GHz gyrotrons. Designs combing TE/sub 0n/-TE/sub 0n-1/ converters with a 6.35-2.779-cm-diameter taper are presented. A TM/sub 01/-TE/sub 11/ serpentine mode converter design for a frequency of 8.6 GHz in a 4.76-cm circular waveguide is also discussed. Measured results are presented. >
Effects of grazing on grassland soil carbon: a global review

Soils of grasslands represent a large potential reservoir for storing CO2, but this potential likely depends on how grasslands are managed for large mammal grazing. Previous studies found both strong positive and negative grazing effects on soil organic carbon (SOC) but explanations for this variation are poorly developed. Expanding on previous reviews, we performed a multifactorial meta-analysis of grazer effects on SOC density on 47 independent experimental contrasts from 17 studies. We explicitly tested hypotheses that grazer effects would shift from negative to positive with decreasing precipitation, increasing fineness of soil texture, transition from dominant grass species with C3 to C4 photosynthesis, and decreasing grazing intensity, after controlling for study duration and sampling depth. The six variables of soil texture, precipitation, grass type, grazing intensity, study duration, and sampling depth explained 85% of a large variation (±150 g m−2 yr−1) in grazing effects, and the best model included significant interactions between precipitation and soil texture (P = 0.002), grass type, and grazing intensity (P = 0.012), and study duration and soil sampling depth (P = 0.020). Specifically, an increase in mean annual precipitation of 600 mm resulted in a 24% decrease in grazer effect size on finer textured soils, while on sandy soils the same increase in precipitation produced a 22% increase in grazer effect on SOC. Increasing grazing intensity increased SOC by 6–7% on C4-dominated and C4–C3 mixed grasslands, but decreased SOC by an average 18% in C3-dominated grasslands. We discovered these patterns despite a lack of studies in natural, wildlife-dominated ecosystems, and tropical grasslands. Our results, which suggest a future focus on why C3 vs. C4-dominated grasslands differ so strongly in their response of SOC to grazing, show that grazer effects on SOC are highly context-specific and imply that grazers in different regions might be managed differently to help mitigate greenhouse gas emissions.
Can Novel Therapies for Arrhythmias Caused by Spontaneous Sarcoplasmic Reticulum Ca2+ Release be Developed Using Mouse Models?

See related article, pages e77–e82 Ventricular arrhythmias are a significant cause of premature death in Western society and occur both in the absence and presence of heart disease. For example, in heart failure close to 50% of patients die of lethal forms of ventricular arrhythmias. In spite of a large amount of basic and clinical investigations, current pharmacotherapy for ventricular arrhythmias is inadequate, demonstrating the need for novel therapeutic approaches. Abnormal automaticity is responsible for induction and maintenance of different types of ventricular tachycardias. The form of abnormal automaticity that results from abnormal release of Ca2+ from a Ca2+ overloaded sarcoplasmic reticulum (SR), referred to as a “triggered arrhythmia”, is the topic of this editorial. In vitro studies have shown that increasing the SR Ca2+ load beyond a critical level causes spontaneous opening of the SR Ca2+ release channel (ryanodine receptor; RYR) and results in spontaneous SR Ca2+ release.1 The subsequent increase in cytosolic [Ca] activates an inward current through the sarcolemmal Na+/ Ca2+ exchanger which causes membrane depolarization.1,2 Spontaneous SR Ca2+ release during the diastolic interval causes depolarization (delayed after depolarizations; DADs) which has been shown to result in action potentials in single cells and in the intact heart when the aberrant release is adequately synchronized within and among cardiac myocytes.3,4 Factors that lead to DADs include increased heart rate and catecholamine stress, which both induce triggered arrhythmias by increasing SR Ca2+ loading.3 Whereas many molecules are involved in SR Ca2+ overload (DAD) related arrhythmias, abnormal opening …
Induction of c-fos, and cytochrome c oxidase subunits I and II by gossypol acetic acid in rat liver cells

The hypothesis that oxidative stress induced by acute, sublethal, gossypol treatment induces transcription of stress genes in a rodent liver cell line was tested. In northern blot analysis of gossypol-treated cells, there was a dose-dependent increase in c-fos, a component of the redox-regulated transcription factor activator protein-1 (AP-1). Induction of c-fos was biphasic. A rapid 3.33+/-1.37 fold induction in c-fos was detected after treatment with 5 micromol/L gossypol for 30 min. Additionally, treatment with 5 micromol/L gossypol for 12 h caused a 2.66+/-0.67 fold increase in c-fos expression. PCR-based subtractive hybridization was used to generate a subtracted complementary DNA (cDNA) pool representing mRNA species increased in response to gossypol exposure. Several thousand clones were grown from bacteria transformed with the subtracted cDNA pool. After screening and confirmation by northern blotting, five clones were confirmed to be induced by gossypol. Sequence analysis confirmed that four of these clones contained DNA sequences from cytochrome-c oxidase subunit II (COX II), and one contained a DNA sequence from cytochrome-c oxidase subunit I (COX I). A five-fold induction (5.13+/-1.39 fold) in COX II occurred after 1 h of gossypol exposure, and a three-fold induction (3.24 fold) in COX I occurred after 3 h of gossypol exposure. These studies provide further evidence that mitochondria are a major site of the cytotoxic action of gossypol based upon an adaptive response to gossypol involving the upregulation of genes from the mitochondrial genome.
Actin-based endosome and phagosome rocketing in macrophages: activation by the secretagogue antagonists lanthanum and zinc.

Although motile endocytic vesicles form actin-rich rocket tails [Merrifield et al., 1999: Nature Cell Biol 1:72-74], the mechanism of intracellular organelle locomotion remains poorly understood. We now demonstrate that bone marrow macrophages treated with lanthanum and zinc ions, well-known secretagogue antagonists, reliably exhibit vesicle motility. This treatment results in accentuated membrane ruffling and the formation of phagosomes and early endosomes that move rapidly through the cytoplasm by assembling actin filament rocket tails. Protein-specific immunolocalization demonstrated the presence of Arp2/3 complex in the polymerization zone and throughout the actin-rich tail, whereas N-WASP was most abundant in the polymerization zone. Although Arp2/3 and N-WASP play essential roles in nucleating filament assembly, other processes (i.e., elongation and filament cross-linking) are required to produce forces needed for motility. Efficient elongation was found to require zyxin, VASP, and profilin, proteins that interact by means of their ABM-1 and ABM-2 proline-rich motifs. The functional significance of these motifs was demonstrated by inhibition of vesicle motility by the motif-specific ABM-1 and ABM-2 analogues. Furthermore, lanthanum/zinc treatment also facilitated the early onset of actin-based vaccinia motility, a process that also utilizes Arp2/3 and N-WASP for nucleation and the zyxin-VASP-profilin complex for efficient elongation. Although earlier studies using cell extracts clouded the role of oligoproline sequences in activating the polymerization zone, our studies emphasize the importance of evaluating motility in living cells.