cssi/SciSciGPT-SciSciNet huggingface dataset:
Positive interactions in ecology: filling the fundamental niche

The role of negative interactions in shaping ecological communities and the realized niches of species has been a focus of considerable research for at least decades. Traditionally, the discrepancy between the size of the fundamental and realized niches of a species was attributed to the effect of negative interactions, such that the realized niche is always smaller than the fundamental niche. However, in the last decade, a series of studies have highlighted the important role that positive interactions played in shaping the structure of communities. This renewed interest in positive interactions has led to a reconsideration of the niche concept. Specifically, some investigators have suggested that positive interactions can lead the realized niche of a species to be larger than its fundamental niche. Here, we show that, although positive interactions can counteract the effects of negative interactions and possibly modify the realized niche of a species, the realized niche of a species can never be larger than the fundamental niche.
AgClimate: A climate forecast information system for agricultural risk management in the southeastern USA

Abstract Seasonal climate variability plays an important role in the production risks faced by producers. The majority of crop failures in the USA are associated with either a lack or excess of rainfall. Climate forecasts can be used to reduce risks faced by an agricultural enterprise, but simply providing better climate forecasts to potential users is not enough. Climate information only has value when there is a clearly defined adaptive response and a benefit once the content of the information is considered in the decision making process. AgClimate is a response to the need for information and tools on proactive adaptations to seasonal and interannual climate variability forecasts in the southeastern USA. Extension agents, agricultural producers, forest managers, crop consultants, and policy makers may use this decision support system to aid in decision making concerning management adjustments in light of climate forecasts. Adaptations include those that might mitigate potential losses as well those with the potential to produce optimal yields. AgClimate is a web-based climate forecast and information system that was designed and implemented in partnership with the Cooperative State Extension Service. It has two main components: the front-end interface and a set of dynamic tools. The main navigation menu includes the AgClimate tools, climate forecasts, and management options for crops, forestry, pasture, and livestock. It also includes a climate and El Nino section with background information. The tools section contains two applications that allow a user to examine the climate forecast for individual counties based on the ENSO phase and to evaluate yield potentials for certain crops. Applied outlooks for individual agricultural sectors are also provided on a quarterly basis. AgClimate is now operational under the Southeast Climate Consortium and several upgrades are under development and consideration.
The current management of skin tears

Each year, there are more than 1 million skin tears among the elderly and disabled. Because of their fragile nature, management of skin tears can be very challenging. Methods of wound closure should minimize additional trauma to the skin and promote an optimal wound healing environment while minimizing the risk of infection. The current article reviews the etiology, risk factors, classification, and therapeutic options for treating skin tears. We also review preventive measures to help reduce the incidence of skin tears.
Type I insulin-dependent diabetes mellitus: a model for autoimmune polygenic disorders.

Insulin-dependent diabetes mellitus (IDD) affects between one in 250 and one in 500 Americans. The inheritance of IDD is non-Mendelian and polygenic. Genetic susceptibility predominantly results from specific alleles in the HLA complex and insulin gene region. Autoimmune destruction of pancreatic beta cells leads to profound insulinopenia (Atkinson and Maclaren, 1990). Without insulin treatment, fatal diabetic ketoacidosis results. Even with insulin treatment, after 10 to 20 years of IDD, devastating micro- and macrovascular complications lead to significant morbidity and premature mortality (Rosenbloom, 1983). In order to prevent this catastrophic disease and its consequences, we must understand the pathogenesis and immunogenetics of insulitis (the histologic lesion characteristic of IDD), whose ultimate expression is beta cell necrosis (Cudworth, 1978; Cahill and McDevitt, 1981; Eisenbarth, 1986). Current advances include recognition of new IDD-autoantigens (e.g., glutamic acid decarboxylase), susceptibility genes (e.g., HLA-DQB1*0201 and 0302), and the development of trials to prevent IDD through tolerization to IDD-autoantigens (e.g., insulin) (Maclaren, 1993; Winter et al., 1993). Unlocking the genetic mechanisms responsible for IDD can also reveal more general mechanisms involved in other organ-specific autoimmune diseases.
Context and Cooperation: Systematic Variation in the Political Effects of Workplace Democracy:

In this article, an argument is made for greater attention to contextuality in the study of workplace democracy and self-management. The central theme is that general statements about the political effects of such workplace arrangements are untenable; they must, instead, be grounded in historically specific politicaleconomic settings. The various political effects of workplace democratization are then explored across a range of such contexts, identified as unmediated market capitalist societies; mediated market capitalist societies; settings of revolutionary upheaval; and post-revolutionary societies. The article concludes by suggesting that workplace democratization generates objectively reactionary political effects in unmediated market capitalist societies like the United States.
Frozen bison and fur trapper's journals: building a prey choice model for Idaho's Snake River Plain

While many archaeological sites from the eastern Snake River Plain attest to the successful acquisition of bison by native hunters, site data alone are not sufficient to assess the relative importance of bison in the regional prehistoric diet. This paper presents a prey choice model that compares the net caloric return rates of bison with other resources available on the eastern Snake River Plain using data from early 19th century fur trapper's journals. The model predicts that although bison likely had a higher net return rate than any other resource, overall diet breadth in the region would have been broad. Although further evaluation of the model is needed, a preliminary examination of bison assemblages from the eastern Snake River Plain suggests that relatively limited numbers of bison were being acquired. If bison were only rarely encountered due to low population densities, the bulk of the diet would have been made up of lower ranked items included in the optimal set, as predicted by the model.
Geostatistical Estimation of Hydraulic Head Gradients

This paper describes a technique for estimating gradients of hydraulic head from scattered measurements of head. Gradients of hydraulic head control the flow of ground water in aquifers and their determination is an important part of any ground-water investigation. A best linear unbiased estimator of hydraulic head is derived which allows direct estimation of head gradients and mean square estimation error. The hydraulic head is broken into continuous and discontinuous components. The discontinuous component, which represents random measurement error and small-scale variability, is filtered from the measurements. The technique is applied to measurements of head in the Wolfcamp aquifer in northern Texas.
Steady laminar flow through modelled vascular stenoses.

Abstract Numerical solutions for steady flow through axisymmetric, contoured constrictions in a rigid tube are presented, utilizing the full Navier-Stokes equations in cylindrical coordinates. No difficulties in convergence are encountered for Reynolds numbers at which the flow is known to be laminar from experimental observation. The theoretical results are compared with available experimental data, and the relationships to occlusive vascular disease are discussed.
The Bomb and Its Discontents

Resisting the Bomb. A History of the World Nuclear Disarmament Movement, 1954–1970. Vol. 2 of The Struggle Against the Bomb, Lawrence S. Wittner (Stanford, Calif.: Stanford University Press, 1997). 641 pp., cloth (ISBN: 0-8047-2918-2), $65.00; paper (ISBN: 0-8047-3169-1), $24.95. Domestic Society and International Cooperation: The Impact of Protest on U.S. Arms Control Policy, Jeffrey W. Knopf (Cambridge, U.K.: Cambridge University Press, 1998). 287 pp., cloth (ISBN: 0-5216-2240-9), $59.95; paper (ISBN: 0-5216-2691-9), $19.95. Atomic Audit: The Costs and Consequences of U.S. Nuclear Weapons Since 1940, Stephen I. Schwartz, ed. (Washington, D.C.: Brookings Institution Press, 1998). 680 pp., cloth (ISBN: 0-8157-7774-4), $59.95; paper (ISBN: 0-8157-7773-6), $24.95. Books reviewed int this article: Resisting the Bomb. A History of the World Nuclear Disarmament Movement, 1954–1970 . Vol. 2 of The Struggle Against the Bomb , Lawrence S. Wittner Domestic Society and International Cooperation: The Impact of Protest on U.S. Arms Control Policy , Jeffrey W. Knopf Atomic Audit: The Costs and Consequences of U.S. Nuclear Weapons Since 1940 , Stephen I. Schwartz, ed.
Induction of cyclooxygenase-2 in brain during acute and chronic ethanol treatment and ethanol withdrawal.

Prostaglandins play an important role in the regulation of nervous system function including thermoregulation, autonomic nervous system function, hypothalamic regulation of pituitary function, and neuronal excitation. Prostaglandin synthesis is catalyzed by cyclooxygenase (COX; prostaglandin synthase) which occurs as two isozymes, COX-1 and COX-2. COX-1 and COX-2 are constitutively expressed in brain whereas COX-2 type is also inducible in brain by excitatory neurotransmission. Ethanol intoxication and the hyperexcitability of ethanol withdrawal may be influenced by inducible proteins, thus we investigated COX-2 in the rat brain during acute and chronic ethanol treatment, ethanol withdrawal, and after peripheral administration of excitatory amino acids. Kainic acid or NMDA treatment increased COX-2 immunoreactivity in the cortex, hippocampus, and amygdala. An acute dose of ethanol (5 g/kg, intragastric-i.g.) increased COX-2, particularly in the CA4 region of the hippocampus and agranular insular cortex. Chronic ethanol treatment (4 days-intragastric) robustly induced COX-2 in limbic cortex, isocortex, and amygdala. Particularly dense immunocytochemical staining was found in perirhinal and piriform cortices, dentate gyrus, and tenia tecta. During ethanol withdrawal, COX-2 expression increased further in some regions, peaking in most areas 16 hr after the last dose of ethanol. These results indicate that COX-2 immunoreactivity is: 1) increased in the brain during acute ethanol exposure that increases further during chronic treatment; 2) sensitive to excitatory amino acid receptor stimulation; and 3) dramatically increased during ethanol withdrawal. These studies suggest that COX-2 induction may be involved in the acute and chronic effects of ethanol.
Uniform self-reference

Self-referential sentences have played a key role in Tarski's proof [9] of the non-definibility of arithmetic truth within arithmetic and Godel's proof [2] of the incompleteness of Peano Arithmetic. In this article we consider some new methods of achieving self-reference in a uniform manner.
Prospects of new real-time radar applications for environmental remote sensing

Remote sensing used to assess geophysical parameters on Earth is increasingly exploited and necessary for sustainable human life on Earth. A goal of using satellites to monitor changes and characteristics of Earth's surfaces is to further understanding of the planet and its systems, as well as understanding of how humans interact with and change the environment. Mostly underexploited, biomass detection via active radar remote sensing could provide a more thorough and in depth analysis of Earth. Upcoming NASA Earth monitoring satellites cover a wide range of science products and applications, but little influence is put on the possibility of harnessing data from biomass reaction to radar pulse. In addition to the benefit of radar remote sensing in observing large areas at once, an added ability of transmitting detected frequencies in nearreal- time has potential to provide countless advantages. Direct Broadcast increases possibilities and practical uses for collected data.
Brain neprilysin activity and susceptibility to transgene-induced Alzheimer amyloidosis

Neprilysin (NEP) is a zinc metalloproteinase that degrades enkephalins, endothelins, and the Alzheimer's disease amyloid beta (Abeta) peptides. NEP-deficient mice possess increased levels of brain Abeta(1-40) and Abeta(1-42). The objective of this study was to determine whether tissue NEP specific activity differs according to age and/or across mouse strains, especially those strains predisposed toward formation of Abeta-amyloid plaques following overexpression of the human Alzheimer amyloid precursor protein (APP). The C57Bl/6J mouse strain appears to be relatively susceptible to cerebral amyloidosis, whereas the Swiss Webster (SW) strain appears more resistant. We investigated whether NEP specific activity in brain and kidney homogenates from SW and C57 mice of 6, 40, and 80 weeks old varied according to mouse strain, age, and gender. Among the variables tested, NEP specific activity varied most dramatically across mouse strain, with the kidney and brain of SW mice displaying the highest activities. Aging was associated with a reduction in brain NEP specific activity in both strains. Gender-specific differences were identified in kidney but not in brain. We conclude that aging- and strain-dependent differences in NEP specific activity may play a role in the differential susceptibility of some mouse strains for developing cerebral amyloidosis following human APP overexpression.
An Alternative Proof of an Equilibrium Existence Theorem in Exchange Economies with Indivisibilities

Abstract Bikhchandani and Mamer (1997, J. Econom. Theory 74 , 385–413) studied an exchange economy with multiple indivisible objects and established a necessary and sufficient condition for the existence of competitive equilibrium by a linear programming approach. This paper provides an alternative proof of their theorem by the core of a coalitional form game. Journal of Economic Literature Classification Number: C71.
Status epilepticus-induced hilar basal dendrites on rodent granule cells contribute to recurrent excitatory circuitry.

Mossy fiber sprouting into the inner molecular layer of the dentate gyrus is an important neuroplastic change found in animal models of temporal lobe epilepsy and in humans with this type of epilepsy. Recently, we reported in the perforant path stimulation model another neuroplastic change for dentate granule cells following seizures: hilar basal dendrites (HBDs). The present study determined whether status epilepticus-induced HBDs on dentate granule cells occur in the pilocarpine model of temporal lobe epilepsy and whether these dendrites are targeted by mossy fibers. Retrograde transport of biocytin following its ejection into stratum lucidum of CA3 was used to label granule cells for both light and electron microscopy. Granule cells with a heterogeneous morphology, including recurrent basal dendrites, and locations outside the granule cell layer were observed in control preparations. Preparations from both pilocarpine and kainate models of temporal lobe epilepsy also showed granule cells with HBDs. These dendrites branched and extended into the hilus of the dentate gyrus and were shown to be present on 5% of the granule cells in pilocarpine-treated rats with status epilepticus, whereas control rats had virtually none. Electron microscopy was used to determine whether HBDs were postsynaptic to axon terminals in the hilus, a site where mossy fiber collaterals are prevalent. Labeled granule cell axon terminals were found to form asymmetric synapses with labeled HBDs. Also, unlabeled, large mossy fiber boutons were presynaptic to HBDs of granule cells. These results indicate that HBDs are present in the pilocarpine model of temporal lobe epilepsy, confirm the presence of HBDs in the kainate model, and show that HBDs are postsynaptic to mossy fibers. These new mossy fiber synapses with HBDs may contribute to additional recurrent excitatory circuitry for granule cells.
Nucleate pool boiling of mercury in the presence of a magnetic field

Abstract This experiment is designed to investigate the fundamental mechanisms for pool boiling on a horizontal surface. The unique feature is the combination of an artificial re-entrant cavity and a multiple sensor conductivity probe located above it. With this arrangement the bubble size and frequency were measured. Furthermore, the number density of the nucleation sites is prescribed (i.e. the single re-entrant cavity built into the heater surface) . These basic data were not previously available for liquid metals with magnetic fields. The most striking result is the suppression of boiling at high values of the magnetic field. Good agreement between the data and a mechanistic model were obtained provided that the bubble frequency was known. The effect of the magnetic field on the bubble frequency needs to be resolved for closure.
Differential effects of breast- and formula-feeding on preterm infants' sleep-wake patterns.

Objective: To compare sleep-wake patterns of breastfed and formula-fed preterm infants. Design: Data were taken from an exploratory study of infant biorhythm maturation. Parents completed a 24-hour diary of infant Sleep, Awake, and Cry states and feedings, recorded at 30-minute intervals. Infant health data were collected from medical records and parents' reports. Setting: Infants were studied in the home after discharge from a neonatal intensive-care unit. Participants: The convenience sample included 12 breastfed and 25 formula-fed preterm infants (gestational age, 26-33 weeks; corrected postnatal age, 4-6 weeks). Groups were comparable in terms of gestational age, postnatal age, Apgar scores, maternal age, and home environment. Main Outcome Measure: The 24-hour recording period was divided into day (0600-1800) and night (1800-0600). Study variables were Day, Night, and 24-hour Sleep, Awake, and Cry. Results: Breastfed preterm infants exhibited more Day Cry and 24-hour Cry than did formula- fed infants. Infants demonstrated a diurnal pattern in Cry, Awake, and Sleep. Breastfed preterm infants cried approximately 1 hour per day more than formula-fed infants. Conclusion: Preterm breastfed infants experienced more cry than did formula-fed infants. The relationship between feeding method and sleep- wake pattern has implications for supporting lactation as well as for research design. JOGNN, 29, 145-152; 2000.
Delayed tracheal rupture following thyroidectomy

Thyroidectomy is a commonly performed, low-risk procedure. Tracheal perforation during thyroidectomy is rare, and delayed rupture of the trachea rarer still. We present the case of a patient who underwent total thyroidectomy secondary to Grave's disease who, on postoperative day 7, developed massive subcutaneous emphysema and respiratory distress. Surgical exploration revealed a rupture of the anterolateral tracheal wall at the level of the first tracheal ring. The defect was repaired primarily and the patient recovered uneventfully. The risk factors for and the management of this rare complication are discussed.
NUMERICAL INTEGRATION OF THE HYDROSTATIC EQUATION

Abstract A numerical process is developed by means of which the pressure thickness of an arbitrary layer of air may be converted to its (approximate) linear thickness, and vice versa. The necessary equipment consists of two simple auxiliary scales and Mannheim-type slide rule, or any calculating machine performing the operations of multiplication, division, and extraction of square roots. The tables, charts, and graphs used in other methods of determining the pressure-height relationship for a given aerological sounding are not required.
Immunologic localization and kinetic characterization of a Na+/Ca2+ exchanger in neuronal and non-neuronal cells

Abstract The plasma membrane Na + /Ca 2+ exchanger is believed to play a role in the regulation of Ca 2+ fluxes in neurons, though the lack of specific inhibitors has limited the delineation of its precise contribution. We recently reported the development of antibodies against a 36-kDa brain synaptic membrane protein which immunoprecipitated exchanger activity from solubilized membranes. In the present study we examined the kinetics of the Na + /Ca 2+ exchanger in primary neurons in culture, in a neuronal hybrid cell line (NCB-20), and in a fibroblast-like cell line (CV-1) to see whether the level of exchanger activity correlated with the degree of immunostaining produced by our antibodies. The V max was determined for each cell type and found to be highest in primary neurons. Exchanger activity increased in primary neurons between days 1 and 6 in culture, but no such time-dependent change occurred in either of the cell lines. Immunoblot analysis of the three cell types probed with the anti-36-kDa protein antibodies revealed significantly greater immunostaining in the primary neurons compared with the other two cell types. Intensity of staining of neurons also increased significantly between days 1 and 6 in culture. Immunocytochemistry showed significant labelling of the primary neurons on the neuritic processes and points of contact between cells. The NCB-20 and CV-1 cells showed considerably lower levels of immunoreactivity. The antibodies immunoextracted ∼90% of the exchanger activity in the primary neurons and ∼70 and 50% of the activity in NCB-20 and CV-1 cells respectively. Thus the expression of the 36-kDa protein appears to be closely associated with the Na + /Ca 2+ exchanger in neuronal cells and, possibly to a lesser extent, in non-neuronal cells.
Amplitude growth rate of a Richtmyer Meshkov unstable two-dimensional interface to intermediate times

The Richtmyer–Meshkov instability in an incompressible and compressible stratified two-dimensional ideal flow is studied analytically and numerically. For the incompressible problem, we initialize a single small-amplitude sinusoidal perturbation of wavelength λ, we compute a series expansion for the amplitude a in powers of t up to t(11) with the MuPAD computer algebra environment. This involves harmonics up to eleven. The simulations are performed with two codes: incompressible, a vortex-in- cell numerical technique which tracks a single discontinuous density interface; and compressible, PPM for a shock-accelerated case with a finite interfacial transition layer (ITL). We identify properties of the interface at time t = tM at which it first becomes ‘multivalued’. Here, we find the normalized width of the ‘spike’ is related to the Atwood number by (wm/λ)−0.5 = −0.33A. A high-order Pad approximation is applied to the analytical series during early time and gives excellent results for the interface growth rate a˙. However, at intermediate times, t > tM, the agreement between numerical results and different-order Pade approximants depends on the Atwood number. During this phase, our numerical solutions give a˙∝O(t−1) for small A and a˙∝O(t−0.4) for A = 0.9. Experimental data of Prasad et al. (2000) for SF6 (post shock Atwood number = 0.74) shows an exponent between −0.68 and −0.72 and we obtain −0.683 for the compressible simulation. For this case, we illustrate the important growth of vortex-accelerated (secondary) circulation deposition of both signs of vorticity and the complex nature of the roll-up region.
An optimization scheme for molecular dynamics simulations of radiation effects

Abstract A method to reduce the CPU time required for molecular dynamics computer simulations of radiation damage problems has been developed. At each time step in the simulation, a force calculation is performed on only those atoms that satisfy at least one of three criteria: (i) its distance moved, (ii) its acceleration, (iii) its change in acceleration. A fourth criterion on the time interval since the forces on all atoms were updated is also employed. A savings in CPU time greater than a factor of 2 is obtained with negligible loss in accuracy.
Trajectories of behavioral adjustment following early placement in foster care: predicting stability and change over 8 years.

Objective To identify trajectories of behavioral adjustment from age 6 through 14 years for youth placed in early foster care, and to examine links between trajectories and early cognitive ability and social competence, caregiver stability, and frequency, timing, and type of maltreatment. Method Participants were 279 youth from the Southwest site of the Consortium for Longitudinal Studies of Child Abuse and Neglect (LONGSCAN). All youth had spent at least 5 months in out-of-home care before age 4 years because of substantiated reports of maltreatment. Behavioral adjustment was assessed using caregiver reports on the Child Behavior Checklist at ages 6, 8, 10, 12, and 14. Cognitive ability and social competence were assessed at age 6. Caregiver stability was recorded every 2 years from age 6 through 14 years and summed. Child protective services (CPS) maltreatment reports were coded for type and frequency. Results Growth mixture modeling identified three internalizing trajectories: stable adjustment (66.7%), mixed/decreasing adjustment (25.4%), and increasing adjustment (7.9%). Four externalizing trajectories were identified: stable adjustment (46.6%), mixed adjustment (28.7%), increasing adjustment (8.2%), and stable maladjustment (16.5%). Trajectories of stable or increasing adjustment were predicted by social competence, cognitive ability, placement stability, and low frequency of physical abuse from ages 6 through 14. Conclusions Many youth who have spent time in early out-of-home care evidence stable, long-term positive behavioral adjustment. Trajectories reflecting more positive adjustment are associated with early child cognitive ability and social competence, long-term caregiver stability, and low frequency of physical abuse in middle childhood and adolescence.
Treatment of Sarcoidosis-Associated Hypercalcemia With Ketoconazole

A 47-year-old patient presented with hypercalcemia secondary to Sarcoidosis and was successfully treated with 1 year of corticosteroids leading to improvement in his hypercalcemia, hypercalcuria, and elevated levels of 1,25-dihydroxyvitamin D. Angiotensin-converting enzyme levels (ACE) normalized and serum creatinine improved. When hypercalcemia recurred after a 3-year symptom-free interval, the patient refused repeat corticosteroid treatment and was placed on ketoconazole (initially 600 and eventually 800 mg/d). Ketoconazole controlled the patient's hypercalcemia (serum calcium, 3.2 to 2.6 mmol/L [12.8 to 10.4 mg/dL]), but only the larger dose suppressed serum 1,25-dihydroxyvitamin D levels into the normal range. Hypercalcuria was markedly improved with ketoconazole, decreasing from a peak of 23 mmol/d (940 mg/d) to less than 8.7 mmol/d (350 mg/d) on a dose of 800 mg. However, serum ACE levels remained elevated on ketoconazole. An attempt to taper the ketoconazole after 1 year resulted in rapid recurrence of hypercalcemia (serum calcium, 2.8 mmol/L [11.1 mg/dL]) and hypercalcuria (urinary calcium excretion, 11 mmol/d [451 mg/d]). After a total of 2 years of ketoconazole treatment, his defect in calcium metabolism remains well controlled despite persistent elevation in ACE levels. Serum cortisol levels and liver function tests remain normal on therapy, although there has been a slight decrease in serum testosterone levels accompanied by some decrease in libido. These data suggest that long-term use of ketoconazole may be a safe and effective alternative to corticosteroid treatment for sarcoidassociated hypercalcemia. Further study is needed to determine whether the long-term side effects of ketoconazole therapy or its failure to control disease activity in sarcoidosis outweigh its advantages in avoiding the known side effects of glucocorticoids.
Influence of Query-Based Decision Aids on Consumer Decision Making in Electronic Commerce

This research investigates the influence of computerized search engines on consumer decision making in the electronic commerce environment. The results indicate that by providing well-designed decision aids to consumers, it is possible to significantly increase consumer confidence, satisfaction, and decision quality. Consumers who have access to query-based decision aids perceive increased cost savings and lower cognitive decision effort associated with the purchase decision. The future challenge in developing consumer-oriented computerized decision aids does not reside in technological advances, but rather in developing systems that are useful and appealing to the intended consumer. This is necessary to avoid consumer perceptions of non-utility, and ultimately non-use of the computerized decision aids. The challenge for marketing managers is to provide consumers with information systems that change over time such that they fulfill the consumers' short-term needs without sacrificing the consumers' long-term interests.
A note on structural models for the circumplex

Joreskog (1974) developed a latent variable model for the covariance structure of the circumplex which, under certain conditions, includes a model for a patterned correlation matrix (Browne, 1977). This model is of limited usefulness, however, in that it employs a known matrix that is rank deficient for many problems. Furthermore, the model is inappropriate for the circumplex which contains negative covariances. This paper presents alternative models for the perfect circumplex and quasi-circumplex that avoids these difficulties, and that includes the important model for a patterned correlation circumplex matrix. Two numerical examples are provided.
Autopsy Findings with Permanent Pervenous Pacemakers

Of 130 patients who received permanent pervenous pacemakers in the last 2 years at the Massachusetts General Hospital, 21 have died; complete postmortem data are available on seven who died 5 days to 18 months after insertion of the pacemaker. No deaths were related to pacemaker malfunction. No patient received routine anticoagulant therapy. The intracardiac portions of all pacemaker electrodes were 30 to 80% endothelialized. In three cases tiny, organized mural thrombi formed on these sheaths, but none appeared to give rise to pulmonary emboli. All pacemaker electrode tips were wedged firmly beneath the trabecular system of the right ventricular apex and elicited varying degrees of local fibrous tissue reaction. Further focal fibrotic attachments occurred in the right atrium and superior vena cava. Although in four cases the electrodes adhered to the chordae tendineae, the long-term presence of an electrode did not appear to compromise tricuspid valve function. Late removal of an electrode may be hazardo...
Recent emergence of the modern genetic code: a proposal.

This article proposes that the genetic code was not fully formed before the divergence of life into three kingdoms. Rather, at least arginine and tryptophan evolved after the diversification of archaea, bacteria and eukaryotes, and were spread by horizontal gene transfer. Evidence for this hypothesis is based on data suggesting that enzymes for biosynthesis of arginine and tryptophan, and for arginine tRNA ligase, have shorter divergence times than the underlying lineages. Also, many of these genes display ‘star’ phylogenies. This proposal is an extension of the idea that the genetic code was unified because of the evolutionary pressure from horizontal gene transfer. These considerations further undermine the need to postulate the existence of a ‘last common ancestor’; a simpler model would be that multiple lineages gave rise to life today.
Constant frequency controlled full-bridge LCC-type parallel resonant converter

A constant-frequency controlled full-bridge LCC-type parallel resonant converter is presented. By using a proper transformation on the state variables, the converter is analyzed by means of a two-dimensional state-plane diagram, which shows that the converter possesses three operation modes. Control characteristics and component stress curves are derived for only operation mode II. It is shown that operating that converter in operation mode II provides the desirable converter gains for a wide load range. In addition, these control characteristics curves reveal that the converter possesses better load regulation when compared to those of the second order full-bridge constant frequency controlled parallel resonant converter. A design example and computer simulation results are given to confirm the analytical work. >
Manipulation of death pathways in desmin-related cardiomyopathy.

Rationale: Transgenic mice with cardiac specific overexpression of mutated αB-crystallin (CryABR120G) display Desmin-related myopathy (DRM) with dilated cardiomyopathy and heart failure. Our previous studies showed the presence of progressive mitochondrial abnormalities and activation of apoptotic cell death in CryABR120G transgenic hearts. However, the role of mitochondrial dysfunction and apoptosis in the overall course of the disease was unclear. Objective: We tested the hypothesis that prevention of apoptosis would ameliorate CryABR120G pathology and decrease morbidity. Methods and Results: We crossed CryABR120G mice to transgenic mice with cardiac specific overexpression of Bcl-2. Sustained Bcl-2 overexpression in CryABR120G hearts prolonged CryABR120G transgenic mice survival by 20%. This was associated with decreased mitochondrial abnormalities, restoration of cardiac function, prevention of cardiac hypertrophy, and attenuation of apoptosis. CryABR120G misfolded protein aggregation was significantl...
Balanced inhibition underlies tuning and sharpens spike timing in auditory cortex

Neurons in the primary auditory cortex are tuned to the intensity and specific frequencies of sounds, but the synaptic mechanisms underlying this tuning remain uncertain. Inhibition seems to have a functional role in the formation of cortical receptive fields, because stimuli often suppress similar or neighbouring responses, and pharmacological blockade of inhibition broadens tuning curves. Here we use whole-cell recordings in vivo to disentangle the roles of excitatory and inhibitory activity in the tone-evoked responses of single neurons in the auditory cortex. The excitatory and inhibitory receptive fields cover almost exactly the same areas, in contrast to the predictions of classical lateral inhibition models. Thus, although inhibition is typically as strong as excitation, it is not necessary to establish tuning, even in the receptive field surround. However, inhibition and excitation occurred in a precise and stereotyped temporal sequence: an initial barrage of excitatory input was rapidly quenched by inhibition, truncating the spiking response within a few (1-4) milliseconds. Balanced inhibition might thus serve to increase the temporal precision and thereby reduce the randomness of cortical operation, rather than to increase noise as has been proposed previously.
Hiring the Right Teacher: a Method for Selection

The process of teacher selection can be more effective if administrators determine what kind of teacher they want, whether the current selection process helps find the best teachers, and whether current teachers have a part in the process.
A Fluid Dynamics Approach to Multi-Robot Chemical Plume Tracing

This paper presents a novel chemical plume tracing algorithm executed by a distributed network of mobile sensing robots that measure the ambient fluid velocity and chemical concentration. The algorithm drives the robotic network to the source of the toxic plume, where measures can be taken to remove or extinguish the source emitter.
Overlooked Implications of Ethnic Preferences for Residential Segregation in Agent-based Models

We investigate the impact of preferences for co-ethnic contact on residential segregation and find support for the Schelling hypothesis that modest preferences can have significant consequences for segregation under certain conditions. Our findings temper and in some instances contradict Laurie and Jaggi's claim that expanding 'vision', the size of the immediate neighbourhood households consider when evaluating residential ethnic mix, makes stable integration a likely outcome in Schelling-like models with weak-to-moderate preferences. We note several reasons why our results differ from Laurie and Jaggi's. The most important of these is that Laurie and Jaggi underestimate the segregation-producing potential of weak-to-moderate preferences because they overlook a powerful interaction between preferences and ethnic demography and perform their simulations using the optimal ethnic mix for achieving integration. We show that the preferences Laurie and Jaggi describe as compatible with stable integration genera...
Highly sensitive RF detection and analysis of DNA solutions

We report the operation of a highly sensitive, tunable and stable RF interferometer, which is based on quadrature-hybrids. The interferometer is used to characterize and analyze DNA molecules, pBluescript (SK+) and pET21a, in ~1 nL DI water solutions. The obtained RF sensitivity at ~10 GHz is better than ~3×10 -15 mol/mL, which is close to the previously reported highest result. DNA molecular compositions are analyzed from RF measurements. The results suggest a new method for DNA solution examinations. We also show that partly damaged DNA molecules exhibit significant dielectric property changes. Additionally, DNA solution dynamics (i.e. relaxation time) is obtained through RF measurements between ~2.5 and ~10 GHz. Thus, the RF technique is promising for sensing and identification applications in biology and chemistry.
MOUNTAIN HEMLOCK GROWTH RESPONDS TO CLIMATIC VARIABILITY AT ANNUAL AND DECADAL TIME SCALES

Improved understanding of tree growth responses to climate is needed to model and predict forest ecosystem responses to current and future climatic variability. We used dendroecological methods to study the effects of climatic variability on radial growth of a subalpine conifer, mountain hemlock (Tsuga mertensiana). Tree-ring chronologies were developed for 31 sites, spanning the latitudinal and elevational ranges of mountain hemlock in the Pacific Northwest. Factor analysis was used to identify common patterns of inter- annual growth variability among the chronologies, and correlation and regression analyses were used to identify climatic factors associated with that variability. Factor analysis identified three common growth patterns, representing groups of sites with different climate-growth relationships. At high-elevation and midrange sites in Wash- ington and northern Oregon, growth was negatively correlated with spring snowpack depth, and positively correlated with growth-year summer temperature and the winter Pacific Decadal Oscillation index (PDO). In southern Oregon, growth was negatively correlated with spring snowpack depth and previous summer temperature, and positively correlated with previous summer precipitation. At the low-elevation sites, growth was mostly insen- sitive to annual climatic variability but displayed sensitivity to decadal variability in the PDO opposite to that found at high-elevation sites. Mountain hemlock growth appears to be limited by late snowmelt, short growing sea- sons, and cool summer temperatures throughout much of its range in the Pacific Northwest. Earlier snowmelt, higher summer temperatures, and lower summer precipitation in southern Oregon produce conditions under which growth is limited by summer temperature and/or soil water availability. Increasing atmospheric CO 2 concentrations could produce warmer temperatures and reduced snowpack depths in the next century. Such changes would likely increase mountain hemlock growth and productivity throughout much of its range in Washington and northern Oregon. Increased summer drought stress and reduced productivity would be likely, how- ever, in mountain hemlock forests of southern Oregon and near the species lower elevation
Life Prediction and Damage Equivalency for Shock Survivability of Electronic Components

There is a fundamental need for development of predictive techniques for electronic failure mechanisms in shock and drop-impact. Presently, one of the primary methodologies for assessment of shock and vibration survivability of electronic packaging is the JEDEC drop test method, JESD22-B111 which tests board-level reliability of packaging. However, packages in electronic products may be subjected to a wide-array of boundary conditions beyond those targeted in the test method. Development of damage-equivalency methodologies will be invaluable in correlating standard test conditions to widely varying design-use conditions. In this paper, the development of a solder-joint stress based relative damage index has been investigated to establish a method for damage equivalency. Modal analysis, wavelet decomposition, and explicit finite element analysis has been used to assess reliability performance of the electronic boards. Deformation kinematics have been measured with the help of ultra high-speed data acquisition and video systems. Experimental data has been correlated to the finite element models. Failure predictions along with their modes and mechanisms have been discussed. Damage proxies for failure mechanisms in first-level interconnects have been developed. The approach is scalable to a wide variety of electronic applications. Component types examined include, plastic ball-grid arrays, flex ball-grid arrays for various pitch sizes between 0.5 mm to 1 mm in both 63Sn37Pb and 95.5Sn4.0Ag0.5Cu solder alloy compositions. Dynamic measurements like acceleration, strain and resistance are measured and analyzed using highspeed data acquisition system capable of capturing in-situ strain, continuity and acceleration data in excess of 5 million samples per second. Ultra high-speed video up to 50,000 fps has been used to capture the deformation kinematics. Experimental results are correlated with finite element models which include reduced integration element formulations
The modeling and evaluation of interplanetary manned missions using system architecting techniques

The manned exploration of the rocky bodies of the solar system has long been one of the primary, if unstated, goals of the aerospace industry. In order to facilitate the design and decision process associated with the development of the systems necessary for such complex operations, an understanding of the system on the highest level must be established. This paper describes the development of a systems architecture-level model used to evaluate the in-space transportation portion of manned exploration missions to other rocky bodies in the solar system. The results of this analysis, including the “best” architectures given the metrics employed as well as technology decision impacts, will also be discussed. The MATLAB-based model utilizes the concepts of decision formulation, set partitioning problems, and technology option analysis. The set of architectures is decoupled from the launch vehicle architecture as well as destination exploration operations, allowing for an iso-performance analysis with science and exploration value while remaining independent of the launch vehicle limitations.
An Open Pilot Feasibility Study of a Brief Dialectical Behavior Therapy Skills–Based Intervention for Suicidal Individuals

This open trial sought to develop and evaluate the preliminary feasibility and effectiveness of a brief, one-time, dialectical behavior therapy skills-based intervention with specific focus on ensuring acceptability to nontreatment-seekers. Treatment-seeking and nontreatment-seeking suicidal individuals were recruited successfully from the community. Both groups found the intervention valuable. Suicide ideation was significantly lower at the 1-month follow-up, while use of the specific skills taught in the intervention increased significantly across time points. These results suggest that the intervention is both acceptable to the target population and that it has potential effectiveness as an intervention for individuals experiencing suicidal ideation.
The Evolution of Instruction in Grant Writing and Research in the Libraries at the University of Utah

An investment in continuing education in the area of grantsmanship for a public services librarian has resulted in the teaching of Grant Writing & Research offered at the J. Willard Marriott Library and the Spencer S. Eccles Health Sciences Library on the campus of the University of Utah . This has led to an unexpected method of library outreach to the university faculty and to the community at large, promoting the overall collections and services of the libraries on campus.
Impaired interleukin-2 production by T-lymphocytes in polycythemia vera

T-lymphocyte function was investigated in a group of eight patients with polycythemia vera (PV) and 13 normals. Responsiveness of T-cells to stimulation by mitogen was significantly impaired in the PV patients (p = .02). Analysis of immune cell subpopulation composition by assessment of cell surface phenotype did not reveal imbalances that could account for impaired T-cell proliferative ability in PV patients. Addition of recombinant human interleukin-1 to PV mononuclear cell cultures did not enhance proliferative ability. Addition of recombinant human interleukin-2 to cultures had no effect on maximum mitogen stimulation in normals but significantly improved responses in PV patients (p less than .02), correcting them to normal levels. Measurement of interleukin-2 production by stimulated cultured mononuclear cells confirmed subnormal IL-2 production by PV T-cells (p less than .00005). Impaired IL-2 production could conceivably contribute to the pathogenesis of PV by limiting the ability of IL-2-dependent cells to regulate hematopoiesis.
Using program transformation to secure C programs against buffer overflows

Buffer overflows are the most common source of securityvulnerabilities in C programs. This class of vulnerability,which is found in both legacy and modern software, coststhe software industry hundreds of millions of dollars peryear.The most common type of buffer overflow is the run-timestack overflow. It is common because programmersoften use stack allocated arrays. This enables the attackerto change a program's control flow by writing beyond theboundary of an array onto a return address on the run-timestack. If the arrays are repositioned to the heap at compiletime, none of these attacks succeed. Furthermore, repositioningbuffers to the heap should perturb the heap memoryenough to prevent many heap overflows as well.We have created a tool called Gemini that repositionsstack allocated arrays at compile time using TXL. Thetransformation preserves the semantics of the program witha small performance penalty. This paper discusses thesemantics-preserving transformation of stack allocated arraysto heap allocated "pointers to arrays". A program thatis amenable to a buffer overflow attack and several Linuxprograms are used as examples to demonstrate the effectivenessand overhead of our technique.
Constrained phrase-based translation using weighted finite-state transducers

Phrase-based translation models have shown clear advantages over word-based models, and weighted finite-state transducers (WFSTs) provide a unified framework for integrating the various components of a speech-to-speech translation system, such as speech recognition and machine translation. The paper combines these two ideas by proposing a constrained phrase-based statistical machine translation system that we implement using WFSTs. We evaluate the proposed model on a bidirectional Chinese-English translation task and show improvements over our previous system.