cssi/SciSciGPT-SciSciNet huggingface dataset:
Hydraulic fracturing to determine the regional in situ stress field, Piceance Basin, Colorado

Several authors have discussed the theoretical aspects of using the techniques of hydraulic fracturing to determine the state of stress within the Earth. Few, however, have attempted systematic hydraulic fracturing for the specific purpose of determining the regional stress field. Using specially designed equipment, the state of stress was determined on a regional scale in the Piceance Oil Shale Basin of northwest Colorado. Structurally, the area is a simple basin that has been subjected to normal faulting. Seven oil-shale, test holes scattered throughout the Piceance Basin were logged with an acoustic borehole televiewer to select unfractured solution-free intervals. Fracture-free intervals, ranging in depth from 60 to 460 m, were isolated between packers and hydraulically fractured. Induced fractures were propped with ground lucite and relogged with the televiewer to determine their strike and dip. These data, combined with pressure measurements made during the fracturing experiments, were used to compute the orientation and magnitude of the stress tensor. Field observations showed that in a tectonically relaxed area, vertical fractures can be induced at hydraulic pressures as low as 0.6 of the overburden stress. Below a depth of 120 m, the induced fractures were approximately vertical, with a prominent strike of N70°W. This orientation parallels the major normal faulting in the basin as well as one of the prominent directions of jointing. These results also agree with those obtained at Rangely, about 50 km to the northwest.
Diaphragm curvature modulates the relationship between muscle shortening and volume displacement

During physiological spontaneous breathing maneuvers, the diaphragm displaces volume while maintaining curvature. However, with maximal diaphragm activation, curvature decreases sharply. We tested the hypotheses that the relationship between diaphragm muscle shortening and volume displacement (VD) is nonlinear and that curvature is a determinant of such a relationship. Radiopaque markers were surgically placed on three neighboring muscle fibers in the midcostal region of the diaphragm in six dogs. The three-dimensional locations were determined using biplanar fluoroscopy and diaphragm VD, curvature, and muscle shortening were computed in the prone and supine postures during spontaneous breathing (SB), spontaneous inspiration efforts after airway occlusion at lung volumes ranging from functional residual capacity (FRC) to total lung capacity, and during bilateral maximal phrenic nerve stimulation at those same lung volumes. In supine dogs, diaphragm VD was approximately two- to three-fold greater during maximal phrenic nerve stimulation than during SB. The contribution of muscle shortening to VD nonlinearly increases with level of diaphragm activation independent of posture. During submaximal diaphragm activation, the contribution is essentially linear due to constancy of diaphragm curvature in both the prone and supine posture. However, the sudden loss of curvature during maximal bilateral phrenic nerve stimulation at muscle shortening values greater than 40% (ΔL/LFRC) causes a nonlinear increase in the contribution of muscle shortening to diaphragm VD, which is concomitant with a nonlinear change in diaphragm curvature. We conclude that the nonlinear relationship between diaphragm muscle shortening and its VD is, in part, due to a loss of its curvature at extreme muscle shortening.
Electromigration-induced propagation of nonlinear surface waves.

Due to the effects of surface electromigration, waves can propagate over the free surface of a current-carrying metallic or semiconducting film of thickness ${h}_{0}.$ In this paper, waves of finite amplitude, and slow modulations of these waves, are studied. Periodic wave trains of finite amplitude are found, as well as their dispersion relation. If the film material is isotropic, a wave train with wavelength $\ensuremath{\lambda}$ is unstable if $\ensuremath{\lambda}{/h}_{0}l3.9027\dots{},$ and is otherwise marginally stable. The equation of motion for slow modulations of a finite amplitude, periodic wave train is shown to be the nonlinear Schr\"odinger equation. As a result, envelope solitons can travel over the film's surface.
Future Directions for U.S. Food, Agricultural, and Trade Policy: Discussion

The Chavas paper has three main sections. First, it surveys research findings regarding the impacts of domestic food programs. Second, it attempts to characterize optimal food policy. Third, the paper specifies a model of optimal transfers and traces the implications of that model. Under the first category, the results on the effectiveness of food subsidies versus cash transfers is noted. Although food subsidies are shown to be generally superior in increasing food intake, a point that is not lost to farm price support lobbyists, one of the interesting results of this research is the heterogeneity of recipient behavior. This is particularly interesting in view of the notion of more or less uniform food stamp eligibility requirements. Chavas goes on to note that the link between nutrition and food intake is not as unambiguous as program proponents might desire. Hence, it appears that some control or pilot-type program would have large payoffs in terms of additional information. Given the multibillion dollar nature of food programs, such pilot programs should be cost effective. Ignorance regarding the recipient population and lack of controlled pilot projects has been one of the hallmarks of government transfer
The ever-evolving landscape for detection of early melanoma: challenges and promises.

Over the past three decades, much progress has been made in reducing deaths from cancers for which preventive strategies are available. Most strikingly, mortality rates have dropped between 20 and 50% for cancers of the breast, cervix, colon, lung, and prostate (SEER, 2012). Conversely, the death rate from melanoma has remained remarkably stubborn, the product of two divergent trends: rising melanoma mortality rates for Americans aged 60 years and above, especially among men, countered by falling melanoma mortality rates for nearly all age groups below 60 years (SEER, 2012). Melanoma was once a rare disease, with fewer than 2 cases per 100,000 in the 1950s, compared with more than 25 cases per 100,000 today (SEER, 2012). It is now the fifth most common cancer in US men and the cause of more than 9,000 American deaths each year (SEER, 2012).
Chaotic behavior in coupled Gierer–Meinhardt equations

Abstract In this paper, a computer program was modified to simulate the dynamics of four modified Gierer–Meinhardt reaction–diffusion equations. A time series analysis was performed on the results. It was found that the modified Gierer–Meinhardt equations demonstrated chaotic behavior under certain conditions. The dynamics included fixed points, limit cycles, transient chaos, intermittent chaos, and strange attractors. The creation and destruction of fractal torii was found.
Two-photon circular dichroism of molecular structures simulating l-tryptophan residues in proteins with secondary structures

Abstract Herein, we report on the calculation and the comparative analysis of the theoretical two-photon circular dichroism (TPCD) spectra of l -tryptophan (Trp) residues in proteins with secondary structures (α-helix, β-strand and random coil) conformation, down to the far-UV region (FUV). The examination of the TPCD spectra of the different conformers in each configuration reveals distinctive fingerprints in the FUV, a dark spectral region for electronic circular dichroism (ECD). Our results show the potential of FUV-TPCD to identify and study protein structures in a region never assessed before but filled with important structural information.
Color Duplex-Guided Compression Therapy for Postcatheterization Pseudoaneurysms in a Community Hospital

Diagnostic or therapeutic arterial catheterization may be complicated by postcatheterization pseudoaneurysm. Pseudoaneurysms have generally been treated surgically, but more recently, encouraging results with duplex-guided compression therapy (DGCT) of pseudoaneurysms have been reported from university hospitals. We reviewed our experience with DGCT to assess the applicability of DGCT in a community hospital setting. Sixty-two patients presented with 63 symptomatic postcatheterization pseudoaneurysms between January 1, 1990, and December 31, 1993. Prior to October 28, 1991, all pseudoaneurysms were treated surgically. Subsequently we initiated DGCT as primary treatment for pseudoaneurysms, reserving surgery for DGCT failures and unstable patients. DGCT patients were indistinguishable from primary surgery patients, and the number of pseudoaneurysms treated did not appear to increase during the study period. DGCT was initially successful in 27 (75%) of 36 patients. Three pseudoaneurysms recurred, yielding cumulative success in 24 (67%) of 36 patients. Three of 12 DGCT failures were due to patient intolerance. DGCT was unsuccesful in three of four intra-aortic balloon pump (IABP)-associated pseudoaneurysms. There was some variation in pseudoaneurysm volume between the successful and failed groups, and a trend toward failure with larger pseudoaneurysms was not significant (13 vs. 6 cm3,p≥0.25). DGCT failure appears more likely in post-IABP pseudoaneurysms and possibly with larger pseudoaneurysms. Anticoagulation, type of procedure (exclusive of IABP), obesity, and other patient characteristics examined did not appear to predict success or failure of DGCT. Treatment was reserved for symptomatic patients throughout the period of study and there was no evidence that patients were more likely to be treated for pseudoaneurysms after DGCT was initiated. We conclude that DGCT is usually successful and is appropriate primary treatment for all symptomatic postcatheterization pseudoaneurysms in stable patients.
Adolescents' Perceptions of Their Consent to Psychiatric Mental Health Treatment

The purpose of this paper is to present the findings of a small-scale study in which the decision-making process of adolescents who consent to psychiatric mental health treatment was examined. Sixteen (16) adolescents were interviewed about their decisions related to initial and continued treatment, along with their understanding of minor consent laws. Interviews were audio-recorded, and transcripts were analyzed through concept analysis. Findings are presented in the context of the decision-making steps and research questions. Most adolescents did not recognize consequences related to psychiatric mental health treatment and did not assimilate and integrate information provided to them about treatment choices. Adolescents disagreed with current minor consent laws that allow minors to consent to certain healthcare treatments without the required consent of the parent. Further, adolescents reported that a collaborative approach in making decisions about the adolescent's psychiatric mental health treatment was most facilitative of achieving the goals of treatment.
The NMDA receptor mediates cortical induction of fos and fos-related antigens following cortical injury

Cortical cavity lesions and lateral ventricular injections of quinolinic acid, a NMDA receptor agonist, induce Fos and Fos-related antigens (FRAs) throughout ipsilateral adult rat brain cortex in similar patterns. c-fos mRNA, assessed using in situ hybridization, was induced by 1 h and disappeared between 3 and 8 h following cortical lesions. Fos proteins, detected using a specific monoclonal antibody, were induced by 1 h and disappeared by 4 h after cortical lesions. FRA proteins, detected using polyclonal antibodies, were induced between 1 and 4 h and persisted for at least 72 h following focal cortical injury. Intraventricular injections of CPP, a competitive NMDA receptor antagonist, completely blocked the induction of these nuclear proteins in cortex ipsilateral to the focal cortical lesions--except around the injury site itself. Intraventricular injections of quisqualate, a non-NMDA glutamate analogue, induced Fos in hippocampus but not in cortex. These data show that NMDA receptors mediate the induction of Fos and FRAs following cortical injury. It is proposed that local cortical injury releases excitatory amino acids that act at NMDA receptors to initiate spreading depression and that the resultant depolarization induces Fos in neurons throughout the cortex. Since Fos and FRAs are proteins that regulate the expression of target genes, they could mediate long-term biochemical adaptations in neurons following cortical injury.
Risk of hip fracture in women with vertebral fracture

In a population-based retrospective cohort study, Rochester women aged 35-69 years who were first diagnosed with one or more vertebral fractures in 1950-1979 were followed for the development of a subsequent hip fracture. The 336 women with no history of hip fracture at the time of their vertebral fracture experienced 52 proximal femur fractures in 4788 person-years of follow-up. The standardized morbidity ratio (SMR) of observed to expected hip fractures was 1.8 (95% CI, 1.3-2.4) and was higher for intertrochanteric than cervical femoral fractures (SMR, 2.3 versus 1.3; P = 0.07). Hip fracture risk among women with symptomatic vertebral fractures was slightly less than in those with asymptomatic vertebral fractures (SMR, 1.8 versus 2.3; not significant), and younger women had no higher risk of a subsequent hip fracture than women who were > or = 60 years of age at the time of their vertebral fracture (SMR, 1.4 versus 1.8; not significant). Alternative explanations are possible, but these data are consistent with heterogeneity in the pathogenesis of different osteoporotic fractures. Language: en
When appearance concerns make women look bad : Solo status and body image concerns diminish women's academic performance

Abstract Women entering male-dominated fields often find themselves the only women present, i.e., they experience solo status. Solo status diminishes women’s performance when women are negatively stereotyped in the testing domain ( Inzlicht & Ben-Zeev, 2000 ) or when the performance is public ( Sekaquaptewa & Thompson, 2002 ). Because women experience greater body image concerns than men and underperform when these concerns are high ( Fredrickson, Roberts, Noll, Quinn, & Twenge, 1998 ), body image concerns may also cause diminished performance in solo women. Women were given a stigmatized (i.e., heavy) or neutral appearance (via a manipulated photograph), then tested as either solos or non-solos. Results showed that women performed more poorly when given a stigmatized appearance and placed under solo status compared to when only one of these factors were present. Social identity threat concerns ( Steele, Spencer, & Aronson, 2002 ) mediated the solo status effect on performance for women given a stigmatized appearance.
Encoding, Memory, and Transcoding Deficits in Childhood Apraxia of Speech

A central question in Childhood Apraxia of Speech (CAS) is whether the core phenotype is limited to transcoding (planning/programming) deficits or if speakers with CAS also have deficits in auditory-perceptual encoding (representational) and/or memory (storage and retrieval of representations) processes. We addressed this and other questions using responses to the Syllable Repetition Task (SRT) [Shriberg, L. D., Lohmeier, H. L., Campbell, T. F., Dollaghan, C. A., Green, J. R., & Moore, C. A. (2009). A nonword repetition task for speakers with misarticulations: The syllable repetition task (SRT). Journal of Speech, Language, and Hearing Research, 52, 1189-1212]. The SRT was administered to 369 individuals in four groups: (a) typical speech-language (119), (b) speech delay-typical language (140), (c) speech delay-language impairment (70), and (d) idiopathic or neurogenetic CAS (40). CAS participants had significantly lower SRT competence, encoding, memory, and transcoding scores than controls. They were 8.3 times more likely than controls to have SRT transcoding scores below 80%. We conclude that speakers with CAS have speech processing deficits in encoding, memory, and transcoding. The SRT currently has moderate diagnostic accuracy to identify transcoding deficits, the signature feature of CAS.
If They Don't Bring Their Women Here: Chinese Female Immigration before Exclusion

"Seven years before the Chinese Exclusion Act of 1882 comprehensively disqualified all members of China's laboring class from immigration status, the Page Law sought to stem the tide of Chinese prostitutes entering the United States. Yet during these seven years it was not just prostitutes but all Chinese females who encountered at best hostility and at worst expulsion when they reached the "Golden Door." In this first detailed account of Chinese American women's lives in the preexclusion era, George Anthony Peffer investigates how administrative agencies and federal courts enforced immigration laws. Peffer documents the habeas corpus trials in which the wives and daughters of Chinese laborers were required to prove their status as legal immigrants or be returned to China. He also surveys the virulently anti- Chinese coverage these trials and the issue of Chinese immigration received in California newspapers, confirming that Chinatown's prostitution industry so dominated the popular imagination as to render other classes of female immigrants all but invisible. In the words of one immigration judge, the United States remained favorable to Chinese immigration in the preexclusion period "if they don't bring their women here." This important study amplifies the voices of immigrant women who did not fit into the preconceived categories American officials created and establishes a place for them within the historiographic framework of Chinese American studies."
Quantitation of atenolol, metoprolol, and propranolol in postmortem human fluid and tissue specimens via LC/APCI-MS.

Abstract Hypertension is a growing medical concern in the United States. With the number of Americans suffering from hypertension increasing, the use of antihypertensives such as beta-blockers is increasing as well. In fact, three beta-blockers – atenolol, metoprolol and propranolol – were among the 200 most prescribed medications in the United States in 2003. Pilots that successfully manage their hypertension can remain certified to fly. The Federal Aviation Administration currently designates approximately 8% of active pilots as “hypertensive with medication”. The Civil Aerospace Medical Institute (CAMI) performs toxicological evaluation on victims of fatal aviation accidents. At CAMI beta-blockers are analyzed using gas chromatography with mass spectrometric detection. We have, however, recently developed a liquid chromatography with mass spectrometric detection (LC/MS) method for the simultaneous quantitation of three commonly prescribed beta-blockers, atenolol, metoprolol and propranolol. One advantage of our LC/MS method is the specificity provided by an ion trap MS. Utilizing an ion trap MS, we were able to conduct MS/MS and MS/MS/MS on each analyte. This method also eliminates the time-consuming and costly derivitization step necessary during GC/MS analysis. Additionally, by utilizing this novel method, any concerns about beta-blocker metabolite and/or sample matrix interference are eliminated. The limits of detection for this method ranged from 0.39 to 0.78 ng/mL and the linear dynamic range was generally 1.6–3200 ng/mL. The extraction efficiencies for each analyte ranged from 58% to 82%. This method was successfully applied to postmortem fluid and tissue specimens obtained from victims of three separate aviation accidents.
Identification of an Invariant Response: Stable Contact with Schwann Cells Induces Veil Extension in Sensory Growth Cones

Growth cones sense cues by filopodial contact, but how their motility is altered by contact remains unclear. Although contact could alter motile dynamics in complex ways, our analysis shows that stable contact with Schwann cells induces motility changes that are remarkably discrete and invariant. Filopodial contact invariably induces local veil extension. Even when contacts are brief, veils always extend before the filopodia retract. Contact at filopodial tips suffices for induction. Moreover, veils extend significantly sooner than on filopodia contacting laminin, which often detach without extending veils. The overall behavioral responses of the growth cone, such as increased area and turning, result from integrating multiple discrete responses. Cycles of veil induction enlarge the growth cone and often lead it onto the cell. Invariant veil induction is abolished by blocking N-cadherin signaling. We propose an axonal guidance model in which different guidance cues act by inducing different but discrete and invariant responses.
Serologic Examination of Aborted Ovine and Bovine Fetal Fluids for the Diagnosis of Border Disease, Bluetongue, Bovine Viral Diarrhea, and Leptospiral Infections:

Fetal serum from most of 994 bovine and 553 ovine aborted fetuses was tested serologically for antibodies to border disease (BD), bovine viral diarrhea (BVD), and bluetongue (BT) viruses, and to Leptospira sp., and the results were compared with the results of isolation procedures, fluorescent antibody tests (FAT), and histologic examinations of the same fetuses. Antibodies to BT virus were not found in any of the 994 bovine and 553 ovine fetuses. Antibody titers to BVD virus were present in 39 of 966 bovine fetuses tested, and BVD virus was detected in 4 of the 39. Four of 74 fetuses in which the BVD virus was detected by FAT or isolation had titers to BVD virus. Microagglutination (MAT) titers to 1 or more of 5 serovars of leptospires were present in 52 of 773 bovine fetal sera tested. Leptospires were not detected by FAT in any bovine fetuses that had leptospiral antibody titers. Leptospires were detected by FAT in 15 aborted calves, and none of these had MAT titers. Antibody titers to BD virus were present in 80 of 486 fetal lamb sera tested, and the virus was detected by FAT or isolation in 3 of the 80 fetuses. Border disease virus was detected in 14 of 486 fetal lambs tested. Twelve of the 14 were tested serologically and 3 had titers to BD virus. Leptospiral antibody titers were present in 27 of 326 ovine fetal sera tested. Leptospires were not detected in any of the 326 ovine fetuses tested by FAT.
Fifty years of cardiovascular science together

Circulation Research began 50 years ago, as I entered medical school in St Louis, and we have grown up together. I have luckily worked during a golden age for cardiovascular medicine, when biological and engineering sciences have prospered and greatly benefited our patients. This remarkable half-century testifies to the power of science to promote health. It is a vindication of the commitment my colleagues and I made to medical science so long ago and a tribute to the mission of Circulation Research . I will trace some of the scientific milestones, reflected by my Cardiology career. Having majored in history, I entered medical school in St Louis seriously deficient in science. I fortunately soon fell into the hands of Earl Sutherland, a physician who studied with Carl Cori and by 1952 was part of the Biochemistry faculty. He was trying to understand epinephrine action on glycogen metabolism, which subsequently led him to discover adenylyl cyclase and cAMP as the prototype “second messenger system,” winning the Nobel Prize in 1971. I worked half-time in his laboratory, purifying phosphorylase and absorbing his enthusiasm for science. During my second-year Pharmacology course, I was taught by Robert Furchgott, who received the Nobel Prize in 1998 for his work on nitric oxide. Medical school was exciting. During internship interviews with the prestigious Chairmen of Medicine, I was surprised that they grilled me on my research, not my clinical skills. So I returned to school and with two other students embarked on my first independent research effort to develop an antibody to lupus protein for immunolocalization. I collected plasma from a patient with severe systemic lupus erythematosus by withdrawing whole blood and returning packed red cells. Surprisingly, the patient immediately went into remission, possibly the first therapeutic plasmapheresis.1 Several supportive faculty provided the resources I …
Plasma deposition of tetraglyme inside small diameter tubing: Optimization and characterization

In this study, a glow discharge plasma deposition system previously used for treating flat substrates was successfully modified and optimized to produce a PEO-like coating on the inner surface of 1-3 mm ID polyethylene tubing by deposition of tetra ethylene glycol dimethyl ether (tetraglyme). The plasma treatment conditions were varied in order to find operating values that would produce coatings with the ultralow (< 5 ng/cm(2)) fibrinogen adsorption (Gamma(Fg)) previously shown necessary to significantly reduce platelet adhesion. The flow rate of gaseous tetraglyme monomer, pressure, and plasma generating power were found to be the most important parameters affecting the uniformity and chemical structure of the coating. The coating uniformity and quality were assessed by measuring Gamma(Fg) at positions 1 cm apart along the entire tube and the fraction of C1s carbon that was in an ether bond (ether-carbon ratio) by electron spectroscopy of chemical analysis. Under optimized conditions, tetraglyme plasma-coated tubes of up to 20 cm in length had ultralow Gamma(Fg). The region of the tube that had ultralow Gamma(Fg) also had C1s ether-carbon ratios that are greater than 50%.
High-frequency characterization of differential signals in a flip-chip organic package

As today's off-chip differential busses operate at a few Gbit/s and move to even higher speeds in the future, the chip package interconnect becomes a critical part of the entire signal transmission path. The package performance could determine the maximum frequency that the data can be transferred. The package interconnects have to be designed properly to maintain a constant characteristic impedance in order to minimize reflection and maximize transmission. To characterize the performance of packages, S-parameter measurement is widely used due to its accuracy and large dynamic range. However, a test fixture is usually required to enable the measurement. This paper describes a different method of characterizing the differential signals in a flip-chip organic package. This measurement technique probes the chip mounting pad side of the signal nets and does not require a test fixture. Both S-parameter and time domain reflectometer (TDR) measurements were compared to models extracted from electromagnetic (EM) simulations with good correlation. This technique is efficient, cost effective and provides a fast turn around time for measurements and models validation.
Performance comparison of matched filter receiver and twin processor for abutted waveforms

A new receiver structure is described for abutted waveform detection and estimation. The authors propose using abutted waveforms for a twin processor processing technique that reduces sidelobe interaction, thereby providing improved clutter rejection. The twin processor requires two looks at the channel, and using abutted waveforms it is possible to obtain both Doppler and range resolution. This makes it possible to design better detectors and to obtain improved estimates of the scattering function. The performance of the abutted waveform matched filter is evaluated and then compared to that of the twin processor. >
Vector analysis of ecoenzyme activities reveal constraints on coupled C, N and P dynamics

The primary goal of this study was to devise a quantitative method of interpreting the simultaneous microbial C, N, and P acquisition through the activities of four, key extracellular enzymes, 1,4-β-glucosidase (BG), leucine aminopeptidase (LAP), 1,4-s-N-acetylglucosaminidase (NAG) and acid/alkaline phosphatases (AP). To this end, the proportional activity of C vs. N acquiring enzymes (BG/[BG + NAG + LAP]) was plotted against C vs. P acquiring enzymes (BG/[BG + AP]). We then calculated the length and angle of the vector created by connecting a line between the plot origin and point represented by these proportions; the length quantifies relative C vs. nutrient limitation and the angle quantifies the relative P vs. N limitation. Analyses of large data sets obtained from soil, freshwater periphyton and aquatic sediments revealed that logarithmic, arcsine, arcsine-square-root and logit transformations did little to improve the statistical distribution of data over raw proportions. More importantly, the vector characteristics of enzyme activity loci are much easier to interpret for raw proportions than when data have been previously transformed. Analyses also revealed the importance of using consistent methods, i.e., omitting NAG assays for an acidic soil led to overestimates of P limitations, and the importance of understanding the nature of the system, i.e., soils of the Antarctic Dry Valleys had low BG activities, likely because there is little to no local production of cellulose. Further, analyses of four sites in Luquillo Forest, Puerto Rico, showed no differences among sites in relative C demand despite differences in BG activities, and higher P demand in the cloud than lower montane forest, despite higher AP activity at the latter site. Finally, analyses of three decomposing litter types over time revealed contrasting patterns of change in relative C, N and P demand over time, reflecting both stoichiometric and C quality effects on decomposer communities. Thus enzyme activity vectors reflect the simultaneous, relative resource demands of the microbial community independent of variations in total enzyme activity, such as may result from variations in total microbial biomass.
Simulation of the three-dimensional hinge flow fields of a bileaflet mechanical heart valve under aortic conditions.

Thromboembolic complications of bileaflet mechanical heart valves (BMHV) are believed to be due to detrimental stresses imposed on blood elements by the hinge flows. Characterization of these flows is thus crucial to identify the underlying causes for complications. In this study, we conduct three-dimensional pulsatile flow simulations through the hinge of a BMHV under aortic conditions. Hinge and leaflet geometries are reconstructed from the Micro-Computed Tomography scans of a BMHV. Simulations are conducted using a Cartesian sharp-interface immersed-boundary methodology combined with a second-order accurate fractional-step method. Physiologic flow boundary conditions and leaflet motion are extracted from the Fluid–Structure Interaction simulations of the bulk of the flow through a BMHV. Calculations reveal the presence, throughout the cardiac cycle, of flow patterns known to be detrimental to blood elements. Flow fields are characterized by: (1) complex systolic flows, with rotating structures and slow reverse flow pattern, and (2) two strong diastolic leakage jets accompanied by fast reverse flow at the hinge bottom. Elevated shear stresses, up to 1920 dyn/cm2 during systole and 6115 dyn/cm2 during diastole, are reported. This study underscores the need to conduct three-dimensional simulations throughout the cardiac cycle to fully characterize the complexity and thromboembolic potential of the hinge flows.
The pressure field due to a large circular capped air bubble rising in water

The pressure field due to a large circular capped air bubble rising in water has been determined experimentally. The results verify the Davies & Taylor cap boundary condition and the frontal pressure field is well approximated by that due to irrotational flow around an oval body.The pressure field extends axially as far as ten bubble half-widths below the bubble floor. Immediately below the floor the pressure is constant for about two-thirds of a bubble height. The wake is closed and contains symmetric pressure minima. For the bubbles studied, turbulence, as well as the diffusion of vorticity, probably controls the momentum distribution and energy dissipation in the wake.
Migration and fuel use in rural Mexico

Many households in developing countries rely on renewable natural resources as their main source of energy. Collecting and burning firewood requires a considerable amount of time, has negative health consequences, and can cause deforestation and depletion of local resources if forests are not properly managed. A transition from traditional to modern fuels can benefit households by reducing these negative effects. Migration, a quintessential feature of development, may facilitate this transition, but its impacts on fuel choice are theoretically ambiguous. It can reduce the household labor available for firewood collection and provide cash to purchase substitutes; however, it has an income effect that changes the demand for home-cooked food and energy to cook it. Firewood or gas could be used to meet the increase in energy demand. To resolve this theoretical ambiguity, we use an instrumental-variables method with household panel data from rural Mexico and investigate the impact of Mexico-to-US migration and remittances on gas expenditures and household labor allocated to firewood collection. Sending a migrant to the United States causes a significant decrease in reliance on firewood collection and an increase in both stove and gas purchases. These findings have potentially far-reaching environmental implications as labor moves off the farm.
Neural Correlates of Perceptual Decision Making before, during, and after Decision Commitment in Monkey Frontal Eye Field

Perceptual decision making requires a complex set of computations to implement, evaluate, and adjust the conversion of sensory input into a categorical judgment. Little is known about how the specific underlying computations are distributed across and within different brain regions. Using a reaction-time (RT) motion direction-discrimination task, we show that a unique combination of decision-related signals is represented in monkey frontal eye field (FEF). Some responses were modulated by choice, motion strength, and RT, consistent with a temporal accumulation of sensory evidence. These responses converged to a threshold level prior to behavioral responses, reflecting decision commitment. Other responses continued to be modulated by motion strength even after decision commitment, possibly providing a memory trace to help evaluate and adjust the decision process with respect to rewarding outcomes. Both response types were encoded by FEF neurons with both narrow- and broad-spike waveforms, presumably corresponding to inhibitory interneurons and excitatory pyramidal neurons, respectively, and with diverse visual, visuomotor, and motor properties, albeit with different frequencies. Thus, neurons throughout FEF appear to make multiple contributions to decision making that only partially overlap with contributions from other brain regions. These results help to constrain how networks of brain regions interact to generate perceptual decisions.
Genetic fusions that help define a transcription termination region in Escherichia coli.

Abstract The trp A gene product was analyzed from a class of strains of Escherichia coli K12 in which the lac operon has been fused by deletion to the trp operon. These are strains that have retained the ability to synthesize tryptophan. Two of these strains are shown to make a wild-type trpA product; these strains retain intact all structural genes of the t trp operon. It is proposed that the lac operon in these strains is fused to a region of the trp operon between trpA , the last gene in the operon, and the region where trp messenger RNA synthesis terminates. The region where trp messenger RNA synthesis terminates thus is distinct from the trp structural genes.
PERT Scheduling Techniques for Engineering Projects

The sections in this article are 1 Introduction and Historical Perspectives 2 PERT/CPM Tools 3 Precedence Structure 4 PERT Network Analysis 5 Complexity of PERT Networks 6 Resource Allocation in PERT Networks 7 Critical Resource Diagramming 8 Resource Scheduling Constraints 9 Resource Profiling 10 Resource Leveling 11 Resource Idleness 12 CRD Network Construction 13 CRD Network Analysis 14 Resource Schedule Chart 15 CRD and Work Rate Analysis 16 Computational Examples 17 Conclusion
Virtual distributed environments in a shared infrastructure

We have developed a middleware system that integrates and extends virtual machine and virtual network technologies to support mutually isolated virtual distributed environments in shared infrastructures like the grid and the PlanetLab overlay infrastructure. Integrating virtual network and on-demand virtual machine creation and customization technologies makes virtual distributed environments a reality. The Violin-based middleware system integrates and enhances such technologies to create virtual distributed environments.
THE ROLE OF DOPAMINE IN REINFORCEMENT: CHANGES IN REINFORCEMENT SENSITIVITY INDUCED BY D1-TYPE, D2-TYPE, AND NONSELECTIVE DOPAMINE RECEPTOR AGONISTS

Dose-dependent changes in sensitivity to reinforcement were found when rats were treated with low, moderate, and high doses of the partial dopamine D1-type receptor agonist SKF38393 and with the nonselective dopamine agonist apomorphine, but did not change when rats were treated with similar doses of the selective dopamine D2-type receptor agonist quinpirole. Estimates of bias did not differ significantly across exposure to SKF38393 or quinpirole, but did change significantly at the high dose of apomorphine. Estimates of goodness of fit (r2) did not change significantly during quinpirole exposure. Poor goodness of fit was obtained for the high doses of SKF38393 and apomorphine. Decrements in absolute rates of responding were observed at the high dose of quinpirole and at the moderate and high doses of SKF38393 and apomorphine. Changes in r2 and absolute responding may be due to increases in stereotyped behavior during SKF38393 and apomorphine exposure that, in contrast to quinpirole, were distant from the response lever. The present data provide evidence that sensitivity to reward is affected more strongly by dopamine D1-like receptors rather than D2-like receptors, consistent with evidence from other studies investigating consummatory dopamine behavior and the tonic/phasic dopamine hypothesis.
Gravitational energy sources in Jupiter

Gravitational sources of the intrinsic luminosity of Jupiter are examined in the context of current hydrogen-helium models. When no gravitational separation of matter occurs, the amount of heat which can be released over the remaining lifetime of the planet is necessarily limited by the size of its existing reservoir of thermal energy. This conclusion rests only on the assumption that its interior is relatively cold and degenerate. If gravitational unmixing occurs, the size of the thermal reservoir does not necessarily limit the heat output. If core formation occurs, for example, then the size of the core formed will be a limiting factor. The energy released with the formation of a helium core is computed for Jupiter. A core growth rate, averaged over several billion years, of 20 trillionths of Jupiter's mass per year is required if gravitational separation is to play a significant role in the thermal evolution.
Federal Spending On Behavioral Health Accelerated During Recession As Individuals Lost Employer Insurance

The 2007–09 recession had a dramatic effect on behavioral health spending, with the effect most prominent for private, state, and local payers. During the recession behavioral health spending increased at a 4.6 percent average annual rate, down from 6.1 percent in 2004–07. Average annual growth in private behavioral health spending during the recession slowed to 2.7 percent from 7.2 percent in 2004–07. State and local behavioral health spending showed negative average annual growth, −1.2 percent, during the recession, compared with 3.7 percent increases in 2004–07. In contrast, federal behavioral health spending growth accelerated to 11.1 percent during the recession, up from 7.2 percent in 2004–07. These behavioral health spending trends were driven largely by increased federal spending in Medicaid, declining private insurance enrollment, and severe state budget constraints. An increased federal Medicaid match reduced the state share of Medicaid spending, which prevented more drastic cuts in state-funded...
Nonlinear Uniaxial Material Model for Reinforcing Steel Bars

Recent advances in nonlinear analysis of reinforced concrete structures have been based primarily on fiber-based discretization of the member cross section at locations of expected inelastic action. However, the accuracy of a fiber-section model is almost entirely dependent on the ability of constitutive material models to represent the overall inelastic behavior of the member. The postyield response of an RC element is controlled by the longitudinal reinforcing steel and the confinement provided by the transverse reinforcement. While adequately confined concrete exhibits stable hysteretic behavior, poorly confined sections degrade rapidly initiated in part by buckling of the longitudinal reinforcement. Particular attention must, therefore, be given to the stress-strain model used to represent the behavior of reinforcing steel bars. The development and validation of an advanced material model for reinforcing bars in RC members is presented in this paper. First, a base material model to describe the primary cyclic stress-strain relationship of reinforcing steel is developed. Using available concepts to initiate bar buckling, low-cycle fatigue fracture, and cyclic degradation, a generic phenomenological material model is developed and implemented in an open-source computational platform. The effectiveness of the new reinforcing bar model is validated through comparison with available experimental data.
Scientific Drilling to Study Physical Properties and the State of Stress in the Earth’s Crust: An Opportunity for Mid-Crustal Measurements Near the San Andreas Fault

In recent years we have conducted studies of the state of stress, distribution of natural fractures, hydraulic conductivity, and P- and S-wave seismic velocity to depths of about 1.5 km in wells drilled primarily in crystalline rock. Similar studies are needed at greater depth and in boreholes drilled at critical locations to provide data to test a variety of hypotheses which affect a broad range of problems in the earth sciences. In this paper, some of these problems are briefly reviewed to indicate the important need for additional data and direct in situ experimentation. One specific site for downhole measurements is presented where in situ stress and temperature measurements would have the opportunity to resolve the order-of-magnitude uncertainty about the level of shear stress on the San Andreas fault.
The role of scattering and absorption on the optical properties of birefringent polycrystalline ceramics: Modeling and experiments on ruby (Cr:Al2O3)

Light scattering due to birefringence has prevented the use of polycrystalline ceramics with anisotropic optical properties in applications such as laser gain media. However, continued development of processing technology has allowed for very low porosity and fine grains, significantly improving transparency and is paving the way for polycrystalline ceramics to be used in demanding optical applications. We present a method for producing highly transparent Cr3+ doped Al2O3 (ruby) using current activated pressure assisted densification. The one-step doping/densification process produces fine grained ceramics with well integrated (doped) Cr, resulting in good absorption and emission. In order to explain the light transmission properties, we extend the analytical model based on the Rayleigh-Gans-Debye approximation that has been previously used for undoped alumina to include absorption. The model presented captures reflection, scattering, and absorption phenomena in the ceramics. Comparison with measured tran...
Electrical uncoupling and impulse propagation in isolated sheep Purkinje fibers.

Alterations in electrical coupling may have a major role in the development of cardiac rhythm and conduction disturbances. We have used microelectrodes and linear Purkinje fibers to analyze the rel...
Acute Cerebellar Ataxia: An Unusual Pediatric Case

Abstract Background Acute cerebellar ataxia is a clinical syndrome with sudden onset of uncoordinated gait and normal mental status in young children. Although it has a benign clinical course, it often requires an exhaustive diagnostic work-up in order to rule out potentially life-threatening etiologies that present similarly. The wide differential encompasses causes from infections, brain masses, drugs, toxins, trauma, paraneoplastic syndromes, as well as hereditary or congenital disorders. Case Report We report on a 4-year-old boy with recent hand-foot-mouth disease who presented with acute cerebellar ataxia. In addition to his marked truncal ataxia and wide-based, staggering gait, he had slowness of speech, which is not commonly reported with this condition in the literature. Why Should an Emergency Physician Be Aware of This? Emergency physicians have a unique role in being first to evaluate pediatric ataxia and can make a significant impact on identifying potentially fatal mimickers of acute cerebellar ataxia. This article will attempt to outline major diagnostic considerations in order to aid emergency physicians through their clinical approach.