cssi/SciSciGPT-SciSciNet huggingface dataset:
Suicidal Behavior and HIV/AIDS: A Partial Test of Joiner's Theory of Why People Die by Suicide

Suicidal behavior occurs among people living with HIV/AIDS. Thomas Joiner has postulated that in order to complete suicide three variables must be present—perceived burdensomeness and thwarted belongingness, and acquired capacity. We examined these three concepts in a partial test of Thomas Joiner's interpersonal-psychological theory of suicidal behavior. Our sample consisted of 52 individuals that were receiving services at HIV/AIDS clinics. These individuals were divided into two groups—one with suicidal behaviors, the other with no suicidal behaviors. Acquired capacity was limited to medication adherence and both groups reported good adherence with their medications. Results show those in the suicidal behavior group experience slightly more perceived burdensomeness and feelings of thwarted belongingness than those in the no suicidal behaviors group. These findings and suggestions for future research are presented.
Specificity and degeneracy in antigen recognition: yin and yang in the immune system.

One of the hallmarks of the immune system is specificity, a concept based on innumerable observations that antibodies react with the substance that elicited their production and only a few other structurally similar substances. The study of T cells has begun to suggest, however, that in responses mediated by their antibody-like receptors (T cell receptor or TCR) an individual T cell, expressing a singular TCR, can discriminate as exquisitely among antigens as the most specific antibodies but also exhibit “degeneracy”: i.e., it can react with many disparate antigens (peptide-MHC complexes). An explanation for this duality (specificity and degeneracy) can be found in (i) the powerful amplifying signal transduction cascades that allow a T cell to respond to the stable engagement of very few TCR molecules, initially perhaps only one or two out of around 100,000 per cell, by their natural ligands (peptide-MHC complexes or epitopes on antigen-presenting cells—or APC) and (ii) the inverse relationship between TC...
Synaptotagmin-7 Is Essential for Ca2+-Triggered Delayed Asynchronous Release But Not for Ca2+-Dependent Vesicle Priming in Retinal Ribbon Synapses.

Most synapses release neurotransmitters in two phases: (1) a fast synchronous phase lasting a few milliseconds; and (2) a delayed “asynchronous” phase lasting hundreds of milliseconds. Ca2+ triggers fast synchronous neurotransmitter release by binding to synaptotagmin-1, synaptotagmin-2, or synaptotagmin-9, but how Ca2+ triggers delayed asynchronous release has long remained enigmatic. Recent results suggested that consistent with the Ca2+-sensor function of synaptotagmin-7 in neuroendocrine exocytosis, synaptotagmin-7 also functions as a Ca2+ sensor for synaptic vesicle exocytosis but operates during delayed asynchronous release. Puzzlingly, a subsequent study postulated that synaptotagmin-7 is not a Ca2+ sensor for release but mediates Ca2+-dependent vesicle repriming after intense stimulation. To address these issues, we here analyzed synaptic transmission at rod bipolar neuron–AII amacrine cell synapses in acute mouse retina slices as a model system. Using paired recordings, we show that knock-out of synaptotagmin-7 selectively impairs delayed asynchronous release but not fast synchronous release. Delayed asynchronous release was blocked in wild-type synapses by intracellular addition of high concentrations of the slow Ca2+-chelator EGTA, but EGTA had no effect in synaptotagmin-7 knock-out neurons because delayed asynchronous release was already impaired. Moreover, direct measurements of vesicle repriming failed to uncover an effect of the synaptotagmin-7 knock-out on vesicle repriming. Our data demonstrate that synaptotagmin-7 is selectively essential for Ca2+-dependent delayed asynchronous release in retinal rod bipolar cell synapses, that its function can be blocked by simply introducing a slow Ca2+ buffer into the cells, and that synaptotagmin-7 is not required for normal vesicle repriming. SIGNIFICANCE STATEMENT How Ca2+ triggers delayed asynchronous release has long remained enigmatic. Synaptotagmin-7 has been implicated recently as Ca2+ sensor in mediating delayed asynchronous release, or vesicle repriming, in cultured neurons. To test the precise function of synaptotagmin-7 in a physiologically important synapse in situ, we have used pair recordings to study the synaptic transmission between retinal rod bipolar cells and AII amacrine cells. Our data demonstrate that the knock-out of synaptotagmin-7 selectively impaired delayed asynchronous release but not synchronous release. In contrast, the readily releasable vesicles after depletion recover normally in knock-out mice. Therefore, our findings extend our knowledge of synaptotagmins as Ca2+ sensors in vesicle fusion and support the idea that synapses are governed universally by different synaptotagmin Ca2+ sensors mediating distinct release.
New Potassium Binders for the Treatment of Hyperkalemia: Current Data and Opportunities for the Future

Hyperkalemia is a clinical problem with potential mechanisms ranging from increased cellular potassium release (eg, pseudohyperkalemia, metabolic acidosis) to reduced potassium excretion (eg, reduced responsiveness to aldosterone, reduced aldosterone secretion, reduced distal sodium, and water delivery).1,2 Patients with chronic kidney disease (CKD), defined as an estimated glomerular filtration rate (eGFR) <45 mL/min per 1.73 m2, are at increased risk of hyperkalemia, resulting from ≥1 of these mechanisms.3 Renin–angiotensin–aldosterone system inhibitors (RAASis) are recommended by guidelines for lowering blood pressure, slowing CKD progression in patients with CKD,4,5 and reducing cardiovascular mortality and heart failure hospitalizations in patients with heart failure and a reduced ejection fraction,6,7 but these drugs compound the hyperkalemia risk.1,8–10 The risk is magnified when the drugs are used in combination (eg, aliskiren in combination with ACE inhibitors or angiotensin receptor blockers;8,11 mineralocorticoid receptor antagonists in combination with ACE inhibitors or angiotensin receptor blockers). Moreover, the risk for hyperkalemia is magnified in diseases, such as diabetes mellitus and heart failure.4,5,12,13 The occurrence or fear of inducing hyperkalemia has led to premature discontinuation, suboptimal dosing, and often failure to use an RAASi, thereby exposing patients to increased cardiovascular risk. Current treatment approaches for chronic hyperkalemia are limited. Options for the management of hyperkalemia include discontinuation or reduced doses of RAASi, administration of loop diuretics, dietary potassium restriction, or sodium polystyrene sulfonate.14 None of these approaches are optimal because they require withholding life-saving or kidney preserving therapy (ie, RAASi), have a low rate of patient adherence (eg, dietary restriction), or have an unfavorable adverse effect profile and low tolerability (ie, sodium polystyrene sulfonate).15 New agents to treat hyperkalemia are in the late …
The long-term outcome of visually directed subendocardial resection in patients without inducible or mappable ventricular tachycardia at the time of surgery.

Visually Directed Subendocardial Resection. introduction: in prior studies, 20% to 40% of patients undergoing subendocardial reaction (SER) for ventricular tachycardia (VT) could not he mapped intraoperatively because the VT was either noninducible or nonmappable following the ventriculotomy. The optimal surgical approach to such patients is not known. Methods and Results: In this study, we retrospectively compared the long-term survival and functional outcome of 29 patients with VT and prior myocardial infarction who were either noninducible or nonmappable intraoperatively and underwent a visually directed extended SER These results were then compared to 85 patients who had inducible VT intraoperatively and underwent a map-guided sequential SER. The two patient groups had different clinical characteristics. The visually directed cohort was more likely to he male, experienced fewer VT episodes before surgery, and underwent fewer antiarrhythmic drug trials prior to reaction. In addition, the visually directed group had slower VT induced at a preoperative electrophysiologic study and was less likely to present to the operating room in stock or incessant VT than the map-guided group. The postoperative VT clinical recurrence or inducibility rate was 14% in both the visually directed and map-guided groups. The long-term actuarial survival at 1, 3, and 5 years was 93%, 86%, and 75%, respectively, in the visually directed group, compared to 77%, 58%, and 58%, respectively, in the map-guided group (P = 0.06). There were no documented nonfatal recurrences of VT in either group. At 24 months following surgery, 77% of patients who had a visually directed SER were in New York Heart Association Functional Class I or II, compared to 46% of patients who underwent a map-guided SER (P < 0.05). Conclusion: In patients with VT and prior myocardial infarction, the inability to induce or map the VT in the operating room does not preclude a favorable long-term outcome if a visually directed extended SER technique is used.
Presynaptic inhibition preferentially reduces the NMDA receptor-mediated component of transmission in rat midbrain dopamine neurons

We used patch pipettes to record whole-cell currents from single dopamine neurons in slices of rat midbrain. Pharmacological methods were used to isolate EPSCs evoked by focal electrical stimulation. Baclofen was significantly more potent for inhibiting NMDA receptor-mediated EPSCs (IC50=0.24 microM) compared with inhibition of EPSCs mediated by AMPA receptors (IC50=1.72 microM). The increased potency of baclofen for inhibiting the NMDA component persisted in superfusate that contained zero Mg2+ and when postsynaptic K+ conductances were reduced by Cs+ and QX-314. Effects of baclofen on EPSCs were blocked by the GABA(B) receptor antagonist CGP-35348. Adenosine was 20 fold more potent for reducing the NMDA component of transmission (IC50=31 microM) compared with inhibition of AMPA receptor-mediated EPSCs (IC50=654 microM). Effects of adenosine on EPSCs were blocked by the A1 receptor antagonist DPCPX. Both baclofen and adenosine significantly increased the ratio of EPSCs in paired-pulse studies, suggesting presynaptic sites of action. Although adenosine (1 mM) did not reduce currents evoked by exogenous NMDA (10 microM), baclofen (1 microM) reduced NMDA currents by 29%. Neither baclofen nor adenosine altered currents evoked by exogenous AMPA (1 microM). We conclude that adenosine acts at presynaptic A1 receptors to cause a preferential reduction in the NMDA component of synaptic transmission. In contrast, baclofen preferentially reduces NMDA EPSCs by acting at both pre- and postsynaptic GABA(B) receptors. By regulating NMDA receptor function, A1 and GABA(B) receptors may play important roles in regulating the excitability of dopamine neurons.
Disorders of the long head of the biceps tendon.

Without a clear understanding of the functional role of the biceps tendon, treatment recommendations have been a subject of controversy. An objective review of the available information would suggest that some humeral head stability may be imparted through the tendon. However, the magnitude of this function is likely to be small and possibly insignificant. In contrast, the symptomatic significance of the long head of the biceps is less controversial, and it has become increasingly recognized as an important source of persistent shoulder pain when not specifically addressed. When present, persistent pain from the long head of the biceps is likely to have more negative functional consequences than loss of the tendon itself. Given these concerns, evaluation and treatment of patients with long head of the biceps disorders should be individualized, based on the likelihood that biceps-related pain will resolve. Although not universally accepted, we recommend tenodesis of the long head of the biceps in those cases in which there are either chronic inflammatory or structural changes, which would make it unlikely that the pain would resolve. These clinical situations in which tenodesis would be required include greater than 25% partial thickness tearing of the tendon, chronic atrophic changes of the tendon, any luxation of the biceps tendon from the bicipital groove, any disruption of associated bony or ligamentous anatomy of the bicipital groove that would make autotenodesis likely (i.e., 4-part fracture), and any significant reduction or atrophy of the size of the tendon that is more than 25% of the normal tendon width. Relative indications for biceps tenodesis also include biceps disease in the context of a failed decompression for rotator cuff tendinitis. It should be emphasized that routine tenodesis is not recommended during operative treatment for the rotator cuff. Rather, we avoid tenodesis whenever it is believed that inflammatory changes to the biceps tendon are reversible. Because of this, tenodesis is not required in most cases.
Kinetics of Localized Laser-Photochemical Deposition

Highly localized metal deposits can be produced at low temperature by direct writing using a focused laser beam to induce photodissociation of gaseous organometallic precursors. The deposition rate and localization of the deposit are influenced by the kinetics of photochemical reaction and transport of reactants and products. Two-dimensional finite-element computations were performed to determine the effect of deposition parameters, such as laser power, precursor concentration, system pressure, and sticking coefficient, on deposition rates and deposit profiles resulting from single-photon gas-phase dissociation of organometallic precursors. The effect of various gas-phase transport regimes and the conditions and importance of reactant depletion have been investigated. Numerical results have also been compared to theoretical and experimental results from the literature.
Reasoning about human participation in self-adaptive systems

Self-adaptive systems overcome many of the limitations of human supervision in complex software-intensive systems by endowing them with the ability to automatically adapt their structure and behavior in the presence of runtime changes. However, adaptation in some classes of systems (e.g., safety-critical) can benefit by receiving information from humans (e.g., acting as sophisticated sensors, decision-makers), or by involving them as system-level effectors to execute adaptations (e.g., when automation is not possible, or as a fallback mechanism). However, human participants are influenced by factors external to the system (e.g., training level, fatigue) that affect the likelihood of success when they perform a task, its duration, or even if they are willing to perform it in the first place. Without careful consideration of these factors, it is unclear how to decide when to involve humans in adaptation, and in which way. In this paper, we investigate how the explicit modeling of human participants can provide a better insight into the trade-offs of involving humans in adaptation. We contribute a formal framework to reason about human involvement in self-adaptation, focusing on the role of human participants as actors (i.e., effectors) during the execution stage of adaptation. The approach consists of: (i) a language to express adaptation models that capture factors affecting human behavior and its interactions with the system, and (ii) a formalization of these adaptation models as stochastic multiplayer games (SMGs) that can be used to analyze human-system-environment interactions. We illustrate our approach in an adaptive industrial middleware used to monitor and manage sensor networks in renewable energy production plants.
Policy reappraisal and maintenance

Abstract The need for policy reappraisal grows out of the dynamics of our modern economic society, including such factors as cyclical changes, competitors' actions, organizational changes, new or changed objectives, and the frequency of use. Policies may need realignment to match organizational changes, to eliminate overlap, and to harmonize with centers of responsibility. Semantic problems are symptoms of the importance of restating policies periodically because of colloquialisms, legal interpretations, and archaic expressions. Devices that can be effectively used to aid in evaluating policies include the “exception principle” to highlight the prospective candidates for review; use of “trial institution”; and check lists found in management literature. Vital to any policy maintenance program is regular use of techniques to ascertain whether those employees guided by the policies understand and use them. Methods of communication must not only be used but the results of the communication must be appraised so that proper policies can be of maximum benefit to a firm.
Control over Fe3+ speciation in colloidal ZnO nanocrystals

The incorporation of potentially redox active dopant ions holds much promise for applications in catalysis and energy. Here we report the room-temperature synthesis of colloidal Fe-doped ZnO nanocrystals. By combining detailed dopant-specific spectroscopy with known single crystal data we are able to elucidate the locations of paramagnetic Fe3+ ions in the colloidal ZnO nanocrystals. Electron paramagnetic resonance (EPR) spectra of 0.15–2.0% Fe-doped ZnO nanocrystals are consistent with the Fe dopants occupying both pseudo-tetrahedral (substitutional at the Zn-site) and pseudo-octahedral (surface and interstitial) coordination environments. The evolution of the spectra as a function of ZnO growth time allow us to provide additional mechanistic insight into the formation of doped colloidal ZnO nanocrystals using a simple room temperature synthetic method. We also demonstrate control over the speciation of the Fe dopants in colloidal ZnO nanocrystals by changing the growth and/or surface-ligand treatment times.
Regulation of natural killer cell cytotoxicity by prostaglandin E in the peripheral blood and cerebrospinal fluid of patients with multiple sclerosis and other neurological diseases part 1. Association between amount of prostaglandin produced, natural killer, and endogenous interferon☆

Abstract MS patients' peripheral blood mononuclear cells (MNC) spontaneously produced more prostaglandin E 1&2 (PGE) in vitro than did OND or normal control MNC correlating with lower levels of NK activity and endogenous interferon (IFN) production while there were no differences between OND and normal controls. MS neat CSF contained significantly higher levels of measurable PGE with concomitantly lower NK activity and % IFN-positive cells than was seen in OND CSF. The PGE producing cells were depleted in the nylon wool-passed (NWP) and enriched in the nylon wool-adherent (NWAd) populations in direct correlation with depletion and enrichment of esterase-positive monocyte/macrophages, respectively, suggesting that at least some of the PGE-producing cells were adherent monocyte/ macrophages. At 24 and 48 h after stimulation with PHA, MS unfractionated MNC produced significantly more PGE than OND and normal MNC; at 24 and 72 h, MS NWAd cells produced significantly more PGE than normals and ONDs, MS and ONDs produced the same amount of PGE at 48 h in the stimulated NWAd fraction.
Eigenmode Analysis of Unsteady Flows about Airfoils

We present a reduced-order modelling technique for analyzing the unsteady subsonic aerodynamic flow about isolated airfoils. To start, we model the flow using the time-linearized full potential equation. The linearized potential equation is discretized on a computational mesh composed of quadrilateral elements using a variational finite element technique. The resulting discretized equations are linear in the unknown potential, but quadratic in the reduced frequency of vibration. We compute the dominant (low frequency) eigenfrequencies and mode shapes of the unsteady fluid motion using a nonsymmetric Lanczos algorithm, and then we use these eigenmodes to construct a low degree-of-freedom reduced-order model of the unsteady flow field. A static correction technique is used to account for the high-frequency eigenmodes not retained in the model. We show that the unsteady flow can be modelled accurately using a relatively small number of eigenmodes.
Peer, parent, and media influences in teen apparel shopping

Recently developed normative versus informative interpersonal influence scales were modified and extended to explore interpersonal influences in teen apparel shopping. Three major influence sources were considered—peers, parents, and the media. Major findings indicated that teens receive significantly more parental influences during special shopping than ordinary shopping; parent- and media-informative influences exceed almost all others whereas media-normative influence is dominated by almost all other influences. These findings suggest that advertisers and marketers could avoid targeting teens with normative messages, since they are more likely to reach teens through informative messages specifically directed at their parents. Teen age, gender, family size, and gift money to teens were found to significantly affect the level and type of teen apparel shopping influences.
A unique sorting nexin regulates trafficking of potassium channels via a PDZ domain interaction

G protein-gated potassium (Kir3) channels are important for controlling neuronal excitability in the brain. Using a proteomics approach, we have identified a unique rodent intracellular protein, sorting nexin 27 (SNX27), which regulates the trafficking of Kir3 channels. Like most sorting nexins, SNX27 possesses a functional PX domain that selectively binds the membrane phospholipid phosphatidylinositol-3-phosphate (PI3P) and is important for trafficking to the early endosome. SNX27, however, is the only sorting nexin to contain a PDZ domain. This PDZ domain discriminates between channels with similar class I PDZ-binding motifs, associating with the C-terminal end of Kir3.3 and Kir3.2c (-ESKV), but not with that of Kir2.1 (-ESEI) or Kv1.4 (-ETDV). SNX27 promotes the endosomal movement of Kir3 channels, leading to reduced surface expression, increased degradation and smaller Kir3 potassium currents. The regulation of endosomal trafficking via sorting nexins reveals a previously unknown mechanism for controlling potassium channel surface expression.
Acetylcholinesterase hydrolysis of halogen substituted acetylcholines.

Abstract The fluoro-, chloro-, dichloro-, trichloro-, bromo- and iodoacetylcholines were synthesized to study the relative roles of: (1) the electronic characteristics of carbonyl keto function, and (2) the configuration and the associated steric effects of the halogenated acyl group of cholinesters on acetylcholinesterase (AChE)-substrate interaction. The reaction kinetics of the hydrolysis by AChE (from bovine erythrocytes) were studied by standard manometric techniques. Although haloacetic acids are stronger acids than acetic acid, their cholinesters exhibit lower affinities (Km × 10−3 M: fluoroacetylcholine, 4.11; chloroacetylcholine, 6.42; bromoacetylcholine, 8.18; iodo-acetylcholine, 6.62; acetylcholine, 1.04) and lower rates of hydrolysis (Vmnx, μl CO 2 hr : fluoroacetylcholine, 309; chloroacetylcholine, 170; bromoacetylcholine, 192; iodoacetyl-choline, 211; acetyleholine, 358) than those of acetylcholine (ACh). The Van der Waals' radius of C-R (where RH in ACh and F, Cl, Br or I in halogen-substituted acetylcholines) gives an indication of the space required for the acyi group at a position adjacent to the esteratic site during AChE-substrate interaction. The initial rates of hydrolysis of cholinesters at their pS-optima could be arranged in the following order: acetylcholine = fluoroacetylcholine > propionylcholine > chloroac etylcholine = bromoacetylcholine = iodoacetylcholine > butyrylcholine. At low substrate concentrations (pS 3.0 to 2.5), the rate of hydrolysis of ACh was higher than that of fluoroacetyl-choline. The Van der Waals' radius of C-R and Km increase from ACh to butyryl-choline. The rate of hydrolysis of dichloroacetylcholine is about 1 5 of that of ACh. The enzymic hydrolysis of trichloroacetylcholine is not significant. Therefore, the steric effects due to halogenation of the acyi group play a significant role in AChE hydrolysis of halogen-substituted acetylcholines.
Model fermion Monte Carlo method with antithetical pairs.

We consider certain model systems within which we seek solutions of the Schr\"odinger equation that are antisymmetric on inversion in the origin. We find geometrical constructions that define sequences of correlated random walks for which the overlap with antisymmetrical test functions are asymptotically constant. The emphasis here is on problems in two dimensions, but the methods generalize to many dimensions and to certain other model problems.
Informal institutions rule: institutional arrangements and economic performance

Institutions are widely believed to be important for economic development. This paper attempts to contribute to our understanding of how institutions matter by examining the effect of formal and informal institutional arrangements on economic progress. Formal institutions represent government defined and enforced constraints while informal institu- tions capture private constraints. The findings suggest that the presence of informal insti- tutions is a strong determinant of development. In contrast, formal institutions are only successful when embedded in informal constraints, and codifying informal rules can lead to negative unintended consequences. This suggests that institutions cannot be easily trans- planted in order to spur economic development.
Utilization of Patient-Reported Outcomes as a Step towards Collaborative Medicine

Patient-reported outcomes (PROs) have been successfully developed for a variety of chronic respiratory diseases, such as asthma and cystic fibrosis (CF). They have recently been used to evaluate the efficacy of new medications and assess current patient functioning. Although regulatory bodies have favored PROs that measures symptoms, other domains of functioning, such as treatment burden, should be considered. This review examines current guidelines for the development and application of PROs in clinical trials, describes methods for selecting appropriate measures for paediatric populations, and presents a model incorporating PROs into clinical practice. Guidance on interpretation of these measures and graphic presentation of results are illustrated. PROs can serve as the link between the health care provider and patient to foster collaborative and personalized medicine. This model promotes greater patient responsibility, facilitates communication with providers, encourages shared decision-making, and enhances adherence.
EMBEDDED ELECTRONICS FOR INTELLIGENT STRUCTURES

Intelligent structures with integrated control systems consisting of large numbers of distributed sensors, actuators, and processors have been proposed for the precision control of structures. This report examines the feasibility of physically embedding the electronic components of such systems. The hardware implications of functionality distribution are addressed, and it is shown that highly distributed systems can have substantially fewer communications lines and faster control loop speeds than conventional approaches, at the cost of embedding electronic circuit chips. A technique for the embedding procedure is presented which addresses electrical, mechanical, and chemical compatibility issues. Test specimens with functioning integrated circuits successfully embedded within graphite/epoxy composite laminates were subjected to static and cyclic mechanical loads, demonstrating nominal electrical function above normal design load limits. Operation of test specimens in a high temperature/humidity environement allowed the identification of a corrosive failure mode of the leads or lead-chip bonds. The application of a single-chip microcomputer to the control of a structural vibration problem demonstrates the potential for the development of monolithic integrated circuit devices capable of performing distributed processing tasks required for fully integrated intelligent structures.
Mid-infrared erbium:YAG laser ablation of bone: the effect of laser osteotomy on bone healing.

A comparative study was undertaken in rabbit tibiae to assess the healing of bone in response to osteotomies by a mid-infrared erbium:YAG (2.94 μm) laser or a mechanical saw. Laser parameters necessary for osteotomy were shown to produce deep cuts with sharp edges and no gross charring or burning of adjacent bone. However, it was noted histologically that there was a delay in healing of the laser osteotomies as compared to saw osteotomies. This delay was caused by a microscopic zone of damage to bone adjacent to the laser cuts. It is concluded that, although the erbium:YAG laser may be a useful tool in orthopaedic surgery to ablate bone, under the conditions used in this study, there will be a delay in the healing process after laser osteotomy.
Alfalfa Establishment with Diverse Annual Ryegrass Cultivars

There is limited information on forage yield and nutritional value of binary mixtures of annual ryegrass (Lolium multiflorum Lam.) with forage legumes in the north-central USA. A diverse set of annual ryegrass cultivars in binary mixtures with alfalfa (Medicago sativa L.) was evaluated for seeding-year forage yield and nutritional value and for forage yield and alfalfa presence the year after seeding. Annual ryegrass cultivars differing in ploidy and maturity were sown at 215 seeds m -2 with alfalfa at two locations in Wisconsin in spring 1990 and 1991. As a control, alfalfa was also sown alone. Seeding-year forage yields of ryegrass-alfalfa mixtures ranged from 5.00 to 10.65 Mg ha -1 in 1990 and from 7.06 to 8.96 Mg ha -1 in 1991. Mixtures of alfalfa with early-maturing ryegrass cultivars were higher in yield and fiber fractions (neutral- and acid-detergent fiber) and lower in crude protein concentration than mixtures with late-maturing ryegrass cultivars, with greater differences observed in 1990 than 1991. The ryegrass-alfalfa mixtures usually were higher yielding but lower in forage nutritional value than alfalfa sown alone, with greater differences observed in 1990 than 1991. Alfalfa stands were reduced by ryegrass in one site-year, where conditions favored vigorous ryegrass development over alfalfa seedling development. In the other three environments, alfalfa was successfully established with all ryegrass cultivars, but alfalfa yields the year after seeding were highest in plots established with early-maturing diploid cultivars. The most suitable annual ryegrass companions for alfalfa establishment in the north-central region are early-maturing diploid cultivars.
Wave function orthogonality in coupled-channel systems

Recent work by Noble and collaborators has pointed out that wave function orthogonality in bound-state to continuum-state transitions can produce large cancellations in transition amplitudes. In single-channel examples, nonorthogonal wave functions (such as plane waves) were shown to greatly overestimate the exact results even at high energies. In this paper we examine a simple coupled-channel model which can be exactly solved for the many-channel scattering and bound wave functions. In such a model, the exact transition amplitude can be compared with standard plane-wave and distorted-wave approximations. Dispersive corrections are shown to be large and to persist even at high energies.
Multiple fraction-per-day radiotherapy for patients with brain stem tumors

Brain stem tumors are among the most resistant brain tumors to therapy. The majority progress within 18 months of diagnosis and treatment. Multiple-fraction-per-day (MFD) radiotherapy would theoretically allow higher total doses of radiotherapy to be delivered in order to improve local tumor control without increasing neurotoxicity secondary to treatment. Seventeen patients with brain stem tumors were evaluated and treated at Duke University Medical Center (DUMC) from 1985 to 1991 with a MFD regimen. Six patients were accrued to Pediatric Oncology Group (POG) Protocol 8495 and were not included in this analysis, leaving eleven patients for review. Local fields were treated with fraction sizes of 110 or 117 cGy twice daily. There were 3 patients who received a total of 60.5–68.2 Gy and 8 who received 70.2–71.5 Gy. Initial and follow-up CT and/or MRI studies were available for review on all but one patient. All patients had progression of disease and have died. Median time to tumor progression was 5.8 months. Median overall survival was 11.2 months. There was no significant influence upon time to tumor progression or survival by total radiation dose received. Patients were classified by imaging group per the criteria of Stroinket al. based on review of their pre-treatment CT or MRI scans. One patient had no initial films available, 2 were in Group II (no contrast was given to separate A or B), 3 in IIA, 4 in IIB, and 1 in III. Autopsy in 3 patients failed to demonstrate histologic evidence of injury attributable to radiotherapy. The results of this study fail to demonstrate a positive impact of MFD radiotherapy on the outcome of children with unresectable brain stem tumors.
SUICIDE IN WRITERS

A high incidence of suicide has been noted among writers from Great Britain, the USSR, Japan, and America, suggesting that general factors must be sought to account for the high rate rather than as...
K-shell ionization cross section measurements of 59Pr, 60Nd and 62Sm using 1.0–3.0 MeV protons and a new normalization method

Abstract We have measured the K-shell ionization cross sections, σ KI , for three selected elements (and isotopes) that are close to the transition point in nuclear shapes from spherical to spheroidal. By selecting spherical isotopes such as 150 62 Sm, we have eliminated the need to correct for the contribution to the measured K X-ray yields from K-shell internal conversion following nuclear Coulomb excitation, IC-CE. A new normalization method for determining σ KI values is proposed which relies on the accurate measurement of lγ 1; 5 X-rays transmitted by a critical absorber foil of the element's Lα 1,2 X-rays. We compare the values of σ KI obtained using this new method to values of σ KI obtained with RBS normalization. Circumstances where this new method of normalization may be an attractive alternative to the RBS method are discussed.
The emission spectra of the premixed methane-fluorine flame

Abstract Premixed flames of methane with fluorine have been stabilized in the pressure range from 3 to 10 torr for the purpose of investigating their emission spectra. The flame spectra reveal the presence of three distinct continua: the C 3 continuum; a continuum in the region from 250 to 340 nm, very likely due to the recombination of the fluorine atoms; and a continous emission due to carbon particles. The bands observed include those of CH, C 2 , and OH, the latter being due to oxygen impurities in the fluorine supply. Although the dominant flame radiation was due to C 3 emission the discrete Swings bands of C 3 could not be identified in these premixed flames. Spectral radiances of the above emissions were obtained for various feed compositions within the limit of flame stability. These measurements revealed that the C 2 band emission intensity was proportional to the 1.6 power of that of CH, giving supporting evidence for the formation of C 2 by the reactions, CH + CH = C 2 + H 2 and CH + C = C 2 + H.
Magnetic resonance angiography of cervicocranial dissection

A retrospective study of five patients with the clinical or magnetic resonance-based diagnosis of carotid dissection was done. Clinical data, imaging studies, treatment, and outcome were reviewed. The potential applicability of three-dimensional time-of-flight magnetic resonance angiography in these settings was evaluated.This modality reliably showed vascular abnormalities and focal, segmental, or aneurysmal dilatation when correlated with conventional angiograms in three patients. Turbulence and magnetic susceptibility at the acute turn of the carotid in the petrous canal led to a false-positive diagnosis on magnetic resonance angiography in one patient (in whom subtle fibromuscular hyperplasia was found with conventional angiography but missed with magnetic resonance angiography).When combined with appropriate clinical signs, magnetic resonance imaging and magnetic resonance angiography can reliably establish the diagnosis of carotid dissection. Pitfalls of magnetic resonance angiography are discussed.
Exercise Tolerance After Repair of Tetralogy of Fallot

Abstract Twelve patients who had undergone complete repair of tetralogy of Fallot at ages ranging from 8 to 27 years were studied for exercise tolerance several years later. Work performance ranged from 58 to 130% of that predicted. Increased physiological dead space and alveolar-arterial Po 2 difference at exercise suggested pulmonary vascular disease, which was confirmed in 1 patient by pulmonary angiography. Exercise tolerance decreased with increasing age at time of repair, underlining the desirability of early corrective operation.
Neonatal Infection-Induced Memory Impairment after Lipopolysaccharide in Adulthood Is Prevented via Caspase-1 Inhibition

We have reported that neonatal infection leads to memory impairment after an immune challenge in adulthood. Here we explored whether events occurring as a result of early infection alter the response to a subsequent immune challenge in adult rats, which may then impair memory. In experiment 1, peripheral infection with Escherichia coli on postnatal day 4 increased cytokines and corticosterone in the periphery, and cytokine and microglial cell marker gene expression in the hippocampus of neonate pups. Next, rats treated neonatally with E. coli or PBS were injected in adulthood with lipopolysaccharide (LPS) or saline and killed 1–24 h later. Microglial cell marker mRNA was elevated in hippocampus in saline controls infected as neonates. Furthermore, LPS induced a greater increase in glial cell marker mRNA in hippocampus of neonatally infected rats, and this increase remained elevated at 24 h versus controls. After LPS, neonatally infected rats exhibited faster increases in interleukin-1β (IL-1β) within the hippocampus and cortex and a prolonged response within the cortex. There were no group differences in peripheral cytokines or corticosterone. In experiment 2, rats treated neonatally with E. coli or PBS received as adults either saline or a centrally administered caspase-1 inhibitor, which specifically prevents the synthesis of IL-1β, 1 h before a learning event and subsequent LPS challenge. Caspase-1 inhibition completely prevented LPS-induced memory impairment in neonatally infected rats. These data implicate IL-1β in the set of immune/inflammatory events that occur in the brain as a result of neonatal infection, which likely contribute to cognitive alterations in adulthood.
Molecular switches for pheromone release from a moth pheromone-binding protein

Pheromone-binding proteins (PBPs) are involved in the uptake of pheromones from pores on the antennae, transport through an aqueous environment surrounding the olfactory receptor neurons, and fast delivery to pheromone receptors. We tested the hypothesis that a C-terminal segment and a flexible loop are involved in the release of pheromones to membrane-bound receptors. We expressed in Escherichia coli 11 mutants of the PBP from the silkworm moth, BmorPBP, taking into consideration structural differences between the forms with high and low binding affinity. The N-terminus was truncated and His-69, His-70 and His-95 at the base of a flexible loop, and a cluster of acidic residues at the C-terminus were mutated. Binding assays and circular dichroism analyses support a mechanism involving protonation of acidic residues Asp-132 and Glu-141 at the C-terminus and histidines, His-70 and His-95, in the base of a loop covering the binding pocket. The former leads to the formation of a new alpha-helix, which competes with pheromone for the binding pocket, whereas positive charge repulsion of the histidines opens the opposite side of the binding pocket.
Simulation of an Arterial Incident Environment with Probe Reporting Capability

Intelligent transportation systems have created new traffic monitoring approaches and fueled new interests in automated incident detection systems. One new monitoring approach utilizes actual travel times experienced by vehicles, called probes, equipped to transmit this information in real time to a control center. The database needed to design and calibrate arterial incident detection systems based on probe travel times is nonexistent. A microscopic traffic simulation package, Integrated Traffic Simulation, was selected and enhanced to generate vehicle travel times for the incident and incident-free conditions on an arterial. We evaluated the enhanced model. Significant variations in probe travel times were observed in the event of incidents. Average travel time, contrary to average occupancy, may increase, decrease, or remain constant on arterial streets downstream of an incident.
Conformational diversity in a yeast prion dictates its seeding specificity.

A perplexing feature of prion-based inheritance is that prions composed of the same polypeptide can evoke different phenotypes (such as distribution of brain lesions), even when propagated in genetically identical hosts1,2,3. The molecular basis of this strain diversity and the relationship between strains and barriers limiting transmission between species remain unclear. We have used the yeast prion phenomenon [PSI+]4 to investigate these issues and examine the role that conformational differences1,2,5 may have in prion strains. We have made a chimaeric fusion between the prion domains of two species (Saccharomyces cerevisae and Candida albicans) of Sup35, the protein responsible for [PSI+]4,6. Here we report that this chimaera forms alternate prion strains in vivo when initiated by transient overexpression of different Sup35 species. Similarly, in vitro the purified chimaera, when seeded with different species of Sup35 fibres, establishes and propagates distinct amyloid conformations. These fibre conformations dictate amyloid seeding specificity: a chimaera seeded by S. cerevisiae fibres efficiently catalyses conversion of S. cerevisiae Sup35 but not of C. albicans Sup35, and vice versa. These and other considerations1,2,5,7,8 argue that heritable prion strains result from self-propagating conformational differences within the prion protein itself. Moreover, these conformational differences seem to act in concert with the primary structure to determine a prion's propensity for transmission across a species barrier.
Headstands: a sexually selected signal in the swordtail fish Xiphophorus nezahualcoyotl

Behaviors associated with aggression in male–male competition may also be used in courtship. Headstands are performed by male Xiphophorus nezahualcoyotl during male–male interactions and by both males and females during courtship. This behavior consists of a descending vertical tilt of the head until the body is at a 45° to 90° angle with the substrate. We examined the function of headstands in male–male contests by investigating differences in their use by winners and losers, and correlations between headstands and other behaviors. We also investigated their function in mate choice by determining if females preferred videos of males performing headstands over videos of the same males not performing headstands. There was no correlation between performing the first headstand and biting first, or the total number of headstands and bites used. However, winners performed more headstands than losers in the second half of contests. We suggest that the headstand is an aggressive display providing information about Resource Holding Potential (RHP) in male contests. In addition, females had a significant preference for males performing headstands as compared to males that did not. We discuss the dual role of this behavior in sexual selection in relation to the information it may contain.
Search for weak transitions in the decay of 125 Sb and accurate gamma intensities

The weak transitions in the decay of125Sb have been investigated through gamma ray measurements with high resolution X-ray and with large volume Ge(Li) detectors. The 172.6, 178.8 and 198.5 keV gamma rays are confirmed, while others previously reported were not. Accurate intensities were obtained for the stronger transitions. The weighted averages of these intensities which cover the range of 116 to 670 keV are useful for calibration of Ge(Li) systems.
Fundamental frequency noise properties of extended cavity erbium fiber lasers

A multimode linear cavity and a single-mode unidirectional ring cavity fiber laser with meter-long cavity lengths are shown to exhibit frequency noise limited by fundamental thermodynamic noise from 100 Hz to 100 kHz. Their measured spectra agree closely with theoretically derived thermodynamic noise and the characteristic dependence of the frequency noise power spectrum on the inverse of the cavity length is observed. The unidirectional ring laser exhibits a frequency noise of 2 Hz/Hz1/2 at 1 kHz, one of the lowest published values to date from a free-running laser. The multimode linear cavity laser is shown to be a suitable candidate for thermal-noise-limited, meter-long fiber laser strain sensors with a strain resolution of 14 fϵ/Hz1/2 at 1 kHz.
The Ponzo Illusion in Virtual Environments: Correctly Applied Size Constancy?:

The perceived size of a stimulus can be greatly influenced by the surrounding depth cues. The effect size of the Ponzo Illusion was tested in a virtual environment with many depth cues (MC) and few depth cues (FC) conditions. The effect of size and the depth cues on the perceived proximal size of the stimulus was measured. Methods. A modified Wheatstone stereoscope was used to present the stimuli on a monitor positioned 80 cm from the subjects. The subjects used a 6AFC confidence rating scale to indicate whether the first or second of two sequentially presented stimuli had a greater proximal extent. The ‘many cues’ (MC) condition included texture, relative height, foreshortening, linear perspective, relative brightness, and relative size. The few cues condition consisted of linear perspective, relative height, and relative size. Stimulus size (proximal extent) was varied independently from all other depth cues. Results. Both depth cue context and proximal size were found to have a significant effect on th...
Computer analysis of visual field loss and optimization of automated perimetric test strategies.

Preliminary investigations of optimal target distribution patterns for automated perimetry were conducted. In the first study, frequency distributions of visual field defects were determined in glaucoma (260 scotomata) and optic nerve disease (110 scotomata) for approximately 30,000 visual field locations. The frequency distributions in glaucoma and optic nerve disease were different, and suggest guidelines for development of target distribution patterns to achieve optimal detection rates. The second study included computer simulation of 20 target distribution patterns currently used in manual and automated perimetry. Each distribution pattern was processed through the 370 glaucoma and optic nerve disease scotomata to assess detection performance. Both the density and distribution of target locations affected overall detection rates. In addition, some target configurations were more susceptible to false alarms than others. These data provide qualitative information for optimization of target distribution patterns in automated perimetry, and serve as a foundation for future quantitative studies.