cssi/SciSciGPT-SciSciNet huggingface dataset:
A compact square wave 15 kJ generator: <15 ns rise-time; 7.5 ohms load impedance; and, pulse width 100-500 ns

Summary form only given, as follows. To broaden our knowledge in radio frequency (RF) and a high power microwave (HPM) generation, it is useful to energize our advanced RF& HPM source with a driver that has low internal impedance. It is useful to find out if our source also suffers from limitation known as "pulse shortening." This means that by increasing the radiative power, the length of the pulse becomes shorter. Hence, there is a limitation in the energy radiated in a single shot. This paper describes a compact six stage-Marx generator. It is built using the concept of pulsed-forming networks. The capacitance per stage is 0.500 F and the charging voltage is organized to vary from 25 to 100 kV. With the matching (dummy) load of 7.5 ohms; used, the maximum output voltage should be 300 kV and the maximum output current 40 kA. The stored energy in the system is 15 kJ and the peak power supplied to the load of 7.5 Ohms is 12 GW. Without crowbaring, the pulse width is 0.82 ns. When the crowbar switch is added, the pulse width can vary from 100 to 500 ns in a predictable manner.
Computer-Based Analysis of Holography Using Ray Tracing

The application of a ray-tracing methodology to holography is presented. Emphasis is placed on establishing a very general foundation from which to build a general computer-based implementation. As few restrictions as possible are placed on the recording and reconstruction geometry. The necessary equations are established from the construction and reconstruction parameters of the hologram. The aberrations are defined following H. H. Hopkins, and these aberration specification techniques are compared with those used previously to analyze holography. Representative of the flexibility of the ray-tracing approach, two examples are considered. The first compares the answers between a wavefront matching and the ray-tracing analysis in the case of aberration balancing to compensate for chromatic aberrations. The results are very close and establish the basic utility of aberration balancing. Further indicative of the power of a ray tracing, a thick media analysis is included in the computer programs. This section is then used to perform a study of the effects of hologram emulsion shrinkage and methods for compensation. The results of compensating such holograms are to introduce aberrations, and these are considered in both reflection and transmission holograms.
Splenic and immune alterations of the Sparc -null mouse accompany a lack of immune response

Sparc-null mice have been used as models to assess tumor-host immune cell interactions. However, it is not known if they have a competent immune system. In this study, the immune systems of Sparc wild-type and null mice were compared. Mice were assessed for differences in total body weight, spleen weight and spleen-to-body weight ratios. Spleens were compared with respect to morphology, and Sparc, Ki-67, MOMA-1 and IgM expression. Immune cells in blood, bone marrow and spleen were assessed by blood smears, automated blood panel, and flow cytometry. Additionally, the ability of Sparc-null mice to respond to immune challenge was evaluated using a footpad model. The morphological and immunohistochemical results indicated that Sparc-null spleens had more white pulp, hyperproliferative B cells in the germinal centers, and decreased marginal zones. Sparc-null spleens lacked normal Sparc expression in red and white pulp, marginal zones, endothelial and sinusoidal cells. By flow analysis, B cells were decreased and T cells were increased in the bone marrow. Finally, Sparc-null mice were unable to mount an immune response following footpad lipopolysaccharide challenge. These data confirm that Sparc-null mice have an impaired immune system.
Infant Colic and Maternal Mental Health: Nursing Research and Practice Concerns

This study compared the mental health of 12 mothers who had infants with colic to 12 mothers of infants without colic. Colic was defined as infant fussing/crying of at least 2 hours/day for at least 5 out of 7 days, infant cry high-pitched and pain-sounding, and maternal report of infant inconsolability. Mental health was operationalized as scores on the Profile of Mood States and the Symptom Checklist-90R. Mothers of infants with colic had multidimensional psychological distress; they reported more bodily dysfunction, fears, disordered thinking, depression, anxiety, fatigue, hostility, impulsive thoughts and actions; and they had stronger feelings of personal inadequacy or inferiority. Implications for nursing research and practice are discussed in the context of study findings.
Sex Differences in the Effectiveness of Early Coronary Computed Tomographic Angiography Compared With Standard Emergency Department Evaluation for Acute Chest Pain The Rule-Out Myocardial Infarction With Computer-Assisted Tomography (ROMICAT)-II Trial

Background—We evaluate sex-based differences in the effectiveness of early cardiac computed tomographic angiography (CCTA) and standard emergency department (ED) evaluation in patients with acute chest pain. Methods and Results—In the Rule-Out Myocardial Infarction With Computer-Assisted Tomography (ROMICAT)-II multicenter, controlled trial, we randomized 1000 patients (47% women) 40 to 74 years of age with symptoms suggestive of acute coronary syndrome to an early CCTA or standard ED evaluation. In this prespecified analysis, women in the CCTA arm had a greater reduction in length of stay, lower hospital admission rates, and lesser increased cumulative radiation dose than men in a comparison of ED strategies (P for interaction ≤0.02). Although women had lower acute coronary syndrome rates than men (3% versus 12%; P<0.0001), sex differences in length of stay persisted after adjustment for baseline differences, including acute coronary syndrome rate (P for interaction <0.03). Length of stay was similar bet...
Stiffness of the transverse carpal ligament under the influence of collagenase

Forming the palmar roof of the carpal tunnel, the transverse carpal ligament (TCL) continues to be the surgical target for carpal tunnel release which aims to relieve the symptoms of patients with carpal tunnel syndrome. However, the surgical procedures may cause several biomechanical and anatomical problems for the carpal tunnel [1]. Therefore, an alternative, aimed at preserving the TCL, might alleviate patients’ post-operative complications. Using a geometrical model, Li et al. showed that the cross-sectional area of the carpal tunnel can be effectively increased by TCL elongation [2]. Theoretically, stiffness reduction could facilitate a ligament’s capability to elongate. Past studies have shown that the utilization of the collagenase enzyme altered the mechanical properties of a soft tissue [3, 4]. It also has been used to treat Dupuytren’s Contracture [5] because collagenase breaks the peptide bonds within collagen fibers [6]. The usage of collagenase could effectively reduce the stiffness of the TCL allowing for the ligament to elongate and for the median nerve to decompress. Thus, the purpose of our study is to determine the effect of collagenase on the stiffness of the TCL. We hypothesize that the stiffness of the ligament will progressively decrease due to the enzymatic effect of collagenase.Copyright © 2011 by ASME
Fracture of WC-Co from a continuum viewpoint

Abstract The fracture of sintered tungsten carbide-cobalt is discussed and analyzed by applying continuum mechanics on the microscale. A plane model of rigid, hexagonal inclusions in an elastic-perfectly plastic matrix is taken to represent WC particles in a Co matrix. The continuum model employed here is used to extend earlier work by Drucker to include effects due to non-uniform particle sizes and variable interparticle spacings on the behavior of WC-Co in tension and bending. Effects on the bending strength due to change of the yield strength of the matrix are discussed. Also, the fracture strength of WC-Co in compression is predicted by using the continuum model along with published bending strength data and is found to be in reasonable agreement with published compressive strength data.
Improving staff safety through an aggression management program

This article provides information regarding the relationship of a formal inpatient Aggression Management Program and subsequent aggression-related staff injuries at one university medical center. Data related to staff injuries, collected before and after the program, were compared as a means of measuring the program's effectiveness. Although the frequency of injury changed only slightly, the results indicate that there was a decrease in the severity of aggression-related staff injuries after institution of the formal program, as well as a reduction in time missed from work and cost to the system. Improvements of other aspects of care such as resource management and staff satisfaction as outcomes of this program are also discussed.
Anoxia: Tolerance in Reptiles

Measurements of the lengths of time various reptiles can continue to breathe in atmospheres of nitrogen have shown that turtles are several times more tolerant of these conditions than are other reptiles. The major correlate of this tolerance is taxonomic, rather than ecological.
First tests of the interferometer in the micro-arcsecond metrology testbed (MAM)

The Space Interferometry Mission (SIM) relies on interferometry and metrology capable of measuring the change in the optical path difference with picometer accuracy.
The Department of Defense Human factors standardization program

The Department of Defense (DoD) Human Factors Standardization Program is the most far-reaching standardization programme in the USA. It is an integrated component of the overall DoD Standardization Program. While only ten major documents are contained in the human factors standardization area, their effects on human factors engineering programmes are profound and wide-ranging. Preparation and updating of the human engineering standardisation documents have grown out of the efforts of several military agencies, contractors, consultants, universities and individuals. New documents, engineering practice studies and revision efforts are continuously planned by the Tri-Service (Army, Navy, Air Force) Human Factors Standardization Steering Committee in collaboration with industry groups and technical societies. The present five-year plan and other standardisation documents are readily available for review and input by anyone with relevant interests. Human factors specialists and other readers of this journal may therefore influence the direction of the human factors standardisation programme and the content of its military specifications, standards and handbooks.
Progesterone Exposure Prevents Matrix Metalloproteinase-3 (MMP-3) Stimulation by Interleukin-1α in Human Endometrial Stromal Cells1

Suppression of endometrial matrix metalloproteinases (MMPs) is necessary to maintain tissue stability during the invasive events of implantation and placental development. Several laboratories have shown that inflammatory cytokines, including interleukin-lalpha (IL-1alpha), can oppose progesterone suppression of MMPs in the human endometrium. Furthermore, we have recently demonstrated colocalization of epithelial cell IL-1alpha and MMP-7 expression at sites of ectopic pregnancy. The current study extends these findings, revealing a previously unrecognized interrelationship between progesterone and IL-1alpha in regulation of MMP-3. Although IL-1alpha is a potent stimulator of MMP-3 in proliferative phase endometrium in organ culture, we demonstrate that progesterone exposure in vivo reduces IL-1alpha stimulation of MMP-3 in secretory phase tissue. This loss of sensitivity to IL-1alpha was duplicated in isolated stromal cells treated with progesterone in vitro, and IL-1alpha stimulation of MMP-3 returned in a dose-dependent manner with progesterone withdrawal. The antiprogestin, onapristone, partially blocked the ability of progesterone to prevent stimulation of MMP-3 by IL-1alpha. These data suggest a novel mechanism by which progesterone may preserve tissue integrity during the establishment and maintenance of pregnancy by limiting stimulation of MMPs by inflammatory cytokines such as IL-1a.
The inhibition of citrate, isocitrate and α-ketoglutarate oxidation in aged potato slices by γ hydroxy α-ketoglutarate

Abstract The effect of γ hydroxy α-ketogluturate (HKG) was determined on the oxidation of citrate, isocitrate and α-ketoglutarate by aged potato slices. Much as in mitochondrial preparations, HKG was found to inhibit the oxidation of each substrate individually. Acetate utilization was also sharply inhibited by HKG. A comparison of the effect of HKG and of malonate on acetate oxidation established that acetate is respired primarily by way of the tricarboxylic acid cycle in aged potato tissue. Fresh potato slices proved as unable to oxidize isocitrate as citrate, while aged slices oxidized both substrates with equal ease. From the foregoing observation and earlier experiments comparing citrate and α-ketoglutarate metabolism, it is deduced that the block in the tricarboxylic acid cycle in fresh tissue is related to the inhibition or inactivity of isocitric dehydrogenase.
Can statistics alone add clinical meaning to non-specific billing databases? Commentary on an article by Richard A. Deyo, MD, MPH, et al.: "Revision surgery following operations for lumbar stenosis".

Revision surgery after an operation for the treatment of lumbar stenosis is an undesired outcome. In an attempt to further understand the incidence of revision surgery after the initial treatment of lumbar spinal stenosis, the authors of the current paper used the Medicare Provider Analysis and Review (MedPAR) billing database from 1999 to 2008. As with any retrospective study relying on billing data to make appropriate clinical conclusions, one must recognize and understand the limitations of the potentially flawed and biased source data that have no easily verifiable inputs or controls. In this case, the authors just accepted the data as presented. The MedPAR database contains information about all Medicare hospital claims submitted for reimbursement. Importantly, the database only contains broad, categorically based, facility ICD-9-CM billing codes selected by billing personnel after the fact rather than the surgeon-selected Healthcare Common Procedure Coding System (HCPCS) Level-I Current Procedure Terminology (CPT) code, which also does not always accurately reflect what was done. These data only reflect what is needed for hospitals to collect payments, and they include no other scientific or clinical facts or discussion of indications or techniques. The multicenter study from 1997 that was cited by the authors to support their analysis regarding the accuracy of coding indicated that seventeen of sixty-one patients who had undergone previous lumbar surgery actually had the appropriate code for the diagnosis1. The abstract states, “Although there were both false-negative and false-positive codes at each institution, most errors were related to the low sensitivity of coding for previous spinal operations: only seventeen (28 per cent) of sixty-one such diagnoses were coded correctly.”1 Newer studies evaluating the accuracy of ICD-9-CM-based databases have shown a similarly …
Efficient Approach to Determine the pKa of the Proton Release Complex in the Photocycle of Retinal Proteins

This work utilizes a photoelectrochemical approach to study the pH dependence of proton release and uptake in the photocycles of two retinal proteins, bacteriorhodopsin (BR) and archaerhodopsin 4 (AR4). By detecting photoinduced potentials that originate from the proton concentration changes (DeltaH(+)) generated by proteins near the indium tin oxide (ITO) electrode, we show that the kinetics of release and uptake can be followed in a broad pH range, and the pK(a) of the proton release complex (PRC) can be easily determined under different conditions. Nonoriented protein films were deposited on the electrode, and photovoltage in an electrochemical cell was detected after illumination with a green flash. The kinetics of proton release and uptake could be measured as light-induced decreases and increases of the photopotential. A kinetic analysis was performed, and a formula describing proton fluxes of wild-type BR and AR4 and D96N mutant of BR was derived. Three componentsfast proton release, slow proton release, and proton uptakewere found in the wild-type retinal proteins; two components, fast and slow proton releases, were found in the D96N mutant. The pH dependence of the fraction of fast release over the whole release was used to determine the pK(a) for proton release in the photocycles of these retinal proteins. Measurements were also performed in conventional buffer solutions and crown ether. The presence of buffer in 10-50 mM concentration did not abolish the light-induced signals, indicating that the electrode response is much less sensitive to buffers than pH-sensitive dyes in a suspension due to a higher protein/buffer ratio near the electrode. This feature enables us to study effects of chemicals with high buffer capacity, and significant effects of buffers and crown ether on proton pumping behaviors of retinal proteins were revealed. In comparison with the classic pH-sensitive dye approach, the photoelectrochemical approach is convenient and efficient for measurements of transient proton concentration changes (DeltaH(+)) generated by a proton pump and thus might be utilized as a powerful tool for the investigation of light-driven proton pumping mechanisms in a wide pH range.
The Oldest Record of a Slug

MISS ALICE MACKIE, writing from Egypt, sends me a photograph showing a couple of slugs represented on a wall at Karnak (Fig. 1). These figures are of course well known to Egyptologists, but probably not to malacologists. They appear to represent the species Veronicella nilotica (Cockerell, Nautilus, January 1910, p. 108), which was found by the Nile above Khartoum. In my original account I could only give the coloration as shown by alcoholic material. Mrs. G. B. Longstaff found a specimen among papyrus on the river bank at Hillet al-Nuwer, an islet on the Bahr el-Gebel. She noted that the living animal was very dark grey above, beneath dirty yellow turning to deeper yellow anteriorly.1 This agrees sufficiently with the Luxor figures, which are shown to be dark above and pale below. As this is the only slug of the kind known from this region, the identity is reasonably certain.
Reflections on Research on Writing and Technology for Struggling Writers.

In this article, I discuss research on the use of technology to support the writing of students with learning disabilities. Struggling writers can benefit from a wide range of computer applications for writing. Word processing, spelling checkers, word prediction, and speech recognition offer support for transcription and revision. Word processing also opens up opportunities for more meaningful publication of writing. Outlining programs and concept mapping software can help with planning. New forms of writing, including Internet chat, blogs, multimedia, and wikis, have not been studied extensively, but they may offer both opportunities and challenges to struggling writers. In addition to describing the research, I try to articulate some general themes and principles that I hope will be helpful to both teachers and researchers.
Homolytic Se−H Bond Energy and Ionization Energy of Benzeneselenol and the Acidity of the Corresponding Radical Cation

The homolytic Se−H bond energy of benzeneselenol, a very efficient radical trap in solution and in the gas phase, was determined experimentally by using two independent approaches in a Fourier-transform ion cyclotron resonance mass spectrometer. The hydrogen−selenium bond strength was concluded to be 76−80 kcal mol-1 based on the measurement of the efficiency of hydrogen atom abstraction from benzeneselenol by several radical cations. The Se−H bond energy was also determined indirectly through the use of a thermochemical cycle. This approach required the measurement of the adiabatic ionization energy of benzeneselenol and the proton affinity of C6H5Se•. An adiabatic ionization energy of 8.3 ± 0.1 eV was obtained by measurement of the efficiencies of various electron transfer reactions in the forward and reverse directions. The proton affinity of C6H5Se• (acidity of the benzeneselenol radical cation) was found to be 200 ± 3 kcal mol-1 based on the measured efficiencies of several proton transfer reactions....
Strategic vote manipulation in a simple democracy

In both the Employee Stock Ownership Plan (ESOP) and employee buyouts, the common and crucial phenomenon is that some workers have two sources of income, namely wages and shares of profit. We analyze that phenomenon in an economy where workers are nonunionized and wages are determined by voting. If the employers sell a certain amount of shares of the capital stock to some non-risk-loving workers, these workers vote for the lowest possible wage along with the employers. As a result, all workers become equally worse off because of the competition among workers to buy those shares.
Risk factors for failed transverse sinus stenting in pseudotumor cerebri patients.

Abstract Background Idiopathic intracranial hypertension (IIH) when no underlying etiology is found, is a clinical syndrome characterized by elevated intracranial pressure (ICP) (>25cmH 2 O), which may lead to headaches and visual symptoms. In patients with IIH who are found to have transverse sinus stenosis, placement of a venous stent across the stenosis has been shown to lower ICP and to resolve the symptoms in several case series, with generally favorable results. In this study, we examine common risk factors associated with failure of transvenous stenting for IIH. If venous sinus stenting fails, CSF diversion should be considered as the next line of treatment. Methods We retrospectively reviewed the records of eighteen patients diagnosed with IIH who underwent venous sinus stenting for transverse sinus stenosis with a mean pressure gradient (MPG) of at least 4mmHg. Fifteen of these patients did not need further treatment. We compared their pre- and post-treatment, neurological and neuro-ophthalmological evaluations to the three patients who went on to have a shunt placement as a second line treatment. Results Shunting after stent placement patients ( n =3) had a mean age of 30 years and a mean body mass index of 36.6kg/m 2 , whereas the group that underwent stent placement alone ( n =15) had a mean age of 40.7 years and a mean body mass index of 33.3kg/m 2 . In the shunting after stent placement group, the mean opening pressure on the most recent lumbar puncture obtained prior to any intervention was 50cm of H 2 O, whereas the group that underwent stent placement alone had an opening CSF pressure of 37cm of H 2 O which was statistically significant ( p Conclusion In patients with IIH and documented evidence of venous sinus stenosis with a pressure gradient, venous sinus stenting should be the primary treatment of choice; however, some patients may be refractory to stenting and still require permanent CSF diversion, which can be complicated in these chronically anticoagulated patients. Patients with persistent papilledema post-stenting and highly elevated opening pressure pre-stenting should be followed closely as they are at greatest risk of requiring a shunt and failing stenting.
Discrete molecular weight components of the organic matrices of mollusc shells

Abstract Discrete molecular weight components form part of the soluble fraction of the organic matrices of mollusc shells. The number of these components, their relative migration distances and concentrations vary greatly in the specimens analysed. The discrete molecular weight constituents from the organic matrices of species of the same genus are most similar. The presence of these components shows that organic matrices are heterogeneous and presumably capable of performing diverse functions.
Nonhistone chromatin proteins from calf thymus and their role in DNA biosynthesis

Abstract The nonhistone chromatin proteins have been isolated from calf thymus nuclei by dissociation of the DNA-protein complex. Chemical fractionation of these proteins separates them into seven fractions which are shown to be acidic by their amino acid compositions. One of the functions of these chromatin acidic proteins is their participation in the biosynthesis of DNA. This has been shown by the partial purification of a DNA-polymerase from these chromatin acidic proteins. The partially purified enzyme depends on a complete complement of all four deoxyribonucleoside 5′-triphosphates for its optimal activity in an in vitro assay system. It preferentially uses heatdenatured DNA as the template.
THE ERGASTOPLASM ITS FINE STRUCTURE AND RELATION TO PROTEIN SYNTHESIS AS STUDIED WITH THE ELECTRON MICROSCOPE IN THE PANCREAS OF THE SWISS ALBINO MOUSE

The fine structure of the ergastoplasm of the pancreatic exocrine cell of Swiss albino mice has been studied with the electron microscope. It was found that this material consists of sac-like structures, which may be called ergastoplasmic sacs, embedded in an amorphous granular ground substance, the cytoplasmic matrix. The membranous wall of the ergastoplasmic sac is a structure approximately 250 A wide. Except for its greater electron density and granular structure, the ergastoplasmic membrane is similar in appearance to the nuclear, plasma, and mitochondrial membranes. From data available in the literature, and from our own evidence, the conclusion can be drawn that the ergastoplasmic membrane contains ribonucleic acid. The mode of formation of the ergastoplasm and secretory granules was studied in animals which were first fasted and subsequently fed. It was found that ergastoplasm is formed within the cytoplasm, near the nuclear membrane, and possibly from the plasma membrane. The secretory granules were observed to arise by accumulation of materials within small ergastoplasmic sacs.
Hibernation "trigger" alters renal function in the primate

Abstract Macaque monkeys acclimatized to a restraint chair were fitted with indwelling venous and urinary catheters. After basal rates of urine production and creatinine clearance were determined, a 50 mg dose of plasma dialysate albumin fraction obtained from the woodchuck was administered intravenously in a total volume of 2.5 ml. Plasma fractions were collected during the winter interval of hibernation (hibernation “trigger” or HT), or during the summer active (SAWA) period. Although the SAWA fraction exerted no effects on renal function, HT caused a significant reduction in creatinine clearance. In addition, a tendency toward reduced urine flow and creatinine production occurred following the HT infusion. These findings suggest that over and above the hypothermia, aphagia and opioid-like behavioral depression induced by HT, the albumin fraction (HT) present endogenously in the woodchuck during winter torpor, exerts a direct action on the kidney of the primate, possibly on the mechanisms underlying glomerular filtration and the tubular reabsorption process.
Randomized, pilot study of intermittent pneumatic compression devices plus dalteparin versus intermittent pneumatic compression devices plus heparin for prevention of venous thromboembolism in patients undergoing craniotomy

BACKGROUND Unfractionated heparin and the low molecular weight heparin, dalteparin, are used for prophylaxis against venous thromboembolism in patients undergoing craniotomy. These drugs were compared in a randomized, prospective pilot study comparing intermittent pneumatic compression devices plus dalteparin to intermittent pneumatic compression devices plus heparin. METHODS One hundred patients undergoing craniotomy were randomly allocated to receive perioperative prophylaxis with subcutaneous (SC heparin, 5000 units every 12 hours, or dalteparin, 2,500 units once a day, begun at induction of anesthesia and continued for 7 days or until the patient was ambulating. Entry criteria were age over 18 years, no deep vein thrombosis (DVT) preoperatively as judged by lower limb duplex ultrasound and no clinical evidence of pulmonary embolism preoperatively. Patients with hypersensitivity to heparin, penetrating head injury or who refused informed consent were excluded. Patients underwent a duplex study 1 week after surgery and 1 month clinical follow-up. All patients were treated with lower limb intermittent pneumatic compression devices. RESULTS There were no differences between groups in age, gender, and risk factors for venous thromboembolism. There were no differences between groups in intraoperative blood loss, transfusion requirements or postoperative platelet counts. Two patients receiving dalteparin developed DVT (one symptomatic and one asymptomatic). No patient treated with heparin developed DVT and no patient in either group developed pulmonary embolism. There were two hemorrhages that did not require repeat craniotomy in patients receiving dalteparin and one that did require surgical evacuation in a patient treated with heparin. Drug was stopped in two patients treated with dalteparin because of thrombocytopenia. None of these differences were statistically significant. CONCLUSION There was no significant difference in postoperative hemorrhage, venous thromboembolism or thrombocytopenia between heparin and dalteparin. The results suggest that, given the small sample size of this trial, both drugs appear to be safe and the incidence of venous thromboembolism by postoperative screening duplex ultrasound appears to be low when these agents are used in combination with intermittent pneumatic compression devices.
Bifurcations of Heteroclinic Orbits

Thesearchfortravelingwavesolutionsofasemilineardiffusionpartialdifferen- tialequationcanbereducedtothesearchforheteroclinicsolutionsoftheordinarydifferential equation ¨ u − c ˙ u + f (u) = 0, where c is a positive constant and f is a nonlinear function. A heteroclinic orbit is a solution u(t) such that u(t) → γ1 as t →− ∞and u(t) → γ2 as t →∞ where γ1 ,γ 2 are zeros of f . We study the existence of heteroclinic orbits under various assumptions on the nonlinear function f and their bifurcations as c is varied. Our arguments are geometric in nature and so we make only minimal smoothness assumptions. We only assume that f is continuous and that the equation has a unique solution to the initial value problem. Under these weaker smoothness conditions we reprove the classical result thatforlarge cthereisauniquepositiveheteroclinicorbitfrom0to1when f (0) = f (1) = 0 and f (u )> 0f or 0< u < 1. When there are more zeros of f , there is the possibility of bifurcations of the heteroclinic orbit as c varies. We give a detailed analysis of the bifurcation of the heteroclinic orbits when f is zero at the five points −1 < − θ< 0 <θ < 1a ndf is odd. The heteroclinic orbit that tends to 1 as t →∞ starts at one of the three zeros, −θ,0 ,θ as t →− ∞. It hops back and forth among these three zeros an infinite number of times in a predictable sequence as c is varied.
DISPERSAL OF MELASTOME SEEDS BY FRUIT‐EATING BIRDS OF TROPICAL FOREST UNDERSTORY

Birds directly affect seed dispersal through (1) the number of seeds they remove and (2) where and in what condition those seeds are deposited. Dispersal effectiveness is a composite of these quality and quantity components of seed dispersal. In this study, number of seeds removed and patterns of seed deposition by six bird species were determined for four shrubs in the Melastomataceae. Bird species differed in both quantity and quality components of seed dispersal. Bird species that contributed most to the quantity component of seed dispersal were not always the same as those that contributed most to the quality component. Thus, to evaluate the ecological roles of frugivores and their effectiveness as seed dispersers requires integration across various processes involved in seed dispersal (removal, deposition, etc.). In contrast to canopy trees, shrubs apparently have a relatively small set of seed dispersers, which makes them more vulnerable to the extinction of a seed disperser.
Francesco Landini and the Florentine cultural élite

The French orientation of Florentine music in the second half of the Trecento, particularly with regard to the practice and theory of notation, has been recognised by music historians since the surveys of medieval sources and style made by Johannes Wolf and Friedrich Ludwig at the beginning of this century. The evidence for the ‘contenance francaise’ that has been most frequently cited includes texting procedures in three-voice compositions, structural features (such as the appearance of verto and chiuso endings in the polyphonic ballata), textual gallicisms and the presence of French compositions in Florentine musical manuscripts. The network of transmission which accounts for the appearance of these features in Italian music and musical sources has remained a matter for speculation. The fusion of French and Florentine traits of style in the last quarter of the fourteenth century has traditionally been viewed, at least in part, as a result of presumed personal contacts between French and Italian composers. The changing face of musical style does not, however, reflect a totally independent musical process; style is a function of the tastes and demands of an audience, as well as of the artistic personalities of specific composers. Florentine receptivity to French stylistic influences was determined by a number of factors, not the least important of which was the nature of the audience for music.
Fair Value Measurement in Financial Reporting

This monograph provides a historically informed discussion of conceptual and procedural issues related to the use of the fair value measurement attribute in financial reporting. Our goal is to provide a structure, based on the conceptual frameworks of the Financial Accounting Standards Board and International Accounting Standards Board, for researchers’ evaluations of empirical research studies that investigate the informational properties of all measurement bases, including fair values. We begin by defining, addressing misconceptions about, and providing a brief history of, the fair value measurement attribute. We next discuss decision usefulness of fair value and other measurement bases, and describe and evaluate examples of empirical research that documents the decision usefulness of recognized and disclosed fair value information, focusing on predictive ability, value relevance and risk relevance. We also discuss the role of verifiability in the context of relevant and faithfully represented accounting information; describe three untested, verifiability-related maintained assumptions that arise in discussions of fair-value-measurement research; and discuss research designs for investigating questions related to accounting measurement verifiability. Finally, we discuss claims that use of the fair value measurement attribute causes procyclical behavior among financial institutions and that accounting standards have become increasingly fair-value-oriented during the last two decades.
P-tree: a p2p index for resource discovery applications

We propose a new distributed, fault-tolerant Peer-to-Peer index structure for resource discovery applications called the P-tree. P-trees efficiently support range queries in addition to equality queries.
The Effects of Involved Nonresidential Fathers’ Distress, Parenting Behaviors, Inter- Parental Conflict, and the Quality of Father-Child Relationships on Children’s Well-Being

Based on data from the 1997 Child Development Supplement to the Panel Study of Income Dynamics, the present study examined a sample of 129 nonresident fathers who had regular contact with their young children to determine how father involvement and father distress are related to children’s well-being. Results revealed a negative relationship between father distress and child well being, with, based on father reports, daughters being more affected than sons. A negative relationship was also found between inter-parent conflict and child w ell being. Further, there was a positive relationship between paternal warmth and child well-being and higher levels of father-child relationship quality were related to higher levels of child well-being. In terms of racial subgroup analyses, limit setting was a positive predictor of child wellbeing only among African-American children.
Thromboembolism during pregnancy. Risks, challenges, and recommendations

Pregnancy is an important risk factor for venous thrombosis, and venous thromboembolism is a leading cause of preventable death in pregnancy. Diagnosis of venous thromboembolism is complicated in that the symptoms of dyspnea and lower extremity edema are relatively common complaints of pregnant patients. Physicians should maintain an appropriately high index of suspicion and request diagnostic imaging in a timely manner. Diagnosis of deep venous thrombosis with Doppler ultrasonography of the lower extremity poses no health risk to the fetus, but other radiographic studies pose a low radiation risk to the fetus. Because anticoagulant therapy poses a greater health risk to mother and fetus than does the radiation required for the diagnosis of pulmonary embolism, clinicians should aggressively pursue objective evidence of venous thromboembolism. Once the diagnosis is made, anticoagulation with intravenous unfractionated heparin or subcutaneous low-molecular-weight heparin should be used prepartum followed by warfarin therapy after delivery.
Desazadesmethyldesferrithiocin Analogues as Orally Effective Iron Chelators

Further structure−activity studies of desferrithiocin analogues are carried out. (S)-Desazadesmethyldesferrithiocin, 2-(2-hydroxyphenyl)-Δ2-thiazoline-4(S)-carboxylic acid, serves as the principal framework in the current paper. Desazadesmethyldesferrithiocin can be structurally altered with facility, and data are already available on its iron-clearing properties and toxicity parameters. Four different kinds of structural modifications of this framework are undertaken: introduction of hydroxy, carboxy, or methoxy groups on the aromatic ring; alteration of the thiazoline ring; increasing the distance between the ligand donor atoms; and benz-fusion of the aromatic rings. The structural modifications described are shown to have a tremendous impact on both the iron clearance and toxicity profiles of the desazadesmethyldesferrithiocin molecule. All of the compounds are assessed in a bile-duct-cannulated rodent model to determine iron clearance efficiency. Ligands which demonstrate an efficiency of greater tha...
Low scores, top 10 finishes, and big money: an analysis of professional golf association tour statistics and how these relate to overall performance.

The present study examined the relationship between primary golf skills of Professional Golf Association (PGA) Touring Professionals, i.e., driving distance, driving accuracy, reaching Greens in Regulation, and putting, and various performance outcomes for these same golfers including their scoring averages. Two additional variables, birdies and eagles, were also analyzed in relation to both the primary skill and performance outcome variables. Multiple regression along with simple correlations were applied. A significant proportion of variance in performance outcome (R2 = .33-.45), utilizing three different dependent variables (Scoring Average, Top 10 Finishes, and Money Won), was explained by measures of the four primary golf skills. Also, Driving Accuracy proved to be a better performance predictor than Driving Distance and accounted for 19% of the variance in Scoring Average. Both putting performance and reaching Greens in Regulation were significantly correlated with all three dependent variables. Iron play, reflected by hitting Greens in Regulation with approach shots, was the shot-making skill most highly correlated with Scoring Average (r = .45).
Nirvana efficiency: a comparative test of residual claims and routines

Two widely adopted views of firm efficiency are agency theorists’ residual claims and organization theorists’ routines. The agency view holds that ownership structures (and their proxies) are the primary source of efficiency differences between firms. The organization theory view holds that organizational routines are the primary source of efficiency differences between firms. We conduct an empirical test that compares the relative value of residual claims and routines in generating firm efficiency, while controlling other factors. We find support for both views, but more importantly find that the average value of routines is roughly an order of magnitude higher than residual claims. # 1999 Elsevier Science B.V. All rights reserved. JEL classification :L 2
The Direct Estimation of Spatial Wavenumber Spectra of Atmospheric Variables

Abstract We attempt to determine the zonal kinetic energy and temperature spectra of the large-scale flow in the atmosphere by utilizing observations, unequally spaced, rather than objectively-analyzed grid point values of the wind and temperature variables. Sample correlation functions, are obtained by forming correlations from all possible pair-wise combinations of stations oriented along a parallel of latitude (∼52N). Formally, the estimated line spectrum is given by a Fourier transform of this sample correlation function, Here, owing to the unequal spacing of this sample function, the Fourier transform takes the form of a set of simultaneous, coupled, linear equations, which are poorly conditioned. Four different methods of effecting the solution are tried, all of which are directed at mitigating the ill-conditioning of the system of equations. Spectra of kinetic energy and temperature for the winter and summer seasons are obtained at 850, 500 and 200 mb. There is no significant difference in the shap...
Parathyroid imaging by Tc/Tl scintigraphy.

Between 1983 and 1988, a total of 22499mTc/201T1 subtraction parathyroid scintigraphy studies were performed in 214 patients (136 women, 78 men, average age 50, ±15 years) with clinical and biochemical signs of hyperparathyroidism. Of the 214 patients, 113 underwent surgical exploration, and 127 benign parathyroid lesions were found, 48 of which were correctly localized by scintigraphy (sensitivity 38%). We detected 30 of 71 adenomas (42%) and 18 of 56 hyperplastic glands (32%). Additionally, the scans localized 2 of 6 parathyroid carcinomas in 5 patients. Overall, 83 parathyroid lesions were missed. There was no significant difference in size between detected and missed lesions. Previous neck surgery (65 of 113 patients) was not a significant detriment to scan sensitivity; but correct detection did depend upon the anatomic site of the lesion: 39% (n=109) were detected in the typical site, 44% (n=9) intrathyroidal, and 11 % (n=9) in the anterior and/or superior mediastinum. In conclusion, these results show only limited value for this99mTc/201T1 subtraction scintigraphy protocol as the initial procedure for localization of abnormal parathyroid tissue prior to surgical exploration.
The effects of free water on the performance of packed towers in vacuum service

This paper describes a semiworks plant study performed to determine why vacuum distillation columns that operated well with trays experienced very poor performance when replaced with structured packings. The possible causes of the malfunctions ranged from poor design to poor wetting to Marangoni effects to phase inversion to liquid holdup problems. An experimental study was conducted to assess these effects and to determine the root cause of the problems. As a consequence of the study, guidelines for the application of structured packings in wet vacuum distillations were established. The study also illustrated a nonconventional flooding mechanism in packed towers that is exclusive to wet hydrocarbon systems; this phenomenon is described in the paper. Included in the paper are semiworks-scale efficiency and capacity data of structured packings operating under wet conditions.
Robust color space conversion and color distribution analysis techniques for date maturity evaluation

Color is important in evaluating quality and maturity level of many agricultural products. Color grading is an essential step in the processing and inventory control of fruits and vegetables that directly affects profitability. Dates are harvested at different levels of maturity that require different processing before the dates can be packed. Maturity evaluation is crucial to processing control, but conventional methods are slow and labor-intensive. Because date maturity level correlates strongly with color, automated color grading could be used. A novel and robust color space conversion and color index distribution analysis technique for automated date maturity evaluation that is well suited for commercial production is presented in this paper. In contrast with more complex color grading techniques, the proposed method makes it easy for a human operator to specify and adjust color preference settings for different color groups representing distinct maturity levels. The performance of this robust color grading technique is demonstrated using date samples collected from field testing.
Air medical helicopter accidents in the United States: a five-year review.

Objective. To determine the number of air medical helicopter accidents in the United States during a five-year period beginning January 1, 1997, and ending December 31, 2001. Methods. The National Transportation Safety Board's (NTSB's) Accident Synopses database was accessed to determine the number of accidents involving air medical helicopters during the five-year study period. The NTSB reports for each accident were downloaded. Results. The NTSB records revealed 47 accident files pertaining to air medical helicopters during the five-year study period. These were analyzed for: date of accident, time of accident, air ambulance operator, location of accident, type of aircraft, number of persons, number of fatalities, number of injuries, cause of accident, and other factors the NTSB investigators deemed appropriate. Of the 47 accidents, there were 40 fatalities and 36 injuries. Overall, there were 13 helicopter types involved. The majority of accidents (70%) were attributed to pilot error. The number of acc...
Still a wedge in the door: women training for the construction trades in the USA

Purpose – This paper aims to evaluate the variations in the entry and exit of women apprentices in the USA, overall and by race/ethnicity, over the 1995‐2003 period. Also aims to examine how women's representation among new apprentices and their attrition and retention rates vary with individual, training program, and occupational characteristics.Design/methodology/approach – An individual‐level dataset from the US Department of Labor is used to estimate econometrically women's representation in apprenticeship programs and women's odds of completing programs.Findings – Women's representation among new trainees is very low and deteriorating. The results confirm previous findings based on data for the early 1990s that program sponsorship has significant impact on women's representation and retention. Women have better chances of joining the high‐skill construction workforce if they enroll in union‐contractor joint programs. Joint programs feature higher shares of women in the incoming classes and higher odd...
Doppler ultrasound technique for measuring capillary-speed flow velocities with strong stationary echoes.

Abstract Ultrasound Doppler is widely used for flow measurement in both medicine and industry, having the advantages of being non-invasive and comparatively simple and therefore inexpensive. The technique has not however been used for capillary blood flow measurement, because of the relatively low velocities encountered and because of the presence of strong interfering signals from the encompassing tissue. An ultrasound Doppler system capable of measuring flow velocities of one millimetre per second in the presence of one thousand times stronger interfering signals is described, as well as test results using both thread and flow phantoms.