cssi/SciSciGPT-SciSciNet huggingface dataset:
National Estimates and Predictors for Pulmonary Hypertension Readmission Categorized by Age Group

Background Pulmonary hypertension (PH) is increasingly recognized but understudied. We sought to determine national estimate measures and predictors of 30-day readmission after PH-related hospitalization categorized by age group. Methods We used the 2014 Healthcare Cost and Utilization Project Nationwide Readmission Database that represents weighted estimates of 35 million discharges in the US. Adult patients with primary ICD-9-CM diagnosis codes of 416.0 and 416.8 for primary and secondary PH with an index admission, and any readmission within 30-days of the index event were identified. Multivariate logistic regression modeling by age groups (Group1 ≥18 to Results Using sampling weights, national estimate of PH related index events was 2338 and readmission rate was 0.20. Predictors of Group1 readmissions were anemia, coagulopathy, congestive heart failure (CHF), lung disease (LD), solid tumor without metastasis (TS), fluid and electrolyte disorders (FED) while Group2 predictors were CHF, LD, renal failure and FED. Mean charges for Group1 admissions and readmissions were $67,183 and $68,874, with Group2 totaling $44,421 and $61,094 respectively. Conclusions 20% of PH-related hospitalizations result in 30-day readmission with underlying predictors varying by age category. Mean readmission charges significantly exceeded that of index hospitalization in age group ≥ 65 years.
How Big Is Too Big: Should Certain Higher Educational Endowments’ Net Investment Income Be Subject to Tax?

Section 13701 of the 2017 Tax Reform Act created new Internal Revenue Code § 4968 that imposes a 1.4% excise tax on the net investment income of certain large private college and university endowments. The affected institutions must have at least 500 tuition-paying students during the preceding taxable year, provided more than 50% of its students are located in the United States, plus assets (other than assets used directly in carrying out the institution’s exempt purpose) with an aggregate fair market value at the end of the preceding taxable year equal to at least $500,000 per full-time or full-time equivalent student. Approximately twenty-seven to thirty-five colleges and universities are affected. This paper argues that the legislation as enacted is politically motivated and fatally flawed. The “assets per student” ratio that triggers the tax is both over and under-inclusive, and irrelevant and arbitrary as a guide to excessive endowment accumulation. The legislation serves to exempt multi-billion dollar endowments of many universities yet ensnare smaller colleges that may have more limited resources, but the endowment to student ration exceeds $500,000. The growing income inequality in American society is reflected in the inequality of access to elite schools with billion dollar endowments. While large endowment schools have increased financial aid, the percentage of students from lower income families has remained the same. A student whose parents come from the top one percent of income distribution is 77 times more likely to attend an Ivy League college than one from the bottom income quintile. Among “Ivy League Plus” colleges (the eight Ivy League colleges plus Chicago, Stanford, MIT and Duke), more students come from families in the top 1% of income distribution (14.5%) than the bottom half of the income distribution (13.5%). Recommended is that the investment income tax be triggered for all billion dollar endowment institutions when the endowment earns $75 million in net investment income ($150 million for public school billion dollar endowments). The endowment per student ratio should be jettisoned. Schools could offset the net income investment tax on a one dollar to one dollar basis by increasing financial assistance to the student body. If the school increases the admission of students from underrepresented constituencies, the tax offset would be two dollars for each dollar spent in expanding the number of such students.
Taking Care Transitions Programs to Scale: Is the Evidence There Yet?

Blum and colleagues have estimated that nurse home visits after hospitalization for heart failure increase quality-adjusted life-years and survival and decrease rehospitalizations. The editorialist...
The Impact of Adopting Computational Storage in Heterogeneous Computing Systems

Heterogeneous computing systems have been the focus of major efforts in pursuit of Exascale computing over the past few years. These heterogeneous computing systems, often contain various accelerators, can significantly improve the computation performance thanks to their parallel compute cores. Much research has exploited accelerators to reduce the computation time; however, I/O access time or end-to-end total execution time is often overlooked. Typically, when I/O access time with the storage is considered, the performance gain from accelerators can be substantially degraded. In this work, we designed a computational storage in a heterogeneous computing system. Our evaluation employs a real-world compute-bound machine learning application on three computing systems: A conventional CPU system, a modern FPGA system, and the computational storage system. Compared to CPU system, we found that the modern FPGA system can achieve a 100x speedup for computation and 62x better energy efficiency, but only 26 × speedup and 16 × energy efficiency improvement when data movement time is taken into account; whereas the computational storage system can achieve 63 × computation speedup and 51 × better energy efficiency including data movement time. The experiment demonstrates that a compute-bound problem on conventional CPU system may become an I/O-bound problem on heterogeneous system. By adopting computational storage in heterogeneous system, we find that both the computation performance and the I/O performance is improved.
Pharmacokinetics, pharmacodynamics and metabolism of caffeine in newborns.

Abstract The plasma elimination half-life of caffeine in the newborn is approximately 100 h. Caffeine is rapidly absorbed with complete bioavailability following oral dosing. Switching between parenteral and oral administration requires no dose adjustments. Caffeine has wide interindividual pharmacodynamic variability and a wide therapeutic index in preterm newborns. Thresholds of measurable efficacy on respiratory drive have been documented at plasma levels around 2 mg/L. At these low levels, caffeine competitively inhibits adenosine receptors (A1 and A2A). The toxicity threshold is ill-defined and possibly as high as 60 mg/L which can be lethal in adults. High doses of caffeine may produce better control of apnea. However, at high systemic drug concentrations, the pharmacodynamic actions of caffeine become more complex and worrisome. They include inhibition of GABA receptors and cholinergic receptors in addition to adenosine receptor inhibition, intracellular calcium mobilization and actions on adrenergic, dopaminergic and phosphodiesterase systems. The role of pharmacogenomic factors as determinants of neonatal pharmacologic response and clinical effects remains to be explored.
English Teacher Interpretive Communities: An Exploratory Case Study of Teachers’ Literacy Practices and Pedagogical Reasoning

In this exploratory case study, the authors employed an “interpretive communities” lens to investigate the ways in which 12 high school English teachers of one district read and reasoned with liter...
Framingham Heart Study (FHS) 10-Year Cardiovascular Risk Is Associated With Marijuana Use in the Miami Adult Studies on HIV (MASH) Cohort

Objectives Illicit drug use can lead to adverse cardiovascular events; it is an additional risk factor for cardiovascular disease. Thus, we sought to determine the association between CVD and drug use in people living with HIV (PLWH) using the FHS 10-year risk.
An Efficient Pipeline for Biophysical Modeling of Neurons

Automation of the process of developing biophysical conductance-based neuronal models involves the selection of numerous interacting parameters, making the overall process computationally intensive, complex, and often intractable. A recently reported insight about the possible grouping of currents into distinct biophysical modules associated with specific neurocomputational properties also simplifies the process of automated selection of parameters. The present paper adds a new current module to the previous report to design spike frequency adaptation and bursting characteristics, based on user specifications. We then show how our proposed grouping of currents into modules facilitates the development of a pipeline that automates the biophysical modeling of single neurons that exhibit multiple neurocomputational properties. The software will be made available for public download via our site cyneuro.org.
The Identification and Use of a Common Language During a Curriculum Redesign: a Case Study of Conceptual Change

Within education, collective inquiry is essential to sustaining and pushing forward innovative educational initiatives. This research sought to determine if collective inquiries with a focus on common language with shared understanding impacted collective teacher efficacy, a construct linked to increased student achievement (Hattie in Scholarship of Teaching and Learning in Psychology, 1(1):79–91, 2015). What follows within this case study is the exploration of the process of common language development in one educational department at a midsized university during a curriculum redesign. The case study results indicated the 17 participants felt common language discussions were important and needed and that discussions during the curriculum redesign did occur resulting in shared understanding of language among the department. Collective teacher efficacy results and directions for future research are also shared.
Teaching The Penguin Book of Migration Literature

The innovative four-point structure—Arrivals, Departures, Generations, and Return—of The Penguin Book of Migration Literature expands the purview established by previous anthologies of immigrant literature by mobilizing a classroom conversation where students’ own lived experiences of migratory crossings combine with the anthology’s narratives to both analyze texts and critique present national and global political climate.
Rethinking the Traditional Textbook: A Case for Open Educational Resources (OER) and No-Cost Learning Materials

As college costs have continued to rise, textbooks now average more than $1,200 per student per academic year as of 2020. Traditional textbooks are not only expensive, but also have fixed and frequently outdated content. In this study, we compared pre-service teacher-student outcomes and perceptions of a traditional textbook versus no-cost, online materials such as open educational resources (OER) in an undergraduate Foundations of Education course. Outcomes were measured by comparison of final course grades. Perceptions were determined through quantitative and qualitative survey questions added to existing end-of-course evaluations. Results revealed students found OER and no-cost online materials more useful to their success in the course and more engaging than a traditional textbook. Qualitative analysis further revealed that while students appreciated there was no cost for the online materials, they preferred them to a traditional textbook because of the customized content. Results suggest students find instructor-curated, no-cost online readings more useful and preferable to a traditional textbook without compromising student academic performance.
Improving Literacy in America: Guidelines from Research

An alarmingly high number of American students continue to lack proficiency in reading, maths and science. The various attempts to address this problem have all too often resulted in 'silver bullet' solutions such as reducing class sizes or implementing voucher programmes. But as the authors of this critically important book show, improving literacy also requires an understanding of complex and interrelated social issues that shape a child's learning. Here, Frederick Morrison, Heather Bachman and Carol McDonald Connor preesent the most up-to-date research on the diverse factors that relate to a child's literacy development, from preschool to early elementary school.
Pharmacodynamics and Pharmacogenomics of Corticosteroids: Microarray Studies

There are multiple potential sites in the pathway from DNA to protein that are available for regulation (Fig. 11) [27]. The CS can regulate gene expression at various steps, alone or jointly with other transcription factors and/or hormones. Our microarray dataset contains substantial information about the mechanisms and extent of CS effects on various genes. The six major dynamic response patterns suggest that a limited number of control processes account for pharmacogenomic effects of steroids. The generalized mathematical models for receptor/gene/transduction dynamics facilitate the understanding of the global picture of CS actions and provide new insights for microarray data analysis. Pharmacogenomics provides an opportunity to examine multiple factors and mechanisms affecting the diverse molecular to whole-body actions of drugs. The PK/PD/PG models of the future will further integrate pharmacokinetics, molecular biology and systems pharmacology.
Foreign Intervention in Africa: Conflict in the Horn, 1952–1993

Simultaneous with the struggle for Southern Africa was the Cold War battle for the Horn. Bordering on the critical Red Sea and Indian Ocean sea-lanes and in close proximity to Middle Eastern oil, Ethiopia and Somalia were both regional rivals and objects of competition between the United States and the Soviet Union. While the dynamics of decolonization established the framework for Cold War battles in North Africa, the Congo, the Portuguese colonies, and the white-ruled regimes of Southern Africa, superpower involvement in the Horn of Africa was primarily linked to postcolonial regional competition. Like African actors elsewhere on the continent, contenders for power in the Horn sought support from Cold War antagonists in order to promote their own national and regional endeavors. Although the effects of American and Soviet intervention were at times decisive, Washington and Moscow responded to African internal dynamics; they did not cause them. African-superpower alliances in the Horn were complex and fluid. In the early 1970s, the United States helped sustain Emperor Haile Selassie's feudal order in Ethiopia while the nominally socialist military regime of Mohamed Siad Barre in Somalia was supported by the Soviet Union. However, by 1978, after a military coup in Ethiopia had brought a self-proclaimed Marxist regime to power and Somalia had attempted to annex Somali-inhabited territory in Ethiopia, Moscow and Washington had switched sides. Each had done so with reluctance, having initially hoped to maintain relations with both countries. Meanwhile, the collapse of Haile Selassie's regime had resulted in a surge of separatist movements among peoples subjugated by the Ethiopian empire. Most significantly, the nationalist movement in the former Italian colony of Eritrea, which had been annexed by Ethiopia in 1962, escalated its war for independence. Although the Soviet Union had long promoted the Eritrean cause, it withdrew its support after shifting its allegiance from Somalia to Ethiopia. Cuba, in contrast, supported Ethiopia in many capacities but refused to support its war against Eritrea.
WE‐EF‐BRA‐10: Prophylactic Cranial Irradiation Reduces the Incidence of Brain Metastasis in a Mouse Model of Metastatic Breast Cancerr

Purpose: Prophylactic cranial irradiation (PCI) is a clinical technique used to reduce the incidence of brain metastasis and improve overall survival in select patients with acute lymphoblastic leukemia and small-cell lung cancer. We examined whether PCI could benefit breast cancer patients at high risk of developing brain metastases. Methods: We utilized our mouse model in which 500k green fluorescent protein (GFP)-labeled breast cancer cells injected into the tail vein of SCID/Beige mice resulted in brain metastases in approximately two-thirds of untreated mice. To test the efficacy of PCI, one set of mice was irradiated five days after cell injection with a single fraction of 4-Gy (two 2-Gy opposing fields) whole-brain irradiation on the XRAD 225Cx small-animal irradiator. Four controls were included: a non-irradiated group, a group irradiated two days prior to cell injection, and two groups irradiated 3 or 6 weeks after cell injection. Mice were sacrificed four and eight weeks post-injection and were evaluated for the presence of brain metastases on a fluorescent stereomicroscope. Results: The incidence of brain metastasis in the non-irradiated group was 77% and 90% at four and eight weeks, respectively. The PCI group had a significantly lower incidence, 20% and 30%, whereas the other three control groups had incidence rates similar to the non-treated control (70% to 100%). Further, the number of metastases and the metastatic burden were also significantly lower in the PCI group compared to all other groups. Conclusion: The timing of irradiation to treat subclinical disease is critical, as a small dose of whole-brain irradiation given five days after cell injection abrogated tumor burden by greater than 90%, but had no effect when administered twenty-one days after cell injection. PCI is likely to benefit breast cancer patients at high risk of developing brain metastases and should be strongly considered in the clinic.
The Design of Natural Photosynthetic Antenna Systems

The nanoscale dimensions of the photosynthetic complexes are of critical importance for their effective function. Ultrafast spectroscopic studies by ourselves and by other groups, advances in obtaining high-resolution structural models, and more realistic light-harvesting models have revealed that the electronic interactions between the light-absorbing components in photosynthetic antenna complexes and reaction centers (RCs) are both qualitatively and quantitatively different than in chemical model systems where chromophores are spaced by distances that are large compared with their size. As a result, there are only a few cases in which the energy transfer within natural photosynthetic antenna can be correctly characterized by conventional Forster theory. In order to obtain a detailed understanding of the interactions between photosynthetic pigments embedded in protein complexes, two additional photosynthetic design features must be taken into account. One is that they utilize confined molecular geometries in which antenna molecules are spaced by distances that are small compared with their size. Such intermolecular distances enable transitions and energy levels that would be ineffective or even inoperative in systems with widely spaced chromophores to play crucial roles in light harvesting and energy transfer. The second is that they exploit energetic disorder in order to improve spectral coverage, reduce energy mismatches, and broaden excitonic manifolds to make the system exceedingly robust with respect to temperature variation and fluctuations in site energy and electronic coupling. Paradoxically, the same pigment interactions that can be used to optimize photosynthesis can also generate efficient photoprotection. Each of these points will be described and exemplified by theoretical and experimental work done in our laboratory on bacteria, cyanobacteria, and plants. 67
American Sexual Character: Sex, Gender, and National Identity in the Kinsey Reports

List of Illustrations Acknowledgments Introduction 1. "Sexual Order in Our Nation": American Sexuality and National Character in the Postwar United States 2. "A Missing Sense of Maleness": Male Heterosexuality, Sexual Behavior in the Human Male, and the Crisis of American Masculinity 3. "Much the Same Desires as Men": Sexual Behavior in the Human Female and the "American Woman" 4. "I'm a Much Better Citizen Than If I Were Single": Remaking Postwar Marriage and Reconfiguring Marital Sexuality 5. "An Age of Sexual Ambiguity": Homosexuality and National Character in the Postwar United States Epilogue. "All America Is One Big Orgone Box": American Sexual Character Revisited Notes Selected Bibliography Index
Beta-blockers and diabetes: The bad guys come good

Type 2 diabetes is becoming very common and is closely linked to physical inactivity and obesity. It is associated with clustering of coronary risk factors and 60-80% of cases have hypertension. The first therapeutic action is appropriate adjustment of life style. Anti-hypertensive therapies such as diuretics, ACE inhibitors and calcium antagonists have been effective in reducing cardiovascular events in type 2 diabetes, though calcium antagonists may be less effective than older therapies and ACE-inhibitors in reducing the risk of heart attacks and heart failure (but possibly more effective in stroke reduction). Beta-blockers (BBs) have a poor image as a potential therapy due to apparent adverse effects on surrogate end-points such as insulin-resistance. However large, controlled trials have shown BBs to be highly effective in reducing the risk of cardiovascular events and death in post myocardial infarction patients with diabetes. The UKPDS study in type 2 diabetics with hypertension showed first-line beta-blockade to be at least as effective as ACE-inhibition in preventing all primary macrovascular and microvascular end-points. The active ingredient appears to be beta-1 blockade, acting not only to lower blood pressure but also to prevent sudden death and cardiovascular damage stemming from chronic beta-1 stimulation associated with raised noradrenaline activity. By contrast, in the LIFE study atenolol was less effective than the angiotensin receptor antagonist losartan in reducing cardiovascular events and all-cause mortality in mainly elderly hypertensives with diabetes. Thus the best beta-blocker results in reducing hard cardiovascular end-points occur in hypertension studies (including the UKPDS study) involving younger/middle aged (say less than 60-65 years) patients, with relatively high sympathetic activity, relatively compliant/elastic arteries (narrow pulse-pressure) and normally functioning beta-1 receptors. In elderly hypertensive patients beta-blockers may be given as second-line therapy on the back of a low-dose diuretic (but possibly as first line agent in elderly hypertensives with prior myocardial infarction). Thus inappropriate attention to surrogate end-points can lead to faulty prescribing habits. Beta-blockers, currently severely underprescribed, should be considered as a first line therapeutic option for all diabetics with ischaemic heart disease or younger/middle aged diabetics with hypertension (but co-prescribed with low dose diuretic therapy in the elderly). The active ingredient for cardiovascular protection appears to be beta-1 blockade; optimal efficacy in lowering blood pressure and safety e.g. reducing risk of bronchoconstriction, is achieved by choosing an agent with high beta-1 selectivity.
Neohumility / Humility and Business Leadership: Do They Belong Together?

This article looks at commonly accepted and newly emerging ideas of effective leadership in the literature. One such quality that has recently emerged in the discourse on leadership is "humility." Humility has traditionally been associated with weakness and even seen as antithetical to the leader persona. This article suggests a new view of humility, "neohumility," humility without weakness and transformed to fit the business world. It operationalizes the definition of neohumility and includes characteristics such as self-awareness, valuing others' opinions, willing to learn and change, sharing power, having the ability to hear the truth and admit mistakes, and working to create a culture of openness where dissent is encouraged in an environment of mutual trust and respect.
A Knot Recognition Algorithm

A number of researchers have applied Monte Carlo techniques to questions of random knotting. (Chen, 1981; Deguchi and Tsurusaki, 1994; Frank-Kamenetskii, et.al., 1975; Jense van Rensburg and Whittington, 1990 and 1991a;Koniaris and Muthukumar, 1991; Mansfield, 1994; Michels and Wiegel, 1986;ten Brinke and Hadziioannou, 1987 ; Vologodskii, et.al., 1974 and 1975.) These studies seek to understand the knotting statistics of randomly grown knots. Their relevance to the physical sciences is primarily in the field of polymer or biopolymer configurations. These computations typically require generation of random knots followed by characterization of the knot state of each generated configuration. So obviously, knot recognition algorithms are essential to such computations.
Disposition of Extended Release Levetiracetam in Normal Healthy Dogs After Single Oral Dosing

Background Levetiracetam is an anticonvulsant used for control of canine epilepsy. An extended release preparation should improve dosing convenience. Objectives To determine the disposition of extended release levetiracetam in normal dogs after single dosing. Animals Pharmacokinetic study: 16 healthy, adult dogs. Methods Using a partially randomized crossover study, levetiracetam (30 mg/kg) was administered intravenously (IV) and orally (PO) as extended release preparation with or without food. Blood was collected for 24 hours (IV) or 36 hours (PO). Serum levetiracetam was quantitated by immunoassay and data were subjected to noncompartmental analysis. Results Pharmacokinetic parameters for fasted versus fed animals, respectively, were (mean ± SEM): Cmax = 26.6 ± 2.38 and 30.7 ± 2.88 μ/mL, Tmax = 204.3 ± 18.9 and 393.8 ± 36.6 minutes, t1/2 = 4.95 ± 0.55 and 4.48 ± 0.48 hours, MRT = 9.8 ± 0.72 and 10 ± 0.64 hours, MAT = 4.7 ± 0.38 and 5.6 ± 0.67 hours, and F = 1.04 ± 0.04 and 1.26 ± 0.07%. Significant differences were limited to Tmax (longer) and F (greater) in fed compared to fasted animals. Serum levetiracetam concentration remained above 5 μ/mL for approximately 20 hours in both fasted and fed animals. Conclusions and Clinical Importance Extended release levetiracetam (30 mg/kg q12h), with or without food, should maintain concentrations above the recommended minimum human therapeutic concentration.
Goal-based requirements analysis

Goals are a logical mechanism for identifying, organizing and justifying software requirements. Strategies are needed for the initial identification and construction of goals. We discuss goals from the perspective of two themes: goal analysis and goal evolution. We begin with an overview of the goal-based method we have developed and summarize our experiences in applying our method to a relatively large example. We illustrate some of the issues that practitioners face when using a goal-based approach to specify the requirements for a system and close the paper with a discussion of needed future research on goal-based requirements analysis and evolution.
Dissociation of Cellular Functions in Bacillus cereus by 5-Fluorouracil

Reich, Melvin (The George Washington University School of Medicine, Washington, D.C.), and H. George Mandel. Dissociation of cellular functions in Bacillus cereus by 5-fluorouracil. J. Bacteriol. 91:517–523. 1966.—5-Fluorouracil (FU) produced a marked inhibition of growth and deoxyribonucleic acid (DNA) synthesis in Bacillus cereus 569H. Protein and ribonucleic acid (RNA) synthesis were not specifically inhibited, and proceeded at the rate of turbidometric increase of the cells. Cell-wall synthesis, respiration, and penicillinase production continued in the presence of FU at essentially the control rate. The addition of equimolar concentrations of uracil and FU prevented growth inhibition but did not restore DNA synthesis. The addition of thymidine with FU did not relieve growth inhibition but did restore the DNA content to normal. Thymidine supplementation also increased the quantity of FU, but not uracil, incorporated into RNA and the acid-soluble fraction. The data indicate that inhibition of growth can be dissociated from inhibition of DNA synthesis and that more DNA is present in normal cells than is needed for growth and reproduction.
Preliminary Imaging Performance of an Ultra-high Resolution Pinhole SPECT System Using an Intensified EMCCD Camera

This paper presents preliminary results achieved using an ultra-high resolution pinhole SPECT system for small animal imaging using I-125 radiotracers. This system is based on a very-high resolution gamma camera that consists of an intensified EMCCD (I-EMCCD) camera coupled to columnar CsI(Tl) scintillators. The I-EMCCD camera provides an active area of ~80mm diameter, an intrinsic resolution of ~60mum and a near perfect photon counting efficiency for detecting 27-35keV photons emitted by I-125. A single pinhole aperture with a 100mum diameter pinhole was used in these imaging studies based on both phantoms and mice injected with 1-125 NaCl solution. A reconstructed spatial resolution of <100 mum has been experimentally achieved. Given the ultra-high spatial resolution and the very low readout noise, the I-EMCCD camera has the potential of offering a further improved spatial resolution for small animal imaging applications with tracers labelled with multiple radioisotopes such as I-125, I-123 and Tc-99m etc. The I-EMCCD based gamma camera can be used for a proposed single photon emission microscope (SPEM) system that provides a sub-hundred micron resolution and a reasonable detection efficiency for small animal imaging.
The impurity susceptibility of dilute AuV alloys: 51V NMR studies☆

Abstract Measurements of the 51V NMR shift in Au V are reported for the temperature range 4–540°K. The results, which can be separated into a temperature-dependent spin contribution and a temperature-independent orbital contribution, are in general agreement with the bulk susceptibility measurements of Van Dam and Gubbens.
The advantages of AMS to field archaeologists

Abstract AMS has successfully resolved several controversies concerning the anomalously early appearance of early objects (domesticated plants in both the Old and New Worlds, Late Pleistocene people in the New World), and will continue to be used for this purpose. However, it may be of greater importance in the future as an integral part of research programs designed to exploit the technique, such as the evaluation of prehistoric settlements, tracing the development of the modern form of humans and the radiation of Upper Paleolithic technology.
ENTREPRENEURIAL DRIVE AND THE INFORMAL ECONOMY IN CAMEROON

There is a growing appreciation for the value and impact of the informal economy on the lives and livelihood of many in developing economies. A key question for researchers has been whether those operating in it do so out of necessity or voluntarily as opportunity seekers? Unlike previous studies that have examined the informal economy as one large block, this paper took a slightly different tangent. First, we analyzed and identified three distinct sub-groups within the informal entrepreneurial sector — the street walker (st. walker), the street corner (st. corner) and store owner (st. owner) — and then examined each group's motives. Reporting the results of face-to-face structured interviews with 200 informal entrepreneurs in Cameroon (West Africa), the finding is that the majority, especially st. walker and st. corner informal entrepreneurs, are predominantly necessity-driven while st. owner entrepreneurs are predominantly opportunity-driven. Our study also revealed a progression pattern whereby st. walkers do progress to st. corner and ultimately to st. owner entrepreneurs. The assumption is that this does create a learning curve effect in the entrepreneurial abilities and effectiveness of store owners. This is an area for future research. There are policy implications for institutional support that can grow the informal economy into the formal economy.
Interpenetrating polymer network approach to tough and microcracking resistant high temperature polymers. Part II. LaRC-RP41

Recently, we reported on the interpenetrating polyimide network (IPN) approach to develop tough and microcracking resistant high temperature matrix resins for use in aircraft/aerospace structural components. One such polymer developed is designated LaRC-RP40. This new simultaneous semi-IPN was prepared from easy-to-process but brittle crosslinking PMR-15 and tough but difficult-to-process linear NR-150B2. Significantly improved toughness, microcracking resistance, and glass transition temperature over PMR-15 were realized from the combination. These property improvements were achieved without compromising ease of processing, high temperature mechanical performance, and cost effectiveness compared to PMR-15. These results encouraged us to further explore this approach for the development of a wider range of polymers of basic technological and economic interest. In the present work, we combine crosslinking PMR-15 and linear LaRC-TPI to provide a new sequential semi-2-IPN called LaRC-RP41. The physical and mechanical properties of the neat resin and composite reinforced with graphite fibers are presented. The phase morphology and phase stability of the neat resin and composite studied by various techniques are also discussed.
Multifunctional Lens Crystallins and Corneal Enzymes: More than Meets the Eye

The abundant water-soluble proteins, called crystallins, of the transparent, refractive eye lens have been recruited from metabolic enzymes and stress-protective proteins by a process called "gene sharing." Many crystallins are also present at lower concentration in nonocular tissues where they have nonrefractive roles. The complex expression pattern of the mouse alpha B-crystallin/small heat shock protein gene is developmentally controlled at the transcriptional level by a combinatorial use of shared and lens-specific regulatory elements. A number of crystallin genes, including that for alpha B-crystallin, are activated by Pax-6, a conserved transcription factor for eye evolution. Aldehyde dehydrogenase class 3 and transketolase are metabolic enzymes comprising extremely high proportions of the water-soluble proteins of the cornea and may have structural as well as enzymatic roles, reminiscent of lens enzyme-crystallins. Inductive processes appear to be important for the corneal-preferred expression of these enzymes. The use of the same protein for entirely different functions by a gene-sharing mechanism may be a general strategy based on evolutionary tinkering at the level of gene regulation.
Improved synthesis of 13C, 2H3- and 2H3-salmeterol by Cs2CO3-mediated monoalkylation of a primary amine

An abbreviated synthesis of isotopically labelled salmeterol has been achieved. The key improvement utilizes a highly selective Cs2CO3-mediated one-pot alkylation of benzylamine by 6-bromo-1-(4′-phenylbutoxy)hexane to prepare the limiting reagent, 6-N-benzylamino-1-(4′-phenylbutoxy)hexane without overalkylation. The method was applied to synthesis of the title compounds in >97 at% isotopic purity. Copyright © 2002 John Wiley & Sons, Ltd.
Frequency of use of suturing and repair techniques preferred by dermatologic surgeons.

BACKGROUND There are many closure techniques and suture types available to cutaneous surgeons. Evidence-based data are not available regarding the frequency of use of these techniques by experienced practitioners. OBJECTIVE To quantify, by anatomic site, the frequency of use of common closure techniques and suture types by cutaneous surgeons. METHOD A prospective survey of the members of the Association of Academic Dermatologic Surgeons that used length-calibrated visual-analog scales to elicit the frequency of use of specific suture techniques. RESULTS A response rate of 60% (61/101) indicated reliability of the received data. Epidermal layers were closed most often, in descending order, by simple interrupted sutures (38–50%), simple running sutures (37–42%), and vertical mattress sutures (3–8%), with subcuticular sutures used more often on the trunk and extremities (28%). The most commonly used superficial sutures were nylon (51%) and polypropylene (44%), and the most common absorbable suture was polyglactin 910 (73%). Bilayered closures, undermining, and electrocoagulation were used, on average, in 90% or more sutured repairs. The median diameters (defined as longest extent along any axis) of most final wound defects were 1.1 to 2.0 cm (56%) or 2.1 to 3.0 cm (37%). Fifty-four percent of wounds were repaired by primary closure, 20% with local flaps, and 10% with skin grafting, with the remaining 15% left to heal by second intent (10%) or referred for repair (5%). Experience-related differences were detected in defect size and closure technique: defects less than 2 cm in diameter were seen by less experienced surgeons, and defects greater than 2 cm by more experienced surgeons (Wilcoxon's rank-sum test: p=.02). But more experienced surgeons were less likely to use bilayered closures (r=−0.28, p=.036) and undermining (r=−0.28, p=.035). CONCLUSIONS There is widespread consensus among cutaneous surgeons regarding optimal suture selection and closure technique by anatomic location. More experienced surgeons tend to repair larger defects but, possibly because of their increased confidence and skill, rely on less complicated repairs.
Age and sex differences in motor performance of 3 through 6 year old children.

Abstract This study examined the relationship of age and sex to the performance of 3, 4, 5, and 6 year olds on seven motor performance test items. Although significant age and sex differences were found on most of the motor tests, it appears that age generally was related more to performance than was gender. Overall, change with age was fairly linear except perhaps for balancing and a general tapering in improvement in the 5 to 6 year old category. On the tests of throwing and balancing, gender was as important as age, or more so, in its relationship to performance. Boys were superior to girls at all ages on the throwing tests; girls were superior to boys at age 6 on the Balance test. Gender differences of a lesser magnitude were found on the Speed Run and Standing Long Jump tests with the performance of boys generally being superior to the performance of girls. Thus, it appears that gender differences in motor performance occur as early as the preschool years. Interestingly, except for the Balance test, ...
Development and characterization of a fusion protein between thermally responsive elastin-like polypeptide and interleukin-1 receptor antagonist: sustained release of a local antiinflammatory therapeutic.

Objective Interleukin-1 receptor antagonist (IL-1Ra) has been evaluated for the intraarticular treatment of osteoarthritis. Such administration of proteins may have limited utility because of their rapid clearance and short half-life in the joint. The fusion of a drug to elastin-like polypeptides (ELPs) promotes the formation of aggregating particles that form a “drug depot” at physiologic temperatures, a phenomenon intended to prolong the presence of the drug. The purpose of this study was to develop an injectable drug depot composed of IL-1Ra and ELP domains and to evaluate the properties and bioactivity of the recombinant ELP-IL-1Ra fusion protein. Methods Fusion proteins between IL-1Ra and 2 distinct sequences and molecular weights of ELP were overexpressed in Escherichia coli. Environmental sensitivity was demonstrated by turbidity and dynamic light scattering as a function of temperature. IL-1Ra domain activity was evaluated by surface plasmon resonance, and in vitro antagonism of IL-1–mediated lymphocyte and thymocyte proliferation, as well as IL-1–induced tumor necrosis factor α (TNFα) expression and matrix metalloproteinase 3 (MMP-3) and ADAMTS-4 messenger RNA expression in human intervertebral disc fibrochondrocytes. IL-1Ra immunoreactivity was assessed before and after proteolytic degradation of the ELP partner. Results Both fusion proteins underwent supramolecular aggregation at subphysiologic temperatures and slowly resolubilized at 37°C. Interaction with IL-1 receptor was slower in association but equivalent in dissociation as compared with the commercial antagonist. Anti–IL-1 activity was demonstrated by inhibition of lymphocyte and thymocyte proliferation and by decreased TNFα expression and ADAMTS-4 and MMP-3 transcription by fibrochondrocytes. ELP domain proteolysis liberated a peptide of comparable size and immunoreactivity as the commercial IL-1Ra. This peptide was more bioactive against lymphocyte proliferation, nearly equivalent to the commercial antagonist. Conclusion The ELP-IL-1Ra fusion protein proved to retain the characteristic ELP inverse phase-transitioning behavior as well as the bioactivity of the IL-1Ra domain. This technology represents a novel drug carrier designed to prolong the presence of bioactive peptides following intraarticular delivery.
Two phase behaviour and the distribution of volume

The short term dynamics of stock prices is largely driven by fluctuations in demand and supply. A balance between demand and supply for the stock results only in mild price fluctuations; in contrast, a large imbalance can cause considerable price movement. Using transactions and quotes data for 116 most-actively traded US stocks for the 2 yr period 1994–1995, we showed empirically that the probability distribution of demand conditioned on its local noise intensity S displays a change from a unimodal distribution for S Sc (Plerou et al. 2003).z We hypothesized that these empirical findings can be interpreted as indicating that, as S changes, the stock market moves between an ‘equilibrium’ state during which the price fluctuates around its consensus value, and an ‘out-of-equilibrium’ state during which there is an excess of buyers or sellers and the stock is evolving to a new consensus value. Lastly, we remarked on the analogy of this bifurcation phenomenon to similar results in phase transition phenomena, and interpreted the different states as distinct ‘phases’. Following the procedure of Plerou et al. (2000), we define demand 1⁄4 P qiai, where qi is the trade size of trade i, ai indicates buy (ai1⁄4 1) or sell (ai1⁄4 1) and the summation is over the N trades in t. In a recent article, Matia and Yamazaki (2005) (MY) construct in a similar way from transactions and quotes data for 102 stocks during a different time period 2001–2002. They then construct P( |S) and confirm our empirical finding of a change of this distribution from an unimodal to a bimodal behaviour as S crosses a threshold Sc. MY then perform a numerical simulation where and S are constructed from q and N with the previouslyreported power-law exponents N1⁄4 3.4 (Plerou et al. 2000) and q1⁄4 3/2 (Gopikrishnan et al. 2000). From this randomly generated time series, MY find that the distribution P( |S) changes from an unimodal to a bimodal shape as S increases. They further observe that the bifurcation behaviour is absent when P(q) is replaced by a Gaussian distribution. MY conclude that the empirically-observed ‘two phase behaviour’ is a consequence of the fat-tailed distribution of volume. A similar explanation was previously proposed by Potters and Bouchaud (2003). In our simulation, we construct time series for and S using the same number of data points as in our empirical data, corresponding to 116 stocks each with length 12 896 data points. Figure 1 shows P( |S) for constructed from a simulation using (a) power-law distributed q with exponent q1⁄4 3/2, (b) power-law distributed q with exponent q1⁄4 3 and (c) exponentially distributed q. Figure 1(a) shows that the bifurcation behaviour is clearly evident for the case q1⁄4 1.5, as found by MY. Figures 1(b) and (c) show that a similar bifurcation is *Corresponding author. Email: hes@bu.edu yPresent address: Goldman Sachs & Co., New York. zA similar bifurcation is found also by conditioning on Q.
Studies in organo-phosphorus chemistry. II. Mechanism of the reaction of tertiary phosphine dihalides with alcohols

STUDIES IN ORGANO-PHOSPHORUS CHEMISTRY. II.1 MECHANISM OF THE REACTION OF TERTIARY PHOSPHINE DIHALIDES WITH ALCOHOLS G. A. Wiley, B. M. Rein, and R. L. Hershkowitz Department of Chemistry, Syracuse University, Syracuse, New York (Received 22 June 1964) The reaction of tertiary phosphine dihalides with alcohols is not only an excellent synthetic method for the preparation of alkyl and aryl halides (l), but provides one of the simplest model systems for the study of mechanisms of the reactions of 'pentavalent" phosphorus compounds (PX,) with alcohols. We now present evidence in support of eq. 1 as representing the gross features of the mechanism of the model reaction,
Is there a “universal” potential of physical adsorption?

Abstract Evidence is presented concerning the hypothesis that all physisorption pontetials have a common form. Input comes from atomic and molecular beam scattering. LEED and thermodynamic data and theoretical calculations. We conclude that a smaller force constant and softer repulsion occur for light gases interacting with insulators than with graphite or metals.
Pharmacological evidence for a discrete neurotoxic action of dieldrin (HEOD) in the American cockroach, Periplaneta americana (L.)☆

Abstract The excitatory effects of HEOD poisoning on spontaneous activity, and synaptic function in the sixth abdominal ganglion of the American cockroach are described. These effects are shown to be antagonized by Mg 2+ , hemicholinium-3, atropine, and d-turbocurarine. HEOD poisoning did not alter the nicotine sensitivity of the ganglion. On the basis of the findings it is hypothesized that HEOD acts at presynaptic membranes of cholinergic junctions, causing excessive and spontaneous release of presynaptic stores of acetylcholine.
White Dwarfs in Cataclysmic Variable Stars: Surface Temperatures and Evolution

A summary is presented of what is currently known about the surface temperatures of accreting white dwarfs (WDs) detected in non-magnetic and magnetic cataclysmic variables (CVs) based upon synthetic spectral analyses of far ultraviolet data. A special focus is placed on WD temperatures above and below the CV period gap as a function of the orbital period, . The principal uncertainty of the temperatures for the CV WDs in the distribution, besides the distance to the CV, is the mass of the WD. Only in eclipsing CV systems, an area of eclipsing binary studies, which was so central to Robert H. Koch`s career, is it possible to know CV WD masses with high precision.
Che vuoi ? Jouir du symptôme pervers dans le cinéma de Pedro Almodóvar☆

Resume Le dernier film de Pedro Almodovar, la Mauvaise education , presente le theme de la pedophilie dans le contexte de l'internat catholique en Espagne sous Franco. De facon plus generale, puisque le film suppose que le choix d'un mode de vie marque par la perversion (toxicomanie, travestisme et prostitution) soit la consequence de l'abus sexuel subi pendant l'enfance, ce film poursuit les recherches entamees par le metteur en scene depuis ses debuts autour de la question de l'image du corps propre et des sexualites paralleles. Cette etude propose un compte rendu et une mise au clair de la structure perverse a partir de l'exemple du fetichisme pour ensuite postuler une difference par rapport au travestisme et en fin de compte poser la transsexualite, categorie souvent evoquee dans le contexte de ce cinema, comme radicalement differente. Cette etude propose que le BDD ( Body Dysmorphic Disorder ) demontre l'importance et la difficulte de la question de la difference entre perversion et psychose.