cssi/SciSciGPT-SciSciNet huggingface dataset:
Selling at the Farmgate or Traveling to the Market: A Conditional Farm-Level Model

This paper seeks to indentify the determinants of smallholder farmer's market participation decisions using a farm level approach. By opening the black box which conceals the complex mechanism guiding farmers' market participation decision, this paper's contribution resides on its ability to take account of the conditional nature of farmers' decision to participate in the market. The paper develops a farm level sequential market participation model while taking account of the conditional nature of farmer's decision to participate in the market. In fact, the paper argues that the farmer's decision to participate in the market of a certain crop is dependent on producing the crop. Therefore, failing to account for this may bias the results. From a policy implication standpoint, the highlights of the results suggest that providing affordable and easily accessible fertilizers will incentivize both greater market participation and market volume supplied of both cash and food crop types.
Dimethyl sulfoxide reversibly inhibits the pigmentation of cultured neural crest cells

Abstract Cranial neural crest cells differentiate into melanocytes when cultured in the presence of fetal calf serum or calf serum and into neuron-like cells in the presence of horse serum. Dimethyl sulfoxide (DMSO) at a concentration of 1% prevented the pigmentation of these cells without affecting their growth rate or the differentiation of neural crest cells into neuron-like cells. After removal of DMSO from the medium, pigmentation was observed within 24 h. It is likely that DMSO blocks a late step in melanogenesis, since cells grown with DMSO contained premelanosomes. Furthermore, these cells did not undergo neurogenesis when shifted to medium containing horse serum. The inhibition of pigmentation by DMSO was prevented in part by supplementing cultures with a higher concentration of fetal calf serum or calf serum or with a fraction of these sera with a molecular weight above 10,000, but not by horse serum or a variety of growth factors and hormones. Although the mechanism by which DMSO exerts its effect is not known, one possibility consistent with the results is that DMSO alters the activity of a factor in serum, thereby preventing it from interacting with the cell to promote pigmentation.
A selected ion monitoring method for glutethimide and six metabolites: Application to blood and urine from humans intoxicated with glutethimide†

A method employing selected ion monitoring for the analysis of glutethimide and six of its metabolites has been developed. Hydroxylated metabolites analyzed as trifluoroacetates, included 4-hydroxyglutethimide, (1-hydroxyethyl)glutethimide and p-hydroxyglutethimide. The unchanged drug, 3-dehydroglutethimide, desethylglutethimide and the internal standard, [2H5]glutethimide, were chromatographed underivatized on OV-225. The assay was used to measure drug and metabolites in the plasma and urine of patients intoxicated with glutethimide. High levels (e.g. 20--35 microgram ml-1) of unconjugated 4-hydroxyglutethimide, an active metabolite, were found in all patients at a time when levels of unchanged drug were lower and declining. Other unconjugated and conjugated metabolites were found in relatively low concentrations in the plasma (i.e. less than 4 microgram ml-1). The major urinary metabolites were conjugates of 4-hydroxyglutethimide and (1-hydroxyethyl)glutethimide. The unchanged drug and other conjugated and unconjugated metabolites were found in lower amounts in the urine. Normal plasma half-lives of glutethimide and the relatively small amounts in urine of unchanged drug and unconjugated metabolites indicated that drug elimination was not markedly impaired in the intoxicated patients.
Indoor air pollution due to emissions from unvented gas-fired space heaters.

Operation of an unvented combustion appliance indoors can elevate pollutant concentrations Under laboratory conditions, oxygen consumption rates and pollutant emission rates of CO, CO2, NO, NO2, HCHO and submicron suspended particles emitted from eight unvented gas-fired space heaters operated with well adjusted air shutters at partial and full fuel consumption rates were determined in a 27-m3 chamber. Emission rates were also determined for some heaters operating under poorly tuned conditions. Four of the eight heaters were subsequently tested in a 240-m3 research house with 0.36-1.14 air changes per hour. Based on measurements near steady state, steady state pollutant and oxygen levels were projected: 1930-11,100 ppm for CO2, 1.0-26 ppm for CO (under well-tuned conditions), 0.40-1.46 ppm for NO2, and 19.1-20.7% for O2. Concentrations of CO2, CO, and NO2 sometimes exceeded outdoor or occupational guidelines. Analysis showed that CO, NO, and NO2 emission rates can vary with time and that, while short-term...
Effect of antihypertensive formulation on health service expenditures

A Major barrier to the management of hypertension is the extent to which patients comply with the treatment regimen. Herein we report the findings of a retrospective analysis designed to discern the relationship between antihypertensive formulation, regimen compliance and the utilization of health care services. Data for this analysis were derived from the state of South Carolina's Medicaid computer archive. The study population consisted of 1 000 randomly selected beneficiaries initially prescribed one of the following antihypertensive regimens as monotheraphy: atenolol (daily); captopril (twice daily); oral clonidine (twice daily); transdermal clonidine (once a week); diltiazem (twice daily); enalapril (twice daily); metoprolol (twice daily); prazosin (twice daily); terazosin (daily); and verapamil-SR (daily). Multivariate regression analysis was used to determine the incremental influence of selected demographic characteristics, utilization of medical services prior to diagnosis for hypertension, initial antihypertensive medication, medication possession ratio for antihypertensive therapy, and the number of maintenance medications for disease state processes other than hypertension on post-period health care expenditure. Results indicate that patients initially prescribed antihypertensive medication requiring daily or weekly administration experience infrequent changes in their therapeutic regimen, far less use of concomitant therapy for blood pressure control, an increased utilization of antihypertensive medication, and a decrease in the use and cost of physician, hospital and laboratory services.
Polypeptide growth factors in metanephric growth and segmental nephron differentiation.

Although the developing nephron expresses receptors for various polypeptide growth factors, the specific roles of such factors in renal organogenesis are unknown. Therefore, the effects of epidermal growth factor (EGF) (8.2×10−11 M-1.6×10−8 M), multiplication stimulating activity (MSA) (6.6×10−10 M-1.3×10−8M) and transforming growth factor beta (TGF-β) (1×10−12 M-1×10−9 M) on organotypic renal growth and segmental nephron differentiation were studied in a serum-free hormonesupplemented, murine metanephric organ culture system. Following culture in control or growth-factor-supplemented medium, explant growth was assessed, and explant growth and differentiation were determined morphometrically in four defined nephron segments which were identified morphologically or immunohistologically with segment-specific antibodies and/or lectins: glomeruli, proximal tubules, thick ascending limb-early distal tubules, and collecting tubules. Results showed that EGF increased overall renal growth and specific differentiation of distal elements, but retarded differentiation of glomeruli and proximal tubules. EGF also induced hyperplastic cystic malformation in proximal tubules. MSA stimulated explant growth and promoted segmental differentiation of all tubular segments. TGF-β globally retarded in vitro nephrogenesis. Such data demonstrate that polypeptide growth factors have multiple and often disparate effects on overall renal growth in relation to differentiation of discrete nephron segments and provide insight into the factors which may regulate normal and abnormal renal embryogenesis.
Transfer of a Dwarf Gene from Brassica rapa to Oilseed B. napus , Effects on Agronomic Traits, and Development of a ‘Perfect’ Marker for Selection

Lodging can be a serious problem in oilseed Brassica napus. Dwarf genes have been used to reduce lodging in other crops, and their use in wheat and rice was a major factor in the success of the ‘Green Revolution’. We previously reported on a single, semi-dominant, gibberellin insensitive dwarf mutant of B. rapa (Brrga1-d), and provided evidence for homology of this gene to the wheat ‘Green Revolution’ dwarf gene. In this paper, we report using interspecific hybridization of B. rapa and B. oleracea and embryo rescue to resynthesize B. napus containing the Brrga1-d dwarf gene. The dwarf gene was backcrossed into two parents of a commercial hybrid combination and evaluated as inbred and hybrid lines in field experiments. The Brrga1-d gene reduced plant height and lodging in inbred and hybrid lines of B. napus, even when present as a single dose in heterozygous genotypes. Seed yields of inbred lines homozygous for Brrga1-d were reduced compared to near isogenic wild-type inbreds, presumably due to damage by insects caused by a slight delay in flowering time. However, yields of hybrids that were homozygous or heterozygous for Brrga1-d were similar to those of near isogenic wild-type hybrids. In addition, we report on a ‘perfect’ PCR marker for selection of the Brrga1-d gene that is based on detecting the nucleotide mutation causing the dwarf phenotype.
Relation between the fluctuations of density and of the conduction band minimum of simple liquids

Abstract Based on the assumption that the local variation of the conduction band minimum is proportional to the deviation of the atomic density from its average value it is shown that a gaussian distribution of disorder generated states is expected near the bottom of the conduction band. The width of the energy distribution depends on the density, structure factor S (0) and a deformation potential.
Characteristics of two new avian tumor virus subgroups.

Abstract Avian tumor viruses capable of growing in cells resistant to the A and B subgroups can be assigned to two new subgroups, C and D. Members of subgroup C are virus B77, Rous-associated viruses types 7 and 49, and a clone-purified line of Prague strain Rous sarcoma virus. These agents plate with equal efficiency in types C O , C A , C B , and C AB chick embryo fibroblast cultures but are excluded from type C BC chicken cells. Rous-associated viruses of subgroup C interfere with sarcoma viruses of that subgroup but do not interfere with sarcoma viruses of subgroups A and B. Conversely, subgroup A and B Rous-associated viruses are unable to interfere alone or in combination with challenge viruses of subgroup C. Neutralization tests and fluorescent antibody staining indicate immunological relatedness of subgroup C viruses and antigenic distinctness from subgroups A and B. Of the subgroup C sarcoma viruses only B77 is oncogenic in hamsters. Members of subgroup D are cloned derivatives of the Schmidt-Ruppin and Carr Zilber strains of Rous sarcoma virus, Carr Zilber-associated virus, and Rous-associated virus type 50. These viruses form foci in C O , C A , C B , C AB , and C BC chick embryo fibroblast cultures. However, their plating efficiency is significantly reduced in all cell types resistant to subgroup B. All subgroup D sarcoma viruses are highly oncogenic for the newborn hamster. The associated viruses are capable of interfering with the sarcoma viruses of subgroup D, but this interference is not seen in all genetic types of chicken cells. The associated viruses of subgroup D also interfere with subgroup B sarcoma viruses, and subgroup B Rous-associated virus induces resistance to subgroup D. Interference does not take place between subgroups A or C and subgroup D. The members of subgroup D are also related immunologically, as indicated by the high incidence and degree of cross reactions in neutralization and fluorescent antibody tests. It appears that the previously described subgroups A and B represent mainly avian tumor viruses of the Western Hemisphere, whereas subgroups C and D are largely composed of viruses propagated in European laboratories.
A directly patternable click-active polymer film via initiated chemical vapor deposition (iCVD)

Abstract A new “click chemistry” active functional polymer film was directly obtained from a commercially available monomer of propargyl acrylate (PA) via easy, one-step process of initiated chemical vapor deposition (iCVD). Fourier transform infrared (FTIR) spectra confirmed that significant amount of the click-active acetylene functional group was retained after the iCVD process. The degree of crosslinking could be controlled by intentionally adding crosslinker, such as ethylene glycol diacrylate (EGDA) that was polymerized with PA to form click-active, completely insoluble copolymer. The formed iCVD polymers could also be grafted on various inorganic substrates with silane coupling agents. These crosslinking and grafting techniques give iCVD polymers chemical and mechanical stability, which allows iCVD polymers applicable to various click chemistry without any modification of reaction conditions. Pre-patterned iCVD polymer could be obtained via photolithography and an azido-functionalized dye molecule was also successfully attached on iCVD polymer via click chemistry. Moreover, pPA film demonstrated sensitivity to e-beam irradiation, which enabled clickable substrates having nanometer scale patterns without requiring the use of an additional e-beam resist. Direct e-beam exposure of this multifunctional iCVD layer, a 200 nm pattern, and QD particles were selectively conjugated on the substrates via click chemistry. Thus, iCVD pPA has shown dual functionality as of “clickable” e-beam sensitive material.
Differential expression and regulation by 20-hydroxyecdysone of mosquito ultraspiracle isoforms.

Abstract Ultraspiracle (USP), the insect homologue of the vertebrate retinoid X receptor, is an obligatory dimerization partner for the ecdysteroid receptor (EcR). Two USP isoforms, USP-A and USP-B, with distinct N-termini, occur in the mosquito Aedes aegypti. In the fat body and ovary, USP-A mRNA is highly expressed during the pre- and late vitellogenic stages, corresponding to a period of low ecdysteroid titer, while USP-B mRNA exhibits its highest levels during the vitellogenic period, correlating with a high ecdysteroid titer. Remarkably, 20-hydroxyecdysone (20E) has opposite effects on USP isoform transcripts in in vitro fat body culture. This steroid hormone upregulates USP-B transcription and its presence is required to sustain a high level of USP-B expression. In contrast, 20E inhibits activation of USP-A transcription. Although EcR·USP-A recognizes the same ecdysteroid-responsive elements, EcR·USP-B binds them with an affinity twofold higher than that of EcR·USP-A. Likewise, EcR·USP-B transactivates a reporter gene in CV-1 cells twofold more strongly than EcR·USP-A. These results suggest that USP-B functions as a major heterodimerization partner for EcR during the vitellogenic response to 20E in the mosquito.
GCM simulations of intraseasonal variability in the Pacific/North American region

General circulation model (GCM) simulations of low-frequency variability with time scales of 20 to 70 days are analyzed for the Pacific sector during boreal winter. The GCM's leading mode in the upper-tropospheric zonal wind is associated with fluctuations of the East Asian jet; this mode resembles, in both structure and amplitude, the Pacific/North American (PNA) pattern found in the observations on these time scales. In both the model and observations, the PNA anomaly is characterized by: (1) a linear balance in the upper-tropospheric vorticity budget with no significant Rossby wave source in the tropics, (2) a barotropic conversion of kinetic energy from the time mean Pacific jet, and (3) a north/south displacement of the Pacific storm track. In the GCM, the latter is associated with synoptic eddy heat flux and latent heat anomalies that appear to contribute to a strong lower-tropospheric source of wave activity over the North Pacific. This is in contrast to the observations, which show only a weak source of wave activity in this region.
High-Energy Deuteron Cross Sections: Charge-Exchange Effects

The effects of charge exchange in collisions of high-energy particles of isotopic spin \textonehalf{} with deuterons are investigated. The diffraction approximation is used to express the deuteron charge-exchange cross section in terms of the elastic-scattering amplitudes of the neutron and proton and the deuteron ground-state wave function. Examinations are also made of the influence of the charge-exchange mechanism on the total cross section of the deuteron, the elastic differential cross section, and the summed angular distribution of scattering (elastic plus inelastic scattering with initial charges preserved). The important role played by double-scattering processes in shaping the differential cross sections of the deuteron is illustrated in a discussion of proton-deuteron elastic scattering at 2 BeV. Double scattering is shown to be the dominant collision mechanism at scattering angles which are not too close to the forward direction. The effect of the double charge-exchange process on the elastic differential cross section is shown to be small but of some significance in the angular range which is dominated by double scattering. The theory developed for charge-exchange reactions is applied to the ${K}^{0}$ angular distribution which has been observed from ${K}^{+}$-deuteron collisions at 2.27 $\frac{\mathrm{BeV}}{c}$. Estimates are found for the differential and integrated ${K}^{+}$-neutron charge-exchange cross sections, and for some related parameters. The effects of double collisions on these cross sections are relatively small and easily evaluated. The effect of the charge-exchange mechanism on the values of the $\mathrm{pn}$, $\overline{p}n$, and ${K}^{\ifmmode\pm\else\textpm\fi{}}n$ total cross sections which are reached indirectly via measurements on the deuteron is shown to be exceedingly small for momenta above \ensuremath{\sim}2 $\frac{\mathrm{BeV}}{c}$.
Operating parameters' effects on the outcome of pure and simple competition between two populations in configurations of two interconnected chemostats

It is known from the literature that two microbial populations competing purely and simply for a common substrate in a spatially inhomogeneous environment may under certain conditions coexist in a steady state. This paper studies pure and simple competition between two microbial species in three alternate configurations of two interconnected ideal chemostats and focuses on the effects of the operating parameters-dilution rate, substrate concentration in the feed to the vessels, recycle ratio, and volume ratio of the two vessels, splitting ratio of the external feed to the chemostats-on the coexistence of the two competitors. It is shown that the coexistence steady state is practically feasible in the sense that it occurs in a finite domain of the operating parameters space. Theoretical and numerical results are presented, some of them in the form of operating diagrams projected on the two-dimensional subspace. A comparison of the three possible configurations is offered.
Zuttiyeh face: A view from the east

We analyze the phylogenetic position of the frontofacial frag- ment from Zuttiyeh, Israel. This specimen is dated to the Middle Pleistocene (the latest estimate is between 250 and 350 kyr) and is associated with the Acheulo-Yabrudian, which makes it the oldest cranium from the region. It has been previously regarded as a Neandertal, and early "anatomically modern Homo sapiens," and a generalized specimen ancestral to both. These different phylogenetic interpretations of its features have a historic basis but in our view also result from a confusion of grade and intraspecies clade as valid sources of variation. We show here that generally the differences that distin- guish Zuttiyeh from Neandertals are similarities it shares with the Zhou- koudian remains. These similarities involve a unique combination of features, and suggest the possibility of an ancestral relationship. It is less likely that Middle Pleistocene remains from Europe or sub-Saharan Africa are uniquely or significantly ancestral to Zuttiyeh. An accurate understanding of the rela- tionship between populations of eastern and western Asia is important for resolving the more general questions surrounding the position of the Upper Pleistocene Levant populations in human evolution, including (1) whether there are significantly different contemporary Mousterian populations in the Upper Pleistocene, (2) whether Neandertals are clearly intrusive in the re- gion, and (3) whether there is an early appearance of (what many workers call) "anatomically modern Homo sapiens." The hypothesis of a recent unique African ancestry for all modern humans is disproved by our study, which shows Asia as a significant source area for at least some living populations. 0 1993 Wiley-Liss, Inc. The critical geographic position and early date of the Zuttiyeh frontofacial fragment combine to make it pivotal in clarifying a number of problems surrounding the evolu- tion of Homo in Asia. In this paper we present the context and associations of the 1925 discovery, discuss the historic basis for the differing interpretations of its phylogeny (including why it was never systematically compared with the Zhoukoudian remains), and establish the best case for its ancestry and relationships by comparing it with the Zhoukoudian sample as well as with Middle Pleistocene humans from Europe and sub- Saharan Africa. It is our intent to examine the issues surrounding local ancestry and evolution in the Levant, because their solu- tions are central to the hypotheses about modern human origins. We will examine the question of different Late Pleistocene lin- eages in the Levant, and the confusion of grade and intraspecies clade in interpreting these hominids-especially over the prob- lem of whether "non-Neandertal" necessar- ily means "modern." Our use of the intraspe- cies clade concept is unconventional, resting on Huxley's (1958) older definition of clades as groups sharing common genetic descent. Because we use clade to describe a regional
Procalcitonin Test in the Diagnosis of Bacteremia: A Meta-analysis

Study objective We seek to evaluate the diagnostic performance of the procalcitonin test for the diagnosis of bacteremia in the emergency department (ED) population. Methods We conducted a search of MEDLINE, bibliographies of previous systemic reviews, and pertinent national meeting research abstracts. We included studies that assessed the diagnostic accuracy of procalcitonin for bacteremia, with blood culture as the reference standard. We included prospective investigations of adults and children with suspected infection studied in the ED or at admission. Two authors independently extracted data and assessed study quality; consensus was reached by conference. The analysis was based on the I 2 statistic for heterogeneity, unweighted summary receiver-operating characteristic curve, and random-effects pooled sensitivity and specificity across studies using the same test threshold. Results The search yielded 348 publications and 1 unpublished study. Seventeen studies met the inclusion criteria and provided a sample of 2,008 subjects. There was a substantial degree of inconsistency ( I 2 =64%). The unweighted summary receiver-operating characteristic curve provided the best overall estimate of test performance, with an area under the curve of 0.84 (95% confidence interval [CI] 0.75 to 0.90). Sensitivity analysis based on study quality did not significantly change the results. Subgroup analysis including only studies that used a test threshold of 0.5 or 0.4 ng/mL yielded pooled estimates for sensitivity and specificity of 76% (95% CI 0.66 to 0.84) and 70% (95% CI 0.60 to 0.79), respectively. Conclusion We found the diagnostic performance of the procalcitonin test for identifying bacteremia in ED patients to be moderate. Future research designed to determine the utility of the procalcitonin test as a diagnostic tool used in isolation for detecting bacteremia in ambulatory patients is needed before widespread clinical use.
Security evaluation of a control system using Named Data Networking

Security is an integral part of networked computer systems. The recent Named Data Networking (NDN) project aims to develop a new Internet architecture that communicates data using names rather than locations, the latter of which is what the current IP-based Internet does with IP addresses. One of the first real-world applications using NDN is a lighting control system. We conduct a red team assessment of the current state of the security of this lighting system and its NDN implementation. The system is representative of a more general class of automated controller systems. Our analysis found that due to NDN's use of named data, the system inherently prevents most attacks that IP-based systems are vulnerable to. Although many parts of the system are secure, we discovered some problems with the verification of timestamps and processing of large packets that led to a severe memory leak. The system also lacks a secure key distribution mechanism. While NDN security is on the right track, there are important security design issues NDN must account for.
Dynamic interaction between rigid foundations in a layered half-space

Abstract A computationally efficient boundary integral equation technique to calculate the dynamic response of a group of rigid surface foundations bonded to a layered viscoelastic half-space and subjected to external forces and seismic waves is presented. The technique relies on an iterative scheme which minimizes in-core memory requirements and takes advantage of any geometrical symmetry of the foundations. Extensive results for the case of two rigid square foundations placed at different separations and bonded to a viscoelastic half-space are presented. It was found that the choice of discretization of the foundations has a marked effect on the calculated impedance functions for extremely small separations. Illustrative results for a case of several closely-spaced foundations bonded to a layered half-space are also presented.
Artemether-Lumefantrine: An Option for Malaria

Objective:To review the pharmacology, pharmacokinetics, safety, and efficacy of artemether-lumefantrine for the treatment of Plasmodium falciparum malaria.Data Sources:English-language articles indexed in PubMed (1947-November 2011) were identified, using the search terms artemether-lumefantrine, artemether-lumefantrine AND malaria, Coartem, and Coartem AND malaria.Study Selection and Data Extraction:Available English-language articles were reviewed. In addition, the malaria treatment regimens recommended by region as provided by the World Health Organization and the treatment guidelines from the Centers for Disease Control and Prevention were reviewed.Data Synthesis:Artemether-lumefantrine is an artemisinin-derived combination antimalarial approved by the Food and Drug Administration in 2009 for the treatment of P. falciparum malaria. The dual mechanisms of action of artemether-lumefantrine provide rapid and sustained parasite clearance. In the reviewed studies, the polymerase chain reaction (PCR)-correc...
Simulation of Distributed Photovoltaic Power Connecting to Grid Based on ETAP

Against the State Grid Corporation of integrated demonstration project pilot project Gong qing smart grid demonstration project 1.5MWp rooftop PV projects access, combined with the actual situation, combined with the ETAP software features of advanced power quality analysis , first proposed using ETAP software for power quality analysis and evaluation of two kinds of access solutions , to establish the model flow calculation example, three different nodes of the short circuit calculation and harmonic calculations for the power sector access system designed to provide a reference.
Some remarks on the Hodge conjecture for abelian varieties

We show how the classical Hodge conjecture for the middle cohomology of an abelian variety is equivalent to the general Hodge conjecture for the middle cohomology of a smooth ample divisor in the abelian variety. This is best suited to abelian varieties with actions of imaginary quadratic fields.
Day Labor Work

▪ Abstract Day labor, the practice of searching for work in open-air, informal markets such as street corners or in formal temp agencies, has become an increasingly visible and important means of securing employment for a broad segment of immigrant, primarily male, displaced workers. Our understanding of day labor has been limited by regionally focused or city-based case studies, poorly constructed methodological approaches, inconsistent definitions, and little comparative research. This review discusses the emerging research on day labor, paying particular attention to the practice of day labor, including the market's origins, its contemporary development, and its hiring and wage practices. The review also provides a synopsis of informal, open-air and formal temp agency day labor practices, their spatial and organizational configurations, and an outline of the legal issues and public policies that structure, to a large degree, worker and employer relations in this industry. The review emphasizes the mult...
On the strength of corporate cultures

Abstract We model corporate culture(s) as production technologies for which employees have to undertake culture-specific investments that improve their effectiveness. At a later date, the organization can adopt cultural changes that make this investment partially redundant. This leads to under-investment. However, as agents invest more, the organization's opportunity cost of a change increases, which in turn increases each agents' incentives to invest. This externality among agents leads to multiple equilibria. Otherwise similar organizations can thus exhibit either high investment levels and low probability of changes (strong culture) or low investment levels and high probability of changes (weak culture). We also explore some implications for the nature and management of corporate culture.
Can Observational Practice Facilitate Error Recognition and Movement Production

Abstract Two experiments are reported that examined the usefulness of observational learning for acquiring both error detection and movement production capabilities. In both experiments, individuals were assigned to a no-practice, physical-practice, or observational practice condition. Those assigned to a physical-practice condition acted as models for those assigned as observers. In both experiments, models were administered a random practice of three serial key-press tasks that had the same spatial pattern and same relative timing requirement but differed in the overall time goal. During the retention test, individuals provided estimates of their overall time after each trial. Data from these experiments revealed that error detection and overall time specification were similar following observation and physical practice. However, data from Experiment 2 indicated that physical practice offered an advantage beyond that afforded via observation, with regard to acquiring the appropriate relative time patter...
Chromatographic Analysis of Naturally Fluorescing Compounds: I. Rapid Analysis of Nanogram Amounts of Indoles in Physiologic Fluids

A chromatographic separation system has been developed for determination of various indole derivatives in physiologic fluids. A coupled-column configuration is used in which a 0.22 x 25 cm, jacketed, stainless-steel anion-exchange column is connected directly to a 0.22 x 50 cm, jacketed, stainless-steel cation-exchange column. The indole compounds are eluted with an ammonium acetate—acetic acid buffer that is 4 molar in ammonia and 5.8 molar in total acetate. An Aminco-Bowman spectrophotofluorometer, with an excitation setting of 292 nm and an emission setting of 330 nm, is used as the detector. The column temperature is 60°C. Effects of pH, temperature, and ionic strength on elution characteristics of the indole compounds have been investigated. The system can provide baseline separation of 50 to 100 ng of 5-hydroxytryptophan, tryptophan, 5-hydroxyindoleacetic acid, serotonin, indoleacetic acid, and tryptamine in 3 h. Use of the system in analyzing urine is illustrated.
Localized bosonic modes in superconductors

We show that a localized bosonic mode acts as a ``defect'' in s- and ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$-wave superconductors, inducing bound or resonance states, whose spectral signatures are peaks in the superconductor's density of states. We study the peaks' shape and energy as a function of temperature and the mode's frequency and lifetime. We identify several signatures of the localized mode that qualitatively distinguishes it from static magnetic or nonmagnetic impurities.
Lipids and Lipoproteins in Women

Coronary artery disease (CAD) is the most common cause of death in women in the United States. Dyslipidemia is a risk factor for CAD in both men and women. Low levels of high-density lipoprotein (HDL) cholesterol and hypertriglyceridemia, especially in association with a dense low-density lipoprotein (LDL) phenotype, may be of greater importance in women than in men. The relationship between CAD and dyslipidemia and the therapeutic approach to disorders of lipid metabolism in women have unique features because of the effects of exogenous and endogenous hormones on lipid pathways. Estrogen decreases LDL cholesterol and Lp(a) lipoprotein and increases triglyceride and HDL cholesterol levels. Progestogens decrease triglycerides, HDL cholesterol, and Lp(a), and they increase LDL cholesterol. Thus, oral contraceptives increase plasma triglycerides, whereas the effect of these agents on LDL cholesterol and HDL cholesterol levels is related to the androgenicity and dose of progestogen. Postmenopausal hormone replacement therapy increases triglycerides and decreases LDL cholesterol. The effect of hormone replacement therapy on HDL cholesterol is influenced by the addition of progestogen. Although no primary prevention studies have analyzed lipid lowering and CAD in women, secondary prevention studies have suggested that the response to drug treatment and the benefit of lipid lowering are similar in women and in men. Hormone replacement therapy should be considered in the treatment of hypercholesterolemia in postmenopausal women; however, individualization of treatment is important to avoid adverse effects.
Weakly nonlinear harmonic acoustic waves in classical thermoviscous fluids: A perturbation analysis

Using regular perturbation analysis, we investigate the propagation of a time-harmonic acoustic signal, generated by a sinusoidal boundary condition, in a half-space filled with a classical thermoviscous fluid. It is assumed that the flow is described by a recently introduced, weakly nonlinear partial differential equation (PDE) that, unlike earlier models, exhibits a Hamiltonian structure in the lossless limit.
Phase I trial of escalating doses of topotecan in combination with a fixed dose of pegylated liposomal doxorubicin in women with müllerian malignancies.

Abstract Background . Topotecan and pegylated liposomal doxorubicin (Doxil) interact with topoisomerase I and II (topo I and II), respectively, with schedule dependent, and potentially synergistic cytotoxicity. Objectives . Define dose-limiting toxicity (DLT) and determine the maximum tolerated dose (MTD) of topotecan delivered by 72-h infusion administered immediately after Doxil delivered at a fixed dose (30 mg/m 2 ) in a cohort of women with recurrent mullerian malignancies. Methods . Topotecan dose was escalated from 0.5 mg/m 2 /day for 3 days in 0.2 mg/m 2 /day increments with treatment repeated every 21 days. Eligibility criteria required ECOG ≤2 and no more than four prior lines of chemotherapy. No dose reductions were allowed in the first two cycles to allow evaluation of cutaneous toxicity. Results . Between November 2000 and August 2002, 18 patients were enrolled. Median age 59 (40–71) years. Patients received a median 1 (1–6) cycles of chemotherapy, with 39 cycles of treatment delivered at DL 1. All patients were evaluable for toxicity and 12 for response. At dose level 2, dose-limiting toxicity consisted of nausea and vomiting, mucositis, cutaneous toxicity, and neutropenia. There was no clinically significant cardiac toxicity. There were no radiologically confirmed partial responses. Conclusions . Doxil 30 mg/m 2 and topotecan 0.5 mg/m 2 /day by 72-h infusion (total dose 1.5 mg/m 2 ), although a rational combination of cytotoxic therapies, have limited clinical activity.
A multi-center phase II study of weekly topotecan as second-line therapy for small cell lung cancer

Summary Purpose To determine the response rate, toxicity, failure free and overall survival of weekly topotecan in patients with relapsed small cell lung cancer who received one prior platinum based chemotherapy. Patients and methods Twenty two patients with relapsed disease after response to one prior chemotherapy with or without radiotherapy and patients with relapse more than 90 days after their last therapy received topotecan 4 mg/m2 intravenous over 30 min on days 1,8,15; every 4 weeks (3 weeks on and 1 weeks off). Chemotherapy was given until disease progression or unacceptable toxicity. Results Of 22 patients, none of the patients responded to weekly topotecan therapy. Four patients had stable disease. After a median follow up of 1 year, median time to progression was 6 weeks and median survival was 5 months. The common toxicities associated with this regimen were anemia, thrombocytopenia, fatigue, GI side effects and alopecia. Conclusion Weekly topotecan was well tolerated but ineffective in this trial. Although commonly used, weekly regimen of topotecan should be used with caution in relapsed SCLC.
Sorting out adaptors

4. Regulation of adaptor interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 4.1. Protein–protein interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 4.2. Chickens or eggs? ARFs, phospholipases, kinases, second messenger generation, and protein–membrane interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 5. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 6. Note added in proof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Effects of cholesterol on thermal stability of discoidal high density lipoproteins

Reverse cholesterol transport in plasma involves variations in HDL cholesterol concentration. To understand physicochemical and functional implications of such variations, we analyzed stability of reconstituted HDL containing human apolipoproteins (apoA-I, apoA-II, or apoC-I), phosphatidylcholines varying in chain length (12–18 carbons) and unsaturation (0 or 1), and 0–35 mol% cholesterol. Lipoprotein heat denaturation was monitored by circular dichroism for protein unfolding/dissociation and by light scattering for particle fusion. We found that cholesterol stabilizes relatively unstable complexes; for example, incorporation of 10–30 mol% cholesterol in apoC-I:dimyristoyl phosphatidylcholine complexes increased their kinetic stability by δΔG* ≅ 1 kcal/mol. In more stable complexes containing larger proteins and/or longer-chain lipids, incorporation of 10% cholesterol did not significantly alter the disk stability; however, 15% or more cholesterol destabilized the apoA-I-containing complexes and led to vesicle formation. Thus, cholesterol tends to stabilize less stable lipoproteins, apparently by enhancing favorable packing interactions, but in more stable lipoproteins, where such interactions are already highly optimized, the stabilizing effect of cholesterol decreases and, eventually, becomes destabilizing. These results help uncouple the functional roles of particle stability and chain fluidity and suggest that structural disorder in HDL surface, rather than chain fluidity, is an important physicochemical determinant of HDL function.—Jayaraman, S., S. Benjwal, D. L. Gantz, and O. Gursky. Effects of cholesterol on thermal stability of discoidal high density lipoproteins. J. Lipid Res. 2010. 51: 324–333.
Cycloaddition of Olefins to Methyl Acrylate

Abstract Some cyclobutane carboxylic acids are prepared by the malonic ester synthesus1,2,3,4. Others have been prepared by the ene-amine synthesis5,6. The present work describes a simple cyclo-addition reaction that can produce some cyclobutanes that might not be available otherwise.
Variability in Life Span Functional Capacity

Aging is a process in which both risk and phenotypic variability have important roles and significant interactions. Other contributions to this volume include examples of age as a determinant of responses to environmental challenges and examples in which variations in longevity are the ultimate consequence of phenotypic variability.
Focal cartilage defect progression detection: measurement of precision and variation in natural characteristics of cartilage thickness maps derived from 3D MRI data

The objective of this work was to develop a procedure for detecting focal and local thickness cartilage changes due to osteoarthritis (OA). These measurements are used to quantify the disease progression over time. Therefore, it is essential to establish a method for measuring the precision of such changes for each subject involved in a longitudinal study. Secondly, we have developed a method which establishes the variation in natural characteristics, such as shape and thickness within a set of normal and mild OA cartilage thickness maps. This method will allow the analysis of disease progression over time and among subjects participating in clinical studies. Both procedures depend on a previously validated segmentation and computation of the cartilage thickness maps from three dimensional multispectral MRI data.
Biotransformation of chlorinated aliphatic solvents in the presence of aromatic compounds under methanogenic conditions

Transformation of carbon tetrachloride (CT) and tetrachloroethylene (PCE) was studied under methanogenic conditions, in the presence or absence of toluene, ethylbenzene, phenol, and benzoate. Microbial inocula for the experiments were derived from three groundwater aquifers contaminated by jet fuel or creosote. CT and PCE were reductively dechlorinated in all the examined cases (CT to chloroform [CF]; PCE to trichloroethylene [TCE], trans-l,2-dichloroethylene [DCE], and vinyl chloride [VC]). In the aquifer microcosms, the electron donors used for the reductive transformations were most likely the unidentified organic compounds present on aquifer solids, or storage materials in microorganisms. Alternatively, molecular hydrogen from the anaerobic incubator atmosphere could have been used. The addition of benzoate caused a decrease in rates of dechlorination if benzoate was transformed. Phenol and ethylbenzene were not degraded and did not influence the transformation of CT or PCE. Toluene, in most of the studied cases, had no influence on reductive dechlorination of either CT or PCE. Only in microcosms derived from a JP-4 jet fuel-contaminated aquifer did the anaerobic degradation of toluene occur simultaneously with reductive dechlorination of PCE, suggesting that toluene might possibly have been used as an electron donor for reductive transformation of chlorinated solvents.
Investments in Rural Air Transportation Networks in Developing Countries

Rural airfields provide vital access to many remote regions of the world, thus enabling their socioeconomic development. While these facilities are usually very simple, their construction and maintenance can be very difficult. Thus, governments must balance the need to provide access with the cost of providing access. In this paper, we present a quantitative methodology for evaluating investment decisions in rural air transportation networks. The intended purpose of the methodology is to provide policymakers with enough understanding so that they can develop strategies that meet the accessibility needs of remote locations while making the best use of available resources. The first step in the methodology is to determine the importance of air links to the different points in the network. Next, the existing and desired infrastructure are evaluated in terms of their ability to support the expected traffic. These evaluations are followed by a gap analysis to determine the infrastructure deficit and provide the basis for the formulation of different investment strategies. In this paper we consider the case of Costa Rica and provide useful insights for policymakers interested in supporting rural air transportation networks.
Adult age differences in acquisition and retention of frequency-of-occurrence information for actions

Adult age differences in frequency-of-occurrence memory for actions performed zero, one, or two times in the laboratory were investigated shortly after the actions had been performed and after a retention interval of 24 h. A moderate age difference in accuracy of frequency judgments was found on the immediate retention test. Forgetting over 24 h was moderate for both young adult and elderly adult subjects. A negligible interaction between age and retention interval suggested comparable forgetting rates for young and elderly subjects, at least over 24 h.
Disease-Modifying Drugs in Parkinson’s Disease

Despite an increased understanding of the pathogenesis of Parkinson's disease (PD), and a number of drugs designed to ameliorate symptoms, finding an effective neuroprotective therapy remains elusive. For decades now, several promising agents targeting different pathways have been explored as potential treatments that could help slow disease progression, but these have met with limited success. There are hurdles to overcome, particularly given that there is no exact animal model of PD and also no reliable biomarkers for PD. Without biomarkers, it is not possible to demonstrate, in the context of a clinical trial, that an intervention prevents neuronal degeneration. However, given the compelling scientific rationale of several compounds, an unrelenting pursuit continues. There have been hundreds of human studies looking at neuroprotection in PD. This article will briefly summarize several of the neuroprotective treatments that have been evaluated in large clinical trials, and will also outline some of the newer therapies that are currently being explored.
What future for quantum dot-based light emitters?

Synthesis of semiconductor colloidal quantum dots by low-cost, solution-based methods has produced an abundance of basic science. Can these materials be transformed to high-performance light emitters to disrupt established photonics technologies, particularly semiconductor lasers?