bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of a novel subfamily of nuclear receptors with members that each contain two DNA binding domains
Authors: Wu Wenjie , Niles Edward G , Hirai Hirohisa , LoVerde Philip T
Published: February 2007

Background

Nuclear receptors (NRs) are important transcriptional modulators in metazoans which regulate transcription through binding to the promoter region of their target gene by the DNA binding domain (DBD) and activation or repression of mRNA synthesis through co-regulators bound to the ligand binding domain (LBD). NRs typically have a single DBD with a LBD.

Results

Three nuclear receptors named 2DBD-NRs, were identified from the flatworm Schistosoma mansoni that each possess a novel set of two DBDs in tandem with a LBD. They represent a novel NR modular structure: A/B-DBD-DBD-hinge-LBD. The 2DBD-NRs form a new subfamily of NRs, VII. By database mining, 2DBD-NR genes from other flatworm species (Schmidtea mediterranea and Dugesia japonica), from Mollusks (Lottia gigantean) and from arthropods (Daphnia pulex) were also identified. All 2DBD-NRs possess a P-box sequence of CEACKK in the first DBD, which is unique to 2DBD-NRs, and a P-box sequence of CEGCKG in the second DBD. Phylogenetic analyses of both DBD and ligand binding domain sequences showed that 2DBD-NR genes originate from a common two DBD-containing ancestor gene. A single 2DBD-NR orthologue was found in Arthropoda, Platyhelminths and Mollusca. Subsequent 2DBD-NR gene evolution in Mollusks and Platyhelminths involved gene duplication. Chromosome localization of S. mansoni 2DBD-NR genes by Fluorescent in situ hybridization (FISH) suggests that 2DBD-NR genes duplicated on different chromosomes in the Platyhelminths. Dimerization of Sm2DBDα indicates that 2DBD-NRs may act as homodimers, suggesting either that two repeats of a half-site are necessary for each DBD of 2DBD-NRs to bind to its target gene, or that each 2DBD-NR can recognize multiple sites.

Conclusion

2DBD-NRs share a common ancestor gene which possessed an extra DBD that likely resulted from a recombination event. After the split of the Arthropods, Mollusks and Platyhelminths, 2DBD-NR underwent a recent duplication in a common ancestor of Mollusks, while two rounds of duplication occurred in a common ancestor of the Platyhelminths. This demonstrates that certain NR gene underwent recent duplication in Prostostome lineages after the split of the Prostostomia and Deuterostomia.
Mechanically-Evoked C-Fiber Activity in Painful Alcohol and AIDS Therapy Neuropathy in the Rat
Authors: Chen Xiaojie , Levine Jon D
Published: February 2007

While altered activities in sensory neurons were noticed in neuropathic pain, caused by highly diverse insults to the peripheral nervous system, such as diabetes, alcohol ingestion, cancer chemotherapy and drugs used to treat AIDS, other infections and autoimmune diseases, as well as trauma, our understanding of how these various peripheral neuropathies manifest as altered neuronal activity is still rudimentary. The recent development of models of several of those neuropathies has, however, now made it possible to address their impact on primary afferent nociceptor function. We compared changes in mechanically-evoked C-fiber activity, in models of painful peripheral neuropathy induced by drinking ethanol (alcohol) or administering 2′,3′-dideoxycytidine (ddC), a nucleoside reverse transcriptase inhibitor for AIDS therapy, two co-morbid conditions in which pain is thought to be mediated by different second messenger signaling pathways. In C-fiber afferents, ddC decreased conduction velocity. In contrast, alcohol but not ddC caused enhanced response to mechanical stimulation (i.e., decrease in threshold and increase in response to sustained threshold and supra-threshold stimulation) and changes in pattern of evoked activity (interspike interval and action potential variability analyses). These marked differences in primary afferent nociceptor function, in two different forms of neuropathy that produce mechanical hyperalgesia of similar magnitude, suggest that optimal treatment of neuropathic pain may differ depending on the nature of the causative insult to the peripheral nervous system, and emphasize the value of studying co-morbid conditions that produce painful peripheral neuropathy by different mechanisms.
Regional distribution of acoustic-based lung vibration as a function of mechanical ventilation mode
Authors: Dellinger R Phillip , Jean Smith , Cinel Ismail , Tay Christina , Rajanala Susmita , Glickman Yael A , Parrillo Joseph E
Published: February 2007

Introduction

There are several ventilator modes that are used for maintenance mechanical ventilation but no conclusive evidence that one mode of ventilation is better than another. Vibration response imaging is a novel bedside imaging technique that displays vibration energy of lung sounds generated during the respiratory cycle as a real-time structural and functional image of the respiration process. In this study, we objectively evaluated the differences in regional lung vibration during different modes of mechanical ventilation by means of this new technology.

Methods

Vibration response imaging was performed on 38 patients on assist volume control, assist pressure control, and pressure support modes of mechanical ventilation with constant tidal volumes. Images and vibration intensities of three lung regions at maximal inspiration were analyzed.

Results

There was a significant increase in overall geographical area (p < 0.001) and vibration intensity (p < 0.02) in pressure control and pressure support (greatest in pressure support), compared to volume control, when each patient served as his or her own control while targeting the same tidal volume in each mode. This increase in geographical area and vibration intensity occurred primarily in the lower lung regions. The relative percentage increases were 28.5% from volume control to pressure support and 18.8% from volume control to pressure control (p < 0.05). Concomitantly, the areas of the image in the middle lung regions decreased by 3.6% from volume control to pressure support and by 3.7% from volume control to pressure control (p < 0.05). In addition, analysis of regional vibration intensity showed a 35.5% relative percentage increase in the lower region with pressure support versus volume control (p < 0.05).

Conclusion

Pressure support and (to a lesser extent) pressure control modes cause a shift of vibration toward lower lung regions compared to volume control when tidal volumes are held constant. Better patient synchronization with the ventilator, greater downward movement of the diaphragm, and decelerating flow waveform are potential physiologic explanations for the redistribution of vibration energy to lower lung regions in pressure-targeted modes of mechanical ventilation.
Extracellular nucleotides mediate LPS-induced neutrophil migration in vitro and in vivo
Authors: Kukulski Filip , Ben Yebdri Fethia , Lefebvre Julie , Warny Michel , Tessier Philippe A , Sévigny Jean
Published: February 2007

Extracellular nucleotides are emerging as important inflammatory mediators. Here, we demonstrate that these molecules mediate LPS-induced neutrophil migration in vitro and in vivo. Apyrase, a nucleotide scavenger, reduced the ability of LPS-stimulated monocytes to recruit neutrophils, as assayed using a modified Boyden chamber. This effect resulted from the inhibition of IL-8 release from monocytes. Furthermore, LPS-induced IL-8 release by monocytes was attenuated significantly by P2Y6 receptor antagonists, RB-2 and MRS2578. Reciprocally, UDP, the selective P2Y6 agonist, induced IL-8 release by monocytes. As for LPS, the media of UDP-stimulated monocytes were chemotactic for neutrophils; IL-8 accounted for ∼50% of neutrophil migration induced by the media of LPS- or UDP-treated monocytes in transendothelial migration assays. It is important that in the murine air-pouch model, extracellular nucleotides were instrumental in LPS-induced neutrophil migration. Altogether, these data imply that LPS induces the release of nucleotides from monocytes and that by autocrine stimulation, the latter molecules regulate neutrophil migration caused by Gram-negative bacteria, suggesting a proinflammatory role of extracellular nucleotides in innate immunity.
Loss of Sexually Dimorphic Liver Gene Expression upon Hepatocyte-Specific Deletion of Stat5a-Stat5b Locus
Authors: Holloway Minita G. , Cui Yongzhi , Laz Ekaterina V. , Hosui Atsushi , Hennighausen Lothar , Waxman David J.
Published: February 2007

Hepatocyte-specific, albumin-Cre recombinase-mediated deletion of the entire mouse Stat5a-Stat5b locus was carried out to evaluate the role of signal transducer and activator of transcription 5a and 5b (STAT5ab) in the sex-dependent transcriptional actions of GH in the liver. The resultant hepatocyte STAT5ab-deficient mice were fertile, and unlike global STAT5b-deficient male mice, postnatal body weight gain was normal, despite a 50% decrease in serum IGF-I. Whole-liver STAT5ab RNA decreased by approximately 65–85%, and residual STAT5 immunostaining was observed in a minority of the hepatocytes, indicating incomplete excision by Cre-recombinase. Quantitative PCR analysis of 20 sexually dimorphic, liver-expressed genes revealed significant down-regulation of 10 of 11 male-specific genes in livers of male hepatocyte STAT5ab-deficient mice. Class I female-specific liver genes were markedly up-regulated (de-repressed), whereas the expression of class II female genes, belonging to the Cyp3a subfamily, was unaffected by the loss of hepatocyte STAT5ab. STAT5ab is thus required in the liver for positive regulation of male-specific genes and for negative regulation of a subset of female-specific genes. Continuous GH infusion strongly induced (>500-fold) the class II female gene Cyp3a16 in both wild-type and hepatocyte STAT5ab-deficient male mice, indicating sex-specific transcriptional regulation by GH that is STAT5ab independent. In contrast, hepatocyte STAT5ab deficiency abolished the strong suppression of the male-specific Cyp2d9 by continuous GH seen in control mouse liver. Analysis of global STAT5a-deficient mice indicated no essential requirement of STAT5a for expression of these sex-specific liver Cyp genes. Thus, the major loss of liver sexual dimorphism in hepatocyte STAT5ab-deficient mice can primarily be attributed to the loss of STAT5b.
Type 1 Parathyroid Hormone Receptor (PTH1R) Nuclear Trafficking: Regulation of PTH1R Nuclear-Cytoplasmic Shuttling by Importin-α/β and Chromosomal Region Maintenance 1/Exportin 1
Authors: Pickard Bryce W. , Hodsman Anthony B. , Fraher Laurence J. , Watson Patricia H.
Published: February 2007

The type 1 PTH/PTH-related peptide receptor (PTH1R) is a class B G protein-coupled receptor that demonstrates immunoreactivity in the nucleus as well as cytoplasm of target cells. Our previous studies on the PTH1R have shown that it associates with the importin family of transport regulatory proteins. To investigate the role of the importins in PTH1R nuclear import, we used small interfering (si)RNA technology to knock down the expression of importin-β in the mouse osteoblast-like cell line, MC3T3-E1. Immunofluorescence microscopy as well as ligand blotting for PTH1R in nuclear fractions of importin-β siRNA-treated cells demonstrated a decrease in nuclear localization of the PTH1R in comparison with control cells. Under normal culture conditions, PTH1R is present in both the nucleus and cytoplasm of cells. Serum starvation favors nuclear localization of PTH1R, whereas returning cells to serum or treatment with PTH-related peptide induced its cytoplasmic localization. To address the nuclear export of PTH1R, interactions between PTH1R and chromosomal region maintenance 1 (CRM1) were investigated. PTH1R and CRM1 coimmunoprecipitated from MC3T3-E1 cells, suggesting that CRM1 and PTH1R form a complex in vivo. After treatment with leptomycin B, a specific inhibitor of CRM1-mediated nuclear export, PTH1R accumulated in the nucleus. Taken together, our studies show that PTH1R shuttles from the nucleus to the cytoplasm under normal physiological conditions and that this nuclear-cytoplasmic transport is dependent upon importin-α/β and CRM1.
KC60 coding: room for improvement – a study into consistencies and inconsistencies in the use of diagnosing codes
Authors: Coyne K M , Cohen C , Mandalia S , McOwan A
Published: February 2007

Twenty mock cases were designed. Thirty-two doctors completed the study, assigning local and KC60 codes for service provision and diagnoses. They gave a wide range of responses, often missing codes or adding inappropriate ones. Where the diagnosis was clear, e.g. gonorrhoea, 97% assigned the correct KC60 code. However, the KC60 codes for service provision (S1, S2, P1A, P3, etc.) were frequently omitted, representing a significant underestimate of workload. Some local codes were given by only 6–28% of clinicians, and when they included them, doctors were more likely to omit KC60 codes. Low response rates for local codes renders these codes unhelpful. Simplification of coding procedures is needed so that diagnoses and workload are documented accurately. This is crucial at a time of modernization of genitourinary (GU) Medicine services and the introduction of Payment by Results.
Implementation of a programme for the prevention of mother-to-child transmission of HIV in a Ugandan hospital over five years: challenges, improvements and lessons learned
Authors: Magoni M , Okong P , Bassani L , Kituka Namaganda P , Onyango S , Giuliano M
Published: February 2007

To identify factors that may limit acceptance of HIV testing and enrolment in the programmes for the prevention of mother-to-child-transmission of HIV, we retrospectively assessed the performance of the service at St Francis Hospital, Nsambya in Kampala. Over five years, a total of 26,556 pregnant women were offered voluntary counselling and confidential HIV testing and, if HIV positive, enrolment in the programme. Acceptance of the HIV test increased in the last two years (from 72.7% in 2001–2002 to 79.9% in 2003–2004). Enrolment in the programme increased over time and was greater among older (64% in women older than 30 years and 44.8% in those aged less than 20 years) and highly educated women. HIV prevalence was associated with age and inversely associated with the level of education. The need for specific personnel for counselling, male partners' involvement and availability of antiretroviral drugs for those who needed treatment were identified as factors possibly affecting implementation.
Contraceptive provision in genitourinary medicine clinics in the UK
Authors: Willcox J R , Huengsberg M , Kell P ,   British Co-Operative Clinical Group of the British Association for Sexual Health and HIV
Published: February 2007

The objective of this study was to assess current and future contraceptive provision in genitourinary (GU) medicine clinics in the United Kingdom. Questionnaires were sent to 18 British Co-Operative Clinical Group regional representatives for distribution to clinical leads. Of 185 clinics, 124 (67%) responded. All clinics provided condoms, 116 (94%) the 'morning after' pill and 31 (25%) would fit an intrauterine contraceptive device (IUCD) for emergency contraception. Twenty-three (18.5%) regarded their clinic as already providing a comprehensive service and most of these could provide a wide range of contraceptive methods. Of all clinics, which included eight (34%) clinics already providing a comprehensive service, 69 (56%) anticipated developing their contraceptive provision within the next five years. In conclusion, contraceptive provision varies between clinics. A reduction in unwanted pregnancies and sexually transmitted infections (STIs) would most likely be achieved if clinics expanded their provision of contraceptive services.
The prevalence, and predictive value, of abnormal anal cytology to diagnose anal dysplasia in a population of HIV-positive men who have sex with men
Authors: Cranston R D , Hart S D , Gornbein J A , Hirschowitz S L , Cortina G , Moe A A
Published: February 2007

Due to the increasing incidence of anal cancer in HIV-positive men who have sex with men, and the potential to detect and treat high-grade anal dysplasia – the putative anal cancer precursor – we have introduced an anal cytology screening service. Patients with abnormal anal cytology have follow-up high-resolution anoscopy (HRA) with biopsy of lesions clinically suspicious for high-grade dysplasia. In total, 244 men were screened and 235 (96%) of the samples were adequate for cytological interpretation using the Bethesda 2001 system. One hundred and sixty-four (67%) men had abnormal anal cytology, and 93 of them had follow-up HRA and anal biopsy. The positive predictive value for any anal cytological abnormality to predict any degree of anal dysplasia was 95.7±2.1%, and for any anal cytological abnormality to predict high-grade anal dysplasia was 55.9±5.1%. Abnormal anal cytology was highly predicative of anal dysplasia on biopsy.
A hat trick of ulcerating pathogens in a single genital lesion
Authors: Samuel M , Aderogba K , Dutt N , Lambert J S , Taylor C
Published: February 2007

We report on a patient from a London clinic, (a Jamaican heterosexual man known to have herpes) who has donovanosis and syphilis in a single genital ulcer. The case highlights the importance of careful clinical examination of genital ulcers.
High hepatitis C virus prevalence and incidence among Canadian intravenous drug users
Authors: Roy É , Alary M , Morissette C , Leclerc P , Boudreau J-F , Parent R , Rochefort J , Claessens C ,   The SurvUDI Working Group
Published: February 2007

We used data and leftover samples collected through the SurvUDI network to describe the epidemiology of hepatitis C virus (HCV) infection among injection drug users (IDUs) in Eastern Central Canada. Among the 1380 selected IDUs, having participated twice or more between 1997 and 2003, the overall HCV prevalence rate was 60.4% (95% confidence interval [CI]: 57.7–63.0%). Among the 543 initially uninfected participants, the HCV incidence rate was 27.1 per 100 person-years (95% CI: 23.4–30.9 per 100 person-years). Independent predictors of seroconversion, identified among 359 participants, were age, injecting for a year or less, injecting with a syringe previously used by someone else, injecting most often cocaine, engaging in prostitution, and being recruited in a major urban centre. The HCV epidemic severely affects IDUs in this area. Actions to prevent HCV transmission, such as distribution of sterile injection equipment, have to be reinforced. Special efforts have to be targeted towards starting IDUs.
Artificial nutrition and hydration: managing the practicalities
Authors: Higham Helen
Published: February 2007

This article considers the nature of Mr Burke's concerns in bringing his action and the practical implications of similar situations. When artificial nutrition and hydration is provided, practical issues arise regarding future, potentially long-term care. This in turn raises concerns about place of care, provision of carers and funding, which may not easily be resolved. The GMC guidance exists to provide direction and help for practitioners when difficult decisions have to be made about future treatment with the intention that the patients' wishes and benefit of any potential treatment will be central to the discussions. Nevertheless, the reality of having these conversations, raising emotive issues with the patient and/or carers, and the implications of the final decision, may be very different in practice.
Strategic IT Investments: The Impact of Switching Cost and Declining IT Cost
Authors: Demirhan Didem , Jacob Varghese S. , Raghunathan Srinivasan
Published: February 2007

The declining cost of information technology (IT) over time provides the later entrant in information-intensive industries a cost advantage. On the other hand, the earlier entrant has the potential to build and retain its market share if consumers incur a cost in switching to the later entrant. We investigate the impact of a decline in the IT cost and the switching cost on IT investment strategies of firms. We find that a declining IT cost always hurts the early entrant’s profit. The early entrant may assume an aggressive investment strategy or a defensive investment strategy in response to a decline in the IT cost, depending on whether the switching cost relative to the extent of decline in the IT cost is high or low, respectively. A decline in IT cost also hurts the later entrant’s profit if the switching cost is high. A surprising result is that when the decline in the IT cost is higher than a critical value, a higher switching cost increases consumer surplus. When firms control the switching cost, the early entrant increases its investment in quality and switching cost and maintains its quality and its market-share leadership irrespective of the extent of decline in the IT cost.
Modularity and the Impact of Buyer–Supplier Relationships on the Survival of Suppliers
Authors: Hoetker Glenn , Swaminathan Anand , Mitchell Will
Published: February 2007

Modularity in product design and flexible supply chains is increasingly common in buyer–supplier relationships. Although the benefits of supply chain flexibility and component modularity for end-product manufacturers are accepted, little is known about their impact on suppliers. We advance the literature on modularity by exploring how three aspects of a supplier’s relationships with its customers affect the supplier’s survival: duration of buyer–supplier relationships, autonomy from customers, and links to prominent buyers. We compared the effects of these aspects of buyer–supplier relationships for low- and high-modularity components. Using data on U.S. carburetor and clutch manufacturers from 1918 to 1942, we found that suppliers of high-modularity components benefited more from autonomy provided by potential customers, whereas suppliers of low-modularity components benefited more from ties to higher status customers. Both benefited from autonomy generated by existing customers. Thus, relationships that require trust and extensive sets of interfirm routines, as do those for low-modularity components, led to both greater relationship benefits and greater constraints.
Comparing neuropsychological function before and during haemodialysis: A habituating selective deficit for prose recall
Authors: Oaksford Karen , Oaksford Mike , Ashraf Mohammad , Fitzgibbon Gillian
Published: February 2007

This study was based on the clinical observation that patients receiving haemodialysis(HD) showed poor retention for complex verbal information. To investigate this hypothesis, 45 patients with endstage renal disease were administered a neuropsychological (NP) test battery, including a test of prose recall on two occasions, 7 days apart (pre‐dialysis and whilst dialysing). A range of demographic, biochemical and mood variables were also assessed. Results revealed a selective deficit for prose recall whilst dialysing compared to pre‐dialysis performance, which habituated in the long‐term. Possible physiological and psychological bases of these effects in HD patients are discussed.
Probing Orientations of Single Fluorescent Labels on a Peptide Reversibly Binding to the Human Delta-Opioid Receptor
Authors: Tokimoto Takahira , Bethea Tomika R. C. , Zhou Min , Ghosh Indraneel , Wirth Mary J.
Published: February 2007

We report the first in-depth study of single-molecule polarization behavior of a species that is undergoing reversible binding with its biological receptor. We examine the utility of the information in single-molecule polarization measurements for investigations of binding. The human δ-opioid receptor, which is a G protein-coupled receptor, was incorporated into a supported lipid bilayer. A Cy3 label was covalently attached by a hydrophilic linker to a peptide agonist, Deltorphin II (5,6 Ile-Ile). The fluorescence excitation was alternated between s- and p-polarization using a microscope having the capability of total internal reflectance fluorescence (TIRF) excitation. The polarization behavior reveals that nonspecific binding events for this system give emission that is mostly s-polarized, while binding to the receptor gives emission that has a strong component of p-polarization. The results show that a high signal-to-noise ratio is achievable with single-molecule polarization measurements. The experiment detected 37 binding events of short duration (<30 s) and 35 binding events of long duration (from 30 s to 500 s). The polarization studies indicate that the receptors in the bilayer do not freely rotationally diffuse in the plane of the bilayer when the peptide is bound. The system exhibits two types of polarization behavior. One type has the dye label with fixed orientation, which sometimes abruptly switches. The other type has the dye orientation continuously fluctuating over time, typically exhibiting occasional periods of fixed orientation. For a long binding event of fixed orientation, it is established through analysis of the variance that the orientation actually is fluctuating through a range of angles on the order of 6°. It is shown that precise measurements of reorientation are achievable, with a detection limit of 1.3° for a typical single-molecule signal.
Application of Two-Dimensional Band-Target Entropy Minimization to Fluorescence Data: Implications for the Recovery of Patterns Arising from Only Bilinear and Not Trilinear Structures
Authors: Liangfeng Guo , Garland Marc
Published: February 2007

Pattern recognition in two-dimensional (2D) spectroscopy, without recourse to spectral libraries, etc., has a number of important potential applications. In the present contribution, two blind source separation techniques (spectral reconstruction) are applied to sets of 2D fluorescence data possessing both Rayleigh scattering and Raman scattering. The two methods used are (1) two-dimensional band-target entropy minimization (2D-BTEM), which models data as a bilinear form (in terms of a weighted sum of 2D patterns) and (2) parallel factor analysis (PARAFAC), which models data as a trilinear form. In addition, an a priori estimate of the number of patterns present is not required by 2D-BTEM but is required in PARAFAC. Both 2D-BTEM and PARAFAC are successfully applied to the real three-component data, and good 2D spectral reconstructions of the three amino acids are achieved. Moreover, 2D-BTEM was also able to recover the 2D Raman scattering directly, whereas PARAFAC did not recover the 2D Raman scatter (the Raman scatter does not possess a trilinear form). The present results suggest that 2D-BTEM can be useful in a wide range of spectroscopic applications for the recovery of underlying 2D patterns.
Vibrational Spectra of Tetrahedral Cyclopentadienyl Halogeno Complexes of Ti(iv) and Zr(iv)
Authors: Maslowsky Edward , Nakamoto Kazuo
Published: February 2007

The ir and Raman spectra of CpTiCl3 and CP2MX2 (Cp = C5H5, M = Ti, Zr and Hf, and X = a halogen) type compounds have been measured. Approximate normal coordinate analyses have been carried out to assign the skeletal modes in the low frequency region.
Isotopic Analysis of Lithium by Atomic Absorption Spectrophotometry
Authors: Wheat J. A.
Published: February 2007

An atomic absorption method was developed to determine the isotopic composition of lithium. The method utilizes neon-filled 6Li and 7Li hollow cathode emission lamps and a flame atomizer. The absolute precision of the method is ±0.5 at.% 6Li.
The Sensitivity Factors of the Rare Earths in an rf Spark Source Mass Spectrograph
Authors: Oblas Daniel W.
Published: February 2007

Experimentally determined sensitivity factors for the rare earths in Y2O3 are presented along with computed values based upon some electrical and physical properties of the elements and compounds. The sample electrodes consisted of 2 mol of pelletizing graphite and 1 mol of Y2O3 powder. The properties considered are (1) the heat of formation of the gaseous metal, (2) the dissociation energy of the monoxide, (3) the ionization potential of the metal, and (4) the experimentally determined charge distribution of the metal ions in the rf spark ion source. Even for the rare earths, a class of elements with similar chemical and electrical properties, the experimentally determined and computed sensitivity factors differ by as much as a factor of 6 from one another.
The Interpretation of the Infrared Spectra of Conjugated Polyenes in the 1000–900 cm−1 Region
Authors: Colthup N. B.
Published: February 2007

The ir spectra of conjugated polyenes such as fatty acids and derivatives are known to have band patterns in the 1000–900 cm−1 region which are characteristic for various arrangements of cis and trans groups within the different polyenes. This paper presents an interpretation of these bands and also predicts absorption patterns for less commonly observed polyenes with cis or trans groups.
Primary and Secondary Publication of Physics Research Results
Authors: Koch H. William
Published: February 2007

The concept of a discipline- and user-oriented information system founded on a strong publication program of quality, refereed primary journals is described. The emphasis on quality input gives the mechanism for controlling the information flood at the source, and the computerized secondary services naturally follow from, and are based on, this foundation. The advantages of such a system to primary journals in the areas of costs and dissemination are illustrated with reference to the publication and information programs of the American Institute of Physics.
Compositional Determination of Sputtered Tantalum—Aluminum Thin Films
Authors: Nohe James D. , Green David A.
Published: February 2007

Tantalum–aluminum thin film composition has been determined destructively by atomic absorption and nondestructively by x-ray fluorescence spectroscopy. Samples representing several compositions (20–80 at.% aluminum) and thicknesses (500–6000 Å) were sputtered on glass, graphite, and platinum substrates. The films were dissolved from the platinum substrates for the determination of aluminum by atomic absorption. The weights of tantalum per unit area obtained by difference using this destructive technique were applied to the same samples on glass substrates for correlation with nondestructive x-ray fluorescence measurements. A linear curve, which is free from enhancement and absorption effects, is obtained for tantalum. This curve relates the nondestructive fluorescence intensities to film weights (µg/cm2) of tantalum. The composition of the film is determined nondestructively by utilizing this curve and the total film weight which is obtained by weighing the substrate before and after sputtering. Alternately, composition may be determined destructively by atomic absorption utilizing films dissolved from platinum substrates
A Combination Flame Atomic Fluorescence—Atomic Emission dc Spectrometer for Analysis of Trace Wear Metals in Jet Engine Oils
Authors: Miller R. L. , Fraser L. M. , Winefordner J. D.
Published: February 2007

The combination of flame atomic fluorescence with a continuum source and flame atomic emission was found to provide a convenient method for analyzing Fe, Cu, Ag, and Mg in jet engine lubricating oils in the parts per million range. Dilution of the oils and oil standards to four times the original volume with carbon tetrachloride was found to be optimum for sample preparation.
Scientists and the Politics of Technology
Authors: von Hippel Frank , Primack Joel
Published: February 2007

Among the first questions which occur to a scientist who has decided to concern himself with the potential dangers posed by a rapidly developing technology are: (1) How effective is the Federal Executive's enormous and often distinguished science-advisory establishment in helping bring about rational decision making for technology? and (2) how effective in comparison can individual or small groups of independent scientists be in affecting crucial decisions by taking the issues to the public? In a number of case studies we have found: (1) In cases where an Executive Agency has large political or bureaucratic interests at stake, unfavorable reports of science-advisory panels are often ignored, kept confidential, and even misrepresented to the public as supporting official policy; and (2) it has been established repeatedly that a small dedicated group of independent scientists can bring to public attention a policy which represents a major threat to the public health and welfare. If the danger is sufficiently clear, the issue is often taken up by politicians or made into a legal issue with a good chance for a modification of official policy being the result.
Burner Design Criteria and Variables Affecting Flashback of Acetylene Flames
Authors: Hieftje Gary M.
Published: February 2007

A study is presented on the operating characteristics of burners employing premixed, laminar flow air–acetylene and nitrous oxide–acetylene flames. The variables affecting flashback of these flames have been investigated and found to be critically dependent on such factors as burner port diameter, gas flow, fuel–oxidant ratio, and burner construction. Because the theory previously developed for stable flame formation on isothermal burners is not directly applicable to most burners used in flame spectrometry, an operational theory of flashback is developed. In accordance with this working model, safe limits of operation for conventional burners are examined and presented and important burner design criteria are established, including experimental quenching diameters for both circular port and slot-type burners.
A Spectroscopic Source with Improved Analytical Properties and Remote Sampling Capability
Authors: Jones James L. , Dahlquist Ralph L. , Hoyt Robert E.
Published: February 2007

A direct current capillary arc operating in argon at atmospheric pressure has been combined with a device which produces fine particles directly from the surface of a solid metal sample. The aerosol generator is a simple device in which the sample acts as the cathode of a dc arc discharge. Rapid movement of the cathode spot produces uniform sampling over a well-defined area. A flowing gas stream transports the aerosol particles to the capillary arc discharge. Reproducibility and analytical curves are shown for ten elements in low alloy, stainless, and tool steel samples, for total analytical times of 10 sec.
Infrared Spectra of Adamantanes
Authors: Broxton T. J. , Deady L. W. , Kendall M. , Topsom R. D.
Published: February 2007

We report the infrared spectra of adamantane 1-deuteroadamantane and 15 other l-substituted derivatives in solution. Errors in the reported spectrum of adamantane are noted. Certain bands in the substituted adamantanes seem characteristic of the system and tentative assignments are discussed.
Atmospheric Influences on Q-Switched Laser Sampling and Resulting Plumes
Authors: Piepmeier E. H. , Osten D. E.
Published: February 2007

When a 10–100-mJ single-spike Q-switched Nd laser pulse is focused on a copper sample, the presence of an atmosphere affects the spectra, the crater size, and the amount of sample vaporized. At 760 Torr the crater diameter (90 µ) and amount of sample vaporized (35 ng) remain relatively constant while at 1 Torr they both increase with increasing laser energy. Spatial changes in the spectra occur with changes in ambient pressure. The continuum intensity of the limited region just above the sample surface appears to be a better measure of the energy reaching the sample than does the energy of the laser beam. The experimental results appear to be caused by absorption of a large fraction of the laser energy in an atmospheric plasma. A radiation-supported shock-wave model is evaluated in detail and compared briefly with similar models as possible mechanisms for production of the atmospheric plasma. The analytical chemical implications of the experimental and theoretical results are discussed.
Rotating Raman Sample Technique for Colored Crystal Powders; Resonance Raman Effect in Solid KMnO4
Authors: Kiefer W. , Bernstein H. J.
Published: February 2007

A simple sample technique which makes it possible to record Raman spectra of highly absorbing solids is described. The main feature is a rotating sample system containing pressed crystal powders, on which the laser beam is focused. The relative motion between laser focus and sample surface avoids heating and decomposition of the crystal powder. With this technique it is, for instance, possible to obtain a Raman spectrum of solid potassium permanganate, displaying a progression of strongly resonance enhanced overtones of the totally symmetric permanganate mode as well as a well-defined weakly enhanced spectrum for the other internal modes.
Evaluation of the Performance of Randomized versus Fixed Time Schedules for Quality Control Procedures
Authors: Parvin Curtis A , Robbins Sanford
Published: February 2007

Background: Although minimum regulatory standards exist for determining QC testing frequency, decisions regarding when and how to run QC samples are not standardized. Most QC testing strategies test control samples at fixed time intervals, often placing the samples in the same position on an instrument during subsequent QC events and leaving large gaps of time when control samples are never run, yet patient samples are being tested.

Methods: Mathematical derivations and computer simulation were used to determine the expected waiting time between an out-of-control condition and the next scheduled QC test for various QC testing strategies that use fixed or random intervals between QC tests.

Results: Scheduling QC tests at fixed intervals yields an average time between the occurrence of an out-of-control error condition and the next scheduled QC test that is equal to half of the fixed time interval. This performance was the best among the QC scheduling strategies investigated. Near-optimal performance, however, was achieved by randomly selecting time intervals between QC events centered on the desired expected interval length, a method that provides variation in QC testing times throughout the day.

Conclusions: If the goal is to vary QC testing times throughout the day while maintaining the shortest expected length of time between error conditions and the next scheduled QC test, then a near-optimal QC scheduling strategy combines randomly selected time intervals centered on the desired length of time between QC events with fixed time intervals.
CONTINGENCYDISCRIMINABILITY AND PEAK SHIFT IN CONCURRENT SCHEDULES
Authors: Krägeloh Christian U. , Elliffe Douglas M. , Davison Michael
Published: February 2007

We investigated the effects of discriminative stimuli on choice in a highly variable environment using a procedure in which multiple two‐key concurrent VI VI components changed every 10 reinforcers and were signaled by differential flashes of red and yellow keylights. Across conditions, five pigeons were exposed to a number of different combinations of the following component reinforcer ratios: 27:1, 9:1, 3:1, 1:1, 1:3, 1:9, 1:27. Overall, there was clear control by the component signals in that preference, early in components and particularly before any reinforcers had been delivered, was ordinally related to the signaled reinforcer ratios. In conditions in which only two components arranged unequal reinforcer ratios (e.g., 27:1 and 1:27) with the remaining components arranging 1:1 reinforcer ratios, preference before the first reinforcer in a component showed peak shift in that the most extreme preference did not occur in the unequal reinforcer‐ratio components, but in 1:1 components further towards the ends of the stimulus dimension. The contingency‐discriminability model (Davison & Nevin, 1999) was fitted to the data and provided an excellent description of the interactions between stimulus and reinforcer effects in a highly variable environment.
SOME TESTS OF RESPONSE MEMBERSHIP IN ACQUIRED EQUIVALENCE CLASSES
Authors: Urcuioli Peter J. , Lionello‐DeNolf Karen , Michalek Sarah , Vasconcelos Marco
Published: February 2007

Pigeons were trained on many‐to‐one matching in which pairs of samples, each consisting of a visual stimulus and a distinctive pattern of center‐key responding, occasioned the same reinforced comparison choice. Acquired equivalence between the visual and response samples then was evaluated by reinforcing new comparison choices to one set of samples, and examining generalization of these choices to the other samples. Three separate experiments found no evidence of such generalization, as indexed by performance on class‐consistent versus class‐inconsistent tests. Other tests showed that the pigeons' center‐key response patterns during training had indeed served as a conditional cue for choice. These results do not support the hypothesis that different defined responses can become members of acquired equivalence classes.
FIX AND SAMPLE WITH RATS IN THE DYNAMICS OF CHOICE
Authors: Aparicio Carlos F. , Baum William M.
Published: February 2007

The generality of the molar view of behavior was extended to the study of choice with rats, showing the usefulness of studying order at various levels of extendedness. Rats' presses on two levers produced food according to concurrent variable‐interval variable‐interval schedules. Seven different reinforcer ratios were arranged within each session, without cues identifying them, and separated by blackouts. To alternate between levers, rats pressed on a third changeover lever. Choice changed rapidly with changes in component reinforcer ratio, and more presses occurred on the lever with the higher reinforcer rate. With continuing reinforcers, choice shifted progressively in the direction of the reinforced lever, but shifted more slowly with each new reinforcer. Sensitivity to reinforcer ratio, as estimated by the generalized matching law, reached an average of 0.9 and exceeded that documented in previous studies with pigeons. Visits to the more‐reinforced lever preceded by a reinforcer from that lever increased in duration, while all visits to the less‐reinforced lever decreased in duration. Thus, the rats' performances moved faster toward fix and sample than did pigeons' performances in previous studies. Analysis of the effects of sequences of reinforcer sources indicated that sequences of five to seven reinforcers might have sufficed for studying local effects of reinforcers with rats. This study supports the idea that reinforcer sequences control choice between reinforcers, pulses in preference, and visits following reinforcers.
THE EMERGENCE OF SYMMETRY IN A CONDITIONAL DISCRIMINATION TASK USING DIFFERENT RESPONSES AS PROPIOCEPTIVE SAMPLES IN PIGEONS
Authors: García Andrés , Benjumea Santiago
Published: February 2007

In Experiment 1, 10 pigeons were exposed to a successive symbolic matching‐to‐sample procedure in which the sample was generated by the pigeons' own behavior. Each trial began with both response keys illuminated white, one being the “correct” key and the other the “incorrect” key. The pigeons had no way of discriminating which key was correct and which incorrect, since these roles were assigned on a random basis with the same probability of 0.5 for each key. A fixed ratio of five responses was required on the correct key. However, each time the pigeon pecked the incorrect key, the correct key response counter reset. Five consecutive pecks on the correct key was the only way to end this component, and switch off both key lights. Two seconds later, these same keys were illuminated again, one green and the other red (comparison stimuli). Now, if the correct white key had been on the left, a peck at one color produced food, and if the correct white key had been on the right, a peck at the other color produced food. When the pigeons had learned this discrimination, they were exposed to several symmetry tests (simultaneous presentations of both keys illuminated the same color—i.e., both red or both green), in order to interchange the sample with the comparison stimuli. In Experiment 2, the importance of requiring discrimination between the samples and between the comparisons was analyzed. In Experiment 3, we compared the results of Experiment 1 with a slightly different experiment, which resulted in discrimination of key position, an exteroceptive stimulus. The results showed that symmetry emerged only when different responses were used as samples.
Change of Sexual Function in Patients Before and After Ho:YAG Laser Enucleation of the Prostate
Authors: Meng Fanwei , Gao Baohua , Fu Qiang , Chen Jun , Liu Yuqiang , Shi Benkang , Xu Zhishun
Published: February 2007

ABSTRACT: The aim of this study is to evaluate the effect of Ho:YAG laser enucleation of the prostate (HOLEP) to the sexual function of patients with benign prostatic hyperplasia (BPH). In the course of the study, 108 patients with BPH were recruited and accepted treatment with HOLEP. The effectiveness of treatment was evaluated by flow rate and the International Prostate Symptom Score (IPSS) before HOLEP and 6 months afterwards. Meanwhile, the sexual functions were evaluated with the Danish Prostate Symptom Score Sexual Function Questionnaire (DanPSS Sex). Before and 6 months after HOLEP treatment, the mean residual urine volume was reduced from 106.0 ± 51.7 mL to 5.6 ± 1.7 mL (P < .01), maximum flow rate was improved from 7.2 ± 3.9 mL/s to 21.7 ± 1.3 mL/s (P < .01), nocturia frequency was reduced from 5.5 to 1.5 (P < .01), and the mean IPSS score was decreased from 19.4 ± 5.6 to 7.4 ± 2.6 (P < .01). The proportion of patients satisfied with their libido was 55% before HOLEP and 57% 6 months afterwards, while 23.5% of the patients had no libido before and after HOLEP; 37% of the patients were satisfied with their erection before HOLEP and 40% after 6 months; 30% of the patients had completely satisfactory sex life before HOLEP, and 32% did 6 months later. The corresponding percentages of fully impotent patients increased from 33% before the procedure to 35% 6 months postoperation. Early morning erections were reported by 45% of the patients before the procedure and by 62% 6 months later (P < .01). In 70% of the patients with normal sex life, ejaculation was retrograde 6 months after HOLEP (P < .01). HOLEP does not affect the sexual function of patients with BPH but does did improve the ability of early morning erection, while causing retrograde ejaculation.
First Steps in the Development of a Functional Assay for Human Sperm Using Pig Oocytes
Authors: Canovas Sebastian , Coy Pilar , Gomez Emilio
Published: February 2007

ABSTRACT: The use of mammalian oocytes to assess human sperm functionality could be a helpful tool with potential applications in clinical and research programs. In an attempt to develop the pig model, the aim of the present work was to study the interaction between human spermatozoa and pig oocytes at the zona pellucida (ZP), the oolemma, and the ooplasm levels. In vitro matured pig oocytes and human spermatozoa from fertile and low‐fertility donors were employed. The induction of the acrosome reaction by the ZP, the ability of the sperm to penetrate the oocyte after cocincubation, and the male pronuclear formation after ICSI were evaluated. Human spermatozoa can bind to pig ZP and undergo the acrosome reaction (15% to 58%, depending on the individual); they are not able to fuse with the oolemma but they can decondense and form a male pronucleus (40%–100%) when injected into pig oocytes. In conclusion, this study shows that pig oocytes can be a useful model to assess human sperm functionality.