bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of N‐ethylmaleimide on transmitter release from the skeletal neuromuscular junction of Bufo marinus
Authors: Knight D. , Bellingham M.C. , Lavidis N.A.
Published: May 2004

N‐ethylmaleimide (NEM) has been used extensively in biochemical assays as an inhibitor of the NEM sensitive fusion protein (NSF). However, examination of the effect of NEM on transmitter release in more physiologically relevant preparations has proved inconclusive. In the present study, we have examined the effect of low concentrations of NEM on synaptic transmission in intact nerve‐muscle preparations from toads (Bufo marinus). Under conditions of low transmitter release probability (0.3 mM calcium, 1 mM magnesium), treatment with NEM (10 μM) caused a significant increase in the amplitude of stimulus‐evoked endplate potentials (EPPs) and a significant increase in the frequency of spontaneously occurring miniature EPPS (MEPPS) without affecting the amplitude of MEPPs. When the calcium concentration in the bath was raised to 4 mM, 10 μM NEM had no effect on EPP amplitude. Under these conditions, NEM treatment reduced paired pulse facilitation and increased depression during stimulus trains. Treatment with NEM also resulted in a significant decrease in the synaptic delay. The effects of NEM on transmitter release in the present study were not due to inactivation of G‐proteins. The results of the present study show a calcium‐dependent facilitation of stimulus‐evoked transmitter release by NEM. These results are discussed in terms of the possible sites of NEM action leading to the observed changes in transmitter release. Synapse 53:151–158, 2004. © 2004 Wiley‐Liss, Inc.
Erste vertikale In‐line Fertigungsanlage für OLEDs. New vertical in‐line solution for OLED production
Authors: Fuchs Frank
Published: June 2004

Das Unternehmen Applied Films hat ein vertikales In‐Line Verfahren zur Herstellung organischer lichtemittierender Dioden (OLEDs) entwickelt. Es zeichnet sich insbesondere durch hohe Durchsatzleistungen und effiziente Materialausnutzung aus. Die Herstellung von OLEDs im industriellen Maßstab rückt damit näher. Derzeit wird das Verfahren am Fraunhofer Institut für Photonische Mikrosysteme in Dresden getestet.
Entwicklungstendenzen von Vakuumpumpen für die Grob‐ und Feinvakuumtechnik. Developing trends of vacuum pumps for the roughly and fine vacuum technology
Authors: Surek D.
Published: June 2004

Gegenwärtig wird Grob‐ und Feinvakuum in technischen Anlagen vorwiegend mit rotierenden Verdrängerpumpen und einigen speziellen Strömungsmaschinen sowie mittels Kombinationen dieser Pumpen erzeugt. Dabei vollzog sich in den vergangenen Jahrzehnten eine bemerkenswerte Veränderung der eingesetzten Bauarten von Vakuumpumpen und ihrer Parameter, die bis zum heutigen Tag nicht abgeschlossen ist. Sie wird sich auch zukünftig mit der Weiterentwicklung von Vakuumpumpen und mit der Neuentwicklung von Maschinen und anlagentechnischen Anforderungen fortsetzen.

Im folgenden Beitrag werden, ausgehend von dem heutigen Entwicklungsstand der meist verwendeten Vakuumpumpen, einige aussichtsreiche Entwicklungstendenzen für die nähere Zukunft skizziert. Das ist sinnvoll, weil in den vergangenen Jahrzehnten wichtige Anwendungsbereiche wie z. B. die Lebensmittelindustrie oder die mikroelektronische und die pharmazeutische Industrie hinzukamen.
Surgical Treatment of Portal Vein Cavernous Transformation
Authors: Zhang Hongkun , Zhang Nan , Li Ming , Jin Wei , Pan Songlin
Published: June 2004

The aim of this study was to explore the treatment of portal cavernous transformation (PVCT). The surgical treatment of 18 patients with PVCT was studied retrospectively. Eight patients underwent mesocaval shunt with artificial grafts, two patients had splenectomy and disconnection, three patients had a central splenorenal shunt, and six patients had a distal splenorenal shunt. There were no deaths or hepatic encephalopathy after operation. Bleeding recurred in two patients (disconnection in one, mesocaval shunt in one). The individualized choice of shunt is ideal for treating PVCT, and the combined procedures of shunt and disconnection are useful. The Rex shunt will be the focus of PVCT surgery in the future.
Vascular Endothelial Growth Factor Expression and Neovascularization in Barrett’s Carcinoma
Authors: Möbius Christian , Stein Hubert J. , Becker Ingrid , Feith Marcus , Theisen Jörg , Gais Peter , Jütting Uta , Siewert J. Rüdiger
Published: June 2004

Angiogenesis is essential for tumor growth and metastasis. An association between microvessel density, a measure of tumor angiogenesis, and conventional prognostic variables has been shown for many tumor entities. For Barrett’s carcinoma, the results are controversial. Immature vessels formed in tumors are structurally and functionally different from those in mature vessels. The relation between mature and immature vessels as a prognostic factor for Barrett’s carcinoma has not been assessed. Specimens from 45 R0‐resected Barrett’s carcinomas were immunostained for vascular endothelial growth factor (VEGF), CD 31, and smooth muscle α‐actin to discriminate between mature and immature vessels. VEGF staining was evaluated quantitatively by measuring optical density with a new computer‐based program and expressed as a percentage of the staining (juvenile placental tissue) on control slides. The neovascularization coefficient (i.e., the relation between mature and immature vessels) was estimated with an interactive analytic computer program. The median survival of the study group was 45.7 months. The neovascularization coefficient correlated with the histopathologic classification (p < 0.001). Survival time in patients with a low neovascularization coefficient was significantly better than the survival time in patients with a high neovascularization coefficient (p = 0.021). VEGF expression did not correlate with clinicopathologic data (p > 0.05) or with patient survival (p > 0.05). The tumors with a high neovascularization coefficient did not have significantly elevated VEGF expression. Based on a strong quantitative computer evaluation program, the present study indicates that neovascularization has an important impact on the survival of patients with Barrett’s carcinoma. However, VEGF does not appear to be the vascular growth factor stimulating neovascularization in Barrett’s carcinoma patients.
Redifferentiation of human hepatoma cells induced by synthesized coumarin
Authors: Pan Jing , Zhang Qi , Zhao Chen‐yang , Zheng Rong‐liang
Published: June 2004

The effects of synthesized 7‐OH‐4‐CH3‐coumarin on proliferation and differentiation of human hepatoma carcinoma cell line, SMMC‐7721, were examined. Results showed that 7‐OH‐4‐CH3‐coumarin suppressed the proliferation of the SMMC‐7721 cells in a dose‐dependent manner, with an IC50 value of 356±1.8 mM, while concentrations ≥ 200 mM could trigger differentiation. After treatment with this compound at 100 mM, the growth curve of human hepatoma cells decreased markedly. When treated with 50 and 100 mM, the cells' electrophoresis rate decreased from 2.2 mm/s/V/cm in the control group to 1.5 and 1.8 mm/s/V/cm, respectively, and the α‐fetoprotein content decreased from 123 ng/mg in the control group to 68 and 45 ng/mg, respectively. The microvilli on the surface of treated cells were also reduced. All the above indexes related to cell malignancy were alleviated significantly. Results showed that 7‐OH‐4‐CH3‐coumarin could reverse human hepatoma cells' malignant phenotypic characteristics and induce redifferentiation.
The role of personality disorders on drug dependence treatment outcomes following inpatient detoxification
Authors: Haro G. , Mateu C. , Martínez-Raga J. , Valderrama J.C. , Castellano M. , Cervera G.
Published: June 2004

Aims

The present 6 month follow-up study was conducted to investigate the possible influence of comorbid personality disorders on drug treatment, as well as associated psychopathology and HIV-related risk behaviors outcomes.

Subjects and methods

Data were collected initially from a consecutive sample of 74 patients with a diagnosis of opiate abuse or dependence, admitted for inpatient detoxification.

Result

During intake, 80.9% of patients reported at least one HIV-related risk behavior in the previous 6 months. Not using condoms during sexual intercourse was the most common and the only risk behavior that showed a statistically significant reduction over the follow-up period. A total of 58.1% of subjects had at least one personality disorder (PD). Borderline PD was the most prevalent. However, antisocial PD was the only PD that influenced substance use outcomes. The presence of this diagnosis increased the chance of worse opiate use outcomes, but decreased likelihood of not using condoms. Patients with low obsessive–compulsive PD dimensional scores showed a significant increase in the number of risk behaviors. However, these influences were only seen at the 3-month follow-up assessment.

Conclusions

These results suggest that personality disorders need to be considered when planning effective interventions for opiate dependent individuals and when preparing and evaluating HIV risk-reduction interventions, particularly for the more severe substance dependent patients.
Stabilization of flagellar filaments by HAP2 capping
Authors: Diószeghy Zoltán , Závodszky Péter , Namba Keiichi , Vonderviszt Ferenc
Published: June 2004

In vivo growth of bacterial flagellar filaments by self‐assembly of flagellin is promoted by a capping structure composed of a pentameric assembly of hook associated protein 2 (HAP2). Isolated native filaments with intact HAP2 cap exhibited higher melting temperature (ΔT
m=4 °C) and significantly increased resistance against heat‐induced depolymerization than non‐capped ones. Reconstituted filaments were also stabilized by HAP2 binding, but the obtained filament–HAP2 complexes were less stable than native assemblies. Their fast depolymerization at elevated temperatures and sensitivity to proteolysis indicated that native‐like filament–HAP2 complexes are rarely obtained by in vitro reconstitution. A procedure was developed to isolate perfectly capped native filaments to facilitate high‐resolution structural analysis.
Congenital diseases of feline muscle and neuromuscular junction
Authors: Gaschen Frédéric , Jaggy André , Jones Boyd
Published: June 2004

Although muscle diseases occur relatively rarely in cats, a number of congenital feline myopathies have been described over the last 20 years and are reviewed in this paper. Some of them have been reported exclusively in specific breeds, including the hypokalaemic myopathy of Burmese cats, type IV glycogen storage disease in Norwegian Forest cats, or the myopathy of Devon Rex. Other congenital disorders of muscle and neuromuscular junction such as myotonia congenita, dystrophin-deficient hypertrophic feline muscular dystrophy, laminin α2 deficiency, or congenital myasthenia gravis may occur in any cat. A systematic approach is essential in order to efficiently obtain a timely diagnosis in cats showing signs of muscle disease. After a thorough clinical examination, this approach includes blood analyses (eg, serum concentration of muscle enzymes), electrophysiology where available (electromyography, nerve conduction studies), and sampling of muscle biopsies for histological, histochemical and immunohistochemical evaluation. When available, detection of healthy carriers of these genetic disorders is important to eliminate the gene mutations from breeding families. Clinicians regularly receiving feline patients must have a good knowledge of congenital feline myopathies and the features which enable a diagnosis to be made and prognosis given. Besides preserving or restoring the well-being of the myopathic patient, rapid and efficient information and counselling of the breeders are of central importance in order to prevent the recurrence of the problem in specific breeding lines.
Clinical Experience with End-to-Side Nerve Transfer
Authors: PIENAAR C. , SWAN M. C. , DE JAGER W. , SOLOMONS M.
Published: June 2004

A retrospective study was undertaken to determine the effectiveness of end-to-side nerve transfer. Twenty patients with peripheral nerve lesions of varying aetiology underwent 23 end-to-side nerve transfers over a 15-month period. The mean patient age was 30 years and 18 were male. The mean delay in presentation was 2.4 months. All underwent end-to-side nerve repairs and were reviewed in outpatients at regular intervals. Ten patients were lost to follow-up before 12 months and were therefore excluded from the study. The remaining ten patients, who had undergone 13 end-to-side procedures, had a mean follow-up period of 16 months. None demonstrated objective evidence of motor recovery at the end of the study period. Four patients had modest recovery of deep protective sensation, and two patients suffered a subtle degree of ”donor“ nerve morbidity. We have abandoned this technique in our centre in preference for standard nerve grafting techniques.
Lead alters parathyroid hormone‐related peptide and transforming growth factor‐β1 effects and AP‐1 and NF‐κKB signaling in chondrocytes
Authors: Zuscik Michael J. , Pateder Dhruv B. , Edward Puzas J. , Schwarz Edward M. , Rosier Randy N. , O'Keefe Regis J.
Published: June 2004

The skeletal system is an important target for lead toxicity. One of the impacts of lead in the skeleton, the inhibition of axial bone development, is likely due to its effect on the normal progression of chondrocyte maturation that is central to the process of endochondral ossification. Since little is known about the effect of lead on chondrocyte function/maturation, its impact on (1) growth factor‐induced proliferation, (2) expression of maturation‐specific markers type X collagen and BMP‐6, and (3) the activity of AP‐1 and NF‐κB was examined in chick growth plate and sternal chondrocyte models. Exposure to lead alone (1–30 μM) resulted in a dose‐dependent inhibition of thymidine incorporation in growth plate chondrocytes. Lead also blunted the stimulation of thymidine incorporation by parathyroid hormone‐related peptide (PTHrP) and transforming growth factor‐β1 (TGF‐β1), two critical regulators of chondrocyte maturation. Lead (1 and 10 μM), TGF‐β1 (3 ng/ml) and PTHrP (10−7 M) all significantly inhibited the expression of type X collagen, a marker of chondrocyte terminal differentiation. However, when in combination, lead completely reversed the inhibition of type X collagen by PTHrP and TGF‐β1. The effect of lead on BMP‐6, an inducer of terminal differentiation, was also examined. Independently, lead and TGF‐β1 were without effect on BMP‐6 expression, but PTHrP significantly suppressed it. Comparatively, lead did not alter PTHrP‐mediated suppression of BMP‐6, but in combination with TGF‐β1, BMP‐6 expression was increased 3‐fold. To determine if lead effects on signaling might play a role in facilitating these events, the impact of lead on NF‐κKB and AP‐1 signaling was assessed using luciferase reporter constructs in sternal chondrocytes. Lead had no effect on the AP‐1 reporter, but it dose‐dependently inhibited the NF‐κB reporter. PTHrP, which signals through AP‐1, did not activate the NF‐κKB reporter and did not affect inhibition of this reporter by lead. In contrast, PTHrP activation of the AP‐1 reporter was dose‐dependently enhanced by lead. These findings, which establish that chondrocytes are important targets for lead toxicity, suggest that the effects of lead on bone growth are derived from its impact on the modulation of chondrocyte maturation by growth factors and second messenger signaling responses. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Posttraumatic stress disorder symptoms, physical health, and health care utilization 50 years after repeated exposure to a toxic gas
Authors: Ford Julian D. , Schnurr Paula P. , Friedman Matthew J. , Green Bonnie L. , Adams Gary , Jex Steve
Published: May 2004

The posttraumatic sequelae of contaminant exposure are a contemporary international concern due to the threats posed to military personnel and civilians by war and bioterrorism. The role of PTSD symptoms as a mediator between potentially traumatic toxin exposure and physical health outcomes was examined with structural equation modeling in a probability sample of 302 male World War II‐era U.S. military veterans 50 years after exposure to mustard gas tests. Controlling for age and psychological distress, the most parsimonious structural model involved PTSD symptoms mediating the relationship between toxin exposure and physical health problems, and physical health problems mediating the relationship between PTSD symptoms and outpatient health care utilization. Implications for researchers, mental health clinicians, and health care providers are discussed.
An experimental study of emotional responding in women with posttraumatic stress disorder related to interpersonal violence
Authors: Orsillo Susan M. , Batten Sonja V. , Plumb Jennifer C. , Luterek Jane A. , Roessner Bonnie M.
Published: May 2004

Although posttraumatic stress disorder (PTSD) is defined by the experience of intense negative emotions and emotional numbing (American Psychiatric Association, 1994), empirical study of emotional responding in PTSD has been limited. This study examined emotional responding among women with and without PTSD to positive and negative film stimuli across self‐reported experience, facial expression, and written expression. Consistent with previous findings, no evidence for generalized numbing was found. In general, women with PTSD exhibited higher levels of negative activation and expressed more negative emotion words to both positive and negative film stimuli, whereas no group differences emerged in facial expressivity. Results are interpreted within the context of the current literature on emotional deficits associated with PTSD.
Nightmares, insomnia, and sleep‐disordered breathing in fire evacuees seeking treatment for posttraumatic sleep disturbance
Authors: Krakow Barry , Haynes Patricia L. , Warner Teddy D. , Santana Erin , Melendrez Dominic , Johnston Lisa , Hollifield Michael , Sisley Brandy N. , Koss Mary , Shafer Laura
Published: May 2004

Eight months after the Cerro Grande Fire, 78 evacuees seeking treatment for posttraumatic sleep disturbances were assessed for chronic nightmares, psychophysiological insomnia, and sleep‐disordered breathing symptoms. Within this sample, 50% of participants were tested objectively for sleep‐disordered breathing; 95% of those tested screened positive for sleep‐disordered breathing. Multiple regression analyses demonstrated that these three sleep disorders accounted for 37% of the variance in posttraumatic stress symptoms, and each sleep disorder was significantly and independently associated with posttraumatic stress symptoms severity. The only systematic variable associated with posttraumatic stress symptoms of avoidance was sleep‐disordered breathing. The findings suggest that three common sleep disorders relate to posttraumatic stress symptoms in a more complex manner than explained by the prevailing psychiatric paradigm, which conceptualizes sleep disturbances in PTSD merely as secondary symptoms of psychiatric distress.
Posttraumatic mental and physical health correlates of forgiveness and religious coping in military veterans
Authors: Witvliet C. V. O. , Phipps K. A. , Feldman M. E. , Beckham J. C.
Published: May 2004

This study assessed mental and physical health correlates of dispositional forgiveness and religious coping responses in 213 help‐seeking veterans diagnosed with PTSD. Controlling for age, socioeconomic status, ethnicity, combat exposure, and hostility, the results indicated that difficulty forgiving oneself and negative religious coping were related to depression, anxiety, and PTSD symptom severity. Difficulty forgiving others was associated with depression and PTSD symptom severity, but not anxiety. Positive religious coping was associated with PTSD symptom severity in this sample. Further investigations that delineate the relevance of forgiveness and religious coping in PTSD may enhance current clinical assessment and treatment approaches.
Emotional deficits in military‐related PTSD: An investigation of content and process disturbances
Authors: Monson Candice M. , Price Jennifer L. , Rodriguez Benjamin F. , Ripley Moira P. , Warner Reid A.
Published: May 2004

To expound on the nature of emotional deficits in PTSD, the current study investigated the relationships among emotion content and process variables and PTSD symptomatology in a sample of 85 veterans with military‐related trauma. Alexithymic externally oriented thinking and negative affectivity emerged as the most consistent predictors of PTSD symptoms; however, depression was the only variable associated with emotional numbing. Theoretical and clinical implications of these findings are discussed, as well as future research directions including the collateral and clinician assessment of emotional functioning, use of other process measures, and inclusion of various control groups.
Suicide Among the Homeless
Authors: Barak Yoram , Cohen Asnat , Aizenberg Dov
Published: May 2004

Summary: Background: Among the homeless there are high rates of mortality and a significant number of attempted and completed suicides. In Tel-Aviv, Israel, there is an ongoing municipal outreach program for the homeless. Objective: The aim of the present study was to describe the subgroup of homeless persons who had died by suicide. Method: Over a 9-year period the records of each homeless person who had died were assessed by two psychiatrists and a clinical criminologist. The project was undertaken in a large city and was feasible due to close cooperation between the municipal welfare department and mental health consultants. Results: Of the 1,192 homeless persons located and contacted, 156 persons had died (13.1%). Nine of the deaths were by completed suicide (5.8%). All were male. Mean age for the suicide subgroup was 34±8.7 years, significantly younger than those who died of other causes (p < .01). The majority had completed high school education. While the majority of deaths were drug or alcohol related, in only 1 of 9 deaths by suicide was there a history of drug abuse. Psychiatric comorbidity was recorded in 4 of the 9 persons. The majority of persons (6/9) had died of suicide by hanging. Conclusion: Suicide is not a negligible cause of death among the homeless population.
A Suicide Prevention Strategy for England
Authors: Mehlum Lars
Published: May 2004

Summary: Over the last decade an increasing number of countries have established national strategies for suicide prevention. In the autumn of 2002 the suicide prevention strategy for England was presented to the general public, introducing what could be called a second generation of national programs for suicide prevention. This strategy uses evidence-based criteria for its priorities more systematically than before. Furthermore, it has put an increased emphasis on goals being specific, preventive measures being practical, and the preventive potential being visible. Other guiding principles for this strategy are that suicide preventive measures and initiatives should be open to monitoring and evaluation, and that revisions and updates of the national strategy should be made regularly—thus constituting an evolving strategy. This paper examines the content of the new national strategy for suicide prevention in England and what new contributions to the field it may make.
Exhumed upper mantle within the ocean‐continent transition on the northern West Iberia margin: Evidence from prestack depth migration and total tectonic subsidence analyses
Authors: Henning Alison T. , Sawyer Dale S. , Templeton Dennise C.
Published: May 2004

The West Iberia continental margin contains an enigmatic north‐south ridge of serpentinized peridotite located within the ocean‐continent transition. We used prestack depth migration and total tectonic subsidence analysis to constrain the basement type adjacent to the ridge in order to learn more about its emplacement. Prestack depth migration was performed on segments of the nine east‐west lines from the Iberia Seismic Experiment (ISE 97), and total tectonic subsidence analyses were performed on the depth sections. The seismic data and subsidence analyses are consistent with exhumed upper mantle occurring immediately landward of the ridge, suggesting that the ridge is located within a broad zone of exhumed mantle that has been serpentinized. The subsidence analyses also provide minimum bounds on the thickness of the serpentinized layer, which extends from the zone of exhumed mantle landward under thinned continental crust. Exhumed upper mantle has previously been identified in the wider ocean‐continent transition to the south in the southern Iberia Abyssal Plain, and we conclude that similar but narrower exposures occur to the north in the Galicia Bank area. While upper mantle appears to have been tectonically exhumed along all the ISE 97 lines, it does not always form a distinct basement ridge. There is no well‐defined ridge on three seismic profiles in the middle of the ISE 97 survey. Where it is well‐developed, the peridotite ridge parallels a deeply‐penetrating, west‐dipping normal fault, and the three middle lines appear to represent a transfer zone where this normal fault is not well‐developed.
Intercomparisons of airborne measurements of aerosol ionic chemical composition during TRACE‐P and ACE‐Asia
Authors: Ma Y. , Weber R. J. , Maxwell‐Meier K. , Orsini D. A. , Lee Y.‐N. , Huebert B. J. , Howell S. G. , Bertram T. , Talbot R. W. , Dibb J. E. , Scheuer E.
Published: June 2004

As part of the two field studies, Transport and Chemical Evolution over the Pacific (TRACE‐P) and the Asian Aerosol Characterization Experiment (ACE‐Asia), the inorganic chemical composition of tropospheric aerosols was measured over the western Pacific from three separate aircraft using various methods. Comparisons are made between the rapid online techniques of the particle into liquid sampler (PILS) for measurement of a suite of fine particle a mist chamber/ion chromatograph (MC/IC) measurement of fine sulfate, and the longer time‐integrated filter and micro‐orifice impactor (MOI) measurements. Comparisons between identical PILS on two separate aircraft flying in formation showed that they were highly correlated (e.g., sulfate r2 of 0.95), but were systematically different by 10 ± 5% (linear regression slope and 95% confidence bounds), and had generally higher concentrations on the aircraft with a low‐turbulence inlet and shorter inlet‐to‐instrument transmission tubing. Comparisons of PILS and mist chamber measurements of fine sulfate on two different aircraft during formation flying had an r2 of 0.78 and a relative difference of 39% ± 5%. MOI ionic data integrated to the PILS upper measurement size of 1.3 μm sampling from separate inlets on the same aircraft showed that for sulfate, PILS and MOI were within 14% ± 6% and correlated with an r2 of 0.87. Most ionic compounds were within ±30%, which is in the range of differences reported between PILS and integrated samplers from ground‐based comparisons. In many cases, direct intercomparison between the various instruments is difficult due to differences in upper‐size detection limits. However, for this study, the results suggest that the fine particle mass composition measured from aircraft agree to within 30–40%.
Analysis of the atmospheric distribution, sources, and sinks of oxygenated volatile organic chemicals based on measurements over the Pacific during TRACE‐P
Authors: Singh H. B. , Salas L. J. , Chatfield R. B. , Czech E. , Fried A. , Walega J. , Evans M. J. , Field B. D. , Jacob D. J. , Blake D. , Heikes B. , Talbot R. , Sachse G. , Crawford J. H. , Avery M. A. , Sandholm S. , Fuelberg H.
Published: June 2004

Airborne measurements of a large number of oxygenated volatile organic chemicals (OVOC) were carried out in the Pacific troposphere (0.1–12 km) in winter/spring of 2001 (24 February to 10 April). Specifically, these measurements included acetone (CH3COCH3), methylethyl ketone (CH3COC2H5, MEK), methanol (CH3OH), ethanol (C2H5OH), acetaldehyde (CH3CHO), propionaldehyde (C2H5CHO), peroxyacylnitrates (PANs) (CnH2n+1COO2NO2), and organic nitrates (CnH2n+1ONO2). Complementary measurements of formaldehyde (HCHO), methyl hydroperoxide (CH3OOH), and selected tracers were also available. OVOC were abundant in the clean troposphere and were greatly enhanced in the outflow regions from Asia. Background mixing ratios were typically highest in the lower troposphere and declined toward the upper troposphere and the lowermost stratosphere. Their total abundance (ΣOVOC) was nearly twice that of nonmethane hydrocarbons (ΣC2‐C8 NMHC). Throughout the troposphere, the OH reactivity of OVOC is comparable to that of methane and far exceeds that of NMHC. A comparison of these data with western Pacific observations collected some 7 years earlier (February–March 1994) did not reveal significant differences. Mixing ratios of OVOC were strongly correlated with each other as well as with tracers of fossil and biomass/biofuel combustion. Analysis of the relative enhancement of selected OVOC with respect to CH3Cl and CO in 12 plumes originating from fires and sampled in the free troposphere (3–11 km) is used to assess their primary and secondary emissions from biomass combustion. The composition of these plumes also indicates a large shift of reactive nitrogen into the PAN reservoir thereby limiting ozone formation. A three‐dimensional global model that uses state of the art chemistry and source information is used to compare measured and simulated mixing ratios of selected OVOC. While there is reasonable agreement in many cases, measured aldehyde concentrations are significantly larger than predicted. At their observed levels, acetaldehyde mixing ratios are shown to be an important source of HCHO (and HOx) and PAN in the troposphere. On the basis of presently known chemistry, measured mixing ratios of aldehydes and PANs are mutually incompatible. We provide rough estimates of the global sources of several OVOC and conclude that collectively these are extremely large (150–500 Tg C yr−1) but remain poorly quantified.
Comparison of daytime and nighttime oxidation of biogenic and anthropogenic VOCs along the New England coast in summer during New England Air Quality Study 2002
Authors: Warneke C. , de Gouw J. A. , Goldan P. D. , Kuster W. C. , Williams E. J. , Lerner B. M. , Jakoubek R. , Brown S. S. , Stark H. , Aldener M. , Ravishankara A. R. , Roberts J. M. , Marchewka M. , Bertman S. , Sueper D. T. , McKeen S. A. , Meagher J. F. , Fehsenfeld F. C.
Published: May 2004

Volatile organic compounds (VOCs) and some of their oxidants (O3, NO3) were measured on board the National Oceanic and Atmospheric Administration research ship R/V Ronald H. Brown along the coast of New England, downwind of New York, Boston, and Portsmouth and large forested areas in New Hampshire, Maine, and Massachusetts in July and August 2002. The diurnal variations of isoprene, monoterpenes, and aromatics were mainly dependent on their emissions and the abundance of the oxidants OH and NO3. Elevated mixing ratios of short‐lived VOCs were only encountered at the ship, which was about 1–6 hours downwind of the sources, when the concentrations of the oxidants were low. For the biogenic compounds this was generally the case during morning and evening hours, when the lifetime of the biogenics was long because of low OH and NO3 concentrations. Most anthropogenic VOCs do not react with NO3, and therefore their mixing ratios remained elevated during the night. The products of isoprene oxidation, methyl vinyl ketone, methacrolein, and peroxymethacrylic nitric anhydride (MPAN) were, on average, more abundant than isoprene itself. Only during the transition periods from day to night, when oxidation rates were at a minimum, could isoprene exceed its products. The loss of the biogenic VOCs was dominated by reactions with NO3, whereas the loss of anthropogenics came mostly from reactions with OH. The oxygenated VOCs are the major contributor to the OH loss, except in close vicinity of emission sources. The total loss of biogenic compounds during the night was so effective that after one night of transport they were in most cases completely reacted away, whereas the mixing ratios of the anthropogenic compounds remained high during the night. The pool of reactive hydrocarbons at sunrise was thus typically dominated by anthropogenic VOCs.
Temperature‐dependent photoabsorption cross sections in the VUV‐UV region: Ethylene
Authors: Wu C. Y. Robert , Chen F. Z. , Judge D. L.
Published: June 2004

Using synchrotron radiation as a continuum light source, we have measured the absolute photoabsorption cross sections of ethylene (C2H4) in the region between 118 nm and 192 nm with a spectral bandwidth (full width at half maximum) of 0.06 nm and at five different temperatures: 370 K, 330 K, 295 K, 200 K, and 140 K. Significant temperature effects are observed in several spectral regions, including the threshold absorption region. From the Pc,370K curve we are able to identify and assign several hot bands. When the gas temperature decreases from 370 K to 140 K, the cross sections of the hot bands in the 190 nm region decrease by an order of magnitude. The line shapes of the Pc,T exhibit characteristic symmetric and asymmetric peaks, as well as the first derivative‐like and second derivative‐like curves associated with various absorption features. The results obtained in the present work provide the required data to the planetary atmospheres community and may have an important contribution to our understanding of the atmospheres of giant planets.
New experimental results on the degradation of polyoxymethylene: Application to the origin of the formaldehyde extended source in comets
Authors: Fray N. , Bénilan Y. , Cottin H. , Gazeau M.‐C.
Published: June 2004

The formaldehyde (H2CO) observed in cometary atmospheres presents a so‐called “extended source,” meaning that its distribution in the coma cannot be explained by sublimation from the nucleus alone; a production inside the coma has to be included. Polyoxymethylene (formaldehyde polymers: (‐CH2‐O‐)n, also called POM) is sometimes evoked as a parent molecule for this extended source. This solid polymer on cometary grains could release gaseous formaldehyde through thermal and photolytic degradation. We have developed an experimental program in order to study the chemical reactions of degradation of POM by UV photolysis and heating. It provides identification of the degradation products and the determination of the photo degradation quantum yields or the thermal degradation kinetics. In this paper we present the improvements of our experimental setup and new measurements on the kinetics of gaseous formaldehyde production by thermal degradation of two types of commercial POM on a greater temperature range than the previous ones. These new data are then included in a model of the outer coma in order to interpret observations. This model takes into account the production of gaseous molecules from solid material present on grains and leads to a very good agreement with Giotto observations of comet 1P/Halley, if we assume that the cometary grains contain 1–16% of POM by mass. Thus, without being final evidence of this polymer presence on comets, we conclude that the degradation of solid POM‐like polymers on cometary grains is to date the best explanation of the H2CO extended source.
Ocean, sea‐ice, atmosphere oscillations in the Southern Ocean as simulated by the SINTEX coupled model
Authors: Carril Andrea F. , Navarra Antonio , Masina Simona
Published: May 2004

This study evaluates the Antarctic Circumpolar Wave (ACW) as simulated by the SINTEX coupled model. We found evidence that sea‐ice treatment plays a crucial role on simulating the ACW. In particular, SST anomalies at interannual time scales describe a propagating ACW‐like pattern when a dynamic thermodynamic sea‐ice model is coupled with the ocean, but when sea‐ice is relaxed to climatology, anomalies occur as zonally symmetric patterns that do not propagate in longitude. Moreover, from the experiment with an active sea‐ice component we saw that ACW‐like oscillations are strongly modulated by low frequency variability. Our result adds some extra confidence to previous studies based on relatively short series of observed data.
Tidally induced turbulent mixing at Irving Seamount—Modeling and measurements
Authors: Lavelle J. W. , Lozovatsky I. D. , Smith D. C.
Published: May 2004

The relationship of tidal currents and turbulence over Irving Seamount is examined by model and measurement. Surface tides are partially scattered into internal tides and, particularly over the seamount summit, current strength and shear greatly increase. Current shear causes the model's turbulent mixing. At Irving, modeled turbulent mixing, as represented by vertical diffusivity, is largest O(10−3 m2 s−1) in the bottom boundary layer and in a turbulent column rising to the sea surface directly above the seamount. Pockets of less intense mixing occur within the turbulent column, but their locations are highly variable. Field measurements confirm a turbulent mixing column atop Irving of comparable intensity. Increased model diffusivity (average of 7 × 10−5 m2 s−1) also occurs to a distance of several hundred kilometers from the seamount flanks in a band vertically centered at ∼800 m depth.
Evolution into the stagnant lid convection regime with a non‐Newtonian water ice rheology
Authors: Freeman J. , Moresi L. , May D. A.
Published: June 2004

We study and compare the evolution into the stagnant lid regime with a non‐Newtonian water ice and a silicate rheology by solving the equations of thermal convection. Dislocation creep of water ice is characterized by a larger stress dependence (n = 4) than silicates (n = 3) and with this water ice rheology, the stagnant lid regime is attained at a temperature determined viscosity contrast greater than 1010 and at an effective viscosity contrast of ∼105. We also determine a Nusselt‐Rayleigh number scaling law for the n = 4 rheology.
Electrical structure across a major ice‐covered fault belt in Northern Victoria Land (East Antarctica)
Authors: Armadillo E. , Ferraccioli F. , Tabellario G. , Bozzo E.
Published: May 2004

A Geomagnetic Depth Sounding profile was performed across the glaciated Rennick Graben and the adjacent fault‐bounded terranes of northern Victoria Land in East Antarctica. Induction arrows analysis and a 2D inversion model provide a unique deep electrical resistivity window beneath these fault zones. The electrical resistivity break across the Lanterman Fault is apparently restricted to the upper crust, suggesting that this strike‐slip fault may not represent a deep lithospheric suture. Further east, a westward‐dipping conductor is traced to a depth of 40 km beneath the Robertson Bay Terrane. It may image a remnant of the paleo‐Pacific oceanic plate, which subducted beneath the Bowers Terrane. Within the Wilson Terrane, the Rennick Graben is an upper‐crust resistive block. The Rennick Graben lacks a deep crustal or upper mantle conductor, in contrast to several continental rifts. However, similar resistive lower crust underlies some other major strike‐slip fault belts.
The low‐level circulation of the North American Monsoon as revealed by QuikSCAT
Authors: Bordoni Simona , Ciesielski Paul E. , Johnson Richard H. , McNoldy Brian D. , Stevens Bjorn
Published: May 2004

Five years (1999–2003) of near‐surface QuikSCAT ocean winds over the Gulf of California and northeast Pacific Ocean are used to characterize the changes in the low‐level circulation associated with the North American Monsoon. Our analysis shows that the onset of the summer season is accompanied by a seasonal reversal of the flow along the Gulf of California, with the establishment of a time‐mean southerly wind throughout the gulf. This reversal, not evident in the global reanalysis products, occurs in late spring and precedes the onset of the monsoonal rains. In the core of the monsoon, the time‐mean flow is found to be modulated by transient events, namely gulf surges, detected in the near‐surface wind field as periods of enhanced southerly flow which typically originate at the southern end of the gulf and propagate northward. The histogram of the summertime along‐shore winds identifies these surges as a distinct population of events, readily distinguishable from the background flow.
A genomic screen identifies Dsk2p and Rad23p as essential components of ER‐associated degradation
Authors: Medicherla Balasubrahmanyam , Kostova Zlatka , Schaefer Antje , Wolf Dieter H
Published: May 2004

We developed a growth test to screen for yeast mutants defective in endoplasmic reticulum (ER) quality control and associated protein degradation (ERAD) using the membrane protein CTL*, a chimeric derivative of the classical ER degradation substrate CPY*. In a genomic screen of ∼5,000 viable yeast deletion mutants, we identified genes necessary for ER quality control and degradation. Among the new gene products, we identified Dsk2p and Rad23p. We show that these two proteins are probably delivery factors for ubiquitinated ER substrates to the proteasome, following their removal from the membrane via the Cdc48–Ufd1–Npl4p complex. In contrast to the ERAD substrate CTG*, proteasomal degradation of a cytosolic CPY*–GFP fusion is not dependent on Dsk2p and Rad23p, indicating pathway specificity for both proteins. We propose that, in certain degradation pathways, Dsk2p, Rad23p and the trimeric Cdc48 complex function together in the delivery of ubiquitinated proteins to the proteasome, avoiding malfolded protein aggregates in the cytoplasm.
Molecular Analysis of GAA Repeats and Four Linked Bi‐allelic Markers in and Around the Frataxin Gene in Patients and Normal Populations from India
Authors: Chattopadhyay B. , Gupta S. , Gangopadhyay P. K. , Das S. K. , Roy T. , Mukherjee S. C. , Sinha K. K. , Singhal B. S. , Bhattacharyya N. P.
Published: June 2004

Friedreich ataxia (FRDA), the most common type of ataxia worldwide, is an autosomal recessive disease. Homozygous expansion of GAA repeats in the first intron of the frataxin gene constitute the major type of mutation that causes the disease. The prevalence of FRDA in diverse ethnic populations of India has not been widely studied. We have studied the distribution of polymorphic GAA repeats in the frataxin gene among 6 clinically diagnosed patients and 160 ethnically matched normal individuals, to gather information on the prevalence of FRDA in the eastern part of India. Homozygous expansion in the range of 250–730 GAA repeats was detected among the patients. Among normal individuals, we observed a unimodal distribution of GAA repeats, consisting of 10 different alleles ranging from 7 to 16 GAA repeats, where the 9 repeat allele had maximal frequency. Only 5.9% of all chromosomes were found to harbour >12 GAA repeats. Haplotype analysis using closely linked four bi‐allelic markers in and around the frataxin gene indicated that 66.7% of the expanded alleles harbour the ATCC haplotype that has been reported worldwide. This haplotype was present in 53.3% of the chromosomes with >12 GAA repeats, and accounted for only 3.8% of chromosomes with 7 to 12 GAA repeats. We found one novel haplotype, ACCT, among the expanded alleles as well as among normal individuals, though at low frequency; this haplotype may be characteristic of Indian populations.
Notes on the Maximum Likelihood Estimation of Haplotype Frequencies
Authors: Mano S. , Yasuda N. , Katoh T. , Tounai K. , Inoko H. , Imanishi T. , Tamiya G. , Gojobori T.
Published: June 2004

The maximum likelihood estimation (MLE) is one of the most popular ways to estimate haplotype frequencies of a population with genotype data whose linkage phases are unknown. The MLE is commonly implemented in the use of the Expectation‐Maximization (EM) algorithm. It is known that the EM algorithm carries the risk that an estimator may converge erroneously to one of the local maxima or saddle points of the likelihood surface, resulting in serious errors in the MLE of haplotype frequencies. In this note, by theoretical treatments we present the necessary and sufficient conditions that the local maxima or saddle points on the likelihood surface appear. As a rule of thumb, that the difference between the coupling and repulsive haplotype frequencies in phase known individuals is 3/2 times larger than the frequency of phase ambiguous individuals is the sufficient condition that the likelihood surface is unimodal. Moreover, we present the analytic solution to the biallelic two‐locus problem, and construct a general algorithm to obtain the global maximum.
Standardizing a Composite Measure of Linkage Disequilibrium
Authors: Hamilton D. C. , Cole D. E. C.
Published: June 2004

The maximum and minimum are obtained for a composite measure of linkage disequilibrium used with genotypic data when the phase of double heterozygotes cannot be determined. These bounds are used to standardize the composite measure in the same way used for D′, the standardized gametic measure of linkage disequilibrium. Standardization produces a measure which lies between −1 and 1, and allows comparison of linkage disequilibrium between populations. The method is illustrated using two loci in the CASR gene.
Heritability of C‐Reactive Protein and Association with Apolipoprotein E Genotypes in Japanese Americans
Authors: Austin M. A. , Zhang C. , Humphries S. E. , Chandler W. L. , Talmud P. J. , Edwards K. L. , Leonetti D. L. , Mcneely M. J. , Fujimoto W. Y.
Published: June 2004

Numerous studies have demonstrated that increased C‐reactive protein (CRP) levels predict coronary heart disease, stroke, peripheral vascular disease, and diabetes, and are associated with features of the metabolic syndrome. Only three previous studies have investigated the heritability of CRP levels, primarily in samples of Caucasian families.The purpose of the present study was to estimate the magnitude of genetic influences on CRP levels, and to examine potential associations between variation in the APOE gene and CRP levels, using a sample of 562 individual Japanese Americans from 68 extended kindreds. In general, correlation coefficients between first‐degree relatives for CRP were approximately 0.2, and spouse correlations did not differ from zero, consistent with genetic influences. Heritability estimates were approximately 0.3 (p < 0.01), even with adjustment for factors known to influence CRP levels. A significant relationship was seen between unadjusted CRP levels and APOE genotypes (p = 0.02), with the highest mean CRP level among ɛ2 carriers (1.20 mg/L), and nearly the same mean levels among ɛ3/ɛ3 subjects and ɛ4 carriers (0.72 and 0.74 mg/L, respectively). However, this relationship was diminished with adjustment for covariates (p = 0.07). These results demonstrate the presence of both genetic and environmental effects on CRP levels among Asian Americans, and additional studies are needed to determine if the APOE gene contributes to these genetic influences.