bluuebunny/crossref_metadata_2025 huggingface dataset:
The evolution of round zero-net-mass-flux jets
Authors: CATER JOHN E. , SORIA JULIO
Published: December 2002

This paper reports on an experimental investigation to determine the structure and
mean flow quantities of round zero-net-mass-flux (ZNMF) jets. These jets are generated
by a piston oscillating in a cavity behind a circular orifice. Several different
flow patterns were observed with dye flow visualization and a parameter map of
these was generated. Cross-correlation digital particle image velocimetry was used to
measure instantaneous two-dimensional in-plane velocity fields in a plane containing
the orifice axis. These velocity fields are used to investigate the existence of a self-preserving
velocity profile in the far field of the ZNMF jet. The mean flow quantities
and turbulent statistics of the ZNMF jets were compared with measurements for
‘equivalent’ continuous jets in the same apparatus. Phase-averaged velocity measurements
were obtained in the near field of the ZNMF jets and were used to determine
the radial entrainment. The out-of-plane vorticity fields were also investigated to gain
an understanding of the mechanisms responsible for the difference in spreading rate
of ZNMF jets compared to conventional continuous jets. A conceptual model of the
ZNMF jet structure in the near field for Strouhal numbers much less than one is
proposed that explains the observed behaviour of these ZNMF jets.
Hydromagnetic Taylor–Couette flow:
wavy modes
Authors: WILLIS A. P. , BARENGHI C. F.
Published: December 2002

We investigate magnetic Taylor–Couette flow in the presence of an imposed axial
magnetic field. First we calculate nonlinear steady axisymmetric solutions and determine
how their strength depends on the applied magnetic field. Then we perturb
these solutions to find the critical Reynolds numbers for the appearance of wavy
modes, and the related wave speeds, at increasing magnetic field strength. We find
that values of imposed magnetic field which alter only slightly the transition from
circular-Couette flow to Taylor-vortex flow, can shift the transition from Taylor-vortex
flow to wavy modes by a substantial amount. The results are compared to those for
onset in the absence of a magnetic field.
Impact of a drop onto a wetted wall: description
of crown formation and propagation
Authors: ROISMAN I. V. , TROPEA C.
Published: December 2002

The impact of a drop onto a liquid film with a relatively high impact velocity, leading
to the formation of a crown-like ejection, is studied theoretically. The motion of a
kinematic discontinuity in the liquid film on the wall due to the drop impact, the
formation of the upward jet at this kinematic discontinuity and its elevation are
analysed. Four main regions of the drop and film are considered: the perturbed liquid
film on the wall inside the crown, the unperturbed liquid film on the wall outside
the crown, the upward jet forming a crown, and the free rim bounding this jet. The
theory of Yarin & Weiss (1995) for the propagation of the kinematic discontinuity is
generalized here for the case of arbitrary velocity vectors in the inner and outer liquid
films on the wall. Next, the mass, momentum balance and Bernoulli equations at the
base of the crown are considered in order to obtain the velocity and the thickness
of the jet on the wall. Furthermore, the dynamic equations of motion of the crown
are developed in the Lagrangian form. An analytical solution for the crown shape is
obtained in the asymptotic case of such high impact velocities that the surface tension
and the viscosity effects can be neglected in comparison to inertial effects. The edge
of the crown is described by the motion of a rim, formed due to the surface tension.

Three different cases of impact are considered: normal axisymmetric impact of a
single drop, oblique impact of a single drop, and impact and interaction of two drops.
The theoretical predictions of the height of the crown in the axisymmetric case are
compared with experiments. The agreement is quite good in spite of the fact that no
adjustable parameters are used.
No shortcuts to power: constraints on women's political effectiveness in Uganda
Authors: Goetz Anne Marie
Published: December 2002

Numbers of women in public representative office have increased dramatically in Uganda since the introduction of the National Resistance Movement's ‘no party’ system, because affirmative action measures have been taken to reserve seats for them in Parliament and local government. This article offers an assessment of the impact of these measures on women's political effectiveness, examining how far women in Parliament have been able to advance gender equity concerns in key new legislation. The article suggests that the political value of specially created new seats has been eroded by their exploitation as currency for the NRM's patronage system, undermining women's effectiveness as representatives of women's interests once in office. This is because the gate-keepers of access to reserved political space are not the women's movement, or even women voters, but Movement elites. The women's movement in Uganda, though a beneficiary of the NRM's patronage, has become increasingly critical of the deepening authoritarianism of the NRM, pointing out that the lack of internal democracy in the Movement accounts for its failure to follow constitutional commitments to gender equity through to changes in key new pieces of legislation affecting women's rights.
Routine administration of Health Related Quality of Life (HRQoL) and needs assessment instruments to improve psychological outcome – a systematic review
Authors: GILBODY S. M. , HOUSE A. O. , SHELDON T.
Published: December 2002

Background. Routine administration of Health Related Quality of Life (HRQoL) and needs assessment instruments has been advocated as part of clinical care to aid the recognition of psychosocial problems, to inform clinical decision making, to monitor therapeutic response and to facilitate patient–doctor communication. However, their adoption is not without cost and the benefit of their use is unclear.

Method. A systematic review was conducted. We sought experimental studies that examined the addition of routinely administered measures of HRQoL to care in both psychiatric and non-psychiatric settings. We searched the following databases: MEDLINE, EMBASE, CINAHL, PsycLIT and Cochrane Controlled Trials Register (to 2000). Data were extracted independently and a narrative synthesis of results was presented.

Results. Nine randomized and quasi-randomized studies conducted in non-psychiatric settings were found. All the instruments used included an assessment of mental well-being, with specific questions relating to depression and anxiety. The routine feedback of these instruments had little impact on the recognition of mental disorders or on longer term psychosocial functioning. While clinicians welcomed the information these instruments imparted, their results were rarely incorporated into routine clinical decision making. No studies were found that examined the value of routine assessment and feedback of HRQoL or patient needs in specialist psychiatric care settings.

Conclusions. Routine HRQoL measurement is a costly exercise and there is no robust evidence to suggest that it is of benefit in improving psychosocial outcomes of patients managed in non-psychiatric settings. Major policy initiatives to increase the routine collection and use of outcome measures in psychiatric settings are unevaluated.
Bipolar depression: relationship between episode length and antidepressant treatment
Authors: FRANKLE W. G. , PERLIS R. H. , DECKERSBACH T. , GRANDIN L. D. , GRAY S. M. , SACHS G. S. , NIERENBERG A. A.
Published: December 2002

Background. The role of antidepressant medications in bipolar depression remains controversial, mainly due to a lack of research in this area. In this study the authors examined the episode length in bipolar depression and the relationship between antidepressant therapy and episode length.

Method. A retrospective chart review of 165 subjects identified 50 (30%) with bipolar illness who experienced a major depressive episode between 1 January 1998 and 15 December 2000. Data gathered utilized a structured instrument completed by the clinician at each visit. This instrument includes modified SCID mood modules as well as continuous ratings for each associated symptom of depression and mood elevation. Survival analysis was employed to calculate the median length of the depressive episodes for the entire group. Further survival analysis compared the episode length for subjects treated with antidepressants during the depression (N = 33) with those who did not receive antidepressants (N = 17). The rate of switch into elevated mood states was compared for the two groups.

Results. The survival analysis for the entire sample demonstrated 25%, 50% and 75% probability of recovery at 33 (S.E. 8.7), 66 (S.E. 17.9) and 215 (S.E. 109.9) days, respectively. Comparing those who received (N = 33) and those who did not receive (N = 17) antidepressants during the episode did not reveal any difference in the length of the depressive episode. Switch rates were not significantly different between those receiving antidepressants and those not taking these medications (15.2% v. 17.6%, respectively).

Conclusions. Over the past 20 years little progress has been made in reducing the length of depressive episodes in those with bipolar illness. This is despite increasing pharmacological options available for treating depression. Clinicians treating bipolar depression should discuss with their patients the likelihood that the episode will last between 2–3 months. Our results also suggest that antidepressant treatment may not reduce the length of depressive episodes, neither did it appear to contribute to affective switch in our sample.
Psychiatric and somatic disorders and multiple chemical sensitivity (MCS) in 264 ‘environmental patients’
Authors: BORNSCHEIN S. , HAUSTEINER C. , ZILKER T. , FÖRSTL H.
Published: December 2002

Background. An increasing number of individuals with diverse health complaints are currently seeking help in the field of environmental medicine. Multiple chemical sensitivity (MCS) or idiopathic environmental intolerances (IEI) is defined as an acquired disorder with multiple recurrent symptoms associated with environmental chemicals in low concentrations that are well tolerated by the majority of people. Their symptoms are not explained by any known psychiatric or somatic disorder.

Method. Within a 2-year period we examined 264 of 267 consecutive patients prospectively presenting to a university based out-patient department for environmental medicine. Patients underwent routine medical examination, toxicological analysis and the structured clinical interview for DSM-IV psychiatric disorders (SCID).

Results. Seventy-five per cent of the patients met DSM-IV criteria for at least one psychiatric disorder and 35% of all patients suffered from somatoform disorders. Other frequent diagnoses were affective and anxiety disorders, and dependence or substance abuse. In 39% a psychiatric disorder, in 23% a somatic condition and in 19% a combination of the two were considered to provide sufficient explanation of the symptoms. Toxic chemicals were regarded as the most probable cause in only five cases. The suspected diagnosis of MCS/IEI could not be sustained in the vast majority of cases.

Conclusion. This investigation confirms previous findings that psychiatric morbidity is high in patients presenting to specialized centres for environmental medicine. Somatoform disorders are the leading diagnostic category, and there is reason to believe that certain ‘environmental’ or MCS patients form a special subgroup of somatoform disorders. In most cases, symptoms can be explained by well-defined psychiatric and medical conditions other than MCS, which need specific treatment. Further studies should focus on provocation testing in order to find positive criteria for MCS and on therapeutic approaches that consider psychiatric aspects.
General practitioners' attitudes to patients who have learning disabilities
Authors: GILL F. , KROESE B. STENFERT , ROSE J.
Published: December 2002

Background. Previous research suggests that the inadequate primary health care received by people with learning disabilities may be the result of general practitioners' (GPs) negative attitudes. Few studies have investigated the evidence for this assumption. This study uses psychological theory to inform an investigation of the attitudes and emotions experienced by GPs when working with learning disabled patients, as assessed by reliable and valid measures.

Method. A questionnaire comprising an attitude measure and emotion measure was developed and tested for reliability and validity. This was mailed out to a total of 613 GPs registered with three Health Authorities, 310 questionnaires (51%) were returned.

Results. GP respondents held positive attitudes to working with patients who have learning disabilities. However, they were less positive about adapting their behaviour. Attitudes varied according to respondents' age and frequency of professional contact with this patient group. There was a strong association between attitudes and emotional experience. Attitudes were unaffected by learning disability training and non-professional contact.

Conclusions. Negative perceptions about working with patients with learning disabilities do not fully explain the inadequate healthcare provided to this group. Other factors may include insufficient awareness of the benefits of adapting the format of a consultation, and the quality of the interface between the GP and the carer accompanying the patient.
The nature and timing of seasonal affective symptoms and the influence of self-esteem and social support: a longitudinal prospective study
Authors: McCARTHY E. , TARRIER N. , GREGG L.
Published: December 2002

Background. Seasonal affective disorder (SAD) is characterized by recurrent episodes of depression occurring regularly with the onset of winter.

Method. The study was a prospective naturalistic follow-up of the emergence of symptoms of seasonal depression with the passage of time and change in seasons. Participants were screened during summer for SAD. Participants were excluded if they were depressed (BDI >14) during the summer recruitment. Eligible participants prospectively monitored their mood and anxiety by completing the BDI and BAI every 2 weeks from 1 September through to the 31 March.

Results. Forty-five participants met criterion for SAD were included in the final data analyses. Depression scores rose gradually over the 30 week period reaching a peak median score around weeks 22 to 24 (January–February). The ‘hallmark’ physiological symptoms (changes in sleep, appetite and fatigue) emerged earlier in the winter period than cognitive symptoms. The emergence of anxiety symptoms was highly correlated with depressive symptoms, although the median anxiety scores did not reach a clinically significant level. Low self-esteem and poor perceived social support were significantly related to an earlier onset in the emergence of depressive symptoms. Both these factors together resulted in the speediest onset of depression. Poor perceived social support, but not low self-esteem, was associated with earlier emergence of anxiety symptoms.

Conclusions. Physiological symptoms may activate negative cognitions in individuals with risk factors of low self-esteem and poor social support so that the disorder is precipitated earlier and is of longer duration.
Dynamics of the interface between two immiscible
liquids with nearly equal densities under gravity
Authors: DANILOV V. G. , OMEL'YANOV G. A.
Published: December 2002

We consider the two-dimensional Rayleigh–Taylor problem for the dynamics of the free
interface Γ
between two layers of immiscible viscous liquids. For a slow flow model (which
corresponds to the case of a small relative jump of density) and under sufficiently wide
assumptions on the geometry of Γ,
we analyze the time dynamics of Γ.
In particular,
we prove that its increase in time t is bounded by an exponential function with exponent
independent of Γ.
Prenatal diagnosis of fetal abnormality: the decision to terminate the pregnancy and the psychological consequences
Authors: Statham Helen
Published: December 2002

In the absence of any prenatal screening, some two percent of babies will be born with a structural anomaly; a further 1 in 700–800 will be born with Down's syndrome, with similar numbers having other chromosomal and serious genetic disorders. The prevalence of abnormalities in early pregnancy is higher because abnormal fetuses are more likely to miscarry than normal ones. A small number of women enter pregnancy at increased risk of conceiving a baby with an abnormality. They may have a maternal condition such as diabetes, need medication for conditions such as epilepsy, or have a family history of a genetic disorder (www3.ncbi.nlm.nih.gov/Omim/searchomim.html). Most abnormalities, however, occur in healthy, low-risk women.
The role of transvaginal ultrasound in the management of a low-lying placenta
Authors: Sallout Bahauddin , Oppenheimer Lawrence
Published: December 2002

Placenta praevia is an uncommon but dangerous and occasionally fatal condition. It increases maternal, fetal and neonatal morbidity and mortality. Placenta praevia is one of the leading causes of third-trimester bleeding and the incidence of both placenta praevia and placenta accreta is steadily increasing due to the rising caesarean section rate. At delivery, women with placenta praevia have an increased risk of abruptio placenta, caesarean delivery, fetal malpresentation, postpartum haemorrhage and disseminated intravascular coagulation. Massive obstetric haemorrhage is still a leading cause of pregnancy-related deaths, and placenta praevia/accreta remains one of the major predisposing factors.
Dynamics and mechanism for sea surface cooling near the Indian tip during winter monsoon
Authors: Luis Alvarinho J. , Kawamura Hiroshi
Published: December 2002

Wintertime sea surface temperature (SST) cooling south of the Indian tip (hereafter tip) is investigated during a 14 day gap wind event (21 January to 3 February 1997) using satellite data and the three‐dimensional, primitive equation, sigma coordinate Princeton Ocean Model (POM). The advanced very high resolution radiometer SST reveals surface cooling of 1.5°C over the 14 day period near west of Sri Lanka. A spatial‐mean time series of surface forcing west of Sri Lanka indicate a bell‐shaped pattern, which is characterized by maximum wind stress and outgoing heat flux (sum of turbulent heat flux and net surface long‐wave radiation) of 0.12 N/m2 and 450 W/m2, respectively, on 27 January. POM simulation is performed with realistic bottom topography, with seasonal stratification, and with daily mean surface forcing derived from NASA scatterometer (NSCAT) winds and National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) meteorological variables. During 21–28 January, Ekman dynamics together with positive wind stress curl promote SST cooling along the west coast of Sri Lanka. Thereafter irregular and shallow topography near the tip promotes diapycnal mixing, and the characteristic surface circulation significantly influences the evolution of the SST pattern along the periphery of the tip. An anticyclonic circulation evolves in the Gulf of Mannar under the influence of local negative wind stress curl after 27 January. Examination of a zonal section of density and vertical heat diffusion reveals that the initial stratification in the vicinity of the tip weakens because of diapycnal mixing and vertical diffusion of the surface heat. The mixed layer heat budget near the west of Sri Lanka and south of the tip reveals that the surface heat depletion dictates SST changes throughout the event. From our earlier works [Luis and Kawamura, 2000, 2001] and from the results of the present investigation it is inferred that the wintertime SST cooling in the vicinity of the tip is a case of topography‐monsoon‐ocean interaction.
Estimating the mean ocean‐bay exchange rate of the Chesapeake Bay
Authors: Austin Jay A.
Published: December 2002

A model of the salt balance in the Chesapeake Bay is discussed, which takes into account only time‐dependent riverine input and mean ocean‐bay exchange. Estimates of (spatial) mean bay salinity are made using two different data sources: a 16 year record of surveys taken by the Environmental Protection Agency's Chesapeake Bay Program, and a 10 year record of hydrographic sections taken in the lower bay by the Center for Coastal Physical Oceanography at Old Dominion University. Using United States Geological Survey river flow data to force the model, both data sets are consistent with this simple model and both imply a mean oceanic exchange (e‐folding) timescale of 90 days, which is equivalent to an effective exchange rate of roughly 8 × 103 m3 s−1.
In situ measurements of hydrogen cyanide in the upper troposphere/lower stratosphere during Arctic spring 2000
Authors: Viggiano A. A. , Hunton D. E. , Miller Thomas M. , Ballenthin John O.
Published: December 2002

The first calibrated in situ measurements of hydrogen cyanide (HCN) concentrations in the upper troposphere/lower stratosphere were made during the March 2000 deployment of the SAGE III—Ozone Loss and Validation Experiment (SOLVE) campaign. The measurements were made from the NASA DC‐8 aircraft flying at cruise altitudes between 10 and 12.5 km in the northern polar region. The average HCN volume mixing ratio was found to be 280 ± 48 (1σ) pptv. No concentration gradient was observed between tropospheric and stratospheric air, and no HCN emissions from the Mount Hekla volcano were found. A very slight increase in mixing ratio with altitude was detected, although it is within the uncertainty in the data. The altitude dependence agrees with recent model calculations. The measurements agree with the most recent concentrations derived from total column densities but are higher than earlier measurements.
Synthesis of overhead and ground‐based infrared spectroscopy at the 2000 FIDO Mars rover field test
Authors: Moersch J. E. , Jolliff B. , McSween H. Y. , Morris R. V. , Gilmore M. S. , Arvidson R. E. , Squyres S. W.
Published: December 2002

In the May 2000 Field Integrated Design and Operations (FIDO) Mars Rover Field Test, an off‐site science team was charged with the goal of characterizing the geology of a previously unknown field location by commanding and collecting observations from a robotic rover, similar to those planned for future Mars missions. One unique feature of this test was the degree to which the science team was able to make use of previously acquired overhead remote‐sensing data together with ground‐based observations by the rover. In particular, an Airborne Visible/Infrared Imaging Spectrometer scene covering the region of the field test was used in concert with observations from the rover's near‐infrared point spectrometer to develop a coherent and essentially correct geologic story for the test site. Using the overhead data, the science team was able to form hypotheses that were testable using rover observations on the ground. The team was able to establish the provenance of exotic samples within reach of the rover by making a spectroscopic link to units observed from above. The science team was also able to “extend” the spectral range of the rover's onboard spectrometer via inferred connections to units mapped from above with greater spectral range. The net result of the success of this rover trial is an increase in experience and confidence for NASA's Mars mission strategy, which features strong ties between early orbital reconnaissance missions for geologic mapping and subsequent rover missions to the surface.
Effects of topography on thermal infrared spectra of planetary surfaces
Authors: Colwell Joshua E. , Jakosky Bruce M.
Published: December 2002

We use a thermal model with large‐scale surface roughness to study the effects of topography and roughness on thermal infrared spectra of planetary surfaces. We study a range of roughness values, illumination geometries, and viewing geometries and find that surface roughness can strongly alter the slope of a thermal infrared spectrum, especially for large solar incidence angles. This roughness‐induced slope in the spectrum can shift the location of the Christiansen frequency and should be removed in order to study the mineralogy and other surface properties. The effect is minimized for viewing near zero phase angle. This makes it possible to measure large‐scale roughness by comparing thermal infrared spectra taken near zero phase angle with those taken at a large solar incidence angle and nonzero phase angle. Changes in apparent emissivity with wavelength in the thermal infrared due to roughness are calculated for Clementine longwave‐infrared images of the Moon. These roughness‐induced spectral slopes observed for the Moon are 5% between 5 and 8 microns for regions of moderate topography.
Fast converging formulation of differential theory for nonsmooth gratings made of anisotropic materials
Authors: Watanabe Koki
Published: December 2002

Li's Fourier factorization rules have contributed greatly to the differential theory that is one of the most commonly used approaches in the analysis of diffraction gratings. This paper gives a differential formulation for nonsmooth profiled anisotropic gratings by taking into account Li's remark, but a coupled first‐order differential‐equation set is derived using only the Laurent rule. The present formulation is applied to sinusoidal and echelette gratings, and numerical results show that the present formulation provides significant improvement of convergence.
Modeling the response of the oceanic Si inventory to perturbation, and consequences for atmospheric CO2
Authors: Ridgwell Andy J. , Watson Andrew J. , Archer David E.
Published: December 2002

It has been suggested that much of the observed glacial‐interglacial variability in the atmospheric mixing ratio of CO2 (xCO2) could potentially be driven by a perturbation of the marine Si cycle. To date, only relatively simple steady‐state analysis has been made of this hypothesis. In this study, we develop a description of the ocean carbon cycle, incorporating novel descriptions for the recycling of Si, both within the water column and in deep‐sea sediments. A high degree of computational efficiency enables model integrations over multiple glacial‐interglacial cycles, driven by a time‐varying input of dissolved Si to the ocean. Due to the long time constant (∼23 ka) of atmospheric xCO2 response to perturbation in Si supply and the highly nonlinear nature of opal preservation in deep‐sea sediments, we find that reduction in the deposition rate of aeolian silicates at the surface ocean can explain little (<3 ppm) of the rapid ∼90 ppm rise in atmospheric xCO2 observed at glacial termination. However, increased Si supply has the potential to make an important contribution to the decline in atmospheric xCO2 associated with the much slower transition from interglacial to full glacial conditions.
An improved parameterization for sulfuric acid–water nucleation rates for tropospheric and stratospheric conditions
Authors: Vehkamäki H. , Kulmala M. , Napari I. , Lehtinen K. E. J. , Timmreck C. , Noppel M. , Laaksonen A.
Published: December 2002

In this paper we present parameterized equations for calculation of sulfuric acid–water critical nucleus compositions, critical cluster radii and homogeneous nucleation rates for tropospheric and stratospheric conditions. The parameterizations are based on a classical nucleation model. We used an improved model for the hydrate formation relying on ab initio calculations of small sulfuric acid clusters and on experimental data for vapor pressures and equilibrium constants for hydrate formation. The most rigorous nucleation kinetics and the thermodynamically consistent version of the classical binary homogeneous nucleation theory were used. The parameterized nucleation rates are compared with experimental ones, and at room temperature and relative humidities above 30% they are within experimental error. At lower temperatures and lower humidities the agreement is somewhat poorer. Overall, the values of nucleation rates are increased compared to a previous parameterization and are within an order of magnitude compared with theoretical values for all conditions studied. The parameterized equations will reduce the computing time by a factor 1/500 compared to nonparameterized nucleation rate calculations and therefore are in particular useful for large‐scale models. The parameterized formulas are valid at temperatures between 230.15 K and 305.15 K, relative humidities between 0.01% and 100%, and sulfuric acid concentrations from 104 to 1011 cm−3. They can be used to extrapolate the classical results down to 190 K. The parametrization is limited to cases where nucleation rates are between 10−7 and 1010 cm−3s−1, and the critical cluster contains at least four molecules.
Identification, regulation and role of tissue inhibitor of metalloproteinases‐4 (TIMP‐4) in human platelets
Authors: Radomski Anna , Jurasz Paul , Sanders Esmond J , Overall Christopher M , Bigg Heather F , Edwards Dylan R , Radomski Marek W
Published: December 2002

Matrix metalloproteinase‐2 (MMP‐2) released during activation of human platelets by aggregating agents and cancer cells is known to stimulate platelet aggregation.

The expression, activity and role of tissue inhibitors of metalloproteinases (TIMPs), natural inhibitors of MMPs, in isolated human platelets were investigated.

Western blot, reverse zymography, immunogold electron microscopy, aggregometry (collagen‐, thrombin and HT‐1080 human fibrosarcoma cells‐induced aggregation), flow cytometry and the release of 14C‐serotonin from labelled platelets recruited to the aggregate were used to characterize the presence and function of platelet TIMPs.

TIMP‐4 (23 kDa) has been identified as the major MMP inhibitor (12–16 ng per 108 platelets) in human platelets. Platelets expressed lower (<1 ng per 108 platelets) amounts of TIMP‐1. No other TIMPs were detected using Western blot analysis.

TIMP‐4 co‐localized with MMP‐2 in resting platelets and was released upon platelet aggregation induced by collagen and thrombin.

Collagen resulted also in the release of higher molecular weight (60 kDa) complexes of TIMP‐4.

The release of TIMP‐4 was reduced by prostacyclin and S‐nitroso‐glutathione (GSNO), an NO donor.

Human recombinant TIMP‐4 (rTIMP‐4), but not human rTIMP‐1, inhibited partially both platelet aggregation and recruitment.

The recombinant TIMP‐4 potentiated the recruitment inhibitor effects of GSNO.

TIMP‐4 was not released during platelet aggregation induced by HT‐1080 cells.

Human rTIMP‐4 exerted a biphasic effect on HT‐1080 cells‐induced aggregation.

Thus, TIMP‐4 is the major intraplatelet MMP inhibitor and it is involved in regulation of platelet aggregation and recruitment.

British Journal of Pharmacology (2002) 137, 1330–1338. doi:10.1038/sj.bjp.0704936
20‐Hydroxyeicosatetraenoic acid potentiates stretch‐induced contraction of canine basilar artery via PKCα‐mediated inhibition of KCa channel
Authors: Obara Kazuo , Koide Masayo , Nakayama Koichi
Published: December 2002

The present study was undertaken to elucidate whether PKCα plays a role in the mechanism of the stretch‐induced contraction potentiated by 20‐hydroxyeicosatetraenoic acid (20‐HETE). The effects of 20‐HETE on the canine basilar artery were compared with those of iberiotoxin, a blocker of large conductance Ca2+‐activated K+ channels (KCa channels), as this blocker was shown earlier to sensitize these arteries to mechanical stretch.

Slow stretch at rates of 0.1 to 3 mm s−1 did not produce any contraction in normal physiological solution.

In the presence of 20‐HETE, the slow stretch could produce contraction, which was inhibited by nicardipine, a 1,4‐dihydropyridine Ca2+ channel blocker, and gadolinium, a blocker of stretch‐activated cation channels.

20‐HETE inhibited whole‐cell K+ current and depolarized the membrane by approximately 10 mV. These effects of 20‐HETE were similar to those of iberiotoxin.

Calphostin C, an inhibitor of protein kinase C (PKC), inhibited the action of 20‐HETE, but not that of iberiotoxin.

In response to 20‐HETE PKCα isoform was translocated from the cytosol to the membrane fraction, which translocation was inhibited by calphostin C.

These results suggest that 20‐HETE induced sensitization of the canine basilar artery to stretch was caused by PKCα‐mediated inhibition of KCa channel activity.

British Journal of Pharmacology (2002) 137, 1362–1370. doi:10.1038/sj.bjp.0704960
4‐aminopyridine‐ and dendrotoxin‐sensitive potassium channels influence excitability of vagal mechano‐sensitive endings in guinea‐pig oesophagus
Authors: Zagorodnyuk Vladimir P , Chen Bao Nan , Costa Marcello , Brookes Simon J H
Published: December 2002

Distension‐sensitive vagal afferent fibres from the guinea‐pig oesophagus were recorded extracellularly in vitro. Most recorded units were spontaneously active firing at 3.2±0.3 Hz (n=41, N=41) and had low thresholds (less than 1 mm) to circumferential stretch. Dynamic and adapted phases of stretch‐evoked firing, as well as a silent period were linearly dependent on the amplitude of stretch.

High K+ (7–12 mM) Krebs solution dose‐dependently increased both spontaneous and stretch‐evoked firing and reduced the duration of the silent period.

Charybdotoxin (ChTX, 100 nM) slightly increased spontaneous and stretch‐evoked firing and decreased the silent period, while neither iberiotoxin (100 nM) nor apamin (0.5 μM) had significant effects. ω‐Conotoxin GVIA (0.5 μM) did not significantly affect firing of vagal mechanoreceptors.

In the majority of single units, 4‐aminopyridine (4‐AP) concentration‐dependently (EC50∼28 μM) increased spontaneous firing, strongly reduced the silent period but did not affect stretch (3 mm)‐induced firing. Firing evoked by 1–2 mm was increased by 4‐AP.

α‐Dendrotoxin (DnTX, 300 nM) and DnTX K (30 nM) slightly increased spontaneous and stretch‐evoked firing. There was no additive effect on spontaneous firing when ChTX and DnTX K were applied simultaneously.

Barium (100 μM) increased stretch‐induced firing, probably due to an increase in intramural tension. Glibenclamide (10 μM) had no effect on spontaneous or stretch‐induced firing.

The results indicate that voltage‐gated 4‐AP‐ and dendrotoxin‐sensitive K+ channels are the main type of K+ channels that influence excitability of vagal mechano‐sensitive endings of the guinea‐pig oesophagus. They were involved in control of spontaneous firing and in stretch‐induced firing evoked by moderate stretch, but none of the K+ channels appeared to be involved in adaptation to maintained stretch by their slowly adapting vagal mechanoreceptors.

British Journal of Pharmacology (2002) 137, 1195–1206. doi:10.1038/sj.bjp.0704964
Modulation of the release of endogenous adenosine by cannabinoids in the myenteric plexus‐longitudinal muscle preparation of the guinea‐pig ileum
Authors: Begg M , Dale N , Llaudet E , Molleman A , Parsons M E
Published: December 2002

Interactions between the cannabinoid system and the adenosine system were investigated in the myenteric plexus‐longitudinal muscle (MPLM) of the guinea‐pig ileum.

Electrically‐evoked contractions of the MPLM were inhibited in a concentration dependent manner by exogenous adenosine and the adenosine receptor agonist 2‐chloroadenosine. These inhibitory effects were reversed by the selective A1 receptor antagonist DPCPX (20 nM).

Preincubation of the MPLM with the cannabinoid receptor agonist CP55,940 (1 nM) or the endogenous cannabinoid ligand anandamide caused a significant leftward shift in the concentration‐effect curves to adenosine and 2‐chloroadenosine.

Electrically‐evoked contractions of the MPLM were inhibited in a concentration dependent manner by the adenosine uptake inhibitor dipyridamole. This inhibition was reversed by DPCPX (20 nM).

Pretreatment with CP55,940 (1 nM) or anandamide (10 μM) significantly reduced the inhibition produced by dipyridamole, an effect which was completely reversed by the selective CB1 receptor ligand SR141716 (100 nM).

Electrically evoked adenosine release, measured in real time by means of adenosine‐specific biosensors, was inhibited by CP55,940 (10 nM). This inhibition was blocked when CP55,940 was applied in the presence of SR141716 (100 nM).

These results confirm the presence of presynaptic CB1 and A1 receptors in the guinea‐pig MPLM, and suggest that CB1 receptor stimulation reduces electrically‐evoked adenosine release. Overall the data raise the possibility that the cannabinoid system plays a role in the modulation of adenosine transmission in the MPLM.

British Journal of Pharmacology (2002) 137, 1298–1304. doi:10.1038/sj.bjp.0704985
Inhibitory mechanism of xestospongin‐C on contraction and ion channels in the intestinal smooth muscle
Authors: Ozaki Hiroshi , Hori Masatoshi , Kim Yoon‐Sun , Kwon Seong‐Chun , Ahn Duck‐Sun , Nakazawa Hiroshi , Kobayashi Motomasa , Karaki Hideaki
Published: December 2002

Xestospongin‐C isolated from a marine sponge, Xestospongia sp., has recently been shown to be a membrane‐permeable IP3 receptor inhibitor. In this study we examined the effects of this compound on smooth muscle from guinea‐pig ileum.

In guinea‐pig ileum permeabilized with α‐toxin, xestospongin‐C (3 μM) inhibited contractions induced by Ca2+ mobilized from sarcoplasmic reticulum (SR) with IP3 or carbachol with GTP, but not with caffeine.

In intact smooth muscle tissue, xestospongin‐C (3–10 μM) inhibited carbachol‐ and high‐K+‐induced increases in [Ca2+]i and contractions at sustained phase.

It also inhibited voltage‐dependent inward Ba2+ currents in a concentration‐dependent manner with an IC50 of 0.63 μM. Xestospongin‐C (3–10 μM) had no effect on carbachol‐induced inward Ca2+ currents via non‐selective cation channels; but it did reduce voltage‐dependent K+ currents in a concentration‐dependent manner with an IC50 of 0.13 μM.

These results suggest that xestospongin‐C inhibits the IP3 receptor but not the ryanodine receptor in smooth muscle SR membrane. In intact smooth muscle cells, however, xestospongin‐C appears to inhibit voltage‐dependent Ca2+ and K+ currents at a concentration range similar to that at which it inhibits the IP3 receptor. Xestospongin‐C is a selective blocker of the IP3 receptor in permeabilised cells but not in cells with intact plasma membrane.

British Journal of Pharmacology (2002) 137, 1207–1212. doi:10.1038/sj.bjp.0704988
Effects of nucleation transience on crystallization kinetics under strongly nonequilibrium conditions
Authors: Demetriou Marios D. , Ghoniem Nasr M. , Lavine Adrienne S.
Published: December 2002

An approach to quantitatively assess the effects of nucleation transience on the kinetics of crystallization under static and dynamic conditions is proposed. The approach is based on an order of magnitude analysis that involves time scales characterizing the rates of nucleation relaxation and processing. The method is implemented to evaluate the effects of nucleation transience on kinetic computations performed in the tungsten–carbon system. The assessment is verified by contrasting the kinetics computed by means of a cluster dynamics simulation that implicitly accounts for transience to those evaluated using a quasi-steady-state model. When interpreting the kinetics of tungsten carbide surface crystallization, the proposed scaling method predicts that under static conditions transient effects need to be accounted for when annealing below 2600 K, while under dynamic conditions transient effects become important when quenching at ultrahigh cooling rates such as 108 K/s. Accordingly, in the case of isothermal annealing the steady-state kinetics appears to be in good agreement with those computed dynamically above 2600 K, but gradually deviates at lower temperatures. Consequently, the steady-state model underestimates the transformation time by more than an order of magnitude at the nose of the TTT curve (∼2200 K). In the case of continuous cooling, the kinetic rate is well approximated by the quasi-steady-state model for processing rates of 104 and 106 K/s; however, for ultrahigh cooling rates of order 108 K/s, the kinetics computed by the quasistatic model deviates substantially from that computed using cluster dynamics. As a consequence, the crystallized fraction computed from the quasistatic model is overestimated by at least an order of magnitude at every undercooling temperature. The results from the two kinetic models appear to validate the assessment of transience based on the proposed scaling method.
Theory and application of Fermi pseudo-potential in one dimension
Authors: Wu Tai Tsun , Yu Ming Lun
Published: December 2002

The theory of interaction at one point is developed for the one-dimensional Schrödinger equation. In analog with the three-dimensional case, the resulting interaction is referred to as the Fermi pseudo-potential. The dominant feature of this one-dimensional problem comes from the fact that the real line becomes disconnected when one point is removed. The general interaction at one point is found to be the sum of three terms, the well-known delta-function potential and two Fermi pseudo-potentials, one odd under space reflection and the other even. The odd one gives the proper interpretation for the δ′(x) potential, while the even one is unexpected and more interesting. Among the many applications of these Fermi pseudo-potentials, the simplest one is described. It consists of a superposition of the delta-function potential and the even pseudo-potential applied to two-channel scattering. This simplest application leads to a model of the quantum memory, an essential component of any quantum computer.
Magnetic and structural properties of Co films deposited onto obliquely sputtered Pt underlayers
Authors: Hadley M. J. , Pollard R. J.
Published: December 2002

Co films deposited on obliquely sputtered Pt underlayers of 100 Å or greater have produced coercivities in excess of 800 Oe, and anisotropy fields over 950 Oe. The coercivity and anisotropy field increase with Pt deposition angle and thickness. A Pt capping layer has a detrimental effect on properties but a Cu capping layer does not. Films with an obliquely deposited underlayer exhibit reduced density and increased interface roughness compared to normally deposited films. Normally deposited Pt underlayers display a (111) texture, while those deposited obliquely show an increasingly random texture with Pt thickness and deposition angle. The trilayers fabricated in this study are presented as candidates for use in giant magnetoresistance sensors.
On the nature of radiative recombination in GaAsN
Authors: Sun B. Q. , Gal M. , Gao Q. , Tan H. H. , Jagadish C.
Published: December 2002

Radiative recombination at low temperatures in GaAsN is often associated with localized excitons. In this short note, we report results from high-resolution time-resolved photoluminescence spectroscopy that indicate that excitons, localized or otherwise, cannot be involved in the recombination process of this alloy system. The risetime of the photoluminescence signal is more than two orders of magnitude shorter than that expected, and found from excitonic recombination in other III–V materials, such as GaAs. We suggest that the radiative recombination in GaAsN takes place between localized electrons and delocalized holes.
Spatial and temporal luminescence dynamics in an InxGa1−xN single quantum well probed by near-field optical microscopy
Authors: Kaneta Akio , Okamoto Koichi , Kawakami Yoichi , Fujita Shigeo , Marutsuki Giichi , Narukawa Yukio , Mukai Takashi
Published: December 2002

Spatial distribution of photoluminescence (PL) with spectral, spatial, and/or time resolution has been assessed in an InxGa1−xN single-quantum-well (SQW) structure using scanning near-field optical microscope (SNOM) under illumination-collection mode at 18 K. The near-field PL images revealed the variation of both intensity and peak energy in PL spectra according to the probing location with the scale less than a few hundredths of a nanometer. PL linewidth, the value of which was about 60 meV in macroscopic PL, was as small as 11.6 meV if the aperture size was reduced to 30 nm. Clear spatial correlation was observed between PL intensity and peak wavelength, where the regions of strong PL intensity correspond to those of long wavelength. Time-resolved SNOM–PL study showed the critical evidence that supports the model of diffusion of carriers to potential minima.
About Hob Idle Distance in Gear Hobbing Operation
Authors: Radzevich Stephen P.
Published: December 2002

This study is focused on some features of geometry and kinematics of gear hobbing operation. The principal goal is to determine minimal hob idle distance required for complete generation of the gear teeth. This task is of importance in two aspects: to cut hobbing time and to reduce axial size of a hobbed cluster gear, gear with shoulder etc. The necessity of cutting hobbing time is evident. Reduction of axial size of a hobbed gear cluster leads to reduction of size and weight of the gear cluster itself and of the gear train housing, and therefore its necessity is also evident. Methods of analytical mechanics of gear are applied to determine an exact minimal length of the gear hob idle distance. The resultant formulas obtained have been derived based on graphical solution of the problem under consideration using methods of descriptive geometry. The results reported in the paper are applicable for manufacturing of spur and helical involute gears. Their application allows one to cut hobbing time and to reduce axial size and weight of gear train and gear train housing. Although the consideration below is focused on hobbing of involute gears, slightly modified results obtained are applicable for hobbing of spline, sprockets, ratchets, and other form tooth profiles. The results obtained are of prime importance for application of multi-start hobs of small diameter.
Differential Modulation of Cellular Signaling Pathways by Mild and Severe Hypovirus Strains
Authors: Parsley Todd B. , Chen Baoshan , Geletka Lynn M. , Nuss Donald L.
Published: December 2002

Hypoviruses persistently alter multiple phenotypic traits, stably modify gene expression, and attenuate virulence (hypovirulence) of their pathogenic fungal host, the chestnut blight fungus
Cryphonectria parasitica
. The pleiotropic nature of these changes is consistent with hypovirus-mediated perturbation of one or more cellular signal transduction pathways. We now report that two hypoviruses that differ in the severity of symptom expression differentially perturb specific cellular signaling pathways. The
C. parasitica 13-1
gene, originally identified as a hypovirus-inducible and cyclic AMP (cAMP)-regulated gene, was used to design a promoter-GFP reporter construct with which to monitor perturbation of cAMP-mediated signaling. Virus-mediated modulation of calcium/calmodulin/inositol trisphosphate-dependent signaling was monitored by measuring transcript accumulation from the
C. parasitica
laccase gene,
lac-1
. Infection by the severe hypovirus strain CHV1-EP713 caused a substantial induction of
13-1
promoter activity and a reduction of total extracellular laccase enzymatic activity (LAC-1 and LAC-3). In contrast,
13-1
promoter activity and total laccase activity were only marginally altered upon infection with the mild hypovirus strain CHV1-Euro7. However, examination of
lac-1
-specific transcript accumulation under previously defined culture conditions revealed that both CHV1-EP713 and CHV1-Euro7 perturbed calcium/calmodulin/inositol trisphosphate-dependent signaling. CHV1-EP713/CHV1-Euro7 chimeric viruses were used to map viral determinants responsible for modulation of cAMP-dependent signaling to domains within the central portion of the second open reading frame.