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PubMed2004

[Functions of different cultivation modes in oasis agriculture on soil wind erosion control and soil moisture conservation].

During 2001-2002, the effects of different cultivation modes including winter irrigation and zero tillage, crop-grass intercropping, and early spring film mulching on sand entrainment, wind velocity gradient and soil moisture conservation were studied in the middle reaches of the Heihe River in the Hexi Corridor region. The results showed that all these modes could reduce soil wind erosion and halt sand entrainment to different degrees. Compared with the bare fields exposed by spring plowing, early spring film mulching could increase soil moisture storage by 35.6%. At present, spring plowing and sowing was a main factor responsible to the occurrence of sand storms and the increase in suspended dust content. Farmlands in the upper and middle reaches of the Heihe River generally produced a dust transport up to 4.8-6.0 million tons per year, which was higher than that of sandy desert in the same region. In the Hexi Corridor region, the suspended dust amount produced from 1 hm2 farmland was equivalent to that of 1.5 hm2 desert.

Crops, Agricultural↗

PubMed2006

[Clinical observation on acupuncture kinetotherapy for acute simple laryngitis of wind-heat type].

OBJECTIVE: To observe clinical therapeutic effect of acupuncture kinetotherapy for acute simple laryngitis of wind-heat type and to probe the mechanism. METHODS: Eighty cases were randomly divided into a test group and a control group, 40 cases in each group. The test group were treated with acupuncture kinetotherapy (Acupuncture was given at Kaiyin point No. 1 combined with deep respiratory movement of the glottis), once daily. The control group were treated with ultrasonic aerosol inhalation of 0.9% sodium chloride injection, gentamicin sulfate injection 80 000 U and Dexamethasone injection 5mg, twice a day. The treatment was given for 5 days for the 2 groups. RESULTS: The cured and markedly effective rate was 90.0% in the test group and 82.5% in the control group with no significant difference between the two groups (P>0.05); in the test group there was a very significant difference before and after treatment in the cumulative score of symptoms and the acoustic parameters (P<0.01). CONCLUSION: Acupuncture kinetotherapy has obvious therapeutic effect on acute simple laryngitis of wind heat type, with no toxic and adverse effects.

Acupuncture Therapy↗

PubMed2005

Drift studies--comparison of field and wind tunnel experiments.

Drift at pesticide application leads to a pollution of non-target crops, non-target species and surface water. Spray drift is influenced by many factors like environmental conditions, vegetation, technical conditions, and physical properties of the tank mixes and influenced by Chemicals. Field experiments to characterise spray drift effects with the risk of permanent changing weather conditions can be supported by wind tunnel experiments. Wind tunnel experiments do not lead to the same soil deposition curves like field experiments, but the ratio of drift reduction potential is comparable.

Agriculture↗

PubMed2006

Pollination intensity influences sex ratios in dioecious Rumex nivalis, a wind-pollinated plant.

Determining the mechanisms governing sex-ratio variation in dioecious organisms represents a central problem in evolutionary biology. It has been proposed that in plants with sex chromosomes competition between pollen tubes of female- versus male-determining microgametophytes (certation) causes female-biased primary sex ratios. Experimental support for this hypothesis is limited and recent workers have cast doubt on whether pollen-tube competition can modify sex ratios in dioecious plants. Here we investigate the influence of variation in pollination intensity on sex ratios in Rumex nivalis, a wind-pollinated alpine herb with strongly female-biased sex ratios. In a garden experiment, we experimentally manipulated pollination intensity using three concentric rings of female recipient plants at different distances from a central group of male pollen donors. This design enabled us to test the hypothesis that increasing pollen load size, by intensifying gametophyte competition, promotes female-biased sex ratios in R. nivalis. We detected a significant decline in pollen load at successive distance classes with concomitant reductions in seed set. Sex ratios of progeny were always female biased, but plants at the closest distance to male donors exhibited significantly greater female bias than more distant plants. The amount of female bias was positively correlated with the seed set of inflorescences. Hand pollination of stigmas resulted in approximately 100-fold higher stigmatic pollen loads than wind-pollinated stigmas and produced exceptionally female-biased progenies (female frequency = 0.96). Our results are the first to demonstrate a functional relation between stigmatic pollen capture, seed set, and sex ratio and suggest that certation can contribute towards female-biased sex ratios in dioecious plants.

Pollen↗

PubMed2006

Effects of trajectory wind direction on ion concentration of PM10.

OBJECTIVE: To study the characterization apportionment of main ion concentrations of PM10 under the influence of trajectory wind direction in London. METHODS: PM10 samples from 1 May 1995 to 30 October 1995 of Oxford Street of Central London were collected, the metals and anions of which were measured using atomic absorption spectrometry (AAS) and ion chromatography (IC). Composite trajectories representative of the air mass arriving in London at the same period were calculated based on basic routine back trajectories from the British Atmospheric Data Centre (BADC). RESULTS: Concentration apportionments of main ions were similar when the trajectory was plotted back at 6 h, 12 h, and 24 h, some were obviously different. Mg, Ba, Pb, and Cu had similar peak apportionments at the area 180 degrees-320 degrees, but Zn and Ni at the area of 90 degrees-270 degrees, NO3 and SO4(2-) at the area of 100 degrees-220 degrees. Cl- concentration peak apportionment was at the area of 220 degrees-300 degrees, which showed that Cl- mainly came from the North Sea. CONCLUSION: Trajectory wind direction has important effect on ion concentration apportionment of PM10 in London. The ions have similar concentration peak apportionments or their correlation coefficients are statistically significant.

Air Pollutants↗

PubMed1998

Particle deposition onto a human head: influence of electrostatic and wind fields.

This study investigates electrostatic fields surrounding the human head and particle deposition onto facial skin and eyes caused by the combined effect of electrostatic and wind fields. The electrostatic fields are calculated by a three-dimensional numerical model calculating the field strength between a field source and a human head. The deposition velocity can be viewed as determined by the sum of two contributions: that of an electrostatic field and that of a wind field. Deposition velocities are calculated by a semiempirical particle deposition model that considers particle transport from the free stream to the human face. The particle deposition model uses the electrostatic field model results as input parameters and is applied to the forehead and eyes of two facial shapes for two different turbulence conditions and aerosol charge distributions. The results of different practical working conditions, under which the potential difference between head (person) and source ranges from 5.6 to 15.0 kV, indicates that the presence of electrostatic fields always increases particle deposition for industrial aerosols. For aged aerosols an effect is only present for submicron particles.

Air↗

PubMed1986

Control of hindlimb posture by wind-sensitive hairs and antennae during locust flight.

Steering movements of tethered, flying locusts, Schistocerca gregaria, subjected to simulated yaw were examined under open-loop conditions. Lateral movements of hindlimbs or curling of the abdomen were monitored with a capacitive movement transducer and were interpreted as indicating the tendency of the animal to turn. Three responses to simulated yaw were noted: Yaw-correcting upwind turning tendencies (Figs. 1, 2, 3). Downwind turning tendencies (Figs. 2, 3, 4, 5), and transient adjustments of hindlimb position consistent with an upwind turning tendency occurred in animals that made either no sustained postural adjustments of hindlimbs, or that exhibited sustained downwind turning tendencies (Figs. 4, 5). Ablations of certain mechanoreceptors tested their roles in wind detection and wind angle determination. The expression of upwind turning tendencies, whether sustained or transient, depends on inputs from cephalic mechanosensory hairplates (Figs. 2, 3, 4, 5). With hairplates occluded, all locusts exhibited downwind turning tendencies. All downwind turning tendencies depend on inputs from the antennae (Figs. 2, 3). Antennae and hairplates operate in an apparent antagonism in the steering responses they produce, which may provide the control flexibility required for complex flight maneuvering.

Animals↗

PubMed2004

Local cultural knowledge and water resource management: the Wind River Indian Reservation.

Ecology and culture comprise interacting components of landscapes. Understanding the integrative nature of the landscape is essential to establish methods for sustainable management. This research takes as a unifying theme the idea that ecological and cultural issues can be incorporated through management. As a first step in developing integrative management strategies, information must be collected that compares and contrasts ecological and cultural issues to identify their areas of intersection. Specifically how can local cultural knowledge enable water resource management that reflects cultural and ecological values? This research examines Native American cultural knowledge for setting water resource management priorities in the Wind River Indian Reservation in central Wyoming. A cross-cultural approach is adopted to assess the relationship between indigenous cultural knowledge and Euro-American perspectives through a comparative examination of the Wind River Water Code and Wyoming Water Law. This research indicates that cultural perspectives provide a rich arena in which to examine management issues. Understanding and identifying cultural practices may be an important first step in collaborative resource management between different cultural groups to prevent conflict and lengthy resolution in court.

Conflict, Psychological↗

PubMed2006

Theoretical, numerical, and experimental modal analysis of a single-winding gradient coil insert cylinder.

The objective of this paper is to find the relatively low-frequency (200-2,000 Hz) mode shapes of a single-winding gradient coil cylinder with intermediate wall thickness. The dynamic behavior of a gradient coil cylinder plays a crucial role in determining and controlling the vibroacoustic performance of magnetic resonance imaging (MRI) scanners. Modal analyses of the gradient coil cylinder were carried out under different boundary conditions to obtain the various mode shapes. Theoretical modes, predicted by using modified Love's governing equations, and numerical modes simulated using a finite element method show close agreement with experimental modal results and reveal the mode shapes for both free-end and fixed-end boundary conditions. These results were further compared to in situ measurements of the mode shapes of the gradient coil cylinder insert during scanning in a 4 Tesla MRI. The general agreement among the analytical, numerical, and experimental mode shapes indicates that a linear combination of basic beam vibration and ring vibration patterns occupy the dynamic vibration modes in the low frequency range. The in situ vibration measurements show that the forcing function developed by the distributed Lorentz forces on the surface of the single-winding gradient coil results in predominantly beam-type bending mode patterns in the low frequency range.

Computer-Aided Design↗

PubMed1990

New arterial prostheses by filament winding.

A new manufacturing method for vascular grafts, based on a filament winding technique, is unveiled. The concept that pilots this method is presented and analysed in detail alongside the experimental results. A basic feature of filament winding is its ability to produce a two-phase structure built of a continuous fibre-reinforced polymeric matrix, shaped according to the shape of a mandrel. This structure offers a number of advantages over common vascular graft designs, e.g. better control of the mechanical properties and closer match with anisotropic properties of native arteries, and more degrees of design freedom with respect to pore size, biodegradability and biocompatibility. The experimental section offers a range of potential constituent materials, and presents an example of a Lycra fibre/Pellethane matrix prototypical prosthesis.

Blood Vessel Prosthesis↗

PubMed1992

Spinal local anaesthetic actions on afferent evoked responses and wind-up of nociceptive neurones in the rat spinal cord: combination with morphine produces marked potentiation of antinociception.

Lignocaine was tested either alone or in combination with a low dose of morphine by intrathecal administration on the C- and A-beta evoked responses of nociceptive neurones in the dorsal horn of the halothane-anaesthetized rat. In addition the effect of prilocaine was compared to lignocaine. The effects of lignocaine on wind-up, a frequency-dependent increase in the responses of the cells produced by repeated C-fibre stimulation was also tested. Lignocaine produced dose-dependent inhibitions of the C-, A-delta and A-beta evoked responses of the cells which became more selective for the noxious evoked responses as the dose increased. The effective doses corresponded well to those used clinically. Wind-up was also decreased by lignocaine. In combination with a low dose of morphine, threshold doses of lignocaine produced a highly marked potentiation of the inhibitions of the C-fibre evoked responses compared to either agent alone. No potentiation of the inhibitions of the A-beta responses was observed. The potentiated inhibitory effects on the C-fibre responses were rapidly reversed by intrathecal naloxone. The finding that spinal local anaesthetic and morphine potentiate markedly to reduce spinal nociception is discussed both in terms of mechanisms of action of the agents and their clinical application.

Afferent Pathways↗

PubMed2004

Blockade of supraspinal 5-HT1A receptors potentiates the inhibitory effect of venlafaxine on wind-up activity in mononeuropathic rats.

In mononeuropathic rats submitted to a C-fiber reflex responses paradigm, repeated administration (five successive injections every half-life) of 10 mg/kg, s.c. of venlafaxine, but not of 2.5 mg/kg, s.c., a mixed monoamine reuptake inhibitor with preferential inhibitory activity in 5-HT reuptake, induced a progressive reduction of spinal wind-up. Repeated co-administration of the selective 5-HT1A receptor antagonist WAY 100,635 i.c.v. (50 microg/injection) significantly increased the effect of venlafaxine s.c., indicating that venlafaxine-induced inhibition of spinal wind-up in mononeuropathic rats is potentiated by blockade of central 5-HT1A receptors.

Animals↗

PubMed2005

The novel analgesic and high-efficacy 5-HT1A receptor agonist F 13640 inhibits nociceptive responses, wind-up, and after-discharges in spinal neurons and withdrawal reflexes.

Evidence shows that serotonin (5-HT) is involved in the transmission of nociception in the central nervous system. Using a new electrophysiological method of simultaneous recordings in rats we examined the actions of the novel analgesic and high-efficacy 5-HT1A receptor agonist F 13640 as well as those of the opioid receptor agonist fentanyl on simultaneously evoked responses of spinal dorsal horn (DH) wide-dynamic range (WDR) neurons and spinal withdrawal reflexes. Spinal withdrawal reflexes were studied by assessing the activity of single motor units (SMUs) electromyographically (EMG). Like that of 0.02 mg/kg fentanyl, intraperitoneal injection of 0.31 mg/kg of F 13640 markedly inhibited nociceptive pinch-evoked responses as well as C-fiber-mediated late responses including wind-up of both DH WDR neurons and SMUs to suprathreshold (1.5 x T) repeated (3 Hz) electrical stimulation. Specifically, in contrast to no significant depressive effects by fentanyl on 20 Hz electrically evoked after-discharge of DH WDR neurons, the after-discharges of DH WDR neurons and SMUs were significantly inhibited by F 13640 (P < 0.05 and P < 0.001, respectively). The inhibitory effects of F 13640 and fentanyl on responses of DH WDR neurons and SMUs were reversed by the specific antagonists WAY 100635 and naloxone, respectively, further indicating that this 5-HT1A receptor-modulated anti-nociception is mu-opioid receptor independent. For the first time, 5-HT1A receptors are clearly proved to be involved in the progressive wind-up to 3-Hz frequency of electrical stimulation as well as after-discharges of sensory input of DH WDR neurons, and simultaneously recorded motor output of spinal reflexes to 20-Hz frequency of electrical stimulation; this suggests that serotonin, through 5-HT1A receptors, exerts an inhibitory role in the control of obstinate pathological pain.

Action Potentials↗

PubMed2005

Wind, rain and bacteria: The effect of weather on the microbial composition of roof-harvested rainwater.

The microbiological and chemical quality of tank-stored rainwater is impacted directly by roof catchment and subsequent run-off contamination, via direct depositions by birds and small mammals, decay of accumulated organic debris, and atmospheric deposition of airborne micro-organisms and chemical pollutants. Previous literature reports on roof water quality have given little consideration to the relative significance of airborne micro-organisms. This study involved analyses of direct roof run-off at an urban housing development in Newcastle, on the east coast of Australia. A total of 77 samples were collected during 11 separate rainfall events, and microbial counts and mean concentrations of several ionic contaminants were matched to climatic data corresponding to each of the monitored events. Conditions both antecedent to, and those prevailing during each event, were examined to investigate the influence of certain meteorological parameters on the bacterial composition of the roof water and indirectly assess the relative contribution of airborne micro-organisms to the total bacterial load. Results indicated that airborne micro-organisms represented a significant contribution to the bacterial load of roof water at this site, and that the overall contaminant load was influenced by wind velocities, while the profile (composition) of the load varied with wind direction. The implications of these findings to the issues of tank water quality and health risk analysis, appropriate usage and system design are discussed.

Aerosols↗

PubMed2002

Cell-based dual snake model: a new approach to extracting highly winding boundaries in the ultrasound images.

Two common deficiencies of most conventional deformable models are the need to place the initial contour very close to the desired boundary and the incapability of capturing a highly winding boundary for sonographic boundary extraction. To remedy these two deficiencies, a new deformable model (namely, the cell-based dual snake model) is proposed in this paper. The basic idea is to apply the dual snake model in the cell-based deformation manner. While the dual snake model provides an effective mechanism allowing a distant initial contour, the cell-based deformation makes it possible to catch the winding characteristics of the desired boundary. The performance of the proposed cell-based dual snake model has been evaluated on synthetic images with simulated speckles and on the clinical ultrasound (US) images. The experimental results show that the mean distances from the derived to the desired boundary points are 0.9 +/- 0.42 pixels and 1.29 +/- 0.39 pixels for the synthetic and the clinical US images, respectively.

Algorithms↗

PubMed2001

Abnormal sensitization and temporal summation of second pain (wind-up) in patients with fibromyalgia syndrome.

Although individuals with fibromyalgia syndrome (FMS) consistently report wide-spread pain, clear evidence of structural abnormalities or other sources of chronic stimulation of pain afferents in the involved body areas is lacking. Without convincing evidence for peripheral tissue abnormalities in FMS patients, it seems likely that a central pathophysiological process is at least partly responsible for FMS, as is the case for many chronic pain conditions. Therefore, the present study sought to obtain psychophysical evidence for the possibility that input to central nociceptive pathways is abnormally processed in individuals with long standing FMS. In particular, temporal summation of pain (wind-up) was assessed, using series of repetitive thermal stimulation of the glabrous skin of the hands. Although wind-up was evoked both in control and FMS subjects, clear differences were observed. The perceived magnitude of the sensory response to the first stimulus within a series was greater for FMS subjects compared to controls, as was the amount of temporal summation within a series. Within series of stimuli, FMS subjects reported increases in sensory magnitude to painful levels for interstimulus intervals of 2-5 s, but pain was evoked infrequently at intervals greater than 2 s for control subjects. Following the last stimulus in a series, after-sensations were greater in magnitude, lasted longer and were more frequently painful in FMS subjects. These results have multiple implications for the general characterization of pain in FMS and for an understanding of the underlying pathophysiological basis.

Female↗

PubMedDate not supplied

Determination of the structural features of (+)-CC-1065 that are responsible for bending and winding of DNA.

Analysis of the anomalous migration in electrophoretic mobilities of (+)-CC-1065-modified oligomers following ligation reveals that (+)-CC-1065 induces DNA bending and winding of the helix. (+)-CC-1065 is a potent antitumor antibiotic produced by Streptomyces zelensis. This drug selectively bonds covalently to N3 of adenine and lies in the minor groove of DNA, reacting in a highly sequence-selective manner. Structurally, (+)-CC-1065 consists of three subunits: two identical pyrroloindole units (subunits B and C) and a third subunit containing the DNA-reactive cyclopropane ring (subunit A). While the bonding reaction is the main determinant of DNA sequence selectivity of (+)-CC-1065, binding interactions between the inside edge substituents of the B and C subunits and the floor of the minor groove of DNA can modulate or fine tune this sequence selectivity, [Hurley, L. H., Lee, C.-S., McGovern, J. P., Mitchell, M. A., Warpehoski, M. A., Kelly, R. C., & Aristoff, P. A. (1988) Biochemistry 27, 3886-3892]. The A subunit of (+)-CC-1065 is responsible for the bending of DNA, and close van der Waals contacts between the inside edge of (+)-CC-1065 and the floor of the minor groove of DNA cause winding equivalent to about 1 base pair per alkylation site and stiffening of DNA. The magnitude of DNA bending induced by (+)-CC-1065 and related compounds is about 14-19 degrees, which is equivalent to that produced by an adenine-thymine tract of about 5-6 base pairs in length. Experiments using oligomers containing both an adenine tract and a unique (+)-CC-1065 bonding site approximately one helix turn apart demonstrate that the directionality of drug-induced bending is in toward the minor groove and the locus of bending is about 2-3 base pairs to the 5'-side of the covalently modified adenine. A circularization efficiency assay shows that the optimum size of circles produced by (+)-CC-1065 and related drugs is between 168 and 180 base pairs. These results are discussed in relation to the molecular basis of the DNA sequence selectivity of (+)-CC-1065, and the (+)-CC-1065-induced DNA bending is compared with the intrinsic bending associated with adenine tracts. Since (+)-CC-1065 induces effects on local DNA structure that appear similar to those produced naturally by adenine tracts and certain DNA binding proteins, the relevance of this phenomenon to biological effects of (+)-CC-1065 and related drugs is considered.

Antibiotics, Antineoplastic↗

PubMed1995

Nitrogen isotope abundances in the recent solar wind.

Although lunar crystalline rocks are essentially devoid of nitrogen, the same is not true of the lunar regolith. The nitrogen contents of individual regolith samples (which can be as high as 0.012% by mass) correlate strongly with abundances of noble gases known to be implanted in the lunar surface by solar radiation, indicating that lunar regolith nitrogen is also predominantly of solar origin. The large variability in 15N/14N ratios measured in different regolith samples may thus reflect long-term changes in the isotopic composition of the solar radiation. But attempts to explain these variations have been hampered by the lack of any firm constraint on 15N/14N in the present solar wind. Here we report measurements of nitrogen isotopes from two lunar samples that have had simple (and relatively recent) exposure histories. We find that nitrogen implanted in the lunar surface during the past 10(5) to 5 x 10(7) years has a 15N/14N ratio approximately 40% higher than that in the terrestrial atmosphere, which is substantially lower than most previous estimates. This isotopic signature probably represents the best measure of 15N/14N in the present-day solar wind.

Extraterrestrial Environment↗