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Several letters to the editor are presented in response to articles in previous issues including "Trend," in the February 2007 issue, "Forest for the Trees" and "Your Say," in the February 2007 issue.

Abstract: The basic features of the leachability of depleted uranium (DU) projectiles in soil was investigated by using 12 projectiles (145–294 g DU) and 16 columns installed in an air-conditioned laboratory. Two soils widely distributed in Europe, a sandy-loamy cambisol and a silty-loamy luvisol, were filled into the columns (3.3 kg dry soil each). The effluents of all columns were collected weekly during the observation period of 1 year. In 648 samples, 235U and 238U were determined by inductively coupled plasma mass spectrometry. The leaching rates of 238U from natural uranium were in general about 0.01 μg week-1 or smaller, while those of 238U from the DU munitions varied considerably and reached values of up to 100 μg week-1, for the different columns. In total, about 0.3 μg natural uranium corresponding to 20 ppm of its inventory in the soil was leached during the observation period. From the projectiles, an average of about 50 μg DU were leached corresponding to 18 ppm of the corroded DU mass (about 1.6% of the mean initial DU mass of the projectiles). Assuming that corrosion and leaching continue as observed, the mobilisation of 238U from DU munitions will last, on an average, for thousands of years in the soils investigated, while the munitions themselves will have been corroded after a much shorter time. It is proposed to use, for the investigated soil types, the mean leaching rates of the six columns with projectiles for transport calculations of 238U to the groundwater and, thus, for a better risk assessment of the water-dependent uptake pathways of DU.

In order to find wheat cultivars with a minimum soil-to-grain transfer of fallout 137Cs, 28 winter wheat cultivars were investigated at 3 different sites with different soil types in Bavaria, Germany. Each cultivar was grown on an area of 10 m 2 and harvested in August 1999. The soil-to-grain concentration ratios (C r) of 137Cs varied by a factor of up to 3 from cultivar to cultivar at a given site and from site-to-site for a given cultivar. The mean C r values at the three sites, 4.2×10 -4, 4.9×10 -4 and 7.5×10 -4, differed significantly. The fact that no cultivar showed similar C r values at the three sites indicates a strong influence of the soil on C r. The cultivars Flair, Kornett and Previa showed a minor uptake of 137Cs compared with the mean of all cultivars at each site. Unlike 137Cs, the 40K concentrations in the wheat grains varied only within a small range (122–190 Bq kg -1) at each site, which is due to the potassium regulation by the plants. For both radionuclides, the differences between the root uptake characteristics of the cultivars may not only be explained by an inter-cultivar variability due to genetic differences between the cultivars, but also by an intra-cultivar variability due to different soil conditions.

In light of various shortcomings of the traditional nosology of women's sexual disorders for both clinical practice and research, an international multi-disciplinary group has reviewed the evidence for traditional assumptions about women's sexual response. It is apparent that fullfillment of sexual desire is an uncommon reason/incentive for sexual activity for many women and, in fact, sexual desire is frequently experienced only after sexual stimuli have elicited subjective sexual arousal. The latter is often poorly correlated with genital vasocongestion. Complaints of lack of subjective arousal despite apparently normal genital vasocongestion are common. Based on the review of existing evidence-based research, many modifications to the definitions of women's sexual dysfunctions are recommended. There is a new definition of sexual interest/desire disorder, sexual arousal disorders are separated into genital and subjective subtypes and the recently recognized condition of persistent sexual arousal is included. The definition of dyspareunia reflects the possibility of the pain precluding intercourse. The anticipation and fear of pain characteristic of vaginismus is noted while the assumed muscular spasm is omitted given the lack of evidence. Finally, a recommendation is made that all diagnoses be accompanied by descriptors relating to associated contextual factors and to the degree of distress.

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This study evaluates the impact of early-stage gynecological cancer and its treatment on sexuality and assessed needs for care regarding sexual rehabilitation.Data from 58 women from a prospective, longitudinal study were compared to data from 220 women from a cross-sectional study. Patients in the prospective study completed questionnaires prior to treatment and then 6 and 12 months post-treatment. A single assessment was obtained from patients in the cross-sectional study. All women had a partner.Both groups were comparable on important independent variables. Both samples had an equal level of sexual contact, but participants in the cross-sectional study (mean time 46 months post-treatment) reported a higher frequency of sexual problems, were more troubled by those problems and reported a lower sexual satisfaction. However, in both groups the level of the reported dysfunctions was relatively low. Around 80% of the patients were satisfied with the information provided on sexual rehabilitation. Little need for extra care on sexual rehabilitation was reported.In conclusion, women with early-stage gynecological cancer were not especially prone to severe sexual problems and seemed to cope well with the consequences of cancer and its treatment on their sexual lives. It was suggested that this relatively positive outcome is a result of the improved patient care and education on sexual aspects in the last decade.

ObjectiveDisturbances in proteoglycan metabolism of hyaline cartilage play an essential role in the pathology of degenerative joint disease. We investigated the relation between transcript expression, protein synthesis and the ultrastructural localization of the matrix-organizing proteoglycans decorin and biglycan within intra- and extracellular compartments of late-stage osteoarthritic human articular cartilage.

Abstract: Naturally occurring soluble-surfactant slicks influence the properties of water waves. This paper describes results from wave tank experiments involving a soluble surfactant, and linear and nonlinear gravity- capillary waves. Instantaneous surface deflections were measured using optical techniques to determine the damping, phase speed, and the frequency content of the waves for wavemaker frequencies from 4 to 22 Hz. Measured linear-wave phase speed and damping agree well with existing theory at surfactant concentrations away from that leading to maximum damping. Under conditions leading to nonlinear waves, an as-yet-unexplained subharmonic wave with one-sixth the wavemaker frequency was found only with soluble surfactant present.

The two most fundamental aspects of sexual relationships, passion and intimacy, are complex concepts, with at least partly paradoxical contents. Intimacy, for example, stands for unity and security, but also for shifting boundaries and exposure. Passion in its turn, stands for enthusiasm and energy, but also for surrender and dependency. It is this 'two sides of the coin' phenomenon that makes sexual relationships as interesting as they are dangerous. In terms of development, a relationship often starts with 'setting each other on fire' and ends with 'sexual burn-out'. In this paper, an analysis is made of the way patients, but also health care providers such as gynecologists and sexologists, cope with these unavoidable phenomena in sexual relationships.

This review summarizes recent experiments on neuronal mechanisms underlying goal-directed behaviour. We investigated two basic processes, the internally triggered initiation of movement and the processing of reward information. Single neurons in the striatum (caudate nucleus, putamen and ventral striatum) were activated a few seconds before self-initiated movements in the absence of external triggering stimuli. Similar activations were observed in the closely connected cortical supplementary motor area, suggesting that these activations might evolve through build up in fronto-basal ganglia loops. They may relate to intentional states directed at movements and their outcomes. As a second result, neurons in the striatum were activated in relation to the expectation and detection of rewards. Since rewards constitute important goals of behaviour, these activitations might reflect the evaluation of outcome before the behavioural reaction is executed. Thus neurons in the basal ganglia are involved in individual components of goal-directed behaviour.

OBJECTIVE: To find out whether taking images of the male and female genitals during coitus is feasible and to find out whether former and current ideas about the anatomy during sexual intercourse and during female sexual arousal are based on assumptions or on facts. DESIGN: Observational study. SETTING: University hospital in the Netherlands. METHODS: Magnetic resonance imaging was used to study the female sexual response and the male and female genitals during coitus. Thirteen experiments were performed with eight couples and three single women. RESULTS: The images obtained showed that during intercourse in the "missionary position" the penis has the shape of a boomerang and 1/3 of its length consists of the root of the penis. During female sexual arousal without intercourse the uterus was raised and the anterior vaginal wall lengthened. The size of the uterus did not increase during sexual arousal. CONCLUSION: Taking magnetic resonance images of the male and female genitals during coitus is feasible and contributes to understanding of anatomy.

Abstract:  Although a fundamental physical parameter, surface tension is difficult to measure. Common tensiometry inaccuracy comes from failure to control air–liquid–solid contact conditions, or account for liquid meniscus geometry and buoyancy corrections. This paper describes an in situ tensiometry technique, based on withdrawal of a thin-walled tube from the liquid interface, that enforces a known air–liquid–solid contact condition. This technique can be pursued at any level of experimental hygiene. Experimental results for filtered tap water, an alcohol–water solution, and a surfactant–water solution show that results repeatable to three significant digits are obtained with modest effort for a variety of geometrical parameters.

Smart-power IC technology has made on-board protection of electronic components from stress feasible and cheap. The MPC2005 from Motorola Inc., for example, integrates a T-MOS SCR with C-MOS control circuitry to provide superior over-voltage and over-temperature protection for circuit board components. When stressful pre-set voltage and temperature thresholds are exceeded, the MPC 2005 will short-circuit the power supply and remove the voltage from the circuit in question.

Bipolar transistors are used for switching high voltages at medium currents and low voltages at high currents. Transistors are available in many packages for many different purposes. Power MOSFETs are faster and easier to drive. Several power MOSFETs are now available and are being used in several applications. These FETs are suitable for low power applications. A circuit diagram of an FET is included.

AbstractAerial surveys covering 5117 linear kilometers were conducted at 91 and 183 m altitude under optimal sighting conditions in an area north of Fyn, Denmark, and in the Bay of Kiel, Germany, in June-July 1991. A total of 116 harbour porpoise, Phocoena phocoena, pods (140 animals) were observed, of which 22 were seen in the Bay of Kiel. Density of pods of porpoises were estimated by use of line-transect theory utilizing measurements of perpendicular distances to sightings and fitting the probability density function by a hazard rate model. The mean of the pod sizes ranged between 1.1 and 1.3, and they were used to estimate the actual number of porpoises present at surface during the survey. The abundance of porpoises in the area north of Fyn was 457 (95% CI: 288–726) which was significantly larger than the estimate of 160 for the Bay ofKiel (95% CI: 96–267). The mean pod size was lower than estimates obtained from shipboard surveys. A more realistic and independent estimate of mean pod size (1.96) was used to calculate abundances of 820 (95% CI: 519–1297) and 251 (95% CI: 153–410) porpoises in the area north of Fyn and the Bay of Kiel, respectively. No corrections were applied for submerged porpoises. Strip census methods are not applicable to harbour porpoise surveys because the width of the strip where an equal detection probability persists is unacceptably narrow. It is recommended that future surveys should be conducted at an altitude of 183 m and that line transect methods should be applied.

Abstract: In this prospective study high tibial osteotomy for medial gonarthrosis was performed in 95 patients (105 knee joints). The patients underwent simultaneously diagnostic and operative arthroscopic surgery of the knee joint. A follow-up arthroscopic examination could be performed in 75 patients (85 knee joints) at the time of implant removal. In group 1 (20 knee joints), the osteotomy was performed after diagnostic arthroscopy without arthroscopic operation of the knee joint. The fixation of the osteotomy was accomplished by staples, postoperative plaster fixation and physiotherapy. In group 2 (20 knee joints), osteotomy was performed without additional operative arthroscopy after diagnostic arthroscopy, internal fixation by AOT-plate, no external fixation postoperatively and physiotherapy. In group 3 (22 knee joints), osteotomy was performed with additional operative arthroscopy (Pridie drilling), internal fixation by AOT-plate no external fixation postoperatively no external fixation, physiotherapy and continuous passive motion. In group 4 (23 knee joints), osteotomy was performed with additional operative arthroscopy (abrasio-arthroplasty), internal fixation by AOT-plate, no external fixation postoperatively, physiotherapy and continuous passive motion. All patients underwent arthroscopic examination of the knee with cartilage biopsies taken from three different regions of the femoral condyle during the same operative session as the osteotomy. At follow-up arthroscopy cartilage biopsies were taken from the same regions. There was no great difference in clinical outcome after 1 year between all groups. Arthroscopy as well as routine and electron microscopy showed better cartilage regeneration in groups 3 and 4. Groups 1 and 2 showed only regeneration isles, sometimes not well fixed to the underlying bone, while in groups 3 and 4 cartilage regeneration was thicker and more stable, sometimes covering all of the pre-existing erosions. Therefore, we recommend osteotomy of the tibia for osteoarthritis together with operative arthroscopy in the same operative session.

The sources of input and the behavioral effects of lesions and drug administration suggest that the striatum participates in motivational processes. We investigated the activity of single striatal neurons of monkeys in response to reward delivered for performing in a go-nogo task. A drop of liquid was given each time the animal correctly executed or withheld an arm movement in reaction to a visual stimulus. Of 1593 neurons, 115 showed increased activity in response to delivery of liquid reward in both go and nogo trials. Responding neurons were predominantly located in dorsal and ventromedial parts of anterior putamen, in dorsal and ventral caudate, and in nucleus accumbens. They were twice as frequent in ventral as compared to dorsal striatal areas. Responses occurred at a median latency of 337 ms and lasted for 525 ms, with insignificant differences between dorsal and ventral striatum. Reward responses differed from activity recorded in the face area of posterior putamen which varied synchronously with individual mouth movements. Responses were directly related to delivery of primary liquid reward and not to auditory stimuli associated with it. Most of them also occurred when reward was delivered outside of the task. These results demonstrate that neurons of dorsal and particularly ventral striatum are involved in processing information concerning the attribution of primary reward.

The oculomotor performance of monkeys was investigated before and after destruction of nigrostriatal dopamine neurons by MPTP (1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine). Stimulus-triggered saccades and their relationships to arm movements were measured in a reaction time task. Spontaneous eye movements were recorded while monkeys sat in a primate chair and looked around the laboratory without performing any task. In the reaction time task, saccades and arm movements were commonly triggered by the rapid, visible and audible opening of a small food-containing box which was located at a constant position in front of the animal at eye level. Median saccadic latencies ranged from 68 to 118 ms in intact animals. Saccades were followed by onset of electromyographic (EMG) activity in the extensor digitorum communis and the biceps brachii, the prime mover muscles for the following arm reaching movement. Latencies of stimulus-triggered saccades showed an absence of linear relationship to EMG or arm movement reaction time in intact animals (correlation coefficients of 0.15–0.56). This suggests that eye and arm movements were initiated independently from each other in this experimental situation. Treatment with MPTP resulted in 98–99.5% loss of striatal dopamine in both monkeys. This induced a 29–93% increase in saccadic latency in the reaction time task. The sequential occurrence of saccade, EMG activity and arm movement in each trial was preserved, although intervals between onset of saccades and onsets of EMGs and arm movements were prolonged by 53–173% and 33–679% respectively. Onsets of individual saccades remained uncorrelated with onsets of EMG activity or arm movement. Spontaneous eye movements were strongly reduced in frequency and amplitude after MPTP. Administration of the dopamine precursor L-Dopa increased spontaneous eye movements for less than two hours. The severe deficits in stimulus-triggered and spontaneous saccadic eye movements are oculomotor components of hypokinesia arising after MPTP-induced lesions of the nigrostriatal dopamine system in primates. The data are further evidence for a role of midbrain dopamine neurons in behavioral responsiveness and spontaneous activity.

Administration of MPTP (1-methyl-1,2,3,6-tetrahydropyridine) to Macaca fascicularis monkeys produced severe parkinsonism (hypokinesia, tremor, rigidity, aphagia, adipsia) and more than 90% loss of nigral dopamine neurons, striatal dopamine content and striatal 3H-mazindol binding. Treatment with the catecholamine uptake blocker nomifensine counteracted the behavioral, histological and neurochemical effects induced by MPTP. For obtaining best protection, nomifensine had to be administered for weeks after MPTP. The results suggest that the selective target-directed neurotoxic action of MPTP on dopamine neurons in monkeys is mediated via the dopamine uptake mechanism.

The somatotopic representation of the hindlimb in the gracile nucleus was studied in two cats who had a congenital defect of one hindfoot. The defect comprised all of the foot downward from and including the heel, and the distal third of tibia and fibula. The part of the sciatic nerve normally supplying the lower hindlimb and the hindfoot was reduced in diameter by one third. The motoneurones corresponding to the absent muscles were lacking and replaced by glial elements. The cross-sectional area of the dorsal columns at segment S2 was reduced by more than 20%. The gracile nuclei, in contrast, were not reduced in size. Only the diameter of its neurones was significantly smaller.

Übersicht Aufgrund des zunehmenden Einsatzes von glasfaserverstärkten Kunststoffen (GFK) in der Freiluftisoliertechnik ist das Verhalten der Werkstoffe unter Feuchtigkeitseinfluß von großem Interesse. In diesem Aufsatz wird der Transportmechanismus von Wasser in GFK beschrieben und mathematisch behandelt. Der Einfluß der aufgenommenen Feuchtigkeit auf die dielektrischen Kenngrößen der Werkstoffe wird untersucht und ein Verfahren zur Berechnung der Dielektrizitätszahl anhand der gemessenen Wasseraufnahmekurven entwickelt. Der Einfluß der Werkstoffzusammensetzung wird ebenfalls diskutiert.

An investigation of the energy dependence of grey prong producing particles in 16O+ emulsion interactions at energies from 2.1 to 200 AGeV is reported. Many of the features of these particles, known from hadron-induced interactions, are shown to be of importance also in heavy-ion interactions, i.e. multiplicity and angular distributions as well as the impact parameter dependence are energy independent. Furthermore the angular distribution seems to be independent of the projectile and target masses as well as centrality of the interactions. Both the Fritiof and Ranft models fail to reproduce this general angular shape.

Chebyshev pseudospectral solutions of the biharmonic equation governing two-dimensional Stokes flow within a driven cavity converge poorly in the presence of corner singularities. Subtracting the strongest corner singularity greatly improves the rate of convergence. Compared to the usual stream function/ vorticity formulation, the single fourth-order equation for stream function used here has half the number of coefficients for equivalent spatial resolution and uses a simpler treatment of the boundary conditions. We extend these techniques to small and moderate Reynolds numbers.

In a prospective cohort study of 210 women who underwent uncomplicated primiparous childbirth the relative effects of episiotomy, first or second degree perineal tears and delivery without tears or episiotomy on perineal pain and dyspareunia have been investigated. After childbirth, women who underwent an episiotomy indicated a significantly higher level of perineal pain than women whose perineum was intact or torn. On physical examination significant differences in the occurrence of hematomas between the various groups of women could be detected, probably accounting for the differences in pain level observed. While perineal pain in the first postpartum week is most likely following episiotomy, dyspareunia at 6 months is most frequently found in women having perineal tears. In comparison to the situation before pregnancy, for the total experimental patient population dyspareunia decreased. This decline in dyspareunia is most obvious for women whose perineum remained intact, less obvious for women with an episiotomy and absent for women with a perineal tear.

In this study, the literature on the concept of vaginismus is reviewed as well as existing ideas about etiology and treatment. The review reveals that consensus only exists on the physiological aspects of vaginismus, whereas a great variety of ideas and opinions are used with regard to the etiology and treatment of this sexual problem. The most recent approaches are the psychoanalytical view, the behavioristic view, the interactional view and the sociocultural view. The study also comprises a review of the Anglo-Saxon literature on the outcome of treatment of vaginismus. Over the last three decades, 37 studies have been published: 17 case studies and 20 survey studies. The review makes it clear that vaginismus is usually treated successfully and that the kind of treatment does not seem to play an important role in this. All treatment modalities report a success rate of about 80%. Differences, however, do exist regarding the therapeutic goals and cost-benefit ratios. Before drawing any firm conclusions, it has to be mentioned that the review also revealed that hardly any of the publications investigated, met even the most basic methodological demands. It is therefore concluded that well designed and controlled studies on the treatment of vaginismus should be conducted in the near future.

Administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to two monkeys led to hypokinesia, tremor, rigidity, adipsia and aphagia. Quantitative assessment of hypokinesia revealed increased reaction time, delayed onset of muscle activity and prolonged movement time in a forelimb reaching task after selective degeneration of the nigrostriatal dopamine (DA) system sparing mesocortical dopamine neurons. The losses of pars compacta cells of substantia nigra, of striatal [3H]mazindol binding and of striatal DA content (more than 90%) quantitatively paralled the severity of behavioral deficits. Additional monoamine systems were affected with stronger MPTP effects.

The behavioral involvement of neurons in the pars reticulata of the substantia nigra (SNpr) in sensory and motor processes was investigated in order to contribute to the understanding of behavior-related neuronal mechanisms in the basal ganglia, of which the SNpr is a major output station. Electrophysiological properties of SNpr neurons were studied with extracellular recordings from single neurons in monkeys performing in a behavioral GO/NO-GO paradigm, employing significant auditory and visual stimuli, forelimb reaching movements, and mouth movements. Neurons in the SNpr discharged impulses of 0.6 to 1.0 ms in duration, at rates of 23 to 145/s (median 68/s). They contrasted with dopaminergic pars compacta neurons of substantia nigra, which discharged longer impulses at rates below 8/s. Two-thirds of more than 100 quantitatively and statistically evaluated SNpr neurons showed changes with temporal relationships to at least one of the events of the behavioral task. One-fifth of all neurons covaried with more than one event. The largest group of task-related neurons increased or decreased activity with contralateral forelimb movements (46% of all neurons). Most of them covaried with large forward reaching of the arm, and only the minority covaried with distal forearm manipulation. None of the SNpr neurons resembled in their changes the timing of activity of single muscles. Many neurons also showed changes with ipsilateral movements, in a similar fashion as on the contralateral side. Changes began rarely before and mostly with or after onset of muscle activity in prime movers. Changes were quantitatively moderate, rarely exceeding a doubling of discharge rate with increases and reductions by 50% with decreases. Movement relations did not appear to be due to somatosensory input. Some neurons increased or decreased their activity in relation to mouth movements (16% of all neurons). Changes were quantitatively moderate as in the case of movement relationships. Nine percent of all neurons decreased their activity after an acoustic preparatory signal and 9% after a light stimulus indicating the GO or NO-GO situation. Latencies were 50-150 ms (median 90 ms) for the auditory and 80-200 ms (median 120 ms) for the visual responses. Twelve percent of all neurons increased or decreased their activity during the waiting and preparation period, which lay between an initial sensory signal and the permission to move for reward.(ABSTRACT TRUNCATED AT 400 WORDS)

Destruction of the midbrain dopamine (DA) system in Parkinsonian man and experimental animals leads to deficits in initiation of behavior, motor performance, and cognitive mechanisms. We have investigated the extracellular impulse activity of single midbrain DA neurons in unlesioned monkeys performing in a controlled behavioral task that was designed to paradigmatically test behavioral reactivity. Animals were trained to execute natural forelimb reaching movements for food reward in response to a trigger stimulus. Presumptive DA neurons were histologically located in the pars compacta of substantia nigra and in neighboring areas A8 and A10. They spontaneously discharged polyphasic impulses of relatively long duration (1.4-3.6 ms) and at low frequencies (0.5-8.5/s). Systemic injections of low doses of the DA autoreceptor agonist apomorphine (0.05-0.2 mg/kg) depressed the activity of virtually all thus tested DA neurons. In following established criteria, these characteristics strongly suggest the DAergic nature of the recorded neurons. The majority of midbrain DA neurons (70 of 128) responded to the behavioral trigger stimulus of the task with a short burst of impulses. Latencies ranged from 39 to 105 ms (median 65 ms) for onset and from 65 to 165 ms (median 95 ms) for peak of responses. Responses occurred before arm movement and at the time of or before onset of electromyographic (EMG) activity in prime mover muscles. Responses were time-locked to the stimulus and not to the onset of movement or EMG. Responses remained present in most neurons but were reduced when vision of the behavioral trigger stimulus was prevented while maintaining the associated acoustic signals. In another variation of the task, most neurons also responded to a stimulus that was physically identical to the behavioral trigger but to which the animal made no movement. The activity of a few DA neurons (11 of 128) was reduced following presentation of the behavioral trigger stimulus, with latencies comparable to those of activations. The activity of many DA neurons was increased (40 of 128) or reduced (22 of 128) during execution of the forelimb reaching movement. These changes were of a slow and moderate nature, and were minor compared with responses to the behavioral trigger stimulus. About half of movement-related neurons also responded to the behavioral trigger. The activity of a few DA neurons was increased (11 to 128) or reduced (1 to 128) when the food reward reached the mouth. These changes did not occur with spontaneous mouth movements. About half of these neurons also responded to the behavioral trigger.(ABSTRACT TRUNCATED AT 400 WORDS)

1. Previous studies have shown that midbrain dopamine (DA) neurons in monkeys respond to external stimuli that are used to initiate behavioral reactions. In the present study, we investigated to what extent changes in neuronal activity would occur when behavioral acts are generated internally or whether they would depend solely on external stimuli. 2. Monkeys performed self-initiated arm movements from a resting key into a covered, food-containing box at a self-chosen moment and without external preparatory or triggering signals. In a second task, the arm movement was triggered by rapid opening of the door of the food box. This stimulus was either audible and visible or only audible to the animal. Impulses of DA neurons were recorded with movable microelectrodes from the pars compacta of substantia nigra (area A9) and areas A8 and A10 and were discriminated from those of other neurons by their long duration (1.5-5.0 ms) and low spontaneous frequency (0.5-8.5 imp/s). 3. The activity of 12% of 104 DA neurons increased slowly and moderately up to 1,500 ms before the onset of individual self-initiated arm movements. Median increases amounted to 91% over background discharge rate. A further 16% of DA neurons were activated together with the onset of muscle activity and during the movement. 4. During self-initiated movements, a nonhabituating, phasic burst of impulses occurred when the monkey's hand touched a morsel of food inside the box. This response was seen in 84% of 154 neurons on the contralateral side, with median onset latency of 65 ms and duration of 160 ms. A comparable percentage of neurons responded to ipsilateral touch with similar latency and duration. 5. The touch response during self-initiated movements was absent, both on the contra- and ipsilateral sides, when the animal's hand touched the bare wire normally holding the food, when touching nonfood objects, or during tactile exploration of the empty interior of the food box. Thus responses appeared to be related to the appetitive properties of the object being touched rather than the object itself. 6. In the task employing stimulus-triggered movements, 77% of 86 DA neurons discharged a burst of impulses in response to door opening but entirely failed to respond to the touch of food in the box. The response to door opening in this task was similar to the touch response during self-initiated movements in the same neurons in terms of latency, duration, and magnitude.(ABSTRACT TRUNCATED AT 400 WORDS)

1. This study investigates the behavioral conditions in which dopamine (DA) neurons of substantia nigra and adjoining areas A8 and A10 respond with impulses to visual and auditory trigger stimuli eliciting immediate arm- and eye-movement reactions. 2. In a formal task, the rapid opening of the door of a small, food-containing box located at eye level ahead of the animal served as visible and audible trigger stimulus. Most DA neurons on the contralateral side responded to this stimulus with a short burst of impulses with median onset latency of 50 ms and duration of 90 ms (75% of 164 neurons). Similar responses were seen in a comparable fraction of DA neurons during ipsilateral task performance, suggesting that responses were not specific for the limb being used. 3. When the sensory components of the door opening stimulus were separated, DA neurons typically responded in a similar manner to the moving visual stimulus of the opening door, the low-intensity sliding noise of the opening door, and the 1-kHz sound of 90-92 dB intensity emitted from a distant source at the onset of door opening. Responses to each component alone were lower in magnitude than to all three together. 4. In a variation of the task, a neighboring, identical food box opened in random alternation with the other box but without permitting animals to reach out (asymmetric, direct-reaction go/no-go task). With each sensory component, DA neurons typically responded both to opening of go and no-go boxes. Responses were enhanced when stimuli elicited limb movements in go trials. 5. Monkeys reacted to door opening with target-directed saccadic eye movements in the majority of both go and no-go trials. Neuronal responses were equally present during the occasional absence of eye movements. Thus responses were not specific for the initiation of individual arm or eye movements. 6. Neuronal responses were absent when the same stimuli occurred outside of the behavioral task with target-direct arm and eye movements lacking. This shows that responses were not of purely sensory nature but were related to the capacity of the stimulus for eliciting behavioral reactions. 7. In a variation of the go/no-go task, an instruction light illuminated 2-3 s before door opening prepared the animal to perform the reaching movement on door opening or to refrain from moving (asymmetric, instruction-dependent go/no-go task).(ABSTRACT TRUNCATED AT 400 WORDS)

Several lines of evidence suggest that the supplementary motor area (SMA) and the premotor cortex (PM) may participate in neuronal mechanisms for the initiation of movements. We recorded the impulse activity of single neurons in monkeys that were trained in two behavioral tasks employing, respectively, self-initiated and externally timed movements. Neurons in both areas were activated up to 2.6 s in advance of self-initiated, reward-related arm reaching movements. In the externally timed task, changes occurred during light instructions that preceded movements by 2 s. Neurons also responded to the trigger stimulus for movement. In view of similar premovement activity in the basal ganglia, these cortical regions appear to be parts of a distributed neuronal system for movement initiation.

The sources of afferent input to the striatum (caudate nucleus and putamen) suggest that this structure may be engaged in neuronal processes related to the initiation of movement. We found that 26% of 508 neurons in both parts of the striatum were activated during the presentation of visual signals which prepared the animals for the execution or withholding of individual arm reaching movements. In a second task, 20% of 382 striatal neurons were activated up to 3 s before self-initiated, non automatic and purposive arm movements which were performed in the complete absence of phasic external stimuli. The data demonstrate an involvement of the striatum in externally and internally generated processes which are related to presetting mechanisms during the initiation of behavioral acts.

The extracellular activity of single pars compacta neurons of the substantia nigra was recorded in awake monkeys. Animals were subjected to a behavioral paradigm consisting of separate phases of preparation for trained movements and their execution. Cell activity was also studied during untrained movements.

The spontaneous activity of neurons in the head of the striatum was studied in rats 3 days and more than 1 year after a 6-hydroxydopamine-induced lesion of the nigrostriatal dopamine system in comparison to unlesioned animals. Cells were detected and tracked by stimulating the excitatory corticostriatal pathway.

Responses in the somatosensory cortical area S I to stimulation of facial sinus hairs were recorded in the anaesthetized cat and compared with activity in primary afferent fibres innervating vibrissae follicles. The specific cortical vibrissa area is somatotopically organized; 39% of the cortical units in that area responded to stimulation of only a single sinus hair but in some cases all maxillary vibrissae activated a single cortical neurone. The responses consisted of three major groups; either a phasic discharge in response to the movement part of a stimulus, or an additional tonic discharge related to the steady period of vibrissa deflection, or a tonic discharge. On the basis of a comparison of response and excitability characteristics of primary afferent and cortical neurones it is concluded that all four kinds of peripheral units innervating sinus hair follicles project to the somatosensory cortical area S I. It appears from these findings that some cortical neurones receive a specific input related to a particular component of the complex primary afferent response in fibres innervating sinus hair follicles. The results are discussed with respect to previous reports on the central representation of facial sinus hairs in different species.

Abstract: 1,16-Diiodohexadecane was obtained by reaction of 1,16-hexadecanediol and potassium iodide. The14C-label was introduced into the 1,16-diiodohexadecan using a substitution reaction which replaced one of the terminal iodine with14C-cyanide. Hydrolysis and HPLC purification of 1-14C-17-iodoheptadecanoic acid yielded a product with a radiochemical yield of 17% and a specific activity of approx. 1850 MBq mol–1.

Summary: In the Wadden Sea, in total, 55 species of spiders are threatened in at least one subregion. Of these, 50 species are threatened in the entire area and are therefore placed on the trilateral Red List. According to the present knowledge, no species of the listed spiders are extinct in the entire Wadden Sea area. The status of 3 species of spiders is (probably) critical; 12 species are endangered; the status of 30 species is (probably) vulnerable and of 6 species susceptible.

Zur Erklärung eines Sammeleffekts, der beim Rühren von auftriebsbehafteten kleinen Teilchen in newtonschen Flüssigkeiten auftreten kann, wird die Bewegung eines einzelnen Teilchens in einer geeignet gewählten, einfachen Modellströmung theoretisch untersucht. Unter gewissen Voraussetzungen läßt sich für den Modellfall eine analytische Lösung angeben. Anhand von experimentellen Ergebnissen aus einem Rührversuch wird gezeigt, daß die Theorie des Modellproblems die wesentlichen Abhängigkeiten des realen Sammeleffekts mit guter Näherung beschreibt.