The surface of Mars: there view from the viking 1 lander.

The first photographs ever returned from the surface of Mars were obtained by two facsimile cameras aboard the Viking 1 lander, including black-and-white and color, 0.12 degrees and 0.04 degrees resolution, and monoscopic and stereoscopic images. The surface, on the western slopes of Chtyse Planitia, is a boulder-strewn deeply reddish desert, with distant eminences-some of which may be the rims of impact craters-surmounted by a pink sky. Both impact and aeolian processes are evident. After dissipation of a small dust cloud stirred by the landing maneuvers, no subsequent signs of movement were detected on the landscape, and nothing has been observed that is indicative of macroscopic biology at this time and place.

Fine particles on Mars: observations with the viking 1 lander cameras.

Drifts of fine-grained sediment are present in the vicinity of the Viking 1 lander. Many drifts occur in the lees of large boulders. Morphologic analysis indicates that the last dynamic event was one of general deflation for at least some drifts. Particle cohesion implies that there is a distinct small-particle upturn in the threshold velocity-particle size curve; the apparent absence of the most easily moved particles (150 micrometers in diameter) may be due to their preferential transport to other regions or their preferential collisional destruction. A twilight rescan with lander cameras indicates a substantial amount of red dust with mean radius on the order of 1 micrometer in the atmosphere.

The surface of Mars: the view from the viking 2 lander.

Viking 2 lander began imaging the surface of Mars at Utopia Planitia on 3 September 1976. The surface is a boulder-strewn reddish desert cut by troughs that probably form a polygonal network. A plateau can be seen to the east of the spacecraft, which for the most probable lander location is approximately the direction of a tongue of ejecta from the crater Mie. Boulders at the lander 2 site are generally more vesicular than those near lander i. Fines at both lander sites appear to be very fine-grained and to be bound in a duricrust. The pinkish color of the sky, similar to that observed at the lander I site, indicates suspension of surface material. However, the atmospheric optical depth is less than that at the lander I site. After dissipation of a cloud of dust stirred during landing, no changes other than those stemming from sampling activities have been detected in the landscape. No signs of large organisms are apparent at either landing site.

Ontogeny of proenkephalin gene expression in the rat hypothalamus.

In the rat hypothalamus, proenkephalin (PE) mRNA synthetizing cells were detected by in situ hybridization, using synthetic oligodeoxy-nucleotides, from embryonic day 14 (E14) in the presumptive anterior hypothalamic area (AHA) and preoptic part of the bed nucleus of the stria terminalis (BST), and from E18 in the developing median preoptic area, perifornical area, suprachiasmatic nucleus, dorsomedial and ventromedial hypothalamic nuclei. In the paraventricular nucleus, cells expressed PE gene in the late prenatal stages; both parvo- and magnocellular neurons synthetized PEmRNA in the early postnatal stages. Cells expressing PE gene were observed after birth in the lateral preoptic area, lateral hypothalamus, medial and lateral parts of the BST. PEmRNA was also found from E14 in the striatum, from E18 in the central and medial amygdaloid nuclei, the medial group of the thalamic nuclei, and postnatally in a second more anterior structure of the thalamus. In the hypothalamus, a clear similarity was observed between adult and developmental distributions of PE gene expressing cells. The early onset of PE gene expression in the developing rat diencephalon suggests an involvement of PE in developmental processes, such as cell proliferation and differentiation; the presence of PE during the perinatal period may also indicate the appearance of adult neural regulations.

Ontogeny of prodynorphin gene expression in the rat hypothalamus.

Opioid peptides, deriving from prodynorphin, proenkephalin and proopiomelanocortin genes, have been shown to modulate brain development. Prodynorphin gene expression was studied here by in situ hybridization in the developing rat hypothalamus using oligodeoxynucleotide probes. Prodynorphin mRNA-synthetizing cells were observed in the ventromedial hypothalamic nucleus, the supraoptic and the paraventricular nuclei from embryonic days 16, 18 and 21, respectively. We detected no transient expression of prodynorphin gene in the rat hypothalamus. Prodynorphin mRNA-containing cells were also observed prenatally in the striatum, the cortex, the hippocampus and the amygdala. When compared with data from the literature, our results suggest that translation may immediately follow transcription of prodynorphin gene in the supraoptic nucleus. The presence of prodynorphin mRNA in the developing rat hypothalamus also raises the possibility of an involvement of prodynorphin-derived peptides in developmental processes and/or in the maturation of adult neural regulations.

Expression of the c-ets1 gene in the hypothalamus and pituitary during rat development.

The Ets gene family codes for transcription factors containing a conserved DNA binding domain: the Ets-binding domain. The proto-oncogene c-ets1 is highly expressed in lymphoid organs and in developing mesodermal-originating structures. We studied c-ets1 gene expression in the developing rat hypothalamo-hypophyseal system, using in situ hybridization on paraformaldehyde-fixed frozen sections. At embryonic day 12 (E12) and E13, cells synthesizing c-ets1mRNA are found in the neural tube where they form small, heavily labeled strand-like and punctate structures; positive mesenchymatous cells, corresponding to the surface capillary network, surround the brain and hypophysis. C-ets1mRNA is synthesized from E14 in the neural pituitary and E15 in the adenohypophysis, during angiogenesis; no c-ets1mRNA is detected in the avascular intermediate pituitary at any stage. Strand-like c-ets1mRNA labeling is intense from E14 to E21 in the diencephalon. This labeling is also detected during perinatal stages in the hypothalamic magnocellular nuclei, one of the most richly vascularized brain areas. In the rat hypothalamo-hypophyseal system, c-ets1 gene expression is maximal during fetal and perinatal stages and progressively decreases thereafter until adulthood. The spatio-temporal correlation observed between c-ets1 gene expression and blood vessel formation in the rat hypothalamus and pituitary suggests a role for c-ets1 in angiogenesis in this system.

Dipyrone and diclofenac do not influence creatinine-clearance, inulin-clearance or PAH-clearance in healthy male volunteers.

The effects of the non-steroidal anti-inflammatory drug diclofenac and the pyrazolone derivative dipyrone on renal function were compared with those of placebo in 12 healthy male volunteers in a randomized, controlled, triple-crossover study with a wash-out period of 4 days between each of the 3 trial periods (dipyrone, diclofenac and placebo) which lasted three days each. The volunteers received dipyrone (1 g, 3 times/day for 2 days, followed by twice 1 g on the main trial day, which was day 3 of each study period) or diclofenac (50 mg, 3 times/day for 2 days, followed by twice 50 mg on the main trial day) or placebo orally. Standardized meals (50 mEq sodium per day) were given from one week before the start until the end of the study and on the main trial days a protein-rich lunch (2 g protein/kg body weight) was taken. Renal function was assessed in each study period by measurement of creatinine-clearance, inulin-clearance and p-aminohippurate (PAH)-clearance to characterize glomerular filtration rate and renal plasma flow. High protein intake induced glomerular hyperfiltration (increased creatinine-clearance, inulin-clearance and PAH-clearance) in all 3 study periods (dipyrone, diclofenac, placebo). Dipyrone and diclofenac had no effect on renal clearance of creatinine, inulin or PAH in comparison to placebo. These results show that dipyrone and diclofenac at therapeutic dosages over 3 days do not decrease glomerular filtration and renal plasma flow in healthy individuals. Furthermore, it is unlikely that prostaglandins play a major role in protein-induced glomerular hyperfiltration.

Selective electroencephalograph-guided microsurgical callosotomy for refractory generalized epilepsy.

Between 1978 and 1985, 35 patients with medically refractory multiform seizures were submitted for sections of variable portions of the corpus callosum. Guided by intraoperative electroencephalographic and electrocorticographic monitoring, the section was carried out only in the portion of callosum that was involved in the maintenance of the bilaterally synchronous slow spike and wave discharge (as documented by intraoperative electrocorticography). In our patients, only part of the frontal corpus callosum needed to be sectioned to interrupt the bilateral synchrony of epileptic discharge. Of the 35 patients, operated on, 28 have had an adequate long-term follow up and are presented herein. All had significant improvement in seizure frequency and psychosocial functioning.

[Clinical study of viloxazine (author's transl)]. / L'étude clinique de la viloxazine.

An open study of viloxazine has been achieved in a psychiatric unit. The drug has been prescribed to 36 patients, all comers, half of them aged 60. Out of them 28 are affected by a psychotic depression, six by a neurotic depression. In terms of the importance of the depressive signs, medium posologies (300 mg a day) or strong ones (600 mg a day) are used. The total result is excellent or good in 65% of the cases: it becomes evident in more than one case out of two during the first week. To get it the treatment must absolutely be extended and process to higher posologies may be necessary. Involutional melancholia and the depressive phase of chronic psychosis constitute the best terms of viloxazine. Hypnotics have to be associated but systematic prescription of anxiety relieving is to be avoided. Tolerance is satisfactory in three cases out of four and the drug is free from the clinical counter-indications belonging to anti-depressants. This allows us to prescribe it to old age in high posologies without any harm.

[Tiapride in disorders of behaviour in the elderly]. / Le tiapride dans les troubles du comportement de la personne âgée.

Our experience with tiapride in 30 elderly inpatients with disorders of behaviour is reported. In a daily dosage of 50 to 600 mg, the drug was effective on sleep disorders, agitation, irritability and aggressiveness. Tolerance was excellent.

Estimation of spectral reflectance curves from multispectral image data.

A technique is presented for estimating spectral reflectance curves from multispectral image data even if the spectral samples are obtained from channels whose spectral responsivity is not narrowband. It is demonstrated that these reflectance estimates can be written as a linear combination of the spectral samples and that, analogous to Shannon's sampling theorem, if the spectral reflectance is a natural cubic spline, it can be estimated exactly provided the number of spectral channels is sufficiently large. Simulation results suggest that the accuracy of the spectral reflectance estimates is quite good and very insensitive to the spectral responsivity shapes.

Image quality prediction: an aid to the Viking Lander imaging investigation on Mars.

Two Viking spacecraft scheduled to land on Mars in the summer of 1976 will return multispectral panoramas of the Martian surface with resolutions 4 orders of magnitude higher than have been previously obtained and stereo views with resolutions approaching that of the human eye. Mission constraints and uncertainties require a carefully planned imaging investigation that is supported by a computer model of camera response and surface features to aid in diagnosing camera performance, in establishing a preflight imaging strategy, and in rapidly revising this strategy if pictures returned from Mars reveal unfavorable or unanticipated conditions.

Optical-mechanical line-scan imaging process: its information capacity and efficiency.

An expression for the information capacity of the optical-mechanical line-scan imaging process is derived, which includes the effects of blurring of spatial detail, photosensor noise, aliasing, and quantization. Both the information capacity for a fixed data density and the information efficiency (i.e., the ratio of information capacity to data density) exhibit a distinct single maximum when displayed as a function of sampling rate, and the location of this maximum is determined by the system frequency response shape, SNR, and quantization interval.

Aliasing and blurring in 2-D sampled imagery.

The quality of image reconstructions from discrete data suffers not only from the blurring of spatial detail caused by limitations in the spatial frequency response of electrooptical systems, but also from the aliasing generated if spatial detail has been undersampled. P. Mertz and F. Grey [Bell Syst. Tech. J. 13, 464 (1934)] and O. H. Schade [J. Soc. Motion Pict. Telev. Eng. 56, 131 (1955); 58, 181 (1952); 61, 97 (1953); 64, 593 (1955)] have observed that reasonable spot intensity profiles and photosensor aperture shapes of equivalent size result in about equal blurring but that some profiles and shapes suppress aliasing better than others. This paper presents quantitative results of the magnitude of aliasing and blurring as a function of random radiancefields typical for natural scenes and of spatial responses and sampling intervals typical for TV cameras and optical-mechanical scanners. These results indicate that aliasing may often be a larger source of degradation than either blurring or electronic noise.

Information efficiency of line-scan imaging mechanisms.

Information theory is used to formulate a single figure of merit for assessing the performance of line-scan imaging systems as a function of their spatial response (PSF or MTF), sensitivity, and sampling and quantization intervals and of the statistical properties of a random radiance field. Information density and efficiency (i.e., the ratio of information density to data density) tend to be optimum when the MTF and sampling passband of the imaging system are matched to the Wiener spectrum of the radiance field. Computational results for the statistical properties of natural radiance fields and the responses of common line-scan imaging mechanisms indicate that information density and efficiency are not strongly sensitive to variations in typical statistical properties of the radiance field and that the best practically realizable performance is approached when the sampling intervals are ~0.5-0.7 times the equivalent diameter of the PSF.

Photosensor aperture shaping to reduce aliasing in optical-mechanical line-scan imaging systems.

Optical-mechanical scanning techniques are generally employed in instruments specifically designed to characterize variations in scene brightness spectrally or radiometrically. The effect of aliasing, which can be caused by line-scan sampling, on the spatial detail of the reconstructed image has therefore been of little concern. Emphasis of some recent applications of optical-mechanical scanning techniques is, however, on the spatial characterization of the scene. As is shown here, such images can be severely degraded by aliasing. Photosensor aperture shaping and line-scan spacing are investigated as a means for reducing this degradation.

Visual communication with retinex coding.

Visual communication with retinex coding seeks to suppress the spatial variation of the irradiance (e.g., shadows) across natural scenes and preserve only the spatial detail and the reflectance (or the lightness) of the surface itself. The separation of reflectance from irradiance begins with nonlinear retinex coding that sharply and clearly enhances edges and preserves their contrast, and it ends with a Wiener filter that restores images from this edge and contrast information. An approximate small-signal model of image gathering with retinex coding is found to consist of the familiar difference-of-Gaussian bandpass filter and a locally adaptive automatic-gain control. A linear representation of this model is used to develop expressions within the small-signal constraint for the information rate and the theoretical minimum data rate of the retinex-coded signal and for the maximum-realizable fidelity of the images restored from this signal. Extensive computations and simulations demonstrate that predictions based on these figures of merit correlate closely with perceptual and measured performance. Hence these predictions can serve as a general guide for the design of visual communication channels that produce images with a visual quality that consistently approaches the best possible sharpness, clarity, and reflectance constancy, even for nonuniform irradiances. The suppression of shadows in the restored image is found to be constrained inherently more by the sharpness of their penumbra than by their depth.

Reducing property of some slow acting antirheumatic drugs.

Many slow acting antirheumatic drugs and several other drugs without antirheumatic activity possess a potential thiol function, i.e., a free SH group or one that is generated by hydrolysis. Since drugs with effective SH activity may react with intracellular disulfides, we evaluated their reducing properties by measuring their redox potential and their ability to react with glutathione, the most prevalent intracellular thiol, and dithiobis (nitrobenzoic acid), a specific reactant for thiols. Drugs containing aromatic thiols are poor reducers and are generally devoid of antirheumatic activity. Antirheumatic drugs, such as D-penicillamine, levamisole, gold salts, thiopronine and captopril, are potential aliphatic thiols with strong reducing properties. These different antirheumatic drugs may therefore operate by a common mechanism through an altered cellular redox equilibrium and sulfide-disulfide exchanges.

Quasi-microscope concept for planetary missions.

Viking lander cameras have returned stereo and multispectral views of the Martian surface with a resolution that approaches 2 mm/lp in the near field. A two-orders-of-magnitude increase in resolution could be obtained for collected surface samples by augmenting these cameras with auxiliary optics that would neither impose special camera design requirements nor limit the cameras field of view of the terrain. Quasi-microscope images would provide valuable data on the physical and chemical characteristics of planetary regoliths.

[Open clinical trial of a new oral galenic form of ketoprofen]. / Expérimentation clinique en essai ouvert d'une nouvelle forme galénique orale du kétoprofène.

Thirty-two patients with rheumatoid arthritis and several other rheumatic diseases were entered into a randomized study to investigate the correlation between the pharmacokinetics and clinical effectiveness of Bi-Profenid 150 mg. Each patient was given, in a variable order, one 150 mg Bi-Profenid tablet twice daily for 2 days, and two 50 mg Profenid capsules each morning and noon with one 100 mg suppository each evening for 2 days. Dosage convenience, effectiveness on pain during the second part of the night and resolution of morning stiffness were considered better with Bi-Profenid by 23 patients and with conventional forms by four, while five reported no preference. In 15 patients treated for one month, only 5 reported mild side-effects which did not require withdrawal from the study. The patients' preference appears to be a result of the bioavailability of Bi-Profenid.