Influence of composition and degradation on the shear strength of municipal solid waste.

This study aimed to evaluate the shear strength of municipal solid waste (MSW) of different landfilling ages exhumed from disposal sites in a subtropical humid environment. Wastes which had been landfilled from ages of 2 up to 25years were characterized using physical, chemical and biochemical tests and were tested in a large scale direct shear device. The results indicate that the tested wastes older than five years had reached similar decomposition stages, but showed different compositions in terms of soft plastics, incompressible material and reinforcing elements.

Characterizing a Brazilian sanitary landfill using geophysical seismic techniques.

Two different geophysical techniques, namely crosshole and multichannel analysis of surface waves - MASW, were applied to investigate the mechanical response of Municipal Solid Waste buried under humid, subtropical climate. Direct investigations revealed that the buried waste was composed mainly of soil-like material (51%) and plastics (31%) with moisture content average values of 43% near the surface and 53% after around 11m depth. Unit weight varied between 9kN/m(3) and 15kN/m(3).

Methane generation in tropical landfills: simplified methods and field results.

This paper deals with the use of simplified methods to predict methane generation in tropical landfills. Methane recovery data obtained on site as part of a research program being carried out at the Metropolitan Landfill, Salvador, Brazil, is analyzed and used to obtain field methane generation over time. Laboratory data from MSW samples of different ages are presented and discussed; and simplified procedures to estimate the methane generation potential, Lo, and the constant related to the biodegradation rate, k are applied.

Adenosine 5'-triphosphate (ATP) concentration and acrosin activity in human spermatozoa. Their relation with the sperm penetration assay (SPA).

Fertility of men depends on the quality of semen. The aim of the present paper is to determine both the acrosin activity by radioimmunoassay and ATP concentration by bioluminescence in human spermatozoa, and evaluate these results in those samples with normal or low sperm penetration according to SPA test. Ejaculates obtained from 42 untreated men, were studied one hour after the obtention.

Adenosine 5'-triphosphate (ATP) activity in normal and pathological human semen. Relationship with round cells of the ejaculate.

The aim of the present paper is deleted to determine ATP activity in the human seminal cells by bioluminescence and to investigate the relationship between these values and the number of round cells either peroxidase positive or peroxidase negative. We studied 244 untreated men, divided into six groups. Our mean value of ATP activity in normal semen was 20.

Glycerylphosphorylcholine in selected forms of male infertility.

GPC was studied in the seminal plasma of 35 normozoospermic men, 34 cases of azoospermia due to bilateral deferent obstruction, 34 cases of azoospermia due to bilateral ejaculatory duct obstruction, 10 vasectomized patients, 6 vasectomized patients after vasovasostomy and 118 cases of spermatogenetic arrest without obstruction of the seminal ducts. Values of GPC in azoospermia due to deferent or ejaculatory ducts obstruction and to vasectomy are significantly lower than in normozoospermic subjects (p less than 0.001).

Changes in sialic acid concentration in human saliva during the menstrual cycle.

Salivary sialic acid concentration was studied daily in 20 fertile women during the menstrual cycle. The Warren method was used and plasma LH and BBT were also determined. The sialic acid concentrations in saliva throughout the cycle showed a peak 4 or 5 days before the LH preovulation surge.

Contractile behaviour of rat seminal vesicle after gonadectomy, testosterone replacement and cyproterone treatment.

The effects of bilateral gonadectomy, testosterone replacement and cyproterone acetate treatment on seminal vesicle contractions were studied in rats in order to contribute new data on the role of androgens in the spontaneous motility of the seminal vesicle. In gonadectomized-testosterone treated rats the glands exhibited a spontaneous rhythmic activity similar to that of entire animals. The seminal vesicles of gonadectomized as well as of cyproterone treated rats also contracted spontaneously but the contractions showed a smaller amplitude.

Effects of methyl xanthines upon the spermatozoa adenosinetriphosphate (ATP) concentration in normal semen.

The aim of the present study was to ascertain the effect of methyl xanthines upon the spermatozoa ATP concentration in normal semen in vitro. 26 normal semen were studied. The specimens were diluted after liquefaction with equal volume of Lopata's buffer or Lopata's buffer plus 1 or 6 mM either of caffeine or pentoxifylline.

Effects of autonomic drugs on contractions of rat seminal vesicles in vivo.

Various autonomic drugs were placed on the peritoneal covering of the seminal vesicles of anaesthetized rats. Adrenaline (which stimulates the alpha-, beta 1- and beta 2-adrenoceptors) and phenylephrine (an alpha-stimulating agent) produced a sudden increase in tonus and in the amplitude and frequency of contractions. Phentolamine (an alpha-blocker) prevented these effects, whereas propranolol (a beta 1- and beta 2-blocker) did not.

In vivo recording of contractile activity of pelvic urethra and seminal vesicle in rats. Effects of electrical stimulations and neurohypophysial hormones.

The spontaneous contractility of the pelvic urethra and seminal vesicles in the rat was recorded in vivo and the effects of the electrical stimulation as well as the neurohypophysial hormones on it were studied. The mean amplitude of pelvic urethra contractions was 3.2 +/- 0.

On the problem of the phagocytic capacity of Sertoli cells. Electron microscopic study in the rat.

To study the real phagocytic capacity of Sertoli cells the following experiments were carried out: carbon colloidal solution or thorium dioxide of particle size 0.01--0.03 micrometer as 2% solution were injected in rat testes at a speed of 50 microliter per minute by means of a infusion pump.

Adenosinetriphosphate (ATP) in human spermatozoa. II. Concentrations in fertile men.

The Bucher's method was applied to establish normal values of ATP in the spermatozoa of fertile men. It was shown that the normal value is 6.5 +/- 0.

Effect of chronic treatment with prostaglandin E2 on male rat fertility.

Adult male rats were treated with prostaglandin E2 (100 microgram/100 g body wt) during 60 days. Neither morphological alterations in genital organs nor modification in epididymal contractility were observed. Nevertheless, a significant diminution of fertility was registered.

Contractile behaviour of rat epididymis after sympathectomy produced by the administration of guanethidine.

The effect of guanethidine (a sympatholytic agent) on epididymal contractions was studied in rats, in order to contribute new data on the role of both the adrenergic and cholinergic nerves in the spontaneous motility of the epididymis and also during ejaculation. The first type of activity was increased when adrenergic innervation was damaged, but the amplitude and frequency of contractions reached normal values approximately 3 hours after beginning the records. Since spermatozoa were eliminated after electroejaculation, the second type of contractions was not affected either.

Biochemical changes of the human semen produced by chlorambucil, testosterone propionate and human chorionic gonadotropin administration.

Biochemical analysis and morphological studies were carried out in six patients with lymphomas during and after withdrawal treatment with chlorambucil, testosterone propionate (TP) and human chorionic gonadotropins (HCG). In the course of the treatment with chlorambucil patients developed severe oligozoospermia or azoospermia. The spermatogenesis recovered after a variable period of time following suspension of treatment.

Multiple complexes in human spermatocytes.

Multiple complexes develop during metaphase I in normal human spermatocytes. Usually they form two separate bodies about 1 micron in diameter, composed of tripartite units and a denser matrix. The tripartite units are structurally identical to the components of the central space of synaptonemal complexes (SCs).