[Changes in neuropsychic activities during work in clean rooms]. / Promeni v nervno-psikhichnata deinost pri rabotaq v chisti stai.

In clean rooms of the system of electronics are carried out work-physiological examinations on two basic professional groups--working in photolithography and operators. At the end of the workings day a considerable prolongation of the sensomotor reactions and deterioration of the dynamometric indices, characterizing the functional status of the neuro-muscular system were found. The time for performing the complex sensomotor reactions (choice of reaction) remains unchanged. At the end of the working day as a result of the performance of a considerably complex work activity, carried out in the clean rooms, was established a significant decrease in the functional state of the central nervous system and development of general and nervous fatigue.

[Stress reaction to work today]. / Reaktsiia na stres pri suvremenniia trud.

The characteristic of stress factors at work and their effect upon humans is of great significance in labour optimization, detection of early changes in organism, assessment of the operative MAC and MAN, standardization and categorization of labour, etc. On the base of such studies (biochemical, physiological and psychophysiological) stress and fatigue in various occupations and working regimes are characterized. The results from the studies on stress reactions at work are presented in a summarized way, making use of complex methodical approach.

[Amino acid composition of kashkaval (cheese made of sheep milk) treated with antimold agents]. / Aminokiselinen sustav na kashkavala, obraboten s pokrivni protivoplesenni sredstva.

Studied were 14 batches of ewe milk kashkaval and 13 batches of Vitosha yellow cheese treated with protective antimold agents, such as antiplessin and 'potassium sorbate with movilit'. Kjeldahl's method was employed to determine the total protein, and acid hydrolysis of proteins by means of an automatic amino acid analysis unit HD 1200 ERDG, CSSR to determine the amount of free amino acids. It was found that on the 60th day of the ripening of kashkaval treated with antiplessin the total protein averaged 25.16 per cent; with the use of 'potassium sorbate with movilit' it was 25.39 per cent, on an average. On the 60th day of ripening Vitosha yellow cheese contained 23.97, resp., 23.81 per cent total protein. With the employment of acid hydrolysis is protein in both types of kashkaval the following amino acids were produced: lysine, histidine, arginine, asparagic acid, treonine, serine, glutamic acid, proline, glycine, alanine, valine, methionine, tyrosine, isoleucine, leucine, and phenylalanine. It was also established that from the 30th up to the 60th day of ripening the amino acids were subjected to transformation. Highest were the amounts of lysine, asparagic acid, glutamic acid, proline, methionine, tyrosine, and leucine. During ripening no production of cystine was demonstrated. Both antiplessin and 'potassium sorbate with movilit' did not have any negative effect on the ripening of these types of kashkaval.

[Age-related changes in work capacity]. / Prouchvane na niakoi promeni v rabotosposobnostta na vuzrastov aspekt.

Bank female employees, aged from 18 to 55, were examined in order to characterize some changes in the nervous-psychic capacity for work in age aspect. The following methods were used: inquiry for the subjective assessment of the strain and fatigue during work, DAM--a test characterizing the activity, disposition and mood, level of neurotism according to Ajsenk, time of single visual-motor reaction and reaction of choice. Some age changes in the subjective assessment of fatigue, disposition, and activity were established. The age changes in psychomotor sphere were enhanced under the effect of work loading. Among the age group 51-55, the subjective assessment of fatigue, disposition and activity were more favourable, not corresponding to the clearly manifested age changes in psychomotor sphere. Prophylactic measures, aiming at the optimization of the work of bank female workers, are elaborated on the base of the examinations carried out.

[Changes in the fats in yellow cheese treated with surface antimold agents]. / Promeni v mazninite na kashkavala, tretiran s pokrivni protivoplesenni sredstva.

Studied were the changes setting in with fats in the process of ripening of the ewe milk yellow cheese, kashkaval type, and cow milk yellow cheese Vitosha treated with the antimold preparations 'antiplessin' and 'potassium sorbate with movilit'. There were slightly expressed hydrolytic and oxidation processes involving the milk fat. On the 60th day fat acidity after Ketstorfer was 2.17 degrees K, resp., 2.25 degrees K, on an average, with ewe milk kashkaval, and 1.92 degrees K, resp., 2.03 degrees C, on an average, with Vitosha cheese. On the 60th day of ripening the peroxide number of milk fat in kashkaval was 0.1316, resp., 0.1335, on an average, and in Vitosha cheese it was within the range of 1.0298 to 0.1454, on an average. The average values of the iodine number of fats dropped up to the 60th day, however, remained within the normal value characteristic of quality fats.--32.77, resp., 32.97 for kashkaval, and 31.40, resp., 29.30 for cheese Vitosha. No epihydrin aldehyde was found in both types of cheese up to the 60th day of ripening with the use of the two preparations.

Diurnal variations in the cortical visual and auditory evoked potentials.

Visual and auditory evoked potentials (VEP and AEP) have been recorded for six subjects during the day (11.00-12.00 h) and during the night (23.00-24.00 h). For each subject the following parameters were estimated separately: the confidence limit of the averaged EP, the mean value and the standard error of the latencies of the EP components, EP energy and the product-manner correlation coefficient to evaluate waveform similarity of two evoked potentials. In order to estimate the diurnal variations of VEP and AEP, a comparison is made for each subject separately of the amplitudes and latencies, and their dispersions at N100, P200 for VEP and N100, P200 and P300 for AEP during the day and during the night. During the night hours the amplitudes of the different components and the EP energy are found to increase. The variativity of VEP and AEP increases during the night, while the degree of EP similarity and especially of their late components, decreases. The symmetry of the interhemispheric distribution of VEP, estimated by the peak amplitudes and the energy during the night hours of investigation, is disrupted.

[Ampicillin tolerance and content in the mammary gland of lactating cows and sheep]. / Ponosimost i zadurzhanie na ampitsilin v mlechnata zhleza na laktirashti kravi i ovtse.

Experiments were carried out with lactating cows and ewes consisting in the intramammary application of ampicillin-trihydrate with the use of syringe cannules, and with paraffin and vaselin as constituents. Cows were treated with 10 cm3 (500,000 IU) (in the respective quarter of the udder), and ewes--with one half of the syringe content. The milk of the treated animals was sampled prior to manipulation, at the 24th, the 48th, 72nd and 96th hour in order to follow up the time during which the antibiotic was retained in the milk as well as the changes in the cell content and the hydrogen ion concentration. It was found that ampicillin persisted in milk up to the 48th hour in therapeutic concentrations. At the 96th hour the milk proved free of the antibiotic in both cows and ewes and could be offered for consumption or technologic processing.

[Development and resistance of staphylococci in Bulgaricus milk]. / Razvitie i ustoichivost na stafilokokite v bulgarskoto kiselo mliako

Studied was the dynamics of development of 9 strains of staphilococci isolated from humans and animals, kept in heat-treated milk, and their resistance in Bulgarian sour milk. It was established that the pathogenic Staph. aureus and Staph. epidermidis develop will in fresh milk kept up to 7 days at 2--6degreesC and 18--22degreesC. In the production of Bulgarian sour milk Staph, aureus was shown to be viable, remaining active for seven days at 2 to 6degreesC. At room temperature (18--22degreesC) the survival rate has been dependent on the dynamics of accumulating metabolite products in connection with the development of Lactobac. bulgaricum and Streptococcus thermophilus. When the total acidity value reaches 160degreesT the pathogenic staphylococci are destroyed. Staphylococcus epidermidis finds no favourable medium to develop in Bulgarian sour milk, and it perishes when the total acidity is 120degreesT and pH -- 3.

[Characteristics of the staphylococci isolated from the udder of cows with mastitis]. / Kharakteristika na stafilokoki, izolirani ot vimeto na kravi s mastit

A total of 175 strains of Staphylococcus aureus and 67 strains of Staphylococcus epidermidis were studied, isolated from 486 samples of milk secretion taken aceptically from the individual quarters of the udder of cows affected with subclinical and purulent (clinical) mastitis. The staphylococci were referred to as the causative agent of mastitis in case they were the only microflora in the seedings of the investigated material. Tests were applied as given in Fig. 1 to characterize the strains. It was found that mastitis in cows could be due to both plasma coagulating staphylococci (Staphylococcus aureus) and coagulase-negative Staphylococcus epidermidis organisms. The two Staphylococcus species were isolated from cows with clinical and subclinical mastitis. The division between pathogenic and nonpathogenic Staphylococcus strains by the plasma-coagulating symptom proved impossible, and this made it necessary to use other tests for pathogenicity. It became evident that the thing Staph. aureus and Staph. epidermidis had in common when isolated from cows with mastitis was the production of a gold-like pigment and delta hemolysin. Similarly to Staph. aureus isolated animals, the bovine Staph. epidermidis organisms did not possess fibrinolysin and rarely produced hemolysin. The isolated organisms belonging to the coagulase-positive staphylococci corresponded by their basic properties to Staphylococcus aureus var. bovis as described in the literature. The cultures of Staphylococcus epidermidis isolated under similar conditions showed in a considerable per cent of the cases somewhat different behaviour.

[Analysis of a subjective assessment of work and morbidity in modern jobs]. / Analiz na subektivnata otsenka na truda i zabolevaemostta pri suvremennite profesii.

An analysis is made of the subjective assessment of work and morbidity in individuals engaged in two groups of up-to-date occupations: a) with considerable, and b) with insignificant nervous strain. The questionnaire study covers 1420 workers. Morbidity analysis is carried out on the basis of data from 1980 temporary disability cards--90 per cent of the workers exposed to a substantial neurosensory stress feel tired at the end of the working day. It is accepted that the cause of fatigue is firstly, the sustained and continuous observation and secondly, the rhythm required. The greater concentration and monotomy are pointed out as the primary cause in group two. The incidence of central nervous system diseases among workshop supervisors and operators of punching machines definitely augments with the length of service. The morbidity rate of gastrointestinal and peripheral nervous system diseases is also rather high.

[Determination of the optimum of physical loading in relation to the maximum potentialities of the body]. / Opredeliane optimuma na fizicheskoto natovarvane v zavisimost ot maksimalnite vuzmozhnosti na organizma.

Determination of the maximum capacity of work is essential for prophylaxis, and is closely related to the problems of scientific organization of work still awaiting solution. The maximum oxygen consumption among female textile workers ranges between 2.2 1/min and 1.6 1/min, while the reak heart rate--from 167 to 153 beats per minute. Allowable physical exertion among female textile workers should not exceed 3.5 kcal/min.