Fluctuations of grass pollen content in the atmosphere of East Perugia and meteorological correlations (year 1989)

Summary Gramineae pollination from a pollen monitoring station located in the eastern suburb of Perugia and meteorological correlations are reported. The data refers to the year 1989. Grass pollen peak pollination was from May to July; in this period the influence of relative humidity and of temperature on pollen concentration was very high. Phenological observations, to identify the time of maximum stamen extension in the most common genera in the area, are also reported. During the period of investigation the counts of pollen grains over four-hour periods showed a regular diurnal rhythm with peaks of concentration in the four-hour period 16.00–20.00. Aerosporological data and meteorological data related to four-hour periods were correlated following different criteria.     

Observing the Temperature Dependent Transition of the GP2 Peptide Using Terahertz Spectroscopy

The GP2 peptide is derived from the Human Epidermal growth factor Receptor 2 (HER2/nue), a marker protein for breast cancer present in saliva. In this paper we study the temperature dependent behavior of hydrated GP2 at terahertz frequencies and find that the peptide undergoes a dynamic transition between 200 and 220 K. By fitting suitable molecular models to the frequency response we determine the molecular processes involved above and below the transition temperature (T _D). In particular, we show that below T _D the dynamic transition is dominated by a simple harmonic vibration with a slow and temperature dependent relaxation time constant and that above T _D, the dynamic behavior is governed by two oscillators, one of which has a fast and temperature independent relaxation time constant and the other of which is a heavily damped oscillator with a slow and temperature dependent time constant. Furthermore a red shifting of the characteristic frequency of the damped oscillator was observed, confirming the presence of a non-harmonic vibration potential. Our measurements and modeling of GP2 highlight the unique capabilities of THz spectroscopy for protein characterization.     

Control of infection in general practice: a survey and recommendations.

Twenty general practices in four areas in Britain were surveyed to establish their needs for and practices of sterilising and disinfecting equipment. Of the 327 items of equipment and instruments examined in the survey, 190 were satisfactorily decontaminated, 100 were treated in a way judged to result in doubtful decontamination, and in 37 cases treatment was considered unsatisfactory. Decontamination apparatuses (autoclaves, hot air ovens, and hot water disinfectors) were generally in good working order, but the use of chemical disinfectants was often inappropriate. Recommendations were made on appropriate methods of decontamination for various items in common use in general practice. By virtue of the large numbers of patients treated by general practitioners there is a substantial possibility of transmitting infection; having appropriate methods for decontaminating instruments and equipment is therefore imperative.     

A selective differential medium for the isolation of Listeria monocytogenes

A new medium has been developed for the isolation of Listeria monocytogenes from clinical specimens with a mixed flora. Almost complete inhibition of unwanted organisms was achieved and recognition of colonies of Listeria spp. was usually possible after 24 h using the aesculin-ferric ammonium citrate indicator system. Compared to McBride agar the new medium was more inhibitory to representative contaminating species in pure culture and more successful in isolating small numbers of L. monocytogenes from artificially seeded clinical specimens.     

Tissue culture and plant regeneration from sunflower (Helianthus annuus) and interspecific hybrids (H. tuberosus x H. annuus)

A method is described for the culture and regeneration of plants from callus of sunflower (Helianthus annuus) andH. annuus x H. tuberosus hybrids. Immature embryos proved to be the only explant which consistently gave regenerable cultures in all genotypes. The most responsive embryos were approximately 12 mm² in area. Genotype had a significant effect on the capacity of cultures to regenerate. Some regeneration was also obtained from cultures of tuber tissue but only from one genotype,H. tuberosus x H. annuus cross 200. None of theH. annuus accessions gave regenerable callus from root tissue. Difficulties included the premature initiation of flowering of regenerating shoots and the frequent occurence of "vitreous" plantlets which could not be transplanted successfully to soil. Some amelioration of both these problems was achieved by replacing inorganic nitrogen partially with amino acids. More effective reduction of these difficulties was accomplished by the addition of 10, 30 and 100 M phloridzin, esculin or naringin.Abbreviations BAP 6-benzylaminopurine; zeatin, trans-6-(4-hydroxy-3-methyl-but-2-enyl) aminopurine; kinetin, 6-furfurylaminopurine - IAA indole-acetic acid - NAA naphthyl acetic acid     

Persistent sympathetic nervous system arousal associated with tethering in cynomolgus macaques

The swivel-tether system has been used extensively in biomedical research involving nonhuman primates, yet there has been little or no investigation into potential adverse influences of this form of restraint on research results. In the study described here, a portable electrocardiographic telemetry system was used for continuous monitoring of the heart rate of 26 cynomolgus monkeys while: (a) pair-caged, 8 weeks prior to tethering; (b) singly-caged, tethered; (c) singly-caged, tethered, administered propranolol (30 mg/kg/day) in the diet; (d) group-housed (five monkeys per group), 1 week after group formation; and (e) group-housed (five monkeys per group), 4 weeks after group formation. Tethering resulted in persistent elevations in heart rate relative to the other conditions. Administration of propranolol, a beta-adrenergic antagonist, resulted in an abrupt, sustained decrease in heart rate indicating that the increase in heart rate associated with tethering was due to persistent stimulation of the sympathetic nervous system. Since multiple aspects of cardiovascular function are influenced by the sympathetic nervous system, and other organs and systems (e.g., pituitary-gonadal) also may be affected, investigators using the swivel-tether system should be cognizant of these potential effects when designing experiments and interpreting the results.     

The role of air temperature in determining dormancy release and flowering ofCorylus avellana L.

Summary 7 years of airborne pollen monitoring in Perugia (central Italy) were used to determine the temperature requirements to break dormancy and to resume growth and bloom ofCorylus avellana L.,Corylus needs 1000 chill-units to complete its dormancy and this value, in the Perugian area, is met by the end of December or the first days of January. MoreoverCorylus trees require 220 growth degree hours before they are able to flower. If air temperature is high, this value can be achieved in only 10 days, but if the temperature remains too low, the heat accumulation can require up to 35 days. With these parameters it is possible to build a model to predict the date of the beginning ofCorylus avellana pollen season.     

Effect of photoperiod on body weight and food intake of obese and lean Zucker rats

Although the rat is usually not considered to be sensitive to photoperiod, under some experimental conditions photoperiod responses are unmasked. In addition, we have observed photoperiod-induced changes in body weight gain in lean and obese Zucker rats. In this experiment, body mass, food intake, body composition, brown adipose tissue (BAT) thermogenic state, and blood concentrations of corticosterone, insulin, and glucose were evaluated under one of two lighting conditions: a short (10 h light: 14 h dark) or a long (14 h light: 10 h dark) photoperiod. Plasma corticosterone and glucose concentrations measured under fasting conditions were unaffected by photoperiod in either genotype. The amount of BAT mitochondrial protein isolated was less in long photoperiod rats. BAT mitochondrial GDP binding was unaffected by photoperiod in the lean rats, but tended to be lower in long photoperiod obese rats than in short photoperiod obese rats. Although, photoperiod had no effect on daily food intake of rats exposed to the short versus long photoperiod, body mass was heaviest in obese rats raised in long photoperiod. Plasma insulin was increased in both lean and obese rats in long photoperiod. In addition, fat storage appeared to shift to internal depots in the lean rats exposed to long photoperiod. Our data demonstrate that photoperiod does have an effect on male Zucker rats with respect to body weight and fat distribution, with the obese rats being more sensitive to changes in photoperiod than the lean rats.