Non-equilibrium phase transition in a model for supercoiling-dependent DNA transcription.

We study a variant of a recently proposed non-equilibrium stochastic model for supercoiling-dependent transcription in DNA. In the case of a circular DNA molecule with overall positive supercoiling, we find a non-equilibrium phase transition between an absorbing phase, where all genes are switched off due to the supercoiling, and an active phase with a non-zero transcription rate. Mean field theory predicts that the transition should be continuous at a critical value of the background supercoiling, and we focus our analysis on this case. Our simulations suggest that the switch between the transcribed and silent phases may actually be a fluctuation-induced discontinuous transition, where the jump in the transcription rate decreases with the number of genes in the system.

Packing density of HS(CH2)(n)COOH self-assembled monolayers.

Self-assembled monolayers (SAMs) of HS(CH(2))(n)COOH, n = 5, 10, 15 deposited from ethanol solution onto gold are prepared by five approaches, and their packing densities are evaluated by X-ray photoelectron spectroscopy (XPS) measurements. The five approaches are: (1) direct deposition; (2) acetic-acid-assisted deposition; (3) butyl-amine-assisted deposition; (4) displacement of a preformed HS(CH(2))(n)CH(3) (n = 5, 10, 15) SAMs; and (5) co-deposition with HS(CH(2))(n)CH(3) (n = 5, 10, 15). Packing density metrics are calculated from measurements of SAM and substrate photoemission intensities and their attenuations by two methods. In one case the attenuated photoemissions are expressed as a ratio relative to comparable measurements on an experimental HS(CH(2))(n)CH(3) model system. In the other case a new method is introduced where a calculated attenuation based on theoretical random coil and extended chain models is used as the reference to determine a packing density fraction. Packing densities are also correlated with the S2p(Au-bonded):Au4f peak area ratios and with shifts in the C1s binding energies. SAMs prepared by the direct deposition are a partial multilayer where a second molecular layer is physisorbed onto the SAM and not removable by solvent washing. The addition of acetic acid to the deposition solution disrupts dimer associations of HS(CH(2))(n)COOH in solution and at the surface of the monolayer and yields the most ordered monolayer with the highest density of -COOH groups. The addition of butyl amine results in a labile ammonium carbonate ion pair formation but results in a lower packing density in the SAM. The displacement of the preformed HS(CH(2))(n)CH(3) SAM and the co-deposition of HS(CH(2))(n)CH(3) with HS(CH(2))(n)COOH result in SAMs with little incorporation of the -COOH component.

Non-associative learning in the mouse. Effect of morphine and naloxone.

The study evaluates the effect of morphine and naloxone on the process of non-associative learning in the mouse. Exploratory behavior was measured in thirty-six male albino mice (Suisse) placed on a Boissier and Simon hole-board, the procedure being repeated 24 h later after administration of naloxone and/or morphine, or bidistilled water i.p. The results show that the inhibitory effect naloxone has on the recollection process of the mnemonic traces appears to be masked by morphine.

Selective DNA-mediated assembly of gold nanoparticles on electroded substrates.

Motivated by the technological possibilities of electronics and sensors based on gold nanoparticles (Au NPs), we investigate the selective assembly of such NPs on electrodes via DNA hybridization. Protocols are demonstrated for maximizing selectivity and coverage using 15mers as the active binding agents. Detailed studies of the dependences on time, ionic strength, and temperature are used to understand the underlying mechanisms and their limits. Under optimized conditions, coverage of Au NPs on Au electrodes patterned on silicon dioxide (SiO2) substrates was found to be approximately 25-35%. In all cases, Au NPs functionalized with non-complementary DNA show no attachment and essentially no nonspecific adsorption is observed by any Au NPs on the SiO2 surfaces of the patterned substrates. DNA-guided assembly of multilayers of NPs was also demonstrated and, as expected, found to further increase the coverage, with three deposition cycles resulting in a surface coverage of approximately 60%.

[Tension, depression, pain. Critical considerations and experimental data regarding idiopathic headache]. / Tensione, depressione, dolore. Considerazioni critiche e dati sperimentali a proposito delle cefalee idiopatiche.

Following a discussion of the main psychodynamic theories concerning the etiology of idiopathic headache, the Authors describe their own research. The data reported suggest the existence of a wide range of psycho-behavioural aspects in the different diagnostic groups and it is therefore misleading to consider these in global terms. A revised method of psycho-genetic interpretation relating to migraine patients is proposed. In the second half of the paper the Authors outline a definitive rather than causal interpretation of psychosomatic disorders.

[Myorelaxants in pediatric anesthesia]. / I miorilassanti in anestesia pediatrica.

The response to muscle relaxants and the dose required change during growth from birth to adolescence. Some physiological factors such as development of neuromuscular junction, the different distribution of the muscle fibres, and the extracellular fluid compartment affect the non depolarizing muscle relaxant (NDMR) ED 95, onset time and recovery time. Infants under 1 year of age are more sensitive to the NDMR and need less drug; children aging more than 1 year are more resistant and need a larger amount of drug; the reversal of the neuromuscular blockade before extubation, is extremely important especially in infants with long-acting agents.

[Dreams and schizophrenia: a qualitative analysis]. / Sogno e schizofrenia: un'analisi qualitativa.

The dreams of a group of 16 patients diagnosed to have schizophrenic disturbance according to DSM III and those of 16 individuals chosen from the general population using the standardised Sheppard and Saul method, have been examined. The results showed that schizophrenic patients present a weaker ego in their dreams. However, a single dream may not be typical of either group and a distinction is only possible on the basis of a series of dreams. Further differences were identified between the dreams of patients diagnosed as having paranoid type schizophrenic disturbance and those with undifferentiated schizophrenia.

[Psychosomatic assessment in patients with gravidic hyperemesis]. / Indagine psicosomatica in pazienti affette da iperemesi gravidica.

Thirty female subjects examined in the first three months of pregnancy took part in the study. Ten of these suffered from severe gravidic hyperemesis, while twenty had a physiological pregnancy. All subjects with hyperemesis and six controls were subjected to measurement of cortisolaemia at the following times: 8, 12, 16, 20, 24 and 4.00 so as to obtain the circadian curve of the hormone, measurement of T3 and T4 and of TSH. The Cattell test in form C was carried out in all patients. The results obtained evidenced a global increase in the production of cortisol in the group of hyperemetic women, with maintenance of the circadian rhythm. The Cattell test identified characteristic personality traits in the subjects suffering from hyperemesis compared to the controls.

Psychological aspects of weekend headache sufferers in comparison with migraine patients.

Sometimes the relaxation after stress may trigger a migraine attack. This is the principle that underlies that particular variant of migraine called "weekend headache". We hypothesize the presence in weekend headache prone subjects of a particular psychological background, different from that of common migraine sufferers. In order to detect possible differences supporting our hypothesis, we studied 104 new outpatients: 46 patients suffering from headache only on weekends (23 males and 23 females) and 58 matched common migraineurs (26 males and 32 females) with no weekend predilection. The psychological assessment was performed using the following psychometric tools: MMPI, BDI, STAIX1-X2. A clinical assessment of each patient was also carried out. Significant differences were found after statistically analyzing the test results. Most of the MMPI scales were found to be more elevated in both male and female weekend headache sufferers. From a clinical point of view, the weekend headache attacks proved to be similar to those of common migraine, but with a significantly higher incidence of concomitant symptoms. Our study confirms the important role that psychological factors play in the pathogenesis and clinical development of migraine and leads us to conclude that a psychic tension component is associated with the vascular one in weekend headache.

[Alexithimia: psychosomatic structure or transcultural trait?]. / Alessitimia: struttura psicosomatica o tratto transculturale?

The these put forward by Marty and Sifneos on the one hand and by Cremerius on the other regarding "psichosomatic structure" have been compared in 66 patients suffering from idiopathic cephalea. Of these, 49 were suffering from migraine and 17 from musculotensive cephalea. The conclusion was that the alexithimic trait is related to the sociocultural level of the patients, not to their clinical picture.

[Depression, neurotic traits and angina type pains in women]. / Depressione, tratti neurotici e dolore anginoso tipico nella donna.

The study examines the relative influence of sundry psychological risk factors on the various forms of angina pectoris found in two groups of women with classic angina pains attributable in one group to critical organic lesions of the coronary arteries and in the other to functional spasm. In all 81 women were examined and no significant difference was found between the two groups.

[Evaluations of respiratory functional parameters in sponge fishers from the island of Kalimnos (Greece)]. / Valutazioni dei parametri di funzionalità respiratoria nei pescatori di spugne dell'isola di Kalimnos (Grecia).

We had intended to study functional respiratory patterns of a sponge-divers group from the Island of Kalymnos (Greece). Such a group constitutes a very homogeneous sample for dietary habits and underwater activity, handed down from father to son. Some of these sponge-divers dives holding his breath; others use "narghilè", a special apparatus consisting in a nosepiece connected to an air compressor placed in the boat. As their activity is continuative and prolonged for several months in the years with repeated dives from dawn to dusk, and because air output of narghilè is nearly constant, it is possible to deduce that in these subjects functional respiratory modifications are occurred. After evaluated three groups (skindivers, narghilè-divers and control-group) we didn't notice any particular change of static and dynamic pulmonary volumes. Only Expiratory Reserve Volume is higher in spite to Knudson's values; this is probably due to psychological and emotional factors.