Common Action and Electricity Trade in Northern Europe

Common action (CA) increases the possibilities to adapt to restrictions on CO₂ emissions. In this paper the value of common action is quantified for Denmark, Norway and Sweden using a systems engineering model, MARKAL. Electricity trade as a means for CA is studied in more detail.     

Tumor progression and metastasis in murine D2 hyperplastic alveolar nodule mammary tumor cell lines

Interaction of a 70-amino acid zinc-binding polypeptide from the regulatory chain of aspartate transcarbamoylase (ATCase) with the catalytic (C) subunit leads to dramatic changes in enzyme activity and affinity for ligand binding at the active sites. The complex between the polypeptide (zinc domain) and wild-type C trimer exhibits hyperbolic kinetics in contrast to the sigmoidal kinetics observed with the intact holoenzyme. Moreover, the Scatchard plot for binding N-(phosphonacetyl)-L-aspartate (PALA) to the complex is linear with a Kd corresponding to that evaluated for the holoenzyme converted to the relaxed (R) state. Additional evidence that the binding of the zinc domain to the C trimer converts it to the R state was attained with a mutant form of ATCase in which Lys 164 in the catalytic chain is replaced by Glu. As shown previously (Newell, J.O. & Schachman, H.K., 1990, Biophys. Chem. 37, 183-196), this mutant holoenzyme, which exists in the R conformation even in the absence of active site ligands, has a 50-fold greater affinity for PALA than the free C subunit. Adding the zinc domain to the C trimer containing the Lys 164-->Glu substitution leads to a 50-fold enhancement in the affinity for the bisubstrate analog yielding a value of Kd equal to that for the holoenzyme. A different mutant ATCase containing the Gln 231 to Ile replacement was shown (Peterson, C.B., Burman, D.L., & Schachman, H.K., 1992, Biochemistry 31, 8508-8515) to be much less active as a holoenzyme than as the free C trimer. For this mutant holoenzyme, the addition of substrates does not cause its conversion to the R state. However, the addition of the zinc domain to the Gln 231-->Ile C trimer leads to a marked increase in enzyme activity, and PALA binding data indicate that the complex resembles the R state of the holoenzyme. This interaction leading to a more active conformation serves as a model of intergenic complementation in which peptide binding to a protein causes a conformational correction at a site remote from the interacting surfaces resulting in activation of the protein. This linkage was also demonstrated by difference spectroscopy using a chromophore covalently bound at the active site, which served as a spectral probe for a local conformational change. The binding of ligands at the active sites was shown also to lead to a strengthening of the interaction between the zinc domain and the C trimer.     

Radiographic estimation of intracuff pressure in mechanically ventilated patients

We evaluated the usefulness of roentgenographic tracheal tube cuff shadow to tracheal wall diameter ratio (CTW ratio) and cuff minus tracheal diameter difference (C-T diameter) in estimating intracuff pressure (ICP) in intubated and mechanically ventilated patients. Seventy-one measurements of ICP, CTW ratio and C-T diameter were obtained from 20 mechanically ventilated male patients intubated with high volume low pressure cuffs in the surgical and medical intensive care units. The mean age was 61 years (range 30 to 83 years). ICP was measured by one observer, while CTW ratio and C-T diameter was measured by another observer. No significant relationship was seen between ICP and CTW ration (r = 0.092, p = 0.873), or between ICP and C-T diameter (r = 0.093, p = 0.42) by linear regression analysis. In conclusion, roentgenographic estimation of ICP by portable plain chest films in intensive care units was not found useful in this study.     

Birth order in homosexual versus heterosexual sex offenders against children, pubescents, and adults

OBJECTIVE: The selection of patients amenable to treatment with a bladder neck sling remains a controversy. In this paper we review our experience with this technique and describe our patient selection criteria. METHODS: Since 1991, 30 patients (24 females and 6 males) aged 4 to 20 years (mean 10) received a bladder neck sling as part of the surgical treatment for their urinary incontinence. The cause of incontinence was neurogenic in 28 of the 30 patients. The 6 male patients were prepuberal. All patients had a preoperative video urodynamic study. The criteria for increasing cervico-urethral resistance included a passive leak point pressure of < 50 cm H2O, stress leak point pressure of < 100 cm H2O, radiological evidence of an open bladder neck and stress incontinence regardless of the other urodynamic and radiologic parameters. The technical aspects of the procedure are described in detail. Augmentation cystoplasty was performed concomitantly in 29 patients. RESULTS: Patient follow-up ranged from 2 to 70 months (mean 37.6). Twenty-eight patients (93%) were continent postoperatively. Two female patients remained incontinent at low leak point pressures. All patients emptied the bladder by intermittent catheterization. Twelve patients perform catheterization through the urethra without difficulty. CONCLUSION: The rectus fascia sling has several advantages over other surgical methods for increasing the cervico-urethral resistance. It is simple, effective, low-cost and has a low complication rate. In our view, the sling is the technique of choice for increasing cervico-urethral resistance in female and prepuberal male patients requiring a cystoplasty concomitantly.     

A molar entropy model of age differences in spatial memory

Two very-short-term-memory, spatial scanning aging experiments were conducted involving a graphics character as a target stimulus. On the probe portion of a trial, the stimulus was presented in the same position as it was on the target portion of the trial (i.e., a same trial) 50% of the time. However, on the remaining 50% of the trials, the probe stimulus was shifted (or transposed) 1, 2, or 3 positions to the right or left of the original presentation (target) position. In Experiment 1, exposure duration was manipulated. In Experiment 2, the number of potential target display positions was manipulated. For both experiments, older adults showed larger transposition distance effects than younger adults for errors. In the past (e.g., P.A. Allen, 1990, 1991), this effect has been attributed to higher levels of internal noise (entropy) in older than younger adults. This research provides converging operations to this contention by using statistical physics methods to rigorously compute the entropy in a molar neural network across age groups. After successfully fitting the statistical mechanics model to the data, the model is proved to have external validity by fitting a simplified version of it to an earlier spatial memory aging experiment reported by P. R. Bruce and J. F. Herman (1986). The results of both traditional reaction time and error rate analyses, as well as the entropy modeling analyses, indicated that older adults exhibited higher levels of entropy than did the younger adults and that this effect appeared to be generalized across processing stage.     

Metabolic consequences of different perioperative fluid therapies in the neonatal period

The rat CNS has been previously shown to synthesize pregnenolone (PREG) and to convert it into progesterone (PROG) and some of its 5 alpha-reduced metabolites. However, the brain cell types involved in the metabolic conversions of PREG are poorly known. Selective conditions were used to obtain purified cultures of neurons and astrocytes from mouse or rat fetal striatum and cerebral cortex. Neurons converted PREG to only one identified metabolite, 20 alpha-dihydro PREG, whereas astrocytes converted PREG also to PROG, 5 alpha-dihydro PROG, and 3 alpha (3 beta)-5 alpha-tetrahydro PROG. Therefore, astrocytes can convert the neurosteroid PREG into the steroid hormone PROG and the neuromodulatory steroid 3 alpha, 5 alpha-tetrahydro PROG, whereas neurons lack the delta 5-3 beta-hydroxysteroid dehydrogenase isomerase activity (and cholesterol side-chain cleavage activity), necessary for the biosynthesis of PROG. Provision of steroid substrates is another example of cross-talk between glial cells and neurons.     

Strain-hardening and residual stress effects in plastic zones around indentations

Plastic zones were revealed by polishing away Vickers indentations made in soda-lime glass, WC–11% Co, W and 7075 Al. Micro and nanohardness traces were used to explore the local mechanical response. The hardness value within the deformed zone increased up to 21% depending on the material. Soda-lime glass was the only material not to show a hardening effect, in fact it showed a small decrease in hardness. Finite element calculations were used to qualitatively determine the influence from residual stresses at indentation of soda-lime glass. The results are discussed in the context of the influence from work-hardening and residual stresses on indentation quantities.     

Interaction of Ca2+ agonist and depolarization on Ca2+ channel current in guinea pig detrusor cells

The interaction of large depolarization and dihydropyridine Ca2+ agonists, both of which are known to enhance L-type Ca2+ channel current, was examined using a conventional whole-cell clamp technique. In guinea pig detrusor cells, only L-type Ca2+ channels occur. A second open state (long open state: O2) of the Ca2+ channels develops during large depolarization (at +80 mV, without Ca2+ agonists). This was judged from lack of inactivation of the Ca2+ channel current during the large depolarizing steps (5 s) and slowly deactivating inward tail currents (= 10-15 ms) upon repolarization of the cell membrane to the holding potential (-60 mV). Application of Bay K 8644 (in 2.4 mM Ca(2+)-containing solutions) increased the amplitude of the Ca2+ currents evoked by simple depolarizations, and made it possible to observe inward tail currents (= 2.5-5 ms at -60 mV). The open state induced by large depolarization (O2*) in the Bay K 8644 also seemed hardly to inactivate. After preconditioning with large depolarizing steps, the decay time course of the inward tail currents upon repolarization to the holding potential (-60 mV) was significantly slowed, and could be fitted reasonably with two exponentials. The fast and slow time constants were 10 and 45 ms, respectively, after 2 s preconditioning depolarizations. Qualitatively the same results were obtained using Ba2+ as a charge carrier. Although the amplitudes of the inward currents observed in the test step and the subsequent repolarization to the holding potential were decreased in the same manner by additional application of nifedipine (in the presence of Bay K 8644), the very slow deactivation time course of the tail current was little changed. The additive enhancement by large depolarization and Ca2+ agonists of the inward tail current implies that two mechanisms separately induce long opening of the Ca2+ channels: i.e., that there are four open states.     

Recidivism rates among child molesters and rapists: a methodological analysis

We address the high variability in sex offender recidivism rates by examining several of the critical methodological differences that underlie this variability. We used a dataset on 251 sex offenders (136 rapists and 115 child molesters) who were discharged over a 25-year period to examine changes in recidivism as a function of changes in dispositional definition of reoffense (e.g., arrest or conviction), changes in the domain of criminal offenses that are considered, and changes in the length of exposure time. The data indicate that: (a) both rapists and child molesters remain at risk to reoffend long after their discharge, in some cases 15-20 years after discharge; (b) there was a marked underestimation of recidivism when calculating a simple proportion (%) consisting of those who were known to have reoffended during the follow-up period, and (c) there was a marked underestimation of recidivism when the criterion was based on conviction or imprisonment. Forensic, clinical and policy implications of this high variability are discussed.