Experimental one-way quantum computing.

Standard quantum computation is based on sequences of unitary quantum logic gates that process qubits. The one-way quantum computer proposed by Raussendorf and Briegel is entirely different. It has changed our understanding of the requirements for quantum computation and more generally how we think about quantum physics. This new model requires qubits to be initialized in a highly entangled cluster state. From this point, the quantum computation proceeds by a sequence of single-qubit measurements with classical feedforward of their outcomes. Because of the essential role of measurement, a one-way quantum computer is irreversible. In the one-way quantum computer, the order and choices of measurements determine the algorithm computed. We have experimentally realized four-qubit cluster states encoded into the polarization state of four photons. We characterize the quantum state fully by implementing experimental four-qubit quantum state tomography. Using this cluster state, we demonstrate the feasibility of one-way quantum computing through a universal set of one- and two-qubit operations. Finally, our implementation of Grover's search algorithm demonstrates that one-way quantum computation is ideally suited for such tasks.

Resonance distribution in open quantum chaotic systems.

In order to study the resonance spectra of chaotic cavities subject to some damping (which can be due to absorption or partial reflection at the boundaries), we use a model of damped quantum maps. In the high-frequency limit, the distribution of (quantum) decay rates is shown to cluster near a "typical" value, which is larger than the classical decay rate of the corresponding damped ray dynamics. The speed of this clustering may be quite slow, which could explain why it has not been detected in previous numerical data.

Effects of an S84E mutation of bovine growth hormone in transgenic mice.

The ability of mutant bovine growth hormones (bGH) to serve as either agonist or antagonist has been demonstrated in transgenic mice. We have prepared two transgenic strains of FVB/N mice, one expressing wild-type bGH and a second with a glutamic acid mutation at serine 84 in helix 2. Comparison of their phenotypes to those of nontransgenic littermates indicates that wild-type bGH induces a previously described phenotype for hyper-somatotrophic mice. In contrast, the replacement of the side chain hydroxyl at serine 84 with acetic acid produced a phenotype that expressed bGH at appreciable concentrations, but failed to elicit the phenotype observed with either an agonist or an antagonist of bGH. These results indicate that serine 84 is crucial for the activity of bGH despite this site being distal to the receptor binding surfaces.

Functional relationship of serine 90 phosphorylation and the surrounding putative salt bridge in bovine prolactin.

The biological activity of bovine prolactin (PRL) is reduced by in vivo phosphorylation of serine 90 (S90) that is located within a putative N+4 salt bridge (R89 and D93). We substituted hydrophobic, polar, or acidic residues for S90 and/or replaced members of the putative R89/D93 salt bridge to determine if a functional relationship between the putative salt bridge and the phosphorylation could be observed. At position 90 the bulk of the residue was the most important factor in modulating biological activity in either the rat Nb2 cell bioassay or PRL receptor binding. Charge played a smaller role. Replacement of either partner of the salt bridge reduced both biological and binding activities indicating the presence of a salt bridge at this position. The combination of replacing a salt bridge member and substituting glutamic acid at S90 produced greater than additive changes in our experimental endpoints, indicating a functional coupling between the salt bridge and phosphorylation site. We interpret the data to indicate that either in vivo phosphorylation or specific mutations that destabilize the salt bridge impairs biological activity.

Effects of growth hormone overproduction on grip strength of transgenic mice.

Growth hormone (GH) is used by athletes like bodybuilders to increase muscle strength and weight gain. On the other hand, chronic hypersecretion of GH in active acromegaly may result in outwardly hypertrophied but functionally weaker muscles. As a model for studying long-term effects of GH on muscle strength, we analysed transgenic mice (TM) carrying rat phosphoenolpyruvate carboxykinase-bovine GH (PEPCKbGH) fusion genes, which are expressed in liver and kidney but not in skeletal muscle. Circulating GH levels in TM ranged between 0.5 and 3 micrograms/ml, resulting in increased (p < 0.001) body weight (wt) as well as increased (p < 0.01) weights of forelimb and hindlimb muscles. However, muscle weight/body wt ratios of TM were 16-20% smaller than in controls (p < 0.05). Forelimb grip strength of hemizygous TM (16 males, 132 +/- 45 days old, body wt = 56.8 +/- 8.3 g; 32 females, 146 +/- 38 days old, body wt = 54.9 +/- 6.1 g) and non-transgenic controls (28 males, 127 +/- 47 days old, body wt = 40.5 +/- 2.9 g; 33 females, 126 +/- 47 days old, body wt = 32.1 +/- 3.6 g) was determined using an automated grip strength meter. Data were computed by analysis of variance, taking into account effects of group, sex and age. Least-squares means estimated for the grip strength (N) of male TM (1.91) and controls (1.92) were significantly (p < 0.05) greater than those of female TM (1.78) and controls (1.61). A significant difference between groups was only seen in females (p < 0.01). Least-squares means estimated for grip strength/body wt ratios (N/10 g) of male (0.34) and female TM (0.33) were 29% and 35% lower than those of male (0.48) and female controls (0.51), respectively (p < 0.001). In summary, long-term elevated GH levels in TM increased muscle weight less efficiently than body weight, and muscle strength did not increase proportionally with muscle weight.

Animal model of portal hypertension with observations regarding the relationship between portal flow and pressure.

RATIONALE AND OBJECTIVES: The feasibility of producing acute portal hypertension in a porcine model was evaluated to test the relationship between portosystemic shunt flow and portal pressure. METHODS: Percutaneous transhepatic cannulation of the portal vein and cutdown of a systemic vein was accomplished in anesthetized pigs. The portal system was subsequently embolized with polyvinyl alcohol (Ivalon) particles. Portosystemic shunting was performed with the assistance of a centrifugal pump. RESULTS: Portal hypertension could be routinely produced, and portosystemic shunting was successfully studied in three of four animals. Linear changes in shunt flow led to exponential pressure changes. CONCLUSIONS: This animal model provides a representation of acute portal hypertension that provides useful data regarding the compliance of the portal system and illustrates the pressure/flow relationship.

[Orbicularis oculi reflexes and evoked response of orbicularis oris muscle in Bell's palsy. A prognostic study (author's transl)]. / Orbicularis oculi-Reflexe und Summenpotentiale des Orbicularis oris bei idiopathischer Facialislähmung. Eine prognostische Studie

In 84 patients with idiopathic, clinically complete Bell's palsy the electrically induced blink reflexes with their two components (OOR I and II) were electromyographically recorded on both sides using skin electrodes. In 67 of these patients the evoked responses of the orbicularis oris muscle were also studied. The latencies and amplitudes were measured and related to the clinical outcome of the facial paralysis. The patients were divided into two groups, one with good recovery of the palsy (46 patients), the other with significant residual paresis and/or strong associated movements of the facial musculature (38 patients). In the group with good recovery the following results were obtained: 1. the OOR I remained elicitable or reappeated during the first 12 days after the onset of palsy; 2. the OOR II began to rise during the first 10 days of palsy; 3. the amplitude of the orbicularis oris response did not decrease to below 10%. In the group with poor recovery: 1. both components of the OOR were absent or diminished to below 4% for more than 12 days after the onset of palsy; 2. the latency difference of the OOR I exceeded 8 msec; 3. the amplitude of the orbicularis oris responses decreased to below 10%. Using these criteria it appears to be possible in about 85% of patients to make a prognosis between the 3rd to 5th and the 10th to 12th day after the onset of Bell's palsy.

Long-latency responses in human thenar muscles mediated by fast conducting muscle and cutaneous afferents.

Electrical stimulation of median nerve at the wrist near motor threshold evokes two distinct reflexes in voluntarily innervated thenar muscles. The first is the Hoffmann reflex (HR) and the second is the long-latency reflex (LLR). Stimulation of the motor branch of the median nerve at the thenar sub-threshold for motor fibers evokes the same pattern suggesting that group IA muscle afferents are mediating the LLR. Stimulation of pure cutaneous afferents evokes a LLR of similar latency without a preceding HR. Statistical analyses of the reflex latencies of HR and LLR are in favor of a fast conduction velocity for the cutaneous afferents involved. Hence for muscular and cutaneous LLR a long-lasting central conduction time has to be assumed.

Rapid detection of CWD PrP: comparison of tests designed for the detection of BSE or scrapie.

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) mainly affecting cervids in North America. The accumulation of an abnormal form of host-encoded prion protein (PrP(CWD) ) in the CNS and lymphoid tissues is characteristic of the disease and known to be caused by pathogenic prion proteins (PrP(res) ), which are thought to be transmitted mainly by contact with body fluids, such like saliva. Species known to be naturally infected by CWD include Rocky Mountain elk (Cervus elaphus nelsoni), white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus). Recently, large-scale disease eradication or control programs have been attempted to curtail the spread of disease. But reports of diseased free-ranging and farmed cervids in many locations in the USA and Canada are still continuing. The goal of this study was to find sensitive rapid test systems that are reliably able to detect CWD-associated PrP(CWD) in cervids, thereby reviewing an important control tool in case the disease spreads further and reaches Europe. Seven tests, originally developed for the detection of other TSE diseases such as Scrapie and bovine spongiform encephalopathy, including two Western blots, four enzyme-linked immunosorbent assays (ELISAs), and one lateral flow device, were included in this study. All seven tests evaluated were able to detect pathogenic prion proteins (PrP(CWD) ) in Northern American infected animals and distinguish physiologic prion protein (PrP(c) ) in brainstem (obex region) and lymph node samples from North American and European cervids, respectively. However, the specificity and sensitivity of the tests differed significantly. Highly sensitive tests for the detection of prion proteins are an important tool both for the design of effective disease surveillance and control strategies and the safety of the food chain. Thus, this study contributes to the emergency preparedness against CWD.

The use of digital infrared thermal imaging to detect estrus in gilts.

Yorkshire/Landrace crossbred gilts (N = 32) were evaluated using digital infrared thermal imaging (DITI) to discriminate between estrus and diestrus phases of the porcine estrous cycle. Gilts (N = 32) were part of an ongoing reproductive efficiency study involving the use of raw soybean (RSB; N = 15) versus soybean meal (SBM; N = 17) as a source of dietary protein. Gilts were monitored daily for signs of estrus using a teaser boar. Thermal images of vulva surface temperatures (TEMP) were recorded at standing estrus and diestrus. Measurements for analysis included minimum (MIN), maximum (MAX), mean (AVG), and standard deviation (SD) of temperature gradients. At imaging, ambient (AMB) and rectal temperatures (RT) were recorded, and blood samples taken for serum progesterone (P(4)) concentration analysis (by RIA) to confirm stage of cycle. Mean serum progesterone values at estrus and diestrus were (mean ± SD) 1.0 ± 0.1 and 10.9 ± 0.8 ng/mL, respectively. Vulva MIN, MAX, and AVG thermal images were positively correlated with one another (P < 0.01), and were positively correlated with ambient temperature (P < 0.01). Vulva MAX and AVG thermal temperatures were greater (P < 0.05) at estrus than at diestrus (36.6 ± 0.2 °C and 33.4 ± 0.3 °C vs. 35.6 ± 0.3 °C and 31.8 ± 0.6 °C, respectively), whereas MIN and SD had no differences (P > 0.05) between stages of the cycle. No differences (P > 0.05) in RT were detected between stages and RT was not significantly correlated with vulva thermal images. Diet had no significant effect on RT or vulva temperature.

Exercising stall-housed gestating gilts: effects on lameness, the musculo-skeletal system, production, and behavior.

Lameness in breeding-age gilts and sows is a major cause of culling, resulting in increased economic losses and welfare concerns. This study determined if exercise during gestation would affect the musculo-skeletal system, production variables, and behavior. Gilts were blocked by BW and assigned to 1 of 3 treatment groups: control (n = 10; no exercise), low exercise (n = 14; 122 m/d for 5 d/wk), and high exercise (n = 14; 122 m/d for 2 d/wk and 427 m/d for 3 d/wk). All gilts were stall-housed during gestation, and gilts were exercised between d 35 and 110 of gestation. Lameness score, BCS, BW, and blood were taken at multiple points before gestation, and during gestation and lactation. Blood serum was analyzed for carboxy-terminal telopeptide of type I collagen. Sow lying behavior was recorded for 3 d after farrowing. Farrowing data included litter weight and size at birth and weaning, and preweaning mortality. After weaning, 38 sows were slaughtered and muscles and the bones of the left fore- and hind-limbs were harvested. Bone density and quality were determined by computed tomography (CT) scans, dual energy x-ray scans, and bone-breaking force tests. The control group took longer to lie down than both exercise groups, and the low exercise group took longer to lie down than the high exercise group (P < 0.05). The number of pigs weaned was greater in the high exercise group than the control group (P < 0.05). Piglet preweaning mortality was greatest in the control group compared with both exercise groups (P < 0.05). The low exercise treatments exhibited a greater bone density (CT) in the humerus, radius, and tibia compared with that of the control group (P < 0.05). The bone density (CT) of the humerus in the low exercise group was greater than that of the high exercise group (P = 0.03). Breaking force in the humerus and femur was greater (P < 0.05) in the low exercise group than the control group. Breaking force in the tibia of the high exercise group was greater than the control group (P = 0.01). The tibia of both the low and high exercise groups had a greater breaking force (P < 0.05) than the control group. Although there was no benefit of exercise on lameness, differences in bone density and quality, lying behavior, and piglet survivability may provide useful insight into alternative housing for sows.

[Familial progressive dystonia with diurnal fluctuation. Case report. Remarkable therapeutic effect of 1-dopa (author's transl)]. / Familiäre progressive Dystonie mit Tagesschwankugen. Fallbeschreibung. Erfolgreiche Behandlung mit L-Dopa

The present report discusses two patients of a same family who have "familial progressive dystonia with diurnal fluctuation" (Segawa). One of them, a severely handicapped nine year-old girl was successfully treated with L-Dopa.

[Alcoholic polyneuropathy. Electrophysiological and clinical findings in 85 patients (author's transl)]. / Alkoholische Polyneuropathie. Elektrophysiologische und klinische Befunde bei 85 Patienten

Maximum motor and sensory nerve conduction velocities, amplitudes of muscle action potentials (surface electrodes) and of sensory nerve action potentials, and needle electromyograms were studied in 80 patients with alcoholic neuropathy and in 5 chronic alcoholics without clinical signs of neuropathy. The electrophysiological results were compared to the clinical findings. Neurographic criteria compatible with the diagnosis "alcoholic neuropathy" were defined. Neurographic findings contrary to a diagnosis of alcoholic etiology were demonstrated in 3 patients. Only in a smaller group of patients could a reduction of conduction velocity be found, especially in regions of peripheral nerve entrapment. A decrease in conduction velocity outside of the entrapment sites can be explained in some cases by segmental demyelination in chronic hepatitis or cirrhosis of the liver.

[Idiopathic blepharospasm. Clinical and electrophysiological investigations in 27 patients (author's transl)]. / Idiopathischer Blepharospasmus. Klinische und elektrophysiologische Befunde bei 27 Patienten.

Idiopathic blepharospasm is reexamined and the differential diagnosis discussed on the basis of the signs and symptoms of 27 unpublished cases. As in tardive dyskinesia, middle-aged and elderly women are mostly affected. Contrary to general opinion, spontaneous improvement occurred in about one-fifth of the patients. The habituation of the orbicularis oculi reflexes (investigated electromyographically) was diminished in 52% of the patients. These and other symptoms indicate an organic cerebral lesion as the main cause of the disease. Similarities existing between blepharospasm and torticollis spasticus are discussed.

[Comparative investigation of somatosensory spinal and cortical evoked potentials in children (author's transl)]. / Vergleichende Untersuchung somatosensibler spinaler und kortikaler Evoked Potentials bei Kindern.

Somatosensory spinal (spinEP) and primary cortical evoked responses (ssEP) to median and tibial nerve stimulation (at forefinger, wrist, and ankle respectively) were investigated by means of summation techniques in 23 normal children aged 6 to 14 years. Amplitude recovery functions of cervical spinEP were tested by paired stimuli and short tetanic stimulation at the wrist; spinEP amplitudes were unchanged for stimulus intervals down to 5 ms. The amplitudes of the cervical spinEP after strong stimuli to the finger were only a quarter as great as those obtained by stimulation of the wrist at motor threshold strength. In one patient with the Brown-Séquard syndrome cervical spinEP were absent for stimuli on the side of position sense impairment, but were unaffected for stimuli on the side of dissociated sensory loss. The normal latencies of spinEP (to the onset of the negative potential) and ssEP (to first negative peak) are presented as functions of body height. The difference between these two latencies yielded a central latency from the lower cervical spinal cord of about 9--10 ms. The spinal afferent conduction velocity, calculated from the difference between the lumbar and cervical latencies after tibial nerve stimulation at the ankle, was found to be 74m/s.

[The effect of tramadol and other analgesics on the pain threshold in human dental pulp (author's transl)]. / Beeinflussung der Schmerzschwelle an der Zahnpulpa durch Tramadol und andere Analgetika.

In 60 young, healthy volunteers the analgesic efficacy of 1-(m-methoxyphenyl)-2-(dimethylaminomethyl)-cyclohexan-1-ol (tramadol; Tramal), dextropropoxyphene and a commercial drug mixture (acetylsalicylic acid 200 mg; phenacetin 200 mg; codeine phosphor. 10 mg; caffeine anhydr. 50 mg; phenobarbital 25 mg) was investigated by determining the pain threshold in dental pulp. All three drugs increased the pain threshold considerably but there was no difference in the analgesic effect of the three drugs.

[The "paired cards" system. A practical and generally applicable procedure for the clinical trial of drugs (author's transl)]. / Das Paarlingskarten-System. Modell eines praktikablen und allgemein anwendbaren Verfahrens zur klinischen Arzneimittelprüfung.

A system is described which is suitable for the simulataneous double-blind study of several drugs effective in the same field of indication (e.g. analgesics). The procedure uses sequential analysis and therefore requires only limited materials, costs and personnel. It produces significant results with a minimum of patients.

[Clinical trial of tramadol by means of the "paired card" system (author's transl)]. / Klinische Prüfung von Tramadol nach dem Paarlingskarten-System.

1. 1-(m-Methoxyphenyl)-2-(dimethylaminomethyl)-cyclohexan-1-ol (tramadol; Tramal) was administered i.v. to patients suffering from pain of various origins. Its efficacy and side effects were compared with those of metamizole and placebo. 2. Tramadol (100 mg) was as effective as metamizole (2.5 mg) and significantly more effective than placebo. 3. All three compounds showed no significant differences in type and number of side effects.

[The effect of tramadol in an open clinical trial (author's transl)]. / Das Analgetikum Tramadol in der offenen klinischen Prüfung.

1. The new analgesic drug 1-(m-methoxyphenyl)-2-(dimethylaminomethyl)-cyclohexan-1-ol (tramadol; Tramal) was administered to a total of 840 patients by i.m. or i.v. injection or in suppository form in an open multi-center trial. The drug was found to be an effective and well-tolerated analgesic. 2. In all three forms of administration more than 80% of the patients treated rated the therapeutic efficacy of tramadol good to very good. In most cases the analgesic effect set in within 30 min and lasted 3--7 h. Tramadol was effective in relieving pain of various origins. 3. Serious side effects were not observed. The most frequent side effect was drowsiness. Transient hot flushes and outbreaks of sweating occurred occasionally following i.v. injection.