As the number falls,alternatives to the Hagberg–Perten falling number method: A review

This review examines the application, limitations, and potential alternatives to the Hagberg–Perten falling number (FN) method used in the global wheat industry for detecting the risk of poor end-product quality mainly due to starch degradation by the enzyme α-amylase. By viscometry, the FN test indirectly detects the presence of α-amylase, the primary enzyme that digests starch. Elevated α-amylase results in low FN and damages wheat product quality resulting in cakes that fall, and sticky bread and noodles. Low FN can occur from preharvest sprouting (PHS) and late maturity α-amylase (LMA). Moist or rainy conditions before harvest cause PHS on the mother plant. Continuously cool or fluctuating temperatures during the grain filling stage cause LMA. Due to the expression of additional hydrolytic enzymes, PHS has a stronger negative impact than LMA. Wheat grain with low FN/high α-amylase results in serious losses for farmers, traders, millers, and bakers worldwide. Although blending of low FN grain with sound wheat may be used as a means of moving affected grain through the marketplace, care must be taken to avoid grain lots from falling below contract-specified FN. A large amount of sound wheat can be ruined if mixed with a small amount of sprouted wheat. The FN method is widely employed to detect α-amylase after harvest. However, it has several limitations, including sampling variability, high cost, labor intensiveness, the destructive nature of the test, and an inability to differentiate between LMA and PHS. Faster, cheaper, and more accurate alternatives could improve breeding for resistance to PHS and LMA and could preserve the value of wheat grain by avoiding inadvertent mixing of high- and low-FN grain by enabling testing at more stages of the value stream including at harvest, delivery, transport, storage, and milling. Alternatives to the FN method explored here include the Rapid Visco Analyzer, enzyme assays, immunoassays, near-infrared spectroscopy, and hyperspectral imaging.     

Allocentric Versus Egocentric Spatial Memory After Unilateral Temporal Lobectomy in Humans.

Thirty patients who had undergone either a right or left unilateral temporal lobectomy (14 RTL; 16 LTL) and 16 control participants were tested on a computerized human analogue of the Morris Water Maze. The procedure was designed to compare allocentric and egocentric spatial memory. In the allocentric condition, participants searched for a target location on the screen, guided by object cues. Between trials, participants had to walk around the screen, which disrupted egocentric memory representation. In the egocentric condition, participants remained in the same position, but the object cues were shifted between searches to prevent them from using allocentric memory. Only the RTL group was impaired on the allocentric condition, and neither the LTL nor RTL group was impaired on additional tests of spatial working memory or spatial manipulation. The results support the notion that the right anterior temporal lobe stores long-term allocentric spatial memories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Failure to cure Mycobacterium gordonae peritonitis associated with continuous ambulatory peritoneal dialysis

Nontuberculous mycobacteria are increasingly recognized as important pathogens in peritonitis associated with continuous ambulatory peritoneal dialysis (CAPD). Mycobacterium gordonae rarely causes human infection and is the least likely mycobacterium to produce clinical infection in CAPD patients. We describe a patient with persistent M. gordonae peritonitis acquired while undergoing CAPD. During 18 months of treatment, clinical improvement occurred but a microbiological cure could not be achieved. Principles of therapy for mycobacterial peritonitis developing during CAPD are reviewed, and potential explanations for our patient's failure to respond to therapy are discussed.     

Fetal alcohol syndrome in twins of alcoholic mothers: concordance of diagnosis and IQ

The effects of teratogens can be modified by genetic differences in fetal susceptibility and resistance. Twins of alcoholic mothers provide a unique opportunity to study this phenomenon with respect to alcohol teratogenesis. Sixteen pairs of twins, 5 MZ and 11 DZ, all heavily exposed to alcohol prenatally, were evaluated. They represented all available twins of alcohol-abusing mothers who were on the patient rolls of the authors. The rate of concordance for diagnosis was 5/5 for MZ and 7/11 for DZ twins. In two DZ pairs, one twin had fetal alcohol syndrome (FAS), while the other had fetal alcohol effects (FAE). In 2 other DZ pairs, one twin had no diagnosis while one had FAE. IQ scores were most similar within pairs of MZ twins and least similar within pairs of DZ twins discordant for diagnosis. Despite equivalent alcohol exposure within twin pairs, alcohol teratogenesis appears to be more uniformly expressed in MZ than in DZ twins. These data are interpreted as reflecting the modulating influence of genes in the expression of the teratogenic effects of alcohol.     

Neural network control of communications systems

Neural networks appear well suited to applications in the control of communications systems for two reasons: adaptivity and high speed. This paper describes application of neural networks to two problems, admission control and switch control, which exploit the adaptivity and speed property, respectively. The admission control problem is the selective admission of a set of calls from a number of inhomogeneous call classes, which may have widely differing characteristics as to their rate and variability of traffic, onto a network. It is usually unknown in advance which combinations of calls can be simultaneously accepted so as to ensure satisfactory performance. The approach adopted is that key network performance parameters are observed while carrying various combinations of calls, and their relationship is learned by a neural network structure. The network model chosen has the ability to interpolate or extrapolate from the past results and the ability to adapt to new and changing conditions. The switch control problem is the service policy used by a switch controller in transmitting packets. In a crossbar switch with input queueing, significant loss of throughput can occur when head-of-line service order is employed. A solution can be based on an algorithm which maximizes throughput. However since this solution is typically required in less than one microsecond, software implementation policy is infeasible. We will carry out an analysis of the benefits of such a policy, describe some existing proposed schemes for its implementation, and propose a further scheme that provides this submicrosecond optimization.     

Partial congenital defect of the left pericardium: angiographic diagnosis and treatment by thoracoscopic pericardiectomy: case report

Twenty-six patients with an intracardiac myxoma underwent surgical resection at our institution from 1977 through 1992. Left atrial myxoma was diagnosed in 22 patients, left ventricular in 1, right atrial in 2, and right ventricular in 1. Six patients were asymptomatic; preoperative symptoms included dyspnea, arrhythmias, embolic episodes, and syncope. The diagnosis was established with transthoracic echocardiography in all cases but one. Surgery was performed in all cases with the aid of cardiopulmonary bypass with moderate hypothermia and cold crystalloid cardioplegia. One patient with a left ventricular myxoma died in a comatose state during the immediate postoperative period. Long-term clinical and echocardiographic evaluation was performed in 19 patients; results were excellent (all the patients were in New York Heart Association functional class I or II), and no recurrences were documented. The clinical characteristics, diagnostic methods, and surgical approach are presented and discussed.     

Metabotropic glutamate receptors are involved in long-term potentiation in isolated slices of rat medial frontal cortex

The prelimbic region of medial frontal cortex in the rat receives a direct input from the hippocampus and this functional connection is essential for aspects of spatial memory. Activity-dependent changes in the effectiveness of synaptic transmission in the medial frontal cortex, namely long-term potentiation (LTP) and long-term depression (LTD) can persist for tens of minutes or hours and may be the basis of learning and memory storage. Glutamatergic activation of ionotropic receptors is required to induce both LTP and LTD. We now present evidence of the involvement of metabotropic glutamate receptors in LTP in isolated slices of frontal cortex. Repetitive bursts of stimulation at theta frequencies (TBS) were applied to layer II, and monosynaptic EPSPs were monitored in layer V neurons of the prelimbic area. TBS was found to be more effective at inducing LTP than tetanic stimulation at 100 Hz and produced LTP that lasted >30 min in 8 out of 14 neurons. Tetanic stimulation at 100 Hz in the presence of the N-methyl--aspartate (NMDA)-antagonist 2-amino-5-phosphonopentanoate (AP5) was reported to be a reliable method of inducing LTD in prelimbic cortex (). However we found that this protocol did not facilitate the induction of LTD. The role of metabotropic glutamate receptors (mGluR) in LTP was assessed by using the selective, broad-spectrum antagonist (R, S)-alpha-methyl-4- carboxyphenylglycine (MCPG). This drug significantly reduced the incidence of LTP after TBS to only 1 of 14 neurons (P < 0.02, chi2 test). The pooled responses to TBS in MCPG showed significantly reduced potentiation [(P < 0.02, analysis of variance (ANOVA)]. The broad-spectrum mGluR agonist (1S, 3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD) and the selective group I agonist S-3 hydroxyphenylglycine(S-3HPG) both produced membrane depolarization, an increase in number of spikes evoked by depolarizing current pulses, and a reduction in the afterhyperpolarization. Similar effects were produced by these agonists even when synaptic transmission was blocked by use of the gamma-aminobutyric acid-B (GABAB) receptor agonist, 200 microM baclofen, which suggests that group I mGluRs are present on layer V neurons. We conclude that mGluRs participate in the production of LTP in prelimbic cortex, and that this excitatory effect could be mediated by the postsynaptic group I mGluRs.     

Autonomic paroxysms: their pathogenesis, diagnosis and treatment

In the article the rules about etiology and pathogenesis of vegetative paroxysms are stated based on careful analysis of the publications of researches as Russian, so foreign authors, and also own experimental and clinical supervision. During experimental and clinical researches the modern methods were used, enabling to estimate from positions of the system analysis different parts of pathogenesis of vegetative paroxysms, and also to offer ways of differential diagnostics of the various forms of disease. The application of some new preparations and direction of therapy of vegetative paroxysms are substantiated, and also the various circuits of treatment of the patients with distinguishing forms of given pathology are motivated.