Familial empirical risks for inflammatory bowel disease: differences between Jews and non-Jews

The Jewish population has an increased frequency of inflammatory bowel disease compared with their non-Jewish neighbours. Genetic factors have been implicated in the aetiology of this disorder and may contribute to ethnic differences. This study determined the familial empirical risks for inflammatory bowel disease in the first degree relatives of inflammatory bowel disease probands (for both Jews and non-Jews) for the purpose of accurate genetic counselling and genetic analysis. A total of 527 inflammatory bowel disease patients from Southern California (291 Jews and 236 non-Jews) were questioned about inflammatory bowel disease in their first degree relatives (a total of 2493 individuals). Since inflammatory bowel disease has a variable and late age of onset, age specific incidence data were used to estimate the life time risks and to make valid comparisons between the different groups. In the first degree relatives of non-Jewish probands, the life time risks for inflammatory bowel disease were 5.2% and 1.6% when probands had Crohn's disease and ulcerative colitis respectively. These values were consistently lower than the corresponding risks for relatives of Jewish patients -7.8% and 4.5% for Crohn's disease and ulcerative colitis probands respectively (p value for comparison between Jews and non-Jews: 0.028; between ulcerative colitis and Crohn's disease: 0.005). These data provide the requisite basis for genetic counselling for these disorders in the white American population. In addition, these different empirical risks for relatives of Jewish and non-Jewish probands allow rejection of single Mendelian gene models for inflammatory bowel disease, but are consistent with several alternative genetic models.     

Statistical significance of coincident spikes: count-based versus rate-based statistics.

Inspired by different conceptualizations of temporal neural coding schemes, there has been recent interest in the search for signs of precisely synchronized neural activity in the cortex. One method developed for this task is unitary-event analysis. This method tests multiple single neuron recordings for short epochs with significantly more coincident spikes than expected from independent neurons. We reformulated the statistical test underlying this method using a coincidence count distribution based on empirical spike counts rather than on estimated spike probabilities. In the case of two neurons, the requirement of stationary firing rates, originally imposed on both neurons, can be relaxed; only the rate of one neuron needs to be stationary, while the other may follow an arbitrary time course. By analytical calculations of the test power curves of the original and the revised method, we demonstrate that the test power can be increased by a factor of two or more in physiologically realistic regimes. In addition, we analyze the effective significance levels of both methods for neural firing rates ranging between 0.2 Hz and 30 Hz.     

Influence of zinc oxide on Aspergillus species: a possible cause of local, non-invasive aspergillosis of the maxillary sinus

Recently the appearance of radiopaque 'concrements' in the maxillary sinus was reported. These radiodense objects could be identified as root-filling material for teeth of the upper jaw containing zinc oxide. This suggested that excess root-filling material containing zinc oxide in the maxillary sinus could favour the formation of a local, non-invasive aspergillosis. To verify this hypothesis in vitro, we tested the influence of zinc oxide on Aspergillus fumigatus, A. flavus, A. terreus, A. nidulans, A. niger and A. niveus. A geometric series of zinc oxide diluted in 0.1 N H2SO4 was used. Czapek-Dox agar was inoculated with the six Aspergillus species. Circular cavities stamped into the centre of each agar plate were filled with an equal amount of the dilutions and all plates were then incubated for 7 days at 37 degrees C. Readings were taken on days 3, 5 and 7. Soluble zinc oxide promoted the growth of all the tested Aspergillus species, the effect diminishing with decreasing concentration. This effect could be observed on all days of measurement. Only with A. niger was stimulation of growth minimal, probably because this species already exhibits a high growth rate on Czapek-Dox agar. Therefore, overfilling of maxillary teeth with a zinc oxide-containing root-filling material may favour the formation of local aspergillosis.     

Zur Frage der Weinbeurteilung

Zusammenfassung Anhand der Analysen österreichischer Weine wird der Einfluß verschiedener Hefen auf den Gärvorgang und die Frage nach einem Gleichgewichtszustand zwischen den Gärungsprodukten untersucht.Herrn Professor Dr. Dr.W. Diemair zum 65. Geburtstag.     

Steel silos with different aspect ratios: II — behaviour under eccentric discharge

The phenomenon of eccentric discharge is widely recognised as the most dangerous condition for thin-walled metal silos and the cause of many catastrophic buckling failures. A realistic pressure model for this condition appears in a regulating standard for the first time in EN 1991-4 (2006) on Actions on Silos and Tanks. However the structural consequences of its application are currently largely unknown. The behaviour of a silo subjected to these pressures is certainly very dependent on the aspect ratio of the silo, the granular solid properties and the discharge channel geometry.This paper explores the behaviour of four thin-walled cylindrical silos with stepwise-varying wall thickness and aspect ratios varying from intermediate to very slender, subject to the codified EN 1991-4 eccentric discharge pressures. It is shown that a silo design that was found to be very safe under the EN 1991-4 concentric discharge pressures becomes very unsafe under eccentric discharge. Further, as it is known that the aspect ratio has an important effect on the flow pattern in discharging granular solids, and that slender silos exhibit very different flow patterns from squat silos, it is currently not certain whether a suitable range of aspect ratio over which the codified eccentric discharge model is to be applied has been prescribed in the standard.This paper is the second of a pair. In the first, the behaviour of a set of example silos under the EN 1991-4 concentric discharge condition was studied. The same example silos are studied here under eccentric discharge.     

Device Characteristics of GaInSb/AlGaSb Quantum Well Lasers Monolithically Grown on GaAs Substrates by Using an Interfacial Misfit Array

We report the device characteristics of GaInSb/AlGaSb quantum well (QW) lasers monolithically grown on GaAs substrates by using an interfacial misfit (IMF) array. The IMF array localized at the GaSb/GaAs interface can accommodate the 7.8% lattice mismatch between GaAs substrates and GaSb buffer layers, resulting in the formation of a GaSb buffer with a very low defect density on GaAs substrates. Top-top and top-bottom metal contact methods are applied to the Ga_0.9In_0.1Sb/GaSb QW edge-emitting lasers monolithically grown on GaAs substrates for characterizing current–voltage (I–V) and output power–current (L–I) curves. The potential drop at the IMF array of ~0.7 V is elucidated by comparing I–V characteristics with these two contact methods. L–I characteristics and electroluminescence spectra shows room-temperature lasing at 1.83 μm from a 1.25-mm-long top-top contact device containing six-layer Ga_0.9In_0.1Sb QWs with a threshold current density (J _th) of 860 kA/cm². This IMF technique will enable a wide range of lasing wavelengths from near- to mid-wavelength infrared regimes on a GaAs platform.     

Relationships between the concentration of insulin-like growth factor-1 in serum in dairy cows in early lactation and reproductive performance and milk yield

The objective of this study was to evaluate the relationships of different insulin-like growth factor-1 (IGF1) measures [5 distinct IGF1 concentrations on particular days, area under the curve (AUC), and linear regression coefficient] in the postpartum period in lactating dairy cows and reproductive performance. A total of 417 healthy multiparous Holstein-Friesian cows were enrolled in the study. Serum samples for the determination of the concentration of IGF1 were collected on d 0, 4, 10, 20, and 40 postpartum (pp). The concentration of total IGF1 in serum was determined by immunometric chemiluminescence immunoassay. All cows were examined for vaginal discharge as a sign of clinical endometritis at 20 d pp by external inspection and rectal palpation. The mean concentration of IGF1 ranged from 57 ± 18.9 ng/mL within the first 12 h pp to 74 ± 19.9 ng/mL at 40 d pp. On d 10 pp, first and all artificial insemination conception rates were greater in cows with IGF1 concentrations above the median compared with cows with IGF1 concentrations below the median. Cows with greater AUC (second to fourth quartile) conceived earlier (11.4, 16.0, and 18.8 d) than cows in the first IGF1 quartile (117.0 ± 43.6). Proportion of cows pregnant within 200 d pp increased significantly from the first to the third IGF1 quartile of AUC (58.7, 66.7, and 74.0%). The proportion of cows culled decreased from the first to the fourth IGF1 quartile. Correlations between IGF1 measures and days to pregnancy were significant (except for the linear regression coefficients) but low (R² = 0.0009 to 0.025). Differences between single or composite measurements of IGF1 were not significant. We could also demonstrate a statistically significant correlation between the concentration of IGF1 in serum and the average 10-d milk production (31.6 to 44.0 kg). In conclusion, our study indicates that single or multiple measurements of IGF1 concentration in the postpartum period have very limited value to predict individual fertility in dairy cows.     

High Field Magnetoelastic Quantum Oscillations of Palladium

The Fermi surface response to external stress is studied by magnetoelastic quantum oscillations at single Pd crystals. The oscillatory magnetization and the magnetostriction of two crystals were measured by capacitive dilatometry at different low temperatures up to 32 T in static field. The experiment confirms the extremal cross sections of the Fermi surface for the L- and X-pockets. The combination of both methods allows to obtain the uniaxial stress dependence of the Fermi surface (using Shoenberg’s formalism). The procedure yields deformation response values in the range from 10 (TPa)^?1 to 100 (TPa)^?1, for stress along [100] and [111]. The new values for the [111] direction seem to have a stronger temperature dependence compared to other directions.     

Evaluation of three enzymic methods as predictors of in-vivo response to enzyme supplementation of barley-based diets when fed to young chicks

The β-glucan degrading ability of several commercial crude enzyme preparations was determined using three different assay procedures. The assays were based on the ability of the enzymes to reduce the viscosity of a β-glucan solution, to produce reducing sugars from β-glucan or to produce a blue-coloured solution upon hydrolysis of azo-barley-glucan. Regression analysis showed that the relationship between the relative improvements in weight gain of chicks fed a barley-based diet that was supplemented with different concentrations of different enzyme and in-vitro enzyme activity when the azo-barley-glucan and reducing sugar assays were used was quadratic. A linear relationship was observed for the viscosity method. The R² values for both weight gain and feed to gain ratio were highest for the azo-barley-glucan method but the other methods yielded similar values under appropriate assay conditions (ie concentration of enzyme). The azo-barley-glucan method, nevertheless, is the assay recommended as it is by far the simplest of the three assays and it yields a low coefficient of variation.     

Group and individual effects in problem solving.

Hypothesized that when working on a single problem, the combination of individual and group sessions would lead to more solutions than only individual or only group sessions. Dividing 128 Ss into 32 real and nominal work groups, the hypothesis was not confirmed. Instead, the individual production of ideas was found to be superior to either group production or the combination of group and individual production (p