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PubMed2006

Diagnostic yield in the clinical genetic evaluation of autism spectrum disorders.

PURPOSE: Clinical geneticists are often asked to evaluate patients with autism spectrum disorders (ASDs) in reference to questions about cause and recurrence risk. Recent advances in diagnostic testing technology have greatly increased the options available to them. It is not currently clear what the overall diagnostic yield of a battery of tests, either collectively or individually, might be. The purpose of this study was to evaluate the diagnostic yield of a stepwise approach we have implemented in our clinics. METHODS: We used a three-tiered neurogenetic evaluation scheme designed to determine the cause of ASDs in patients referred for clinical genetic consultation. We reviewed the results of our diagnostic evaluations on all patients referred with a confirmed diagnosis of autism over a 3-year period. RESULTS: By using this approach, we found an overall diagnostic yield for ASDs of more than 40%. This represents a significant increase in the diagnostic yield reported just a few years ago. CONCLUSIONS: Given the implications of these diagnoses on recurrence risk and associated medical conditions, a targeted neurogenetic evaluation of all persons with ASDs seems warranted. We discuss the issues in the future implementation of a fourth tier to the evaluation with the potential for an even higher diagnostic yield.

Autistic Disorder↗
PubMed2003

Improved islet yield and function with ductal injection of University of Wisconsin solution before pancreas preservation.

BACKGROUND: Ensuring sufficient islet yield from preserved pancreases is a critical step in clinical islet transplantation. The aim of this study was to investigate whether pancreatic ductal injection, performed at procurement, using a small volume of preservation solution before cold storage (ductal preservation method) would improve islet yield and function from rat pancreases preserved for 6 and 24 hr. MATERIALS AND METHODS: Islets were isolated from Lewis rats. Pancreases were classified into five groups: fresh (group 1); preserved for 6 hr in University of Wisconsin solution without and with ductal preservation (groups 2 and 3); and preserved for 24 hr in University of Wisconsin solution without and with ductal preservation (groups 4 and 5). We assessed islet yield, function, and viability of pancreatic ductal cells. RESULTS: Islet yields per pancreas in groups 1 to 5 were 2010+/-774, 674+/-450, 1418+/-528, 527+/-263, and 1655+/-618 (islet equivalent) (+/-SD), respectively. Stimulation indices in groups 1 to 5 were 11.97+/-3.17, 6.48+/-4.04, 12.44+/-5.65, 2.56+/-2.03, and 5.55+/-2.71. Functional success rates in groups 1 to 5 were 100%, 0%, 100%, 0%, and 66.7%. Percentages of nonviable pancreatic duct cells in groups 1 to 5 were 3.8+/-2.7%, 59.7+/-4.4%, 19.5+/-7.3%, 64.7+/-4.5%, and 17.2+/-2.6%. In all experiments, the differences were significant between the groups without versus the groups with ductal preservation (P<0.05, group 2 vs. group 3 and group 4 vs. group 5). CONCLUSIONS: Ductal preservation improved islet yield and function after 6 and 24 hr of preservation. Well-preserved pancreatic ducts maintained good distribution of collagenase solution.

Adenosine↗
PubMed2005

Differences in MEG/EEG epileptic spike yields explained by regional differences in signal-to-noise ratios.

Controversy remains regarding the preferred modality, magnetoencephalography (MEG) or EEG, for the presurgical evaluation of patients with epilepsy. In general, it appears that the spike yields for MEG and EEG are similar in patients with temporal lobe epilepsy, and that for neocortical epilepsy the MEG spike yields may be larger than for EEG. In general, MEG/EEG spike yields depend on factors such as (1) the number of sensors, (2) the source depth and orientation, (3) the background activity, and (4) the smearing of the potential fields due to variations in skull resistivity in EEG. Because the contribution of all these factors are of the same order of magnitude, the authors took them all into account to predict the signal-to-noise ratio (SNR) of hypothetical spikes in different brain areas. In this study, it was assumed that spike sensitivity (and therefore the spike yield) increases with SNR. The estimated SNR values at temporal areas were comparable for MEG and EEG, which is in agreement with clinical findings that spike yields in temporal lobe epilepsy are similar. Furthermore, the SNR of MEG was substantially higher in the frontal area, indicating that in frontal lobe epilepsy MEG may be highly relevant to prescreening of epilepsy patients. This model-based approach indicates that SNR mapping clarifies differences between MEG and EEG findings that are difficult to understand on the basis of patient studies only.

Action Potentials↗
PubMed2005

Global food insecurity. treatment of major food crops with elevated carbon dioxide or ozone under large-scale fully open-air conditions suggests recent models may have overestimated future yields.

Predictions of yield for the globe's major grain and legume arable crops suggest that, with a moderate temperature increase, production may increase in the temperate zone, but decline in the tropics. In total, global food supply may show little change. This security comes from inclusion of the direct effect of rising carbon dioxide (CO2) concentration, [CO2], which significantly stimulates yield by decreasing photorespiration in C3 crops and transpiration in all crops. Evidence for a large response to [CO2] is largely based on studies made within chambers at small scales, which would be considered unacceptable for standard agronomic trials of new cultivars or agrochemicals. Yet, predictions of the globe's future food security are based on such inadequate information. Free-Air Concentration Enrichment (FACE) technology now allows investigation of the effects of rising [CO2] and ozone on field crops under fully open-air conditions at an agronomic scale. Experiments with rice, wheat, maize and soybean show smaller increases in yield than anticipated from studies in chambers. Experiments with increased ozone show large yield losses (20%), which are not accounted for in projections of global food security. These findings suggest that current projections of global food security are overoptimistic. The fertilization effect of CO2 is less than that used in many models, while rising ozone will cause large yield losses in the Northern Hemisphere. Unfortunately, FACE studies have been limited in geographical extent and interactive effects of CO2, ozone and temperature have yet to be studied. Without more extensive study of the effects of these changes at an agronomic scale in the open air, our ever-more sophisticated models will continue to have feet of clay.

Acclimatization↗
PubMed2003

Agricultural management practices to sustain crop yields and improve soil and environmental qualities.

In the past several decades, agricultural management practices consisting of intensive tillage and high rate of fertilization to improve crop yields have resulted in the degradation of soil and environmental qualities by increasing erosion and nutrient leaching in the groundwater and releasing greenhouses gases, such as carbon dioxide (CO2) and nitrous oxide (N2O), that cause global warming in the atmosphere by oxidation of soil organic matter. Consequently, management practices that sustain crop yields and improve soil and environmental qualities are needed. This paper reviews the findings of the effects of tillage practices, cover crops, and nitrogen (N) fertilization rates on crop yields, soil organic carbon (C) and N concentrations, and nitrate (NO3)-N leaching from the soil. Studies indicate that conservation tillage, such as no-till or reduced till, can increase soil organic C and N concentrations at 0- to 20-cm depth by as much as 7-17% in 8 years compared with conventional tillage without significantly altering crop yields. Similarly, cover cropping and 80-180 kg N ha(-1) year(-1) fertilization can increase soil organic C and N concentrations by as much as 4-12% compared with no cover cropping or N fertilization by increasing plant biomass and amount of C and N inputs to the soil. Reduced till, cover cropping, and decreased rate of N fertilization can reduce soil N leaching compared with conventional till, no cover cropping, and full rate of N fertilization. Management practices consisting of combinations of conservation tillage, mixture of legume and nonlegume cover crops, and reduced rate of N fertilization have the potentials for sustaining crop yields, increasing soil C and N storage, and reducing soil N leaching, thereby helping to improve soil and water qualities. Economical and social analyses of such practices are needed to find whether they are cost effective and acceptable to the farmers.

Agriculture↗
PubMed1998

Neutron yields from 435 MeV/nucleon Nb stopping in Nb and 272 MeV/nucleon Nb stopping in Nb and Al.

Neutron fluences were measured from 435 MeV/nucleon Nb ions stopping in a Nb target and 272 MeV/nucleon Nb ions stopping in targets of Nb and Al for neutrons above 20 MeV and at laboratory angles between 3 degrees and 80 degrees. The resultant spectra were integrated over angles to produce neutron energy distributions and over energy to produce neutron angular distributions. The total neutron yields for each system were obtained by integrating over the angular distributions. The angular distributions from all three systems are peaked forward, and the energy distributions from all three systems show an appreciable yield of neutrons with velocities greater than the beam velocity. Comparison of the total neutron yields from the two Nb + Nb systems suggests that the average neutron multiplicity decreases with decreasing projectile energy. Comparison of the total yields from the two 272 MeV/nucleon systems suggests that the total yields show the same dependence on projectile and target mass number as do total inclusive neutron cross sections. The data are compared with Boltzmann-Uehling-Uhlenbeck model calculations.

Aluminum↗
PubMed2003

Identification of a locus increasing rice yield and physiological analysis of its function.

I identified a new locus responsible for increased yield potential and evaluated its physiological function to understand how to improve potential yield in rice (Oryza sativa) plants. Quantitative trait loci (QTLs) for 1,000-grain weight (TGW) were analyzed under different environments over 3 years in backcross inbred lines of rice japonica cv Nipponbare x indica cv Kasalath. Four QTLs for this trait were detected across environments; rice cv Kasalath had a positive allele only at one QTL on chromosome 6 (tgw6). A near-isogenic line (NILtgw6) that carried a rice cv Kasalath chromosomal segment corresponding to tgw6 in the rice cv Nipponbare genetic background was selected and analyzed to clarify the physiological function of this locus. The carbohydrate storage capacity before heading in NILtgw6 was superior to that in rice cv Nipponbare (control), but other characters (e.g. photosynthetic ability in flag leaf and traits related to plant type) were the same in both plants. In the leaf sheath, the main organ that accumulates carbohydrate before heading in rice, higher contents of carbohydrate and transcripts of genes related to starch synthesis were found in NILtgw6 than in rice cv Nipponbare. Compared with those in rice cv Nipponbare, a high-yield modern cultivar, TGW and yield per plant were significantly higher in NILtgw6, by 10% and 15%, respectively (P[f] < 0.01). These results suggest that tgw6 improves the carbohydrate storage capacity and consequently increases the yield potential in NILtgw6.

Amylopectin↗
PubMed1983

Variation in Quantum Yield for CO(2) Uptake among C(3) and C(4) Plants.

The quantum yield for CO(2) uptake was measured on a number of C(3) and C(4) monocot and dicot species. Under normal atmospheric conditions (330 microliters per liter CO(2), 21% O(2)) and a leaf temperature of 30 degrees C, the average quantum yields (moles CO(2) per einstein) were as follows: 0.052 for C(3) dicots, 0.053 for C(3) grasses, 0.053 for NAD-malic enzyme type C(4) dicots, 0.060 for NAD-malic enzyme type C(4) grasses, 0.064 for phosphoenolpyruvate carboxykinase type C(4) grasses, 0.061 for NADP-malic enzyme C(4) dicots, and 0.065 for NADP-malic enzyme type C(4) grasses. The quantum yield under normal atmospheric conditions was temperature dependent in C(3) species, but apparently not in C(4) species. Light and temperature conditions during growth appeared not to influence quantum yield. The significance of variation in the quantum yields of C(4) plants was discussed in terms of CO(2) leakage from the bundle sheath cells and suberization of apoplastic regions of the bundle sheath cells.

Journal Article↗
PubMed1987

Boron stem infusions stimulate soybean yield by increasing pods on lateral branches.

Studies were carried out to determine if supplemental B (H(3)BO(3)) and Ca (CaCl(2)) injected via a stem infusion technique into soybeans could stimulate yield by increasing pods on lateral branches, seed number, and overall seed yield. Boron treatments caused a significant 84.8% increase in the number of lateral pods/plant and a 17.6% increase in total seed weight/plant. This corresponded to a seed yield of 4170 kilograms per hectare in the B-treated plants compared to 3540 kilograms per hectare in the injected control plants, indicating that B deficiency may have been a factor in limiting yield of control plants. Ca treatments tended to accentuate the negative yield effects of apparent B deficiency.

Journal Article↗
PubMed1988

Depression of Photosynthesis, Growth, and Yield in Field-Grown Green Pepper (Capsicum annuum L.) Exposed to Acidic Fog and Ambient Ozone.

The relationship among physiological, injury, growth, and yield responses was examined in field-grown green pepper (Capsicum annuum L. ;California Wonder') subjected to two airborne environmental stresses. The primary objectives were to determine if the stresses could cause alterations in the plant responses, and to determine if any stress induced alterations in physiological or injury responses were correlated with effects on growth or yield. Responses were monitored in green pepper exposed to simulated acidic fog alone, or in combination with ambient concentrations of ozone in open-top field chambers. Both highly acidic fog and ambient ozone depressed green pepper growth and yield responses via the inhibition of photosynthesis. Applications of highly acidic fog (i.e. two exposures of pH 1.68 fog per week for 11 weeks) caused a significant depression of net photosynthesis, reduction in leaf buffering capacity, and an extensive amount of leaf injury. These alterations closely paralleled decreases in growth and yield on a percentage basis. In contrast, ambient ozone had similar impacts on net photosynthesis, growth and yield, but enhanced leaf buffering capacity, and caused no visible injury. The pollutant-specific differences in plant response are discussed with respect to whole-plant carbon metabolism and physiological compensation.

Journal Article↗
PubMed2006

Peripheral blood stem cell yield in 400 normal donors mobilised with granulocyte colony-stimulating factor (G-CSF): impact of age, sex, donor weight and type of G-CSF used.

Mobilised peripheral blood is now the main source of stem cells collected from normal donors. We report our experience of mobilising and collecting 400 normal healthy donors using standardised procedures and techniques. Target recipient doses were reached with one aphaeresis in 63% of donors and with two aphereses in 81% of donors. Approximately 2% of donors yielded such low progenitor values that they were termed 'poor mobilisers'. There were minor effects of donor age, weight and sex and where possible, larger male donors under the age of 55 years should be selected. Two forms of granulocyte colony-stimulating factor (G-CSF) were used at the same dose and no significant difference was seen in the yield of CD34+ cells collected/l of blood processed. However, a greater number of granulocyte-macrophage colony-forming cells were harvested using lenograstim (glycosylated G-CSF) compared with filgrastim (non-glycosylated G-CSF; P = 0.002). CD34+ cell yields were also measured halfway through the aphaeresis procedure. This was found to be highly predictive of final yield and facilitated distribution of the stem cell product to other centres. The observation that CD34+ yields did not decline in the second half compared with the first half of aphaeresis suggests that the circulating cell numbers are not static.

Adolescent↗
PubMed2006

Genotypic difference in canopy diffusive conductance measured by a new remote-sensing method and its association with the difference in rice yield potential.

There have been few practical ways of measuring physiological determinants of rice yield. Rapid evaluation of yield determination traits may expedite breeding of high-yielding rice. Here, we report a new remote-sensing technique for the evaluation of canopy ecophysiological status under field conditions developed based on simultaneous measurements of sunlit and suddenly shaded canopy temperatures. This technique has the advantage of instantaneous estimation of aerodynamic resistance (r(a)) and canopy diffusive resistance (r(c) without measuring wind velocity. Canopy diffusive conductance (1 / r(c)) estimated by the remote sensing method was closely related to leaf stomatal conductance (g(s)) measured with a portable gas exchange system. This result supported the validity of this new method for quantitative estimation of canopy physiological characteristics. Significant genotypic differences were obtained in canopy-air temperature difference (Tc-Ta), r(c) and 1 / r(c) during the 2-week period preceding full heading for two years, and 1 / r(c) was highly correlated with crop growth rate (CGR), which was closely related to the final yield. These results suggest that 1 / r(c) can be an effective criterion for the selection of high-yielding rice genotypes, and the remote sensing technique proposed here can be a powerful tool for the rapid evaluation of 1 / r(c) under field conditions.

Agriculture↗
PubMed1982

Granulocyte yields using the Haemonetics 30. Effects of variations in corticosteroid regimen and donor selection.

The factors of donor selection, corticosteroid drug choice, dose, timing and route of administration were studied to optimize granulocyte yield employing the Haemonetics Model 30 Blood Processor. Our data suggest that donors giving one excellent yield do not necessarily do so again. Donors with high initial granulocyte counts had only marginal increases in counts after taking corticosteroids. Selecting donors on the basis of high previous yield or granulocyte count is not a feasible strategy for improving granulocyte yields. Highest yields of granulocytes (16 X 10(9) total; 4 X 10(9)/liter processed) were obtained with any of four split-dose corticosteroid regimen. This increment is almost twice as large as the previously reported improvement using continuous-flow centrifugation. The choice of steroid, the route of administration and the timing of the split doses are not critical.

Administration, Oral↗
PubMed2005

Leukapheresis for the extraction of monocytes and various lymphocyte subpopulations from peripheral blood: product quality and prediction of the yield using different harvest procedures.

BACKGROUND AND OBJECTIVES: Leukapheresis of non-mobilized healthy donors is performed to harvest monocytes and lymphocyte subpopulations for use in various therapeutic regimens. In this methodological study, we compared two different leukapheresis programs, using equivalent volumes of processed blood over similar processing periods, to determine the influence of the procedures on the donor peripheral blood count and to establish the procedure that yields the highest quality product. MATERIALS AND METHODS: The target variables obtained in 41 healthy blood donors who underwent short-term leukapheresis (80-105 min) were retrospectively compared. Twenty-one volunteers were processed on a COBE Spectra machine at the MNC setting and 20 volunteers were processed at the AutoPBSC setting. Data were collected on pre- and postleukapheresis samples and on the product. RESULTS: AutoPBSC and MNC procedures resulted in a decrease of haemoglobin (5-7%), platelets (17-20%), monocytes (22%) and lymphocytes (23-27%), but not of granulocytes in peripheral blood. Both procedures produced nearly identical leucocyte and lymphocyte yields. AutoPBSC products contained a greater number of granulocytes, monocytes and red cells, but fewer platelets. The preleukapheresis values correlated with the yields for monocytes, T-helper and T-suppressor cells, B-lymphocytes and natural killer cells, but not for granulocytes or platelets. CONCLUSIONS: Leukapheresis is a safe and efficient procedure for collecting large numbers of peripheral blood monocytes and different lymphocyte populations from non-mobilized donors. The two programs yield comparable leucocyte harvests. Based on our results, yields can be predicted from the peripheral cell counts.

Blood Cell Count↗
PubMed2005

Estimation of genetic parameters for lactational milk yields using two-dimensional random regressions on parities and days in milk in Chinese Simmental cattle.

A two-dimensional random regression model with regressions on days in milk (DIM) and parity number was applied to lactational milk yields in Chinese Simmental cattle. Random regressions were fitted for additive genetic and permanent environmental effects using a two-dimensional polynomial on DIM and parity number. A total of 4340 lactational milk yields from Chinese Simmental cattle which calved between 1980 and early 2000 were used in this study. Variance components were estimated using Bayesian methodology via Gibbs sampling. Variances of random regression coefficients associated with all terms of the polynomials were significant. A covariance function showed that heritabilities of lactational milk yields between 200 and 400 DIM over parities varied between 0.25 and 0.45. Heritabilities of 305-day milk yields from 1st to 6-8th parities were 0.28, 0.30, 0.32 0.32, 0.32, and 0.31, respectively. Ratios of permanent environment variances to total variances at each DIM were greater than corresponding heritabilities. Generally, genetic correlations were higher between lactational milk yields with similar DIM and parity number.

Animals↗
PubMed2004

Analysis of maternal and neonatal factors that influence the nucleated and CD34+ cell yield for cord blood banking.

BACKGROUND: It would be beneficial to be able to predict the cord blood (CB) cell yield from volunteer donors before cell processing. STUDY DESIGN AND METHODS: The maternal and neonatal factors that influence the total nucleated cell (TNC), CD34+ cell, and CFU-GM yields in CB collected for the Chugoku-Shikoku Cord Blood Bank were evaluated. RESULTS: In a univariate analysis, the volume of CB collected was significantly correlated with the TNC, CD34+ cell, and CFU-GM yields (p < 0.001). A longer cord (p < 0.001), larger placenta (p < 0.001), and bigger baby (p < 0.001) were associated with a greater volume of CB. A female baby (p < 0.05) and longer gestational age (p < 0.005) were associated with a higher TNC concentration. A younger maternal age (p < 0.05), larger birth weight (p < 0.001), shorter gestational age (p < 0.001), and shorter time from collection to processing (p < 0.05) were associated with a higher CD34+ cell concentration. A multivariate linear regression analysis was performed to predict the yield and determine first-level selection criteria to start processing when the volume of CB units was on the borderline. However, this formula might not be suitable for actual use. CONCLUSION: Maternal and neonatal factors appeared to affect CB cell yields. These findings might be useful for efficiently collecting more qualified CB units.

Age Factors↗
PubMedDate not supplied

A reassessment of ground water flow conditions and specific yield at Borden and Cape Cod.

Recent widely accepted findings respecting the origin and nature of specific yield in unconfined aquifers rely heavily on water level changes observed during two pumping tests, one conducted at Borden, Ontario, Canada, and the other at Cape Cod, Massachusetts. The drawdown patterns observed during those tests have been taken as proof that unconfined specific yield estimates obtained from long-duration pumping tests should approach the laboratory-estimated effective porosity of representative aquifer formation samples. However, both of the original test reports included direct or referential descriptions of potential supplemental sources of pumped water that would have introduced intractable complications and errors into straightforward interpretations of the drawdown observations if actually present. Searches for evidence of previously neglected sources were performed by screening the original drawdown observations from both locations for signs of diagnostic skewing that should be present only if some of the extracted water was derived from sources other than main aquifer storage. The data screening was performed using error-guided computer assisted fitting techniques, capable of accurately sensing and simulating the effects of a wide range of non-traditional and external sources. The drawdown curves from both tests proved to be inconsistent with traditional single-source pumped aquifer models but consistent with site-specific alternatives that included significant contributions of water from external sources. The corrected pumping responses shared several important features. Unsaturated drainage appears to have ceased effectively at both locations within the first day of pumping, and estimates of specific yield stabilized at levels considerably smaller than the corresponding laboratory-measured or probable effective porosity. Separate sequential analyses of progressively later field observations gave stable and nearly constant specific yield estimates for each location, with no evidence from either test that more prolonged pumping would have induced substantially greater levels of unconfined specific yield.

Environmental Monitoring↗
PubMed1983

Available electron and energetic yields in fermentation processes.

Microbial growth and product yields have been investigated for several cultures. Available electron and free energy balances may be used to examine the efficiency of microbial energetics. Energetic yields based on free energy analysis were obtained and compared with yields from available electron analysis. Estimates of true growth yields under anaerobic conditions have been obtained using statistical methods and the results were compared with theoretical maximum yields.

Adenosine Triphosphate↗