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Purpose: Would [P.sub.ETCO2] be an acceptable approximation of [P.sub.aCO2] in severe COPD patients to be used in the calculation of Cardiac output by the non invasive Fick [CO.sub.2] rebreathing method [...]

Foraging ecology and food patch studies are commonly used to elucidate the environmental perceptions of wild, free-ranging animals. Their application to captive animals, however, especially those in zoos, is still in its infancy. To illustrate some specific applications of zoo foraging ecology, we provide a study that evaluated: (i) whether patch use and giving-up densities (GUDs) can reveal areas of preference within an exhibit for zoo species; (ii) if food patches provide an effective form of behavioural enrichment; and (iii) if visitor interest and behaviour is affected by food patch presence. A combination of behavioural observations, and experimental food patches and giving-up densities were used to address these objectives in Parma wallabies (Macropus parma) and Patagonian cavies (Dolichotis patagonum) at Lincoln Park Zoo, Chicago, Illinois USA. GUDs revealed distinct areas of preference and aversion within the exhibit for cavies, but not so for the wallabies. For both species, presence of food patches increased foraging behaviours, decreased inactive behaviours, and increased within-exhibit movement, demonstrating that food patches serve as an effective behavioural enrichment technique. The use of food patches also revealed striking differences between individuals, particularly for the pair of cavies. There were encouraging trends toward increased visitor number and stay-time when food patches were present in each exhibit, but the effect was not statistically significant. These results suggest that utilising patch use, GUDs, and foraging theory in zoo populations may enhance animal welfare, and can inform improvements to exhibit design directly from the animal's perspective. We conclude with a broader discussion of zoo foraging ecology as an emerging field, with suggestions for future avenues of research. [ABSTRACT FROM AUTHOR]

We explore two ways in which the mechanical properties of rock potentially influence fluvial incision and sediment transport within a watershed: rock erodibility is inversely proportional to rock cohesion, and fracture spacing influences the initial grain sizes produced upon erosion. Fault‐weakened zones show these effects well because of the sharp strength gradients associated with localized shear abrasion. A natural example of fault erosion is used to motivate our calibration of a generalized landscape evolution model. Numerical experiments are used to study the sensitivity of river erosion and transport processes to variable degrees of rock weakening. In the experiments, rapid erosion and transport of fault gouge steers surface runoff, causing high‐order channels to become confined within the structure of weak zones when the relative degree of rock weakening exceeds 1 order of magnitude. Erosion of adjacent, intact bedrock produces relatively coarser grained gravels that accumulate in the low relief of the eroded weak zone. The thickness and residence time of sediments stored there depends on the relief of the valley, which in these models depends on the degree of rock weakening. The frequency with which the weak zone is armored by bed load increases with greater weakening, causing the bed load to control local channel slope. Conversely, small tributaries feeding into the weak zone are predominantly detachment limited. Our results indicate that mechanical heterogeneity can exert strong controls on rates and patterns of erosion and should be considered in future landscape evolution studies to better understand the role of heterogeneity in structuring landscapes. Heavily fractured rocks erode more easily than strong bedrock, and the sediments produced upon erosion are also easier to transport because they tend to be a finer grain size. Larger gravels that come from the erosion of strong bedrock will often be deposited over the weaker rock, causing an armoring effect. The pattern of river drainage tends to reflect the underlying pattern of rock strength. Rock damage associated with shear abrasion locally enhances erodibility and transport of substrateRapid erosion of weak zones causes accumulation of coarse sediments from adjacent sourcesSediment residence time scales with erodibility of weak zone

Little is known about the impact of treatment-resistant hypertension (TRH) on health-related quality of life (HrQoL). We aimed to compare HrQoL measures in adults with apparent TRH (aTRH) and non-resistant hypertension among nationally representative US Medical Expenditure Panel Survey data pooled from 2000 to 2011. Cohorts compared were adults with aTRH (⩾2 unique fills from ⩾4 antihypertensive classes during a year) versus non-resistant hypertension (those with hypertension not meeting the aTRH definition). Key outcomes were cohort differences in SF-12v2 physical component summary (PCS) and mental component summary (MCS) scores and disease-state utility using the SF-6D. Of 57 150 adults with hypertension, 2501 (4.4%) met criteria for aTRH. Persons with aTRH, compared with non-resistant hypertension, were older (mean, 68 vs 61 years), had a higher BMI (30.9 vs 29.7 kg m−2) and were more likely to be Black (20% vs 14%), but less likely to be female (46% vs 54%). Persons with aTRH, compared with non-resistant hypertension, had lower mean PCS scores (35.8 vs 43.2; P<0.0001), and utility (0.68 vs 0.74; P<0.0001), but similar MCS scores (49.1 vs 50.4). In multivariable-adjusted analyses, aTRH was associated with a 2.37 (95% CI 1.71 to 3.02) lower PCS score and 0.02 (95% CI 0.01 to 0.03) lower utility, compared with non-resistant hypertension. In conclusion, aTRH was associated with substantially lower HrQoL in physical functioning and health utility, but not in mental functioning, compared with non-resistant hypertension. The multivariable-adjusted reduction in physical functioning was similar in magnitude to previous observations comparing hypertension with no hypertension.

Grade 3 follicular lymphoma (FL) has aggressive clinical behavior. To evaluate the optimal first transplantation approach in relapsed/refractory grade 3 FL patients, we compared the long-term outcomes after allogeneic (allo-) vs autologous hematopoietic cell transplantation (auto-HCT) in the rituximab era. A total of 197 patients undergoing first reduced-intensity conditioning (RIC) allo-HCT or first auto-HCT during 2000–2012 were included. Rituximab-naive patients were excluded. Allo-HCT recipients were younger, more heavily pretreated and had a longer interval between diagnosis and HCT. The 5-year probabilities of non-relapse mortality (NRM), relapse/progression, PFS and overall survival (OS) for auto-HCT vs allo-HCT groups were 4% vs 27% (P<0.001), 61% vs 20% (P<0.001), 36% vs 51% (P=0.07) and 59% vs 54% (P=0.7), respectively. On multivariate analysis, auto-HCT was associated with reduced risk of NRM (relative risk (RR)=0.20; P=0.001). Within the first 11 months post HCT, auto- and allo-HCT had similar risks of relapse/progression and PFS. Beyond 11 months, auto-HCT was associated with higher risk of relapse/progression (RR=21.3; P=0.003) and inferior PFS (RR=3.2; P=0.005). In the first 24 months post HCT, auto-HCT was associated with improved OS (RR=0.42; P=0.005), but in long-time survivors (beyond 24 months) it was associated with inferior OS (RR=3.6; P=0.04). RIC allo-HCT as the first transplant approach can provide improved PFS and OS, in long-term survivors.

In an international analysis of solid organ transplant recipients with primary central nervous system posttransplant lymphoproliferative disease, the authors find that the disease is associated with renal transplantation, typically occurs late and retains EBV positivity, and the dominant prognostic factor for survival is response to first‐line therapy.

Empirical mode decomposition (EMD) is an adaptive, data-driven algorithm that decomposes any time series into its intrinsic modes of oscillation, which can then be used in the calculation of the instantaneous phase and frequency. Ensemble EMD (EEMD), where the final EMD is estimated by averaging numerous EMD runs with the addition of noise, was an advancement introduced by Wu and Huang (2008) to try increasing the robustness of EMD and alleviate some of the common problems of EMD such as mode mixing. In this work, we test the performance of EEMD as opposed to normal EMD, with emphasis on the effect of selecting different stopping criteria and noise levels. Our results indicate that EEMD, in addition to slightly increasing the accuracy of the EMD output, substantially increases the robustness of the results and the confidence in the decomposition.

OBJECTIVE: This study sought to determine if ambulance service users differ in their health behaviours to "walk-in" patients attending an emergency department (ED) with acute asthma. METHOD: Retrospective cross-sectional study of people with acute asthma stratified by ambulance use attending two ED. The health-promoting lifestyle profile and health risk appraisal tools assessed health and risk-taking behaviours, and the clinical variables assessed include: forced expiratory volume in 1 s, admission rates, severity, asthma medications, anxiety and depression. RESULTS: Of the 142 patients, 26% used the ambulance service as transport to the ED. Ambulance users were significantly older than walk-in patients (40 vs 32 years, p0.05) and were less likely to return to follow-up appointments (odds ratio (OR) 2.93, 95% CI 1.16 to 7.37). Walk-in patients were more likely to report higher levels of education (OR 4.36, 95% CI 1.11 to 17.09). There was no difference between the groups for health-promoting behaviours. In reducing risks to their health and after adjusting for age and gender, there was a trend towards ambulance users undertaking preventive health measures more often than walk-in patients. CONCLUSIONS: Ambulance users with acute asthma are more likely to be older, married and less educated. There is no evidence that this group is less responsible in managing their health; however, fewer ambulance users attended their follow-up appointment and the implication for ongoing care requires further investigation.

To investigate the relationship between markers of vitamin B12status and brain volume loss per year over a 5-year period in an elderly population.

Harvested tomato (Solanum lycopersicum L.) fruit can absorb water via stem scar tissues. Decay incidence {bacterial soft rot (Erwinia carotovora Jones), sour rot (Geotrichum candidum Link), bacterial sour rot [Leuconostoc mesenteroides (Tsenkovskii) van Tieghem ssp. mesenteroides], and certain species of Lactobacillus Beijerinck} has been positively linked with the degree of water absorption. Previous studies have shown that cultivars differ in their tendencies to take up water during a simulation of packinghouse handling procedures. The inheritance of water absorption tendency was examined in two seasons of tests where six inbred tomato lines were intercrossed to develop a complete diallel. Following harvest at the mature-green stage, fruit were weighed, submerged in water for 2 min, and then reweighed to determine water absorption. Parental lines were tested in three seasons. Two parental lines, Fla. 7776 and Fla. 7946, were always in the low-absorption grouping, and NC84173 also had relatively low absorption. Fla. 8059 and Fla. 7777 were always in the high-absorption group, and Fla. 8000 tended to have high absorption. General combining ability for the low water absorption fruit characteristic was significant for both seasons with a higher level of significance in the spring over the fall season (P≤0.001 and P≤0.05, respectively), while specific combining ability was not significant for either season. Thus, the low water absorption fruit characteristic appears to be additively inherited. Accurate knowledge of parental absorption should allow prediction of hybrid performance. None of the hybrids absorbed unexpected amounts of water over both seasons. Reciprocal effects were significant (P≤0.05) for fall, and maternal effects were significant (P≤0.05) in spring. However, there was no general trend in water absorption due to the direction of the cross and thus no clear evidence for cytoplasmic inheritance. Water absorption was much greater in spring than in fall. Based on previous observations, the greater absorption in spring was due to higher field temperatures. Because of such environmental effects, parent lines should be replicated and tested over several seasons to accurately assess their relative water absorption. Crosses between consistently low water absorption parents should provide low-absorption hybrids, but testing of hybrids before release is suggested to verify this. [ABSTRACT FROM AUTHOR]

Estimates of cerebral critical closing pressure (CrCP) and resistance-area product (RAP) are often derived using noninvasive measurements of arterial blood pressure (ABP) in the finger, but the errors introduced by this approach, in relation to intra-vascular measurements of ABP, are not known. Continuous recordings of ABP (Finapres and solid-state catheter-tip transducer in the ascending aorta), cerebral blood flow velocity (CBFV, bilateral Doppler), ECG and transcutaneous CO2were performed following coronary catheterization. CrCP and RAP were calculated for each of 12?784 cardiac cycles from 27 subjects using the classical linear regression (LR) of the instantaneous CBFV-ABP relationship and also the first harmonic (H1) of the Fourier transform. There was a better agreement between LR and H1for the aortic measurements than for the Finapres (p< 0.000?01). For LR there were no significant differences for either CrCP or RAP due to the source of ABP measurement, but for H1the differences were highly significant (p< 0.000?03). The coherence functions between either CrCP or RAP values calculated with aortic pressure (input) or the Finapres (output) were significantly higher for H1than for LR for most harmonics below 0.2 Hz. When using the Finapres to estimate CrCP and RAP values, the LR method produces similar results to intra-arterial measurements of ABP for time-averaged values, but H1should be preferred in applications analysing beat-to-beat changes in these parameters.

The synthesis of nanostructured polymer gels via polymerization of hydrophilic monomers in lyotropic liquid crystal (LLC) phases has recently been of great interest. This work describes the effects of monomer organization on the photopolymerization kinetics of acrylamide in various LLC phases of surfactant/water systems. Resulting polymer morphology is reported as well. The polymerization rate of acrylamide is significantly enhanced when performed in the presence of various LLC phases. An unprecedented 10-fold increase in polymerization rate is observed in bicontinuous cubic and hexagonal phases as compared to polymerizations in water. This significant increase in polymerization rate is a result of diffusional limitations on the propagating polymer as well as segregation and ordering phenomena induced by the LLC phase. ¹³C T1 relaxation times and ¹⁴N NMR spectra show that the monomer strongly associates with the interface of the surfactant/water assemblies and assumes the orientational order of the LLC phases to some degree. When formed using photopolymerization, the resulting polymer morphology appears to be a direct template of the parent LLC phase.

Recently, a considerable amount of research has centered on the synthesis of nanostructured hydrogels via the polymerization of monomers in lyotropic liquid crystal (LLC) phases. Because of the potential for controllable nanostructures, these materials have exhibited tremendous potential for a variety of applications. This work describes the impact of photopolymerization kinetics and polymer nanostructure on the physical properties of hydrogels synthesized from LLC templates. Both acrylamide and 2-hydroxyethyl methacrylate (HEMA) photopolymerize more rapidly in the highly ordered LLC phases, resulting in higher molecular weight polymers. The photopolymerization of these monomers in organized surfactant/water assemblies allow formation of highly ordered polymeric hydrogels. The ultimate physical properties appear to be a function of the different polymerization kinetics and polymer nanostructure. Nanostructured polyacrylamide hydrogels swell faster and to a greater extent than isotropic hydrogels. Compressive moduli are also higher for nanostructured polyacrylamide hydrogels when compared to isotropic analogues. The photopolymerization of HEMA results in nanostructured hydrogels, although some structural changes are evident. As a result of the different nanostructures, vastly different physical properties are observed. The isotropic polyHEMA hydrogels swell to a greater extent and considerably faster than any of the organized hydrogels. Additionally, the isotropic polyHEMA hydrogels exhibit higher compressive modulus than the hydrogels synthesized in the organized LLC phases. For both polyHEMA and polyacrylamide gels, different nanostructures produce different physical properties, implying that characteristics such as swelling and mechanical strength can be optimized simply by changing the parent LLC phase.

To assess cortical gray matter (GM) changes in MS and establish their relevance to clinical disability and to inflammatory changes of white matter (WM) in patients with the relapsing–remitting (RR) and primary progressive (PP) forms of the disease.

The chemical vapor deposition of zinc oxide thin films can be carried out with diethyl zinc and water vapor. The present study uses molecular orbital methods to examine complexes of one and two molecules of H2O with Zn(C2H5)2, and the subsequent hydrolysis, elimination, and oligomerization reactions which may occur in the gas phase. Geometry optimizations were carried out at the B3LYP/6-311G(d) level of theory. Hydrolysis of Zn(C2H5)2 by a single water has an enthalpy barrier of 19 kcal/mol relative to separated reactants, which is reduced to 4 kcal/mol by the presence of a second water. Further hydrolysis of Zn(C2H5)OH to Zn(OH)2 is facile, but elimination of C2H6 or H2O to form ZnO is very endothermic. Zn(C2H5)OH and Zn(OH)2 form very stable dimers and tetramers. Elimination of C2H6 and H2O from the dimers and tetramers is also endothermic and leads to ring opening.

The purpose of this study was to evaluate the effects of estrogen and progesterone on the vaginal mucosa and their role in vaginal transmission of simian immunodeficiency virus. Incidentally, endometrial hyperplasia was observed in estrogen-treated monkeys at necropsy. Six adult female rhesus monkeys (Macaca mulatta) were ovariectomized and 120 days later received two subcutaneous implants, each containing 200 mg estradiol. The animals were sacrificed 17–27 months later and the uterus examined at necropsy. All the monkeys had simple endometrial hyperplasia, some with polyps or adenomyosis, at the time of necropsy. The severity of the changes correlated with the time between implantation and necropsy. The lesions were similar to endometrial hyperplasia caused by unopposed estrogen in women, but occurred over a time period that is suitable for experimental manipulation. Rhesus monkeys could be used as a model to test the safety of various combinations of sex steroids for the prevention of postmenopausal symptoms in women.

An effective vaccine against AIDS is unlikely to be available for many years. As we approach two decades since the first identification of human immunodeficiency virus, type 1 (HIV-1), currently, only one subunit vaccine candidate has reached phase 3 of clinical trials. The subunit approach has been criticized for its inability to elicit effectively cytotoxic T-lymphocyte (CTL) response, which is felt by many to be needed for protection against HIV-1 infection. In subhuman primates, a live attenuated simian immunodeficiency virus (SIV) vaccine candidate, capable of inducing CTL, has been found to confer prophylactic immunity sufficient to prevent simian AIDS. Because replication competent (live) attenuated viruses could over time revert to virulence, such a live attenuated approach has largely been dismissed for HIV-1. Here, we describe the creation of constitutively dead conditionally live (CDCL) HIV-1 genomes. These genomes are constitutively defective for the Tat/TAR axis and are conditionally dependent on tetracycline for attenuated replication with robust expression of viral antigens. Our results suggest that CDCL genomes merit consideration as safer "live" attenuated HIV-1 vaccine candidates.

The dimerization of Ti(NH2)2NH has been used as a model for the generalized oligomerization of Ti(NR2)2NH in the chemical vapor deposition (CVD) of titanium nitride films. This study uses molecular orbital methods (specifically the B3LYP/6-311G(d) level of theory) to examine the dimerization process and the subsequent elimination of N2H4 from this model compound by two different reaction paths. There is no transition structure for the formation of the dimer from two Ti(NH2)2NH molecules, and this reaction is barrierless. The binding energies of the singlet and triplet dimer complexes are 99.1 and 49.0 kcal/mol, respectively. Both N2H4 elimination pathways are endothermic, and enthalpies of reaction are 26.2 and 17.7 kcal/mol for the singlet and triplet pathways, respectively. In both pathways, there is a crossing from the singlet to triplet surface prior to the N2H4 elimination transition state. Structures on a reaction path for the exchange of amido and imido ligands in the ring of the dimer complex were also found. This pathway could lead to the formation of higher oligomers.

Intracellular flow cytometry analysis of perforin production by CD8(+) T cells showed levels were greatly reduced in tuberculosis (TB) patients compared to healthy controls. Reduced cytotoxic-T-lymphocyte activity was also obtained with CD8(+) T cells from TB patients compared to healthy controls in The Gambia. A change in antigen recognition was noted between the two groups of donors: in addition to recognition of Ag85A and Ag85B, as seen in healthy donors, a prominent ESAT-6 response was found in TB patients.

Gamma interferon (IFN-gamma)-secreting CD4+ T cells have long been established as an essential component of the protective immune response against Mycobacterium tuberculosis. It is now becoming evident from studies with the murine model of tuberculosis that an important role also exists for major histocompatibility complex (MHC) class I-restricted CD8+ T cells. These cells are capable of acting as both IFN-gamma secretors and cytotoxic T lymphocyte (CTL) effectors; however, their exact role in immunity against tuberculosis remains unclear. This study demonstrates the presence of Mycobacterium bovis BCG-reactive CD8+ T cells in healthy BCG-vaccinated donors and that these CD8+ T cells are potent cytokine producers as well as cytotoxic effector cells. Using FACScan analysis, we have shown that restimulation with live M. bovis BCG induced more CD8+-T-cell activation than the soluble antigen purified protein derivative and that these cells are actively producing the type 1 cytokines IFN-gamma and tumor necrosis factor alpha (TNF-alpha). These CD8+ T cells also contain the cytolytic granule perforin and are capable of acting as potent CTLs against M. bovis BCG-infected macrophages. The mycobacterial antigens 85A and B (Ag85A and Ag85B, respectively), and to a lesser extent the 19- and 38-kDa proteins, are major antigenic targets for these mycobacterium-specific CD8+ T cells, while whole-M. bovis BCG activated effector cells from these BCG-vaccinated donors, as expected, failed to recognize the 6-kDa ESAT-6 protein. The use of metabolic inhibitors and blocking antibodies revealed that the CD8+ T cells recognize antigen processed and presented via the classical MHC class I pathway. These data suggest that CD8+ T cells may play a critical role in the human immune response to tuberculosis infection.

Regeneration of damaged, mature muscle occurs by differentiation of satellite cells. In culture, satellite cell myoblasts proliferate, align, and fuse to form cross-striated, contracting myotubes. The biochemical changes and the factors that regulate differentiation in satellite cells have not been investigated previously. We report here that no significant differences in glucose uptake rate or glucose oxidation rate were observed between regenerating myoblasts and myotubes, whereas the aerobic oxidation of palmitic acid increased 7.3-fold between these differentiation states. Specific activities of enzymes of critical importance in aerobic metabolism or in production of ATP were increased 2- to 3.5-fold during fusion. Addition of 20 microM hemin to regenerating muscle cultures potentiated the aerobic capacity as evidenced by a 23.6% increase in palmitate oxidation rate. Hemin also increased the specific activities of all nonheme enzymes investigated with the exception of phosphofructokinase. This augmentation of aerobic metabolism together with the time frame of active muscle differentiation suggests a complex role for hemin in myogenesis.

Twenty lakes in the Matamek and nearby watersheds were sampled in the summer of 1983 for water chemistry and surficial sediments. Thirty-two physical and chemical variables, including pH, alkalinity, cations and metal concentrations were measured on samples from the epilimnion and hypolimnion of each lake. In three lakes, two to four replicate cores were collected to estimate spatial variability of the sediment flora.

In addition to their traditional role in counseling about contraception and sterilization, psychiatrists are becoming increasingly involved in decisions surroundingin vitro fertilization, surrogate motherhood, and artificial insemination. The medical-legal and ethical ramifications of these issues are other significant areas involving the psychiatrist. Exploration of feelings and fears about reproduction can benefit from psychiatric involvement for successful outcomes.

1. Caesium ions (Cs+), applied extracellularly, caused a decrease in the input resistance of cultured spinal cord (s.c.) neurones and depolarized the neurones when they contained 140 mM‐CsCl. 2. The reversal potential for Cs+‐activated currents shifted 56 mV on average for a 10‐fold reduction in the intracellular chloride ion (Cl‐) activity, indicating that the Cs+‐activated currents were specific to Cl‐. 3. The activation of Cl‐ currents by Cs+ was not due to the depolarization‐evoked release of neurotransmitter from presynaptic terminals. We therefore suggest that Cs+ were acting directly on the extracellular surface of the s.c. neurones to activate Cl‐ currents. 4. Cs+‐activated currents showed desensitization in the presence of 140 mM‐Cs+. 5. The log‐log plot of the dose‐response data could be fitted with a straight line with a slope of 1.7 +/‐ 0.4 (n = 6), indicating that at least 2 Cs+ were needed to activate a single Cl‐ channel. The KD of the Cs+‐induced response was greater than 69 mM. 6. In outside‐out patches Cs+ activated single Cl‐ channels. These channels were not activated by sodium or potassium ions. 7. The Cs+‐activated channels displayed a total of five distinct conductance states which had mean conductances of 20, 30, 43, 66 and 92 pS. The 30 and 43 pS states were the most frequently occurring states. 8. The conductance states of the Cs+‐activated channel have the same conductances as those reported for gamma‐aminobutyric acid (GABA)‐ and glycine‐activated channels in rat s.c. neurones. We therefore conclude that Cs+ activate the same type of Cl‐ channel as GABA and glycine through an unidentified receptor.

Twenty-eight species of nine families of caddisflies (Trichoptera) were identified in 170 samples taken over an 8-month period from five emergence traps placed on a second-order, forested, cold-stenothermal stream on the Niagara Escarpment, Ontario, Canada.

The influence of structural complexity on the foraging success for host eggs (Ephestia kuehniellaZeller) by Trichogramma minutumRiley was investigated in the laboratory. Naive females were released into arenas with structurally different paper models or foliage (simple: trembling aspen Populus tremuloidesMichx., complex: balsam fir Abies balsameaL.). Observations of individual females were made every 15 min and searching success was measured by the number of host egg clusters found and the amount of time taken to find them, within a period of 196 min. Females found significantly more egg clusters and were quicker at finding them on the sample paper and foliage surfaces than on the most complex paper or foliage surfaces. Older females (2–3 days) were more successful and searched quicker than younger (<24 h) females on all paper surfaces. The timed observations suggested that wasps which spent more time walking had a significantly decreased probability of finding an egg mass and were significantly slower at finding them. Females that spent more time on paper surfaces had an increased probability of finding an egg mass. The significance of searching differences is discussed in relation to the potential effects of plant surfaces on Trichogrammamovements and to the physiological readiness of the wasp.

AbstractDamage caused by Empoasca fabae(Harris) and Philaenus spumarius(L.), caged on second and third alfalfa harvests, was additive. Numbers of E. fabaewere linearly correlated negatively with plant height, leaf area, and percentage protein, and positively with percentage chlorosis. Perceptible stunting and yellowing occurred with mean infestations per stem of 0.09 E. fabaeand 0.6 P. spumariusnymphs. P. spumariusadults reduced plant height only at infestations of 0.3/stem, while 0.6 nymph/stem also reduced dry weight. E. fabaereduced protein at 0.11/stem and dry weight and leaf area at higher populations of 0.17/stem. None of these parameters was affected on subsequent regrowths. Lygus lineolaris(P. de B.) could not be maintained on pre-bloom alfalfa and was not considered a pest. Adelphocoris lineolatus(Goeze) reduced protein at levels of 0.01 bug/stem and dry weight at 0.06 bug/stem but results were confounded by high mortality. Field populations of all these species were reduced by the second cutting but redeveloped on the regrowth. Although applications of dimethoate (200 g AI/ha) and dimethoate (200 g AI/ha) plus endosulphan (280 g AI/ha) were effective in reducing populations of E. fabae, Acyrthosiphon pisum(Harris), A. lineolatus, and Hypera postica(Gyllenhal), insecticides were cost-effective on only one field. This field had 1.9 E. fabae/sweep and a 3% loss in protein resulted. Plant height, density, dry weight, protein content, and overwintering survival were not significantly affected at harvest in other fields. With the exception of E. fabae, the sum of the maximum field populations, each expressed as a fraction of its threshold, did not reach 50% of an economic threshold.

Several investigators have reported lipid A as the biologically active unit in the lipopolysaccharide (LPS) molecule. To determine if lipid A was responsible for the reported increases in pyruvate kinase, mice were injected with endotoxin from Salmonella typhimurium SR-11, the Re mutant of Salmonella minnesota R 595, and lipid A-bovine serum albumin conjugate. The livers were homogenized and the activity of pyruvate kinase was measured. Similar increases in enzyme were obtained with all three preparations. These data imply that the lipid portion of the LPS molecule was responsible for alterations in host enzyme activity. To further determine if the lipid portion was the active unit, a lipid-degraded endotoxin (endotoxoid) prepared by potassium methylate treatment was inoculated into mice. An initial increase in liver pyruvate kinase activity was observed with all preparations. The marked increase observed at 16 h with the native product and lipid A conjugate was not obtained with the endotoxoid. These experiments extend and confirm previous observations that lipid A is responsible for the effects associated with LPS. Animals tolerant to endotoxin from S. typhimurium SR-11 were challenged with endotoxin from the Re mutant. A significant increase in pyruvate kinase activity was not obtained, suggesting that anti-O antibodies are not important in the development of tolerance.

Eleven species of five families of stoneflies (Plecoptera) were identified in 170 samples taken over a period of 8 months from 5 emergence traps placed on a second-order, forested stream on the Niagara Escarpment, Ontario, Canada.A mean of 2570 stoneflies m-2 of streambed was obtained over the entire sampling period. The maximum daily emergence occurred during the week of 29 August - 5 September. Of the six common species, the larvae of two were fairly uniformly distributed whereas the others were patchily distributed in the streambed. Leuctra ferruginea was the only species that exhibited a significantly changing distribution over time. Residual variances of adult catches were large, suggesting a refined degree of microhabitat selection by the larvae.Except for Amphinemura delosa, females either outnumbered males or were the only sex collected. Most species were protandrous, with males preceding females by 1-2 weeks.The emergence periods and patterns of the six common species (making up 97.6% of the total number of individuals collected) are described and the factors that might regulate the emergence are discussed. Except for L. ferruginea. all species had a synchronized, unimodal pattern of emergence with a peak between 25 April and 20 June at water temperatures of 8 to 12.3°C. L. ferruginea showed an extended pattern and emerged over a period of 28 weeks. Water temperatures during the aquatic-development period are postulated as the major factor influencing the time of onset and the duration of emergence.

Three species of blackflies were found in emergence-trap samples taken overa period of 8 months from a second-order, forested, cold-stenothermal stream in southern Ontario. The emergence phenologies of the two common species, Prosimulium mixtum and Stegopterna mutata, are described and compared with their phenologies in other streams in North America. Hypotheses are presented for the poor faunal diversity and prolonged emergence of the two species in the stream studied. Emergence data are used to describe the pupal distribution in the stream.

Nitric oxide synthases (NOSs) are classified functionally, based on whether calmodulin binding is Ca2+-dependent (cNOS) or Ca2+-independent (iNOS). This key dichotomy has not been defined at the molecular level. Here we show that cNOS isoforms contain a unique polypeptide insert in their FMN binding domains which is not shared with iNOS or other related flavoproteins. Previously identified autoinhibitory domains in calmodulin-regulated enzymes raise the possibility that the polypeptide insert is the autoinhibitory domain of cNOSs. Consistent with this possibility, three-dimensional molecular modeling suggested that the insert originates from a site immediately adjacent to the calmodulin binding sequence. Synthetic peptides derived from the 45-amino acid insert of endothelial NOS were found to potently inhibit binding of calmodulin and activation of cNOS isoforms. This inhibition was associated with peptide binding to NOS, rather than free calmodulin, and inhibition could be reversed by increasing calmodulin concentration. In contrast, insert-derived peptides did not interfere with the arginine site of cNOS, as assessed from [3H]NG-nitro-L-arginine binding, nor did they potently effect iNOS activity. Limited proteolysis studies showed that calmodulin's ability to gate electron flow through cNOSs is associated with displacement of the insert polypeptide; this is the first specific calmodulin-induced change in NOS conformation to be identified. Together, our findings strongly suggest that the insert is an autoinhibitory control element, docking with a site on cNOSs which impedes calmodulin binding and enzymatic activation. The autoinhibitory control element molecularly defines cNOSs and offers a unique target for developing novel NOS activators and inhibitors.

Intracellular applications of ribozymes have been limited partly by the availability of suitable high-expression systems. For RNA effectors, consideration of an RNA virus vector system for delivery and expression is reasonable. We show that alphavirus replicons can be highly efficient nonintegrating ribozyme-expressing vectors. Using a hammerhead ribozyme targeted to a highly conserved sequence in the U5 region of the human immunodeficiency virus type 1 (HIV-1) long terminal repeat, we demonstrate that a full-length 8.3-kb Semliki Forest virus ribozyme (SFVRz) chimeric RNA maintains catalytic activity. SFVRz is packaged into viral particles, and these particles transduce mammalian cells efficiently. SFVRz-transduced BHK cells were found to produce large amounts of genomic and subgenomic forms of ribozyme-containing RNAs that are functional in cleaving a U5-tagged mRNA. The RNase protection assay shows that HIV-1 U5-chloramphenicol acetyltransferase mRNA expressed intracellularly from an RNA polymerase II promoter is quantitatively eliminated in SFVRz-transduced BHK cells.