Short communication: Detection of lameness in dairy cows using a grooming device

Lameness in dairy cattle is a common welfare problem with significant economic implications. All too often, appropriate treatment is delayed or neglected due to insufficient detection of lame cows. Brush usage is considered a low-resilience activity; that is, one that typically decreases when energy resources are limited or when the cost involved in the activity increases, such as during sickness and stress. The aim of this study was to determine the association between brush usage and different degrees of lameness. Locomotion scores of 209 lactating Holstein dairy cows were collected individually once a week for 14 consecutive weeks, using a 5-point visual assessment scoring system (1 = nonlame, 2 = uneven gait, 3 = mild lameness, 4 = lameness, 5 = severe lameness). Daily brush usage was collected automatically from 3 cowsheds of similar size and structure located on a commercial dairy farm. In each of the 3 cowsheds, 2 brushes were installed, one next to the feed bunk, and the other away from the feed bunk (on the opposite side of the cowshed). Linear and generalized linear mixed-effects models were used to evaluate the association between locomotion scores and daily measures of brush usage. We found a significant interaction between locomotion score and brush location (near to/distant from feed bunk) on the daily proportion of cows using the brush at least once and on daily duration of brush usage. Specifically, we showed that lame and severely lame cows did not use brushes that were installed away from the feed bunk but continued to use brushes that were installed next to the feed bunk. Brush usage by cows with uneven gait (locomotion score 2) or with mild lameness (locomotion score 3) did not differ from that of nonlame cows (locomotion score 1). The results of this study suggest that monitoring of daily usage of brushes located away from the feed bunk could be a useful method for detecting lameness and severe lameness in dairy cows. However, the use of this method to detect mild lameness or cases of abnormal gait is, at this stage, less promising.

Development of Ascites-Resistant and Ascites-Susceptible Broiler Lines

The rapid growth of modern broilers is associated with enhanced appetite and high metabolic rate and, consequently, high O(2) demand. Ascites syndrome (AS) develops in individuals that fail to fully supply the increasing demand for O(2) in their bodies under ascites-inducing conditions (AIC) such as high altitude or low temperatures. The tendency of broilers to develop AS is heritable, but efficacious selection against AS susceptibility (without affecting the normal expression of other important traits) requires identification of indirect selection criteria. In the present study, divergent AS-susceptible (AS-S) and AS-resistant (AS-R) lines were developed to confirm the heritability of AS and to facilitate future detection of criteria for indirect selection against AS susceptibility. The base population consisted of 85 sire families with a mean of 73 progeny per sire, reared in a commercial broiler house under low-challenge AIC (cold environment and pelleted feed). Chicks dying with AS manifestations were designated AS-susceptible, whereas the surviving birds were designated AS-resistant. By the end of the trial (d 48), AS mortality had accumulated to 17.2%, but AS incidence per family (%ASF) ranged from 0 to 49%, with a high heritability (0.57). Parents of 7 families with very high %ASF produced the first generation (S(1)) of the AS-S line, and parents of 7 families with very low %ASF produced the S(1) of the AS-R line. The S(1) males and females reproduced generation S(2) of the selected lines, whereas additional S(1) males were tested under high-challenge AIC (individual cages, cool wind, and pelleted feed). Progeny testing under this high-challenge AIC, followed by sib selection, was repeated in generations S(2) and S(3), resulting in a divergence of 86.6% in the incidence of AS between the AS-S (91.3%) and AS-R (4.7%) lines. The rapid genetic divergence, and family analysis of %ASF suggested that a single or few major genes are responsible for the difference between the 2 selected lines. These lines may facilitate more sensitive and effective genomic research aimed at detecting these genes or identifying the primary physiological cause of AS.

Genetic and phenotypic correlations between antibody responses to Escherichia coli, infectious bursa disease virus (IBDV), and Newcastle disease virus (NDV), in broiler lines selected on antibody response to Escherichia coli

The genetic control of antibody (Ab) response to Escherichia coli (EC), infectious bursa disease virus, and Newcastle disease virus and the genetic and phenotypic correlation between these Ab responses, were evaluated under farm conditions in which chicks were simultaneously exposed to these antigens. The experimental population comprised five groups: two lines divergently selected for high (HH) or low (LL) Ab response to EC vaccination; a commercial broiler dam-line (CC), from which HH and LL had been derived; and the HH x CC and LL x CC hybrid groups (HC and LC, respectively). Lines LL and HH expressed similar symmetric divergence to all three antigens. The ranking of the LL, LC, CC, HC, and HH genetic groups according to their mean Ab responses and their very high linear correlation with the LL vs. HH genomic scale clearly indicate the additive nature of the genetic divergence between these lines. Several estimates of correlation were calculated between Ab responses of each pair of antigens and between BW and Ab to each antigen. The high correlation between group means, the near-zero within-group correlation, and the low phenotypic correlation indicate the strongly positive genetic correlation between Ab responses and no correlation with BW. The results of this study suggest that overall immunocompetence of commercial broilers can be improved by selection for high Ab response of young chicks to controlled immunization with a single antigen, without counteracting further selection for high BW.

Antibody responses and morbidity following infection with infectious bronchitis virus and challenge with Escherichia coli, in lines divergently selected on antibody response

We evaluated the association between antibody (Ab) production and disease resistance. A controlled-challenge protocol was developed to mimic natural infection and to yield a higher rate of mortality following Escherichia coli (EC) challenge. Chicks were first infected with infectious bronchitis virus (IBV) by injecting a high dose of vaccine (attenuated virus) into their air sacs and then were infected with pathogenic EC introduced intratracheally. The experimental population consisted of lines divergently selected for high (HH) or low (LL) Ab response to EC vaccination, an HH x LL cross (HL), and commercial broilers (CC). When chicks were vaccinated with EC vaccine, mean Ab titer 15 d post-EC challenge was threefold higher in HH than LL lines, but both lines exhibited very low mortality (approximately 2%). When chicks were not vaccinated prior to EC challenge, high mortality (8 to 20%) occurred in the slow-growing HH, LL, and HL lines, and much higher mortality (approximately 40%) occurred among the CC broilers that were 38% heavier than the HH, LL, and HL lines. Mean level of Ab to EC, 7 d after EC challenge, was about twofold higher in HH vs. LL chicks and intermediate in HL and CC chicks. Within each line, Ab levels were higher in chicks exhibiting colibacillosis than in healthy ones, suggesting that these Ab were produced as a result of ongoing infection but were too late to fully prevent morbidity and mortality. These results indicate that rapid growth rate substantially reduces broiler viability, whereas Ab levels produced in response to acute pathogenic challenge without prior vaccination do not contribute to disease resistance. Among the relatively slow-growing lines, mortality was about twofold higher in HH than in LL lines. This finding may confirm previous reports that without prior vaccination, high Ab response to acute challenge increases consequent mortality; alternatively, the LL line may be superior in nonspecific defense mechanisms.

Renoprotective effect of angiotensin II receptor antagonists in experimental chronic renal failure

We compared the antihypertensive and renoprotective effects of the angiotensin II receptor antagonist losartan and the calcium channel blocker verapamil in the rat with chronic renal failure. One month after five-sixths nephrectomy, male WKY rats were treated for 2 months with either losartan or verapamil. Both resulted in a similar reduction in blood pressure: from 147.1 to 112 mm Hg in losartan-treated and from 155 to 118 mm Hg (p = NS) in verapamil-treated rats. Losartan improved the creatinine clearance (difference + 17.1% as compared with + 6.6% for verapamil, p = 0.039) and prevented the increase in proteinuria: 12.26 +/- (SE) 2.33 mg/day before and 18.48 +/- 2.19 mg/day (p = NS) after therapy in the losartan-treated and 17.27 +/- 2.73 mg/day before and 32.27 +/- 10.29 mg/day after therapy (p = 0.0484) in the verapamil-treated group. In addition, losartan resulted in minimal mesangial proliferation and significantly less glomerular sclerosis and thickening of the small arterial and arteriolar walls. The changes in interstitial fibrosis and tubular hypertrophy, however, were similar in both the verapamil- and losartan-treated groups. Treatment with losartan 1 month after five-sixths nephrectomy in male WKY rats resulted in reduced blood pressure, similar to that of the verapamil-treated group. However, despite similar antihypertensive properties, losartan improved creatinine clearance and reduced proteinuria. The losartan-treated group also had a marked reduction in mesangial proliferation and less glomerular sclerosis and less reduced vascular wall thickness in renal small arteries and arterioles. However, losartan did not totally eliminate nephrosclerosis. The tubular and interstitial changes were fewer in the losartan-treated group. Thus losartan has an additional, although only partial, renoprotective effect when compared with verapamil.

CT findings in ten patients with failed renal allografts: comparison with findings in functional grafts

Our aim is to report the computed tomography (CT) features of the long-term failed renal allograft. Ten patients with failed renal transplants in whom the graft was left in situ underwent CT for various unrelated indications. The majority of the failed grafts showed marked shrinkage and coarse punctate diffuse parenchymal calcifications. Small cysts were seen in four grafts. A long-term failed renal transplant appeared on CT as a small rounded soft tissue mass. The graft was almost always heavily calcified. Lack of awareness of the nature of such a mass may mislead the radiologist in interpreting it as a space-occupying lesion.

Immunocompetence and viability under commercial conditions of broiler groups differing in growth rate and in antibody response to Escherichia coil vaccine

Mortality and morbidity due to infectious diseases are an increasing source of losses to the broiler industry. Breeding chickens for improved disease resistance may reduce these losses. A study was designed to evaluate the contribution of selection for immune response to viability of broilers under farm conditions. The experimental populations consisted of six groups: two lines divergently selected for high (HH) or low (LL) antibody (Ab) response to Escherichia coli vaccination; commercial broilers (CC); and the HH x CC, LL x CC, and HH x LL crosses. Chicks were tested under standard vaccination program and management on commercial farms in two years (1997 and 1998). Mortality was recorded in the whole groups, each consisting of several hundred or thousand of chicks, whereas BW and Ab to natural exposure to E. coli and to vaccination with Newcastle disease virus (NDV) were determined in samples of 50 to 120 chicks/group per yr. Groups were clustered into three levels of BW: CC representing contemporary fast-growing broilers; HH, LL, and HL representing broilers 10 yr earlier; and HC and LC with intermediate BW. The HH and LL groups exhibited the highest and lowest E. coli Ab titers, respectively. Mean Ab of the CC group equaled the average of the selected lines, and all crosses exhibited mid-parent Ab titers, indicating additive genetic control. Group means for Ab to NDV were highly correlated with those of E. coli, suggesting a common genetic control for the immune response to these two antigens. In both years, the highest mortality was found in the fast-growing group (CC), and the lowest mortality was in the slow-growing HH, LL, and HL groups. In the crosses, despite their similar mean BW, mortality was one-third higher among LC vs. HC birds. These results suggest that Ab response and potential growth rate interact in their effect on mortality due to infectious diseases.

Backscattering measurements of atmospheric aerosols at CO2 laser wavelengths: implications of aerosol spectral structure on differential-absorption lidar retrievals of molecular species

The volume backscattering coefficients of atmospheric aerosol were measured with a tunable CO2 lidar system at various wavelengths in Utah (a desert environment) along a horizontal path a few meters above the ground. In deducing the aerosol backscattering, a deconvolution (to remove the smearing effect of the long CO2 lidar pulse and the lidar limited bandwidth) and a constrained-slope method were employed. The spectral shape beta(lambda) was similar for all the 13 measurements during a 3-day period. A mean aerosol backscattering-wavelength dependence beta(lambda) was computed from the measurements and used to estimate the error Delta(CL) (concentration-path-length product) in differential-absorption lidar measurements for various gases caused by the systematic aerosol differential backscattering and the error that is due to fluctuations in the aerosol backscattering. The water-vapor concentration-path-length product CL and the average concentration C = <CL>/L for a path length L computed from the range-resolved lidar measurements is consistently in good agreement with the water-vapor concentration measured by a meteorological station. However, I was unable to deduce, reliably, the range-resolved water-vapor concentration C(r), which is the derivative of the range-dependent product CL, because of the effect of residual noise caused mainly by errors in the deconvolved lidar measurements.

Anti-cardiolipin, anti-endothelial-cell and anti-malondialdehyde-LDL antibodies in uremic patients undergoing hemodialysis: relationship with vascular access thrombosis and thromboembolic events

Patients with chronic renal failure requiring regular hemodialysis are known to be prone to thromboembolic events due to a hypercoagulable state. Vascular access thrombosis (VAT; including thrombosis of the vascular shunt or graft) represents a serious complication and jeopardizes life in these patients. In the current study, conducted on 81 consecutive patients from the Hemodialysis Unit, we have employed ELISA for the estimation of various autoantibody levels (anti-endothelial cell antibodies, anti-cardiolipin, anti-beta 2GPI and anti-modified LDL antibodies) and correlated them with the occurrence of thromboembolic events in general, and VAT in particular. We have found that the levels of antibodies reactive with human umbilical vein endothelial cells (HUVEC) but not with other EC lines (microvascular or EaHy 929) were significantly higher in hemodialysed patients with VAT in comparison with patients with no VAT (p = 0.001). A weaker but yet positive correlation was observed between the levels of anti-HUVEC and anti-cardiolipin antibodies and the occurrence of thromboembolic events including deep vein thrombosis, pulmonary infarction, cerbrovascular events and VAT (both p-values equal 0.02). Anticardiolipin antibodies (aCL) were not cross reactive with beta 2GPI or with HUVEC. Antibodies to modified LDL, although higher in hemodialyzed patients, did not correlate with thromboembolic events. The results of this study suggest that antibodies to HUVEC may prove as a fairly good marker of VAT in hemodialysis. High levels of aCL are weakly associated with thromboembolic events and antibodies to modified LDL do not correlate with a prothrombotic state.

Hantavirus seropositivity in Israeli patients with renal failure

The hantavirus is known to cause hemorraghic fever with renal syndrome (HFRS), which is widely spread in Europe and Asia. Several reports have shown an association of hantavirus antibody titers and the occurrence of renal dysfunction. From these observations, it appears that the virus is widely distributed, and different strains prevail in various areas. In the present work we studied 81 patients with end-stage renal-failure under hemodialysis (HD) treatment, 55 with mild to moderate renal failure, and 50 healthy subjects for the presence of antibodies to Hantaan and Puumala viruses. We found that 12.3% of the hemodialysis patients and 9% of the mild to moderate renal failure patients had elevated IgG anti-body titers to Puumala virus compared with 2% of the controls. IgM antibodies to Puumala virus was principally elevated in patient with chronic renal failure (CRF) not on hemodialysis (14.5%) compared with the hemodialyzed (1.2%) and controls (0%) subjects. Hantaan virus IgG antibodies were detected in 3.7% of the HD patients, 5.5% of the CRF not on HD, and in none of the controls. IgM Hantaan antibodies were found only in the non-HD renal failure patients. None of the sera were found to contain antibodies to phospholipids or single-stranded DNA. These results emphasize the widespread nature of infection with hantaviruses and imply that elaborate testing for these serologies should be performed, especially in patients with unexplained renal failure.

Mueller matrices and information derived from linear polarization lidar measurements: theory

A Mueller matrix M is developed for a single-scattering process such that G(theta, phi) = T (phi(a))M T (phi(p))u, where u is the incident irradiance Stokes vector transmitted through a linear polarizer at azimuthal angle phi(p), with transmission Mueller matrix T (phi(p)), and G(theta, phi) is the polarized irradiance Stokes vector measured by a detector with a field of view F, placed after an analyzer with transmission Mueller matrix T (phi(a)) at angle phi(a). The Mueller matrix M is a function of the Mueller matrix S (theta) of the scattering medium, the scattering angle (theta, phi), and the detector field of view F. The Mueller matrixM is derived for backscattering and forward scattering, along with equations for the detector polarized irradiance measurements (e.g., cross polarization and copolarization) and the depolarization ratio. The information that can be derived from the Mueller matrix M on the scattering Mueller matrixS (theta) is limited because the detector integrates the cone of incoming radiance over a range of azimuths of 2pi for forward scattering and backscattering. However, all nine Mueller matrix elements that affect linearly polarized radiation can be derived if a spatial filter in the form of a pie-slice slit is placed in the focal plane of the detector and azimuthally dependent polarized measurements and azimuthally integrated polarized measurements are combined.

Israeli and Palestinian families in the peace process: sources of stress and response patterns

The Israeli-Palestinian peace process is characterized by its unknown outcomes and consequences for the families involved. The purpose of this study was to identify family processes under conditions of prolonged uncertainty. Data were collected from both Israeli and Palestinian families in the West Bank by means of semi-structured interviews. Qualitative and quantitative analyses showed cross-cultural differences in the perception of the situation; different kinds of concerns and sources of stress; different coping responses; and differences in dyadic interaction patterns and intrafamily processes. The findings are discussed in social-contextual terms, particularly the ways in which political and cultural contexts shape the perception of the situation and family processes under prolonged stressful conditions.

Multiple-scattering effects on differential absorption for the transmission of a plane-parallel beam in a homogeneous medium

The transmission, including all scattering orders, of a plane-parallel beam in a homogeneous scattering medium containing aerosols (e.g., water cloud) mixed with an absorbing gas (e.g., ozone) is computed with a two-stream radiative transfer model. From differential transmission the concentration of the gas is deduced. The effect of multiple-scattering on the deduced concentration is shown for conservative scattering aerosols for which the multiple scattering by the aerosols is differentially absorbed by the gas and for nonconservative scattering aerosols for which the multiple scattering is differentially absorbed by the aerosols as well as differentially absorbed by the gas. The two-stream analytical model (with no dependence on the field of view) shows good qualitative agreement (especially for a small field of view) with a numerical radiative transfer model in which the trace gas concentration is computed for the different detector's field of view.

Family, migration, and psychosocial adjustment to illness

The present study examines the coping style of new immigrants in Israel from the former Soviet Union who have been diagnosed with cancer. One hundred and six new immigrants, who were being treated at the Linn Clinical Oncological Institute in Haifa during the first six months of 1992, participated in the study. They were assessed regarding family functioning, the stresses of the migratory process, other life stresses, and psychosocial adjustment to the illness. Contrary to expectations about the influence of family adaptability and cohesion on coping with illness, immigrant participants reported that the combination of stressful events related both to the migratory process and to the illness itself is the best predictor of coping with illness.

Optimal bandwidth for topographical differential absorption lidar detection

A detected laser signal backscattered from a tilted target is modeled with a laser-pulse shape as a response of a high-pass filter to an exponential input that describes the gain buildup within the laser cavity before a laser pulse is emitted and a single-pole low-pass RC filter for the electronic amplifier. The model is used to maximize the signal-to-noise ratio of the detected peak signal with a proper choice of the integration time constant τ as a function of the laser-pulse shape and the tilt angle of the backscattering target.

Successful treatment of secondary hyperparathyroidism in hemodialysis patients with oral pulse 1-alpha-hydroxy-cholecalciferol therapy

We have used high-dose oral pulse therapy with 1 alpha-hydroxycholecalciferol (1 alpha-OH-D3) to treat 40 hemodialysis patients suffering form secondary hyperparathyroidism. Forty patients with intact parathyroid hormone (PTH) levels of > 150 pg/ml were treated with 4 micrograms oral 1 alpha-OH-D3 twice weekly for 1 year. The mean PTH level was 515 +/- 50 pg/ml prior to treatment, which fell to 191 +/- 42 pg/ml after 6 months of treatment (p < 0.00001), and to 164 +/- 39 pg/ml after 12 months of treatment. Patients with very high PTH levels (> 800 pg/ml) suppressed less well than patients with lower levels (150-300 pg/ml). The therapeutic end point of PTH < 100 pg/ml was achieved in 23 patients (58%). The main side effect of the treatment was hypercalcemia, but this was symptomatic in only 3 patients, all above the age of 70 years. In summary, oral high-dose pulse therapy with 1 alpha-OH-D3 was highly effective in suppressing PTH levels in hyperparathyroid hemodialysis patients, and side effects were relatively few.

Comparison of the Gauss-Seidel spherical polarized radiative transfer code with other radiative transfer codes

Calculations that use the Gauss-Seidel method are presented of the diffusely scattered light in a spherical atmosphere with polarization fully included. Comparisons are made between this method and the Monte Carlo calculations of other researchers for spherical geometry in a pure Rayleigh atmosphere. Comparisons with plane-parallel atmospheres are also presented. Single-scatter intensity comparisons with spherical geometry show excellent agreement. When all orders of scattering are included, comparisons of polarization parameters I, Q and U as well as the plane of polarization show good agreement when allowances are made for the statistical variability inherent in the Monte Carlo method.

Comparison of the Gauss-Seidel spherical polarized radiative transfer code with other radiative transfer codes

Calculations that use the Gauss-Seidel method are presented of the diffusely scattered light in a spherical atmosphere with polarization fully included. Comparisons are made between this method and the Monte Carlo calculations of other researchers for spherical geometry in a pure Rayleigh atmosphere. Comparisons with plane-parallel atmospheres are also presented. Single-scatter intensity comparisons with spherical geometry show excellent agreement. When all orders of scattering are included, comparisons of polarization parameters I, Q and U as well as the plane of polarization show good agreement when allowances are made for the statistical variability inherent in the Monte Carlo method.

Multiple-scattering transmission and an effective average photon path length of a plane-parallel beam in a homogeneous medium

A two-stream radiative transfer model is used to derive expressions for the multiple-scattered transmitted flux (including single-scattering contributions) and the total effective average photon path length on transmission of a normally incident plane-parallel beam on a homogeneous layer characterized by the optical depth, the single-scattering albedo, and the asymmetry parameter of the scatterers. The results are simple analytical expressions that are useful for modifying the Beer-Lambert transmission law for a thick scattering medium in which the multiple-scattering contribution to the transmission is not negligible.

Cloud-droplet-size distribution from lidar multiple-scattering measurements

A method for calculating droplet-size distribution in atmospheric clouds is presented, based on measurement of laser backscattering and multiple scattering from water clouds. The lidar uses a Nd:YAG laser that emits short pulses at a moderate repetition rate. The backscattering, which is composed mainly of single scattering, is measured with a detector pointing along the laser beam. The multiple scattering, which is mainly double scattering, is measured with a second detector, pointing at a specified angle to the laser beam. The domain of scattering angles that contribute to the doublescattering signal increases monotonically as the pulse penetrates the cloud. The water droplets within the probed volume are assumed to have a constant size distribution. Hence, from the double-scatteringmeasured signal as a function of penetration depth within the cloud, the double-scattering phase function of the scattering volume is derived. Inverting the phase function results in a cloud-droplet-size distribution in the form of a log-normal function.

Numerical technique for solving the radiative transfer equation for a spherical shell atmosphere

A method for numerically solving the equation of radiative transfer in a spherical shell atmosphere is presented. The method uses a conical boundary and a Gauss-Seidel iteration scheme to solve for all orders of scattering along a single radial line in the atmosphere. Tests of the model indicate an accuracy better than 1% for most Earth-atmosphere situations. Results from this model are compared with flat-atmosphere model results for a scattering-only atmosphere. These comparisons indicate that excluding spherical effects for solar zenith angles greater than 85° leads to errors larger than 5% at optical depths as small as 0.10.

Temperature dependence of water vapor absorption coefficients for CO(2) differential absorption lidars

A temperature correction of water vapor differential absorption coefficients for the CO(2) transition line pairs (10R20, 10R18) and (10R20, 10R22) for temperatures between -0.5 °C and 20 °C is computed, with a reference temperature of 27 °C, from medium-range CO(2) lidar field measurements. The empirical temperature correction, X(T), is fitted with the polynomial X(T) = α(0) + α(1) × T + α(2) × T(2). For the transition line pair (10R20, 10R18) the temperature dependence ranges from 1.62%/°C to 3.47%/°C, and the temperature correction for the transition line pair (10R20, 10R22) ranges from 1.32%/°C to 2.43%/°C.

Backscattering and polarization ratio for cylindrical graphite fibers at CO(2) laser wavelengths

Measurements are presented of backscattering from an artificial cloud composed of cylindrical graphite fibers at a distance of 730 m with a CO(2) lidar system at 20 wavelengths and two incident polarizations (horizontal and vertical). The backscatter measurements and the polarization ratio are in good agreement with single-scattering calculations for an infinitely long cylinder at normal incidence. The measurements give experimental evidence of the predominant orientation of graphite fibers with their long axes in a random position in the x-y plane (i.e., parallel to the ground).

Wavelength dependence of backscattering and extinction of kaolin dust at CO(2) laser wavelengths: effect of multiple scattering

A multiple wavelength, pulsed CO(2) lidar system is used to measure spectral backscattering and extinction of kaolin dust of different optical thicknesses. The measurements show that the wavelength dependence of spectral backscattering changes with increased multiple scattering, whereas the spectral extinction remains relatively unchanged. A simple analytical two-stream radiative transfer model is used to confirm the measurements qualitatively. Several equations were derived from the model to show that in general the wavelength dependence of backscatter is less dependent on wavelength for a multiplescattering case. Therefore, the aerosol cloud becomes a diffuse target that is more flat in its spectral reflectance as multiple scattering increases. An application to differential absorption detection is discussed and shows that, in general, the effect of multiple scattering on the backscattered signal from aerosols will tend to reduce the error in deducing the average path-length concentration of the absorbing tr ce gas.

High pulse repetition frequency, multiple wavelength, pulsed CO(2) lidar system for atmospheric transmission and target reflectance measurements

A multiple wavelength, pulsed CO(2) lidar system operating at a pulse repetition frequency of 200 Hz and permitting the random selection of CO(2) laser wavelengths for each laser pulse is presented. This system was employed to measure target reflectance and atmospheric transmission by using laser pulse bursts consisting of groups with as many as 16 different wavelengths at a repetition rate of 12 Hz. The wavelength tuning mechanism of the transversely excited atmospheric laser consists of a stationary grating and a flat mirror controlled by a galvanometer. Multiple wavelength, differential absorption lidar (DIAL) measurements reduce the effects of differential target reflectance and molecular absorption interference. Examples of multiwavelength DIAL detection for ammonia and water vapor show the dynamic interaction between these two trace gases. Target reflectance measurements for maple trees in winter and autumn are presented.

Effect of intrahypothalamic injections of norepinephrine and serotonin on plasma arginine vasotocin and mesotocin in the White Leghorn cockerel

1. Saline (10 microliters), norepinephrine (NE) and Serotonin (5-HT), 500 nmol each, were injected into the anterior third ventricle (A3V; n = 7) or the posterior third ventricle (P3V; n = 11) of ananesthetised, unrestrained White Leghorn cockerels. Plasma arginine vasotocin (AVT) and mesotocin (MT) were measured 20, 60 and 120 min after injection. 2. Injection of NE into both the A3V and P3V had no significant effect on either plasma AVT or plasma MT at any of the sampling times. 3. Administration of 5-HT into the A3V significantly increased plasma MT about two-fold 20 min following injection. At 120 min time, plasma MT returned to normal. 4. In P3V birds, 5-HT had no effect on plasma MT in the first 20 min, but a significant increase in plasma MT occurred 60 to 120 min after injection. The magnitude of the response was lower than in the A3V cockerels. 5. Plasma AVT was not affected by 5-HT administration into the A3V at any of the sampling times, but 5-HT administration into the P3V caused significant rises in plasma AVT at 120 min. 6. Serotonergic, but not noradrenergic, induction of neurohypophysial peptide secretion was demonstrated.

Cardiac arrest in an explosives factory worker due to withdrawal from nitroglycerin exposure

A 34-year-old munitions worker suffered an unexplained cardiac arrest on a Sunday morning. In retrospect, the cardiac arrest as well as previous complaints of chest pains during weekends fit the syndrome of withdrawal from occupational exposure to nitroglycerin.

Inverse problem and the pseudoempirical orthogonal function method of solution. 1: Theory

In situations where a large library of observed distributions of a function, such as temperature vs height, is available, these distributions may be used to form a set of empirical orthogonal functions. When sufficient observed distributions are not available, but when the general mathematical form of the distributions is known, a library may be constructed from the set of mathematical functions. A set of pseudoempirical orthogonal functions may then be constructed from this mathematical library. It is assumed that any distribution of the function may then be constructed from a linear sum of this pseudoempirical orthogonal set. This idea is employed to develop an inversion method using pseudoempirical orthogonal functions when a sufficient library of observations is not available. The technique employs a smoothing constraint as well as a positivity constraint, when warranted by the physical nature of the unknown.

Inverse problem and the pseudoempirical orthogonal function method of solution. 2: Use

The information content about tropospheric rural aerosol size distributions (i.e., functional form, accuracy of solution, and moments of the solution) that may be obtained from measurements of the backscattered radiation with no additional information is discussed. The need for additional information in the form of constraints is demonstrated. The resulting solution depends on these constraints and is thus not entirely objective. The accuracy of the solution will depend, to some degree, on the validity of the constraints. The influence of constraints is examined for the inverse problem of determining aerosol size distributions from multiwavelength measurements of backscattered radiation. Using the method of pseudoempirical orthogonal functions, two types of constraint are employed: positivity and positivity combined with smoothing. A discussion of the effects on the solutions of the two constraints is presented.

The calcium channel blocker nisoldipine delays progression of chronic renal failure in humans (preliminary communication)

Chronic renal failure (CRF) patients with a stable course were asked to participate in a follow-up program in which they were randomized into two groups: 1) the placebo group taking their standard antihypertensive therapy without any calcium ion blocker: and 2) the nisoldipine group, those patients taking the calcium channel blocker nisoldipine as the only antihypertensive drug. The two groups had similar blood pressures on entering the study (151 +/- 21.3/90.7 +/- 7.4 mmHg in the nisoldipine and 146.7 +/- 18/94 +/- 9.4 mmHg in the placebo group). Their protein intake was also similar (daily average throughout the follow-up period: 0.83 +/- 0.18 g protein per kg body weight in the nisoldipine and 0.9 +/- 0.12 g in the placebo group). The patients were checked monthly. The follow-up averaged 11.1 +/- 4.8 months in the nisoldipine group and 13.7 +/- 4.2 months in the placebo group. The rate of progression of CRF, as expressed by the slope of the regression line of 1/serum creatinine versus time, decreased in the nisoldipine group from the initial (-8.03 +/- 4.91) x 10(-3) to (-5.57 +/- 5) x 10(-3) (two-tailed P-test = 0.016) after intervention. The slopes tended to become steeper in the placebo group, with an initial slope of (-4.1 +/- 3.2) x 10(-3) changing to (-7.9 +/- 5) x 10(-3) after intervention. This difference did not reach statistical significance (two-tailed P = 0.072). The rate of progression of CRF decreased in 12 of 14 patients in the nisoldipine-treated group versus 3 of 11 patients in the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of the calcium channel blocker nisoldipine on the progression of chronic renal failure in man

Patients with stable renal insufficiency were randomized into two groups: (1) patients given the channel blocker nisoldipine (n = 17) and (2) placebo-treated patients (n = 17) also taking their regular antihypertensive therapy which did not include calcium blockers. Patients were already on low protein diet with a protein intake of 0.80 +/- 0.2 in the nisoldipine group versus 0.85 +/- 0.25 g/kg body weight in the placebo-treated group. The monthly progression of their renal failure was assessed by the reciprocal of serum creatinine versus time in months. After a mean follow-up of 17.4 +/- 8.2 (range 6-30) months, the nisoldipine-treated group had a significant decrease in their slope of progression, whereas the placebo-treated patients, after 16.94 +/- 7.2 (range 6-30) months of follow-up, had no significant change in their slope. The protein intake during follow-up was similar, being 0.85 +/- 0.2 g/kg actual body weight in the nisoldipine-treated group and 0.88 +/- 0.26 g/kg in the placebo group. The changes in slope did not correlate with the changes in blood pressure.

Successful contact sensitization to chromate in mice

Mice of the randomly bred strain ICR and of the inbred strain BALB/c could be successfully sensitized to chromate by repeated topical applications of a solution of potassium bichromate in dimethyl sulfoxide. The specificity of chromium sensitization was ascertained by ear tests, specific desensitization by intravenous injection of potassium bichromate and by histological ear sections showing marked infiltrates of leukocytes following ear application of chromium-dimethyl sulfoxide in already sensitized animals. It is concluded that mice may provide a useful experimental model for study of contact sensitivity to chromium.

Split immunosuppression of contact cell-mediated and of IgE hypersensitivity responses to dinitrofluorobenzene in mice

Contact sensitivity (CS), anti-DNP (dinitrophenyl) IgG and IgE type antibodies were induced by skin applications of the contact sensitizer dinitrofluorobenzene. CS response was suppressed by treatment with the monovalent hapten dinitrobenzene sulfonate (DNBS) but was not affected by treatment with the DNP-conjugates (DNP22-Ficoll, DNP17-polyethylene glycol and DNP2-polyvinylpyrrolidone). On the other hand, IgE type response was depressed by treatment with the various DNP conjugates but was not affected by DNBS. The IgG type response was not appreciably affected by any of the treatments.

Dextran induces changes in immunological responses to unrelated antigenic and haptenic stimuli

Clinical grade, low molecular weight dextran administered intravenously to guinea-pigs altered the course of immunological events that follow unrelated antigenic and haptenic stimuli. Delayed hypersensitivity detectable by dermal responses was initially postponed and upon later retesting was greatly heightened. In addition, the synthesis of circulating antibody that mediates passive cutaneous anaphylaxis was depressed.

Infusion of dextran into guinea-pigs with established immunological responses did not alter either delayed hypersensitivity or PCA antibody synthesis.