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Autism spectrum disorder (ASD) is a behaviorally defined condition that manifests in infancy or early childhood as deficits in communication skills and social interactions. Often, restricted and repetitive behaviors (RRBs) accompany this disorder. ASD is polygenic and genetically complex, so we hypothesized that focusing analyses on intermediate core component phenotypes, such as RRBs, can reduce genetic heterogeneity and improve statistical power. Applying this approach, we mined Caucasian genome-wide association studies (GWAS) data from two of the largest ASD family cohorts, the Autism Genetics Resource Exchange and Autism Genome Project (AGP). Of the 12 RRBs measured by the Autism Diagnostic Interview-Revised, seven were found to be significantly familial and substantially variable, and hence, were tested for genome-wide association in 3104 ASD-affected children from 2045 families. Using a stringent significance threshold (P<7.1 × 10-9), GWAS in the AGP revealed an association between ‘the degree of the repetitive use of objects or interest in parts of objects’ and rs2898883 (P<6.8 × 10-9), which resides within the sixth intron of PHB. To identify the candidate target genes of the associated single-nucleotide polymorphisms at that locus, we applied chromosome conformation studies in developing human brains and implicated three additional genes: SLC35B1, CALCOCO2 and DLX3. Gene expression, brain imaging and fetal brain expression quantitative trait locus studies prioritize SLC35B1 and PHB. These analyses indicate that GWAS of single heritable features of genetically complex disorders followed by chromosome conformation studies in relevant tissues can be successful in revealing novel risk genes for single core features of ASD.

The Cancer Genome Atlas (TCGA) network study of 12 cancer types (PanCancer 12) revealed frequent mutation of TP53, and amplification and expression of related TP63 isoform ΔNp63 in squamous cancers. Further, aberrant expression of inflammatory genes and TP53/p63/p73 targets were detected in the PanCancer 12 project, reminiscent of gene programs comodulated by cREL/ΔNp63/TAp73 transcription factors we uncovered in head and neck squamous cell carcinomas (HNSCCs). However, how inflammatory gene signatures and cREL/p63/p73 targets are comodulated genome wide is unclear. Here, we examined how the inflammatory factor tumor necrosis factor-α (TNF-α) broadly modulates redistribution of cREL with ΔNp63α/TAp73 complexes and signatures genome wide in the HNSCC model UM-SCC46 using chromatin immunoprecipitation sequencing (ChIP-seq). TNF-α enhanced genome-wide co-occupancy of cREL with ΔNp63α on TP53/p63 sites, while unexpectedly promoting redistribution of TAp73 from TP53 to activator protein-1 (AP-1) sites. cREL, ΔNp63α and TAp73 binding and oligomerization on NF-κB-, TP53- or AP-1-specific sequences were independently validated by ChIP-qPCR (quantitative PCR), oligonucleotide-binding assays and analytical ultracentrifugation. Function of the binding activity was confirmed using TP53-, AP-1- and NF-κB-specific REs or p21, SERPINE1and IL-6promoter luciferase reporter activities. Concurrently, TNF-α regulated a broad gene network with cobinding activities for cREL, ΔNp63α and TAp73 observed upon array profiling and reverse transcription–PCR. Overlapping target gene signatures were observed in squamous cancer subsets and in inflamed skin of transgenic mice overexpressing ΔNp63α. Furthermore, multiple target genes identified in this study were linked to TP63 and TP73 activity and increased gene expression in large squamous cancer samples from PanCancer 12 TCGA by CircleMap. PARADIGM inferred pathway analysis revealed the network connection of TP63 and NF-κB complexes through an AP-1 hub, further supporting our findings. Thus, inflammatory cytokine TNF-α mediates genome-wide redistribution of the cREL/p63/p73, and AP-1 interactome, to diminish TAp73 tumor suppressor function and reciprocally activate NF-κB and AP-1 gene programs implicated in malignancy.

A nestling white-faced ibis (Plegadis chihi) with multifocal skin ulcerations on the wings, neck, head, and limbs was found in a wetland agricultural region of the central valley in California. Pathologic, microbiologic, and molecular findings were consistent with restricted, cutaneous infection by the oomycete Pythium insidiosum.The microscopic features of the disease, including intense, necrotizing eosinophilic and granulomatous inflammation, are similar to those previously described in mammals. Pythiosis, which is most typical in tropical and subtropical climates, has recently emerged in California as a cause of cutaneous and enteric disease in horses and dogs, respectively. Environmental stability and persistence of a “water-mold” in the arid central valley of California could be associated with agricultural and community watering practices. To the best of the authors' knowledge, this is the first published report of pythiosis in birds.

Epizootic bovine abortion (EBA), a tick-transmitted disease of pregnant cattle grazing foothill pastures, is a major cause of reproductive failure in California and adjacent states. Affected fetuses develop a chronic disease, resulting in late-term abortion or premature calving. Despite investigations spanning 50 years, to the authors' knowledge, the etiologic agent of EBA has not yet been isolated from affected fetuses or the tick vector. The diagnosis of EBA is based on gross and microscopic lesions. Recently, documentation that the etiologic agent is susceptible to antibiotics and identification of a unique 16S deltaproteobacterial rDNA gene sequence in 90% of thymus tissues from aborted fetuses have supported the role of a bacterial infection as the cause of EBA. To determine whether bacteria could be detected in the tissues, histochemical staining and immunohistochemical procedures were used on formalin-fixed, paraffin-embedded tissues. Use of a modified Steiner silver stain revealed small numbers of intracytoplasmic bacterial rods in 37 of 42 thymic samples from EBA-affected fetuses. Improved detection was achieved by use of immunohistochemical staining with serum from EBA-affected fetuses that resulted in detection of numerous bacterial rods in the cytoplasm of histiocytic cells in the thymus from all 42 EBA-affected fetuses. Immunohistochemical examination of additional tissues from 21 field and experimental EBA cases revealed positively stained intracytoplasmic bacterial rods in many organs with inflammatory lesions. Use of the modified Steiner stain and immunohistochemical staining of tissues from negative-control fetuses failed to reveal organisms. To the authors' knowledge, this is the first report to document morphologic evidence of a bacterium associated with the lesions of EBA.

Sequence analysis of the 5.8S rRNA gene and the internal transcribed spacer regions (ITSRs) was used to compare trichomonadid protozoa (n= 39) of varying morphologies isolated from the bovine preputial cavity. A multiple sequence alignment was performed with bovine isolate sequences and other trichomonadid protozoa sequences available in GenBank. As a group, Tritrichomonas foetusisolates (n= 7) had nearly complete homology. A similarity matrix showed low homology between the T. foetusisolates and other trichomonads recovered from cattle (<70%). Two clusters of trichomonads other than T. foetuswere identified. Eighteen isolates comprised 1 group. These isolates shared >99% homology among themselves and with Pen-tatrichomonas hominis.The other non–T. foetuscluster (n= 14) did not exhibit a high degree of homology (<87%) with other bovine isolates or any of the trichomonad sequences available in GenBank. The sequence homology among isolates in that cluster was >99%, except for 1 isolate that varied from the others in both ITSRs (∼2% dissimilarity). Sequence analysis of the 5.8S rRNA gene and ITSRs was useful for comparing trichomonadid protozoa isolated from the bovine preputial cavity and demonstrated that 2 distinct types of trichomonads constituted the non–T. foetusisolates recovered from the bovine preputial cavity.

ABSTRACTPapillomatous digital dermatitis (PDD), an emerging infectious disease of cattle, is characterized by painful, ulcerative foot lesions. The detection of high numbers of invasive spirochetes in PDD lesions suggests an important role for these organisms in the pathogenesis of PDD. PDD-associated spirochetes have phenotypic characteristics consistent with members of the genus Treponema. Partial 16S ribosomal DNA (rDNA) sequence analysis of clonal isolates from California cattle showed that they comprise three phylotypes which cluster closely with human-associated Treponemaspp. of the oral cavity (T. denticolaand T. medium/T. vincentii) or genital area (T. phagedenis). The goal of our study was to apply 16S-23S rDNA intergenic spacer region (ISR) sequence analysis to the molecular typing of U.S. PDD-associated Treponemaisolates. This methodology has potentially greater discriminatory power for differentiation of closely related bacteria than 16S rDNA analysis. We PCR amplified, cloned, and sequenced the ISRs from six California PDD-associated Treponemaisolates and, for comparative purposes, one strain each of T. denticola, T. medium, T. vincentii, and T. phagedenis.Two ISRs that varied in length and composition were present in all the PDD-associated Treponemaisolates and in T. denticola, T. medium, and T. phagedenis. ISR1 contained a tRNAAlagene, while ISR2 contained a tRNAIlegene. Only a single ISR (ISR1) was identified in T. vincentii.Comparative analyses of the ISR1 and ISR2 sequences indicated that the California PDD-associated Treponemaisolates comprised three phylotypes, in agreement with the results of 16S rDNA analysis. PCR amplification of the 16S-tRNAIleregion of ISR2 permitted rapid phylotyping of California and Iowa PDD-associated Treponemaisolates based on product length polymorphisms.

BACKGROUND AND AIMS: Interstitial cells of Cajal (ICC) are pacemakers and mediators of motor neurotransmission in gastrointestinal smooth muscles. ICC require cellular signalling via Kit, a receptor tyrosine kinase, for development and maintenance of phenotype. Much of the evidence demonstrating the functions of ICC comes from studies of W/W(V) mice, which have reduced Kit function and reductions in specific populations of ICC. The aim of the present study was to differentially examine gene expression in the small intestines of wild-type and W/W(V) mutant mice. METHODS AND RESULTS: RNA from the jejunums of wild-type and W/W(V) mutants was analysed using a differential gene display method. Eighteen queries were identified as novel genes that were differentially displayed in wild-type and W/W(V) mice. One candidate gene, encoding a novel acid phosphatase-like protein, was significantly suppressed in fed and starved W/W(V) mice. The full length clone of the murine gene and its human counterpart were designated acid phosphatase-like protein 1 (ACPL1). Human ACPL1 cDNA encodes a protein of 428 amino acids with homology to human prostatic acid phosphatase protein. This gene is located at 1q21. ACPL1 was abundantly expressed in the human small intestine and colon. Gene products were found to be cytoplasmic in transfected COS-7 cells. Reverse transcription-polymerase chain reaction analysis revealed expression of ACPL1 mRNA within single isolated ICCs. CONCLUSIONS: Gene analysis showed that ACPL1 was differentially expressed in the small intestines of normal and W/W(V) mice. ICC within the small intestine expressed mRNA for ACPL1. Specific downregulation of ACPL1 in the jejunums of W/W(V) mice and high expression in human intestinal tissue suggest that the ACPL1 gene could be associated with ICC function in mice and humans.

ABSTRACTDirect amplification and sequencing of the 16S rRNA gene and a variable region of the flagellin gene from fetal liver-associated spirochetes belonging to the Borrelia parkeri-B. turicataetick-borne relapsing fever spirochete group with a late-term abortion in a mare are described.

Electronic records from the California Animal Health and Food Safety Laboratory System between January 1, 1991, and June 30, 1998, were reviewed, and data on 593 Salmonellaserotypes isolated from feces or intestinal contents of adult dairy cattle with diarrhea were analyzed to determine spatial and temporal clustering. A statistically significant clustering in space was detected with 10 (Typhimurium, Montevideo, Muenster, Anatum, Give, Menhaden, Kentucky, Agona, Derby, and Newport) of the 13 serotypes examined. Significant temporal clustering was also detected with 10 serotypes (Typhimurium, Montevideo, Muenster, Anatum, Give, Newbrunswick, Menhaden, Kentucky, Derby, and Newport). Six serotypes (Anatum, Menhaden, Montevideo, Muenster, Newbrunswick, and Newport) were significantly spatially and temporally clustered. A difference in temporal and spatial distribution patterns of some serotypes associated with diarrhea in adult dairy in California was found. Knowledge of the specific type of clustering, if present, should improve our understanding of the transmission and control of salmonellosis in the field.

Randomly amplified polymorphic DNA (RAPD) analysis was used to differentiate 7 strains of Mycoplasma gallisepticum.Six commercially available primers or primer combinations were screened for their ability to differentiate vaccine and type strains. Although major and minor bands were produced with each primer, many of the primers were unsuitable for strain differentiation. The use of primer 6 and combined primers 3 and 4 resulted in complementary RAPD banding patterns for each M. gallisepticumstrain. Eleven different isolates representing 7 different strains were segregated into 7 different patterns, corresponding to the 7 strains.

Randomly amplified polymorphic DNA (RAPD) analysis was used to investigate the molecular epidemiology of 26 Mycoplasma gallisepticum(MG) isolates obtained from turkeys located in the central valley of California. The MG isolates were recovered from 5 different companies and 13 ranches. Each company had unique MG strains. No evidence of spread of MG between companies was detected. RAPD analysis of MG isolates within a ranch during an outbreak revealed only a single strain involved in each outbreak. RAPD analysis identified an isolate from 1 ranch with a banding pattern identical to that of the 6/85 vaccine strain, which had been used on that particular ranch. Similar RAPD banding patterns of isolates from different ranches within the same company suggested horizontal spread of MG between ranches. The use of 2 primer sets in RAPD analysis was critical to prevent misinterpretation of relationships between different isolates.

A sensitive, isotope dilution technique has been developed for the analysis of sub-microgram amounts of zirconium. The analysis is based on the increased thermal ion emission for Zr adsorbed on a single anion resin bead. Zr is isolated from a solution containing the sample and a highly enriched 94Zr (96%) spike. The determination is made possible by using a high-sensitivity pulse-counting 2-stage 30-cm radius mass spectrometer. The detection limit depends upon the amount of the isotope spike added and the desired precision. Fifty nanograms of zirconium (sample plus spike) produce sufficient ion signals for reliable isotopic analysis so that fission Zr can be measured with blank correction to a precision of 3%. By this method for fission Zr in spent reactor fuel particles, contamination from normal Zr and Mo can be corrected out by making isotopic measurements before and after spiking and scanning masses 90 and 95 during analysis. Since neither masses 90 nor 95 are stable fission products, their presence is due to sample contamination and can be used for correction based on their normal isotopic distributions. Zone-refined tantalum ribbon, essentially free of normal Zr and Mo was selected as the ionizing filament. This method can be adapted to a wide variety of samples.

A method is described for extracting representative uranium and plutonium samples from highly radioactive solutions for isotopic mass spectrometric analysis. Anion resin beads in the nitrate form are used to effect separation from fission products and other actinides. Conditions required to achieve separation are proper adjustment of the uranium and nitric acid concentrations. Once uranium and plutonium are adsorbed, each bead serves as a sample for mass spectrometric analysis, with plutonium and uranium being run sequentially from the same bead. Quantitative determination of the two elements is effected through the technique of isotopic dilution.

Immunoblots were used to study the immunoglobulin G response to Borrelia burgdorferi in experimentally and naturally exposed dogs. Adsorption studies confirmed that the antibodies were specific for B. burgdorferi. Experimentally exposed dogs were asymptomatic. Naturally exposed dogs included both asymptomatic animals and animals showing signs compatible with Lyme disease. Naturally exposed dogs were from four geographic regions of the country. No differences were detected between immunoblot patterns of naturally exposed symptomatic or asymptomatic dogs from different areas of the country. The immunoblot patterns obtained with sera from experimentally exposed dogs were different from those obtained with sera from naturally exposed dogs and were characterized by reactivity to fewer and different protein bands. Immunoblot analysis using an OspA-protein-producing Escherichia coli recombinant showed that experimentally exposed dogs produced antibodies to OspA, whereas naturally exposed dogs did not. Modifications of the immune response over time, different routes of antigen presentation, and strain variation are factors postulated to account for the observed differences.

From the onset of the Three-Mile Island reactor incident (March 28, 1979), the distinct possibility existed that actinide and fission product pollutants could escape into the surrounding environment. Experienced analytical chemists in command of techniques which achieve the highest sensitivity were called upon for assistance in performing analyses. Cooling water was analyzed for uranium and plutonium, certain fission products, additives, and possible corrosion products by isotope dilution mass spectrometry. In particular, the thermal emission isotope dilution technique, in which an anion exchange resin bead was used to concentrate the uranium and plutonium, provided technical information on samples orders of magnitude smaller than those necessary for conventional counting techniques. The resin-bead-loaded sample acts as a point source in a pulse counting two-stage high abundance sensitivity mass spectrometer, enhancing the sensitivity so that levels as low as 10-13 plutonium and 10-11M uranium concentrations have been detected in one ml of water; a full description of the methodology involved will be presented. The methodology employed for this exercise also provided isotopic information which was informative with respect to material source, located, and condition. Sample chronology and trace element data will also be presented on water from the Three-Mile Island site. Other potential applications of the technique will be discussed.

Between April of 1990 and March of 1992, calves on a Holstein calf ranch experienced subcutaneous decubital abscesses involving the brisket region, dorsal aspect of the carpus, and lateral aspect of the stifle joints. Fifty out of 2,500 (2%) Holstein calves between the ages of 3 and 12 weeks were affected. Needle aspirates of brisket abscesses from 8 calves and 6 live or dead calves with 1 or more decubital abscesses were submitted for examination. Two of the 6 calves in addition had bronchopneumonia. Mycoplasma boviswas isolated from all abscesses and 1 lung. Formalin fixed tissues taken from the affected areas also revealed M. bovisby immunoperoxidase staining. No evidence of joint involvement was apparent, and no mycoplasma was isolated from the joints adjacent to affected areas. Attempts to isolate mycoplasma from milk and environmental samples were unsuccessful.

The resin bead sample loading technique has been applied to a conventional single-stage mass spectrometer equipped with pulse counting. Isotopic data obtained for U and Pu are comparable to those obtainable from similar instruments using conventional techniques.

The method uses basic anion resin to adsorb plutonium and uranium from 7–8 M HNO3 solutions containing dissolved spent reactor fuels. After equilibrating the resin with the solution, a single bead is used to determine the isotopic composition of plutonium and uranium on sample sizes as small as 10-9 to 10-10 g of each element per bead. Isotopic measurements are essentially free of isobaric interferences and fission product contamination in the mass spectrometer is eliminated. A very small aliquot of dissolver solution containing 10-6 g of U and 10-8 g of Pu is sufficient sample for chemically preparing several resin beads. A single prepared bead is loaded onto a rhenium filament and analyzed in a two-stage mass spectrometer using pulse counting for ion detection to obtain the high sensitivity required. Total quantity of the elements, in addition to isotopic abundances, can be determined by isotope dilution. Other areas where the method may be useful are: in plutonium production, isotope separations, and for trace detection of contamination on reactor parts.

Adult rainbow trout, acclimated to external calcium concentrations ranging from 60–5700 μequiv/1, were exposed to pH 4·0–4·1 for 44 h. Initially, this exposure provoked massive net losses of sodium and chloride across the gills which arose through a combination of an inhibition of active transport and, more importantly, a stimulation in diffusional efflux. Subsequently, ion losses declined substantially, largely due to a rapid decline in passive efflux but also to a slower, partial recovery in sodium transport. External calcium concentration was virtually without effect on ion fluxes either prior to or following acid exposure but had a definite effect during acid exposure. This effect was initially upon the ratio of Cl− to Na+ loss and later upon the degree of inhibition of sodium and chloride transport. Possible mechanisms to explain the complex interactions of calcium and pH are proposed.

Blood gases, acid-base status, plasma ions, respiration, ventilation and cardiovascular function were measured in white suckers, using standard cannulation methods. Basic respiratory parameters under normoxia were compared to those in the active, pelagic rainbow trout and in other benthic teleosts. Sustained environmental hyperoxia (350-550 torr) increased arterial O2 (102-392 torr) and venous O2 (17-80 torr) tensions so that blood O2 transport occurred entirely via physical solution. Dorsal aortic blood pressure and heart rate fell, the latter due to an increase in vagal tone. Ventilation volume declined markedly (by 50%) due to a decrease in ventilatory stroke volume, but absolute O2 extraction rose so that O2 consumption was unaffected. While the preceding effects were stable with time, arterial and venous CO2 tensions approximately doubled within 4 h, and continued to increase gradually thereafter. This CO2 retention caused an acidosis (7·993-7·814) which was gradually compensated by an accumulation of plasma [HCO3–]. However, even after 72 h, arterial pH remained significantly depressed by 0·10 units. The gradual rise in plasma [HCO3–] was accompanied by a progressive fall in both [Na+] and [Cl–] ; [K+] and [Ca2+] remained unchanged. The responses of the sucker to hyperoxia are compared to those of the rainbow trout.

This study examined the branchial, renal and blood acid-base responses of a marine teleost to intravascular infusion of mineral acid (HC1 at 1000 μequiv/kg). In all animals the renal response was insignificant for at least 3 days following infusion. Two types of branchial and blood acid-base response were seen. Either the infused load disappeared rapidly from the extracellular into the intracellular compartment and was slowly cleared from the body (+16h following infusion) or, more commonly, remained in the extracellular compartment until rapidly cleared by a pronounced increase in branchial excretion. In the latter the amount excreted exceeded that infused by about twofold on average. These responses are discussed in relation to those of freshwater teleosts.

An outbreak of salmonellosis in foals occurred on a large Thoroughbred farm in California. Only foals <8 days of age exhibited clinical signs, which included depression, anorexia, and diarrhea. Three foals died from septicemia. The agent responsible was Salmonella ohio, which is rarely involved in salmonellosis in horses. During the course of the outbreak, S. ohiowas isolated from 27 of 97 mares (27.8%) and 34 of 97 foals (35.1%). Mares were the presumed source of infection for foals. The absence of clinical signs in mares allowed for increased exposure of foals through environmental contamination. Although foals continued to become infected after strict control measures were adopted, none became ill. Salmonellaserotypes of seemingly low virulence can produce serious disease outbreaks.

After 10 days’ exposure to an environmental salinity of 300mosmol kg−1 NaCl, the freshwater stenohaline teleost Catostomus commersoni exhibited an increase in plasma osmolality and a reduction in plasma strong ion difference (SID). There were reductions in plasma pH (pHe), red blood cell (RBC) pH (pHi), plasma total CO2 and erythrocyte nucleoside triphosphate (NTP) concentration, and increases in mean erythrocyte volume and plasma catecholamine levels. Despite the acidosis, the in vitro haemoglobin oxygen-affinity of blood from saline-acclimated fish was not significantly different from that of control fish (held in fresh water) which had higher pHe and pHi values at the tensions used. In vitro adjustment of SID of blood from control fish to approximate that of the saline-acclimated fish by the addition of NaOH and HC1 significantly reduced pHe, pHi and the haemoglobin oxygen-affinity. Adjustment of the plasma osmolality of blood from control fish to values identical to those of the saline-acclimated fish by the addition of NaCl in vitro did not alter the haemoglobin oxygen-affinity. An increase in catecholamine concentration and a decrease in red blood cell N IP concentration in the saline-acclimated fish may have been compensatory mechanisms to maintain haemoglobin oxygen-affinity against acidosis-induced Bohr and Root effects during saline exposure.

This study evaluated the differences in immunoblot patterns when serum specimens from seropositive dogs were reacted against four strains of Borrelia burgdorferi. Intense bands were consistently detected for the 83-, 66-, 61- to 60-, 41-, and 31-kilodalton regions for all four strains. Most variations were observed in the regions of 45 to 34 and 26 to 15 kilodaltons. Adsorption studies suggested that one reason for the observed variability was a difference in proteins among the organisms, rather than a difference in migration of proteins. Therefore, knowledge and consistency of the test antigen are essential when evaluating and comparing canine immunoblot patterns to B. burgdorferi, but for diagnostic purposes all of the serum samples would have been considered positive regardless of the strain used.

2,4‐D was incubated in the laboratory with different depths of Duffield silty clay loam, and its disappearance therefrom was determined by a cucumber root elongation test. The lag period before onset of decomposition and the time required for complete decomposition of 2,4‐D increased with depth. The lag period varied from 14 days in the 0‐ to 6‐inch sample to 42 days in the 18‐ to 21‐inch sample. On retreatment with 2,4‐D the differences among the depths were much smaller than with the original treatment. Disappearance of 2,4‐D and of 2,4,5‐T under field conditions was studied in plots treated with these compounds at rates of 0.0, 0.2, 1.0, and 2.5 grams per square yard in 1949, and retreated with one gram per square yard in 1950. 2,4,5‐T persisted more than 19 weeks; its persistence was not influenced by previous treatment. The effective concentration of 2,4‐D was reduced more rapidly in soils in which it had decomposed previously. This compound persisted 5 and 6 weeks, respectively, in plots which had and had not been treated previously. A substance which stimulated root elongation of cucumber was produced during the decomposition of 2,4‐D.

An analytical system for measuring total nitrogen and its isotopic abundance in a variety of environmental samples has been developed. A reductive pyrolysis system and a directional focusing 6-inch gas mass spectrometer were combined into the analytical system. In the reductive part of the system, nitrogen species are converted to ammonia with an atmosphere of hydrogen in the presence of a heated nickel catalyst. Five percent of the gas stream is split away for measuring total nitrogen by a conductivity detector. The ammonia is removed from the gas stream employing a cold finger reaction vessel.The hydrogen-free ammonia is decomposed thermally to nitrogen and hydrogen at 1000°C, employing a hot rhenium filament. The N2 produced from the decomposition is used for measuring the abundance of masses 28 and 29 by mass spectrometry. From this ratio, the 15N atom fraction is calculated.Standard samples of N2, ammonia, orchard leaves and urea have been successfully analyzed to determine isotopic compositions. Samples containing as little as 20 g of total nitrogen can be analyzed by this system. By the addition of multi-reaction vessels, three samples may be completed per hour.

Because of the increased concern over use of human body fluids in physiology teaching laboratories, we developed an exercise in renal function that utilizes laboratory rats. The purpose is to demonstrate the role of the kidneys in the homeostatic control of extracellular fluid volume, plasma ionic concentrations, and osmolarity. Three treatment groups are utilized: a volume-expanded (access to 1 g/100 ml sucrose) group, a volume-expanded and salt-loaded (access to 0.9 g/100 ml NaCl) group, and a volume-depleted (water-deprived) group. A normovolemic control group (access to tap water) is also included. Rats are housed individually in metabolic cages that allow accurate measurement of fluid intake and urine output. Blood samples are removed via cardiac puncture. The animals recover from this procedure and can be reutilized within 2-3 wk. When class data are pooled, clear trends are seen that demonstrate the volume-, osmo-, and ionoregulatory abilities of the kidneys.

Thimet and Bayer 19639 applied at 10, 20, and 30 pounds per acre as a side dressing significantly decreased the numbers of cotton aphids (Aphis gossypii Glov.) for 15 months. Seed or fur-row treatments with 1 to 3 pounds per acre at time of planting significantly reduced aphid populations for one growing season. Control of green bugs on oats in rotation with cotton that had received Thimet side-dressings was indicated.

Fifteen of 75 materials evaluated at 1% concentrations against Musca autumnalis De Geer were highly repellent based on the results obtained in 10 minutes with a sandwich bait. Repellent activity was found with 2 general types of compounds: certain sullides and sulfoxides and a variety of N,N-disubstituted amides.