Search

Previous reports, based on studies involving approximately 10 genera of the higher red algae, have concluded that floridean starch is composed of amylopectin only. Our investigations on seven members of the Porphyridiales and a member of the Bangiales (Erythrocladia) have demonstrated conclusively the presence of amylose in red algal starch.

The main objective of the study was to gather information about the current controls and levels of exposure to 4,4'-methylene-bis (2-chloroaniline) (MbOCA) in a representative cross section of workplaces that use it to manufacture polyurethane elastomers. The study also aimed to investigate whether controls and guidance could be improved and to investigate exposure to isocyanates in these workplaces using biological monitoring.An occupational hygienist and a field scientist visited the two UK suppliers and 20 out of the 25 workplaces known to be using MbOCA in the UK during 2005 and 2006. They collected air samples, surface wipes, gloves, and urine samples and made observations to assess exposure and the adequacy of controls. All samples were analysed for MbOCA and urine samples were additionally analysed for isocyanate metabolites. A statistical analysis was made of the results.Only 2.5% of the 80 personal inhalation exposures to MbOCA exceeded the workplace exposure limit of 5 microg m(-3) 8-h time-weighted average and 84% were below the limit of detection (LOD). Surface samples (n = 334) were collected from MbOCA users and suppliers and 60% had detectable levels of MbOCA ranging from 0.019 to 400 microg cm(-2). The highest levels were around a hopper, ovens, and the weighing and pouring areas. MbOCA was also detected in 8 of the 75 samples collected from areas not likely to be in contact with MbOCA. At the two suppliers, samples (n = 28) were collected from the outside surfaces of recently imported kegs, pallets, and the floor around kegs. Six samples had detectable levels and four of these (0.2, 0.8, 1, and 6 microg cm(-2)) were from the floor and pallets in both suppliers. The other two positive results were found on the outside rim (18 microg cm(-2)) and side (23 microg cm(-2)) of a keg at one supplier indicating contamination by the manufacturer. Urine samples (n = 79) were collected and 49% were below the LOD for MbOCA and only three samples had levels of MbOCA that exceeded the biological monitoring guidance value (BMGV) of 15 micromol mol(-1) creatinine. The highest urinary MbOCA concentrations were in samples from workers casting and moulding. The 90th percentile of the urine MbOCA results was 8.6 micromol MbOCA per mol creatinine. Urine samples were also analysed for the diamine metabolites of toluene diisocyanate and hexamethylene diisocyanate and 33% had detectable levels with 22 and 13% of results, respectively, above the BMGV for isocyanates (1 micromol isocyanate-derived diamine per mol creatinine). The maximum urinary concentration of toluene diamine and hexane diamine were 15.6 and 10.1 micromol mol(-1) creatinine, respectively.The survey found that the measures used to control exposure to MbOCA could be improved. Although air levels of MbOCA were generally low, there was evidence of spread of surface contamination and poor maintenance of controls such as local exhaust ventilation. A BMGV based on the 90th percentile of data from workplaces with good control would be less than the 90% value of 8.6 micromol mol(-1) creatinine found in this study and suggests that the current BMGV of 15 micromol mol(-1) creatinine is no longer acting as a stimulus to reduce exposure. The metabolites of isocyanates found in urine samples in this study could arise from inhalation exposure to isocyanates or from dermal exposure to either isocyanates or their diamine breakdown product and need further investigation.

BACKGROUND Colophony (rosin) is a natural product derived from the resin of coniferous trees with many industrial applications including soldering fluxes. Exposure to colophony fume through soldering is one of the leading causes of occupational asthma in the UK. AIMS To assess occupational exposure to colophony from solder fume at selected workplaces in the UK and to investigate the use of dehydroabietic acid (DHA) as a biomarker of exposure. METHODS Six companies in the UK electronics industry were visited and occupational hygiene assessments of extent and control of exposure to rosin-based solder flux fume were undertaken. Urine samples were analysed for one of the main constituents of rosin, DHA. RESULTS There was a positive linear relationship between airborne exposure to solder fume and urinary DHA level. The levels of urinary DHA measured in UK workers were significantly lower than those previously measured in African workers because of the use of appropriate exposure control measures, for example, local exhaust ventilation with fixed ducting and flexible hose, tip extraction, etc. It is suggested that good occupational hygiene practice would result in urinary DHA levels of

Hand soldering using rosin core solder wire is common in the electronics industry and several studies have implicated the aerosol produced when rosin flux is heated in causing respiratory sensitisation. Control of solder fume is generally achieved using local exhaust hoods, simple blowers with a filter or low-volume high-velocity (LVHV) ventilation systems. None of these provide an ideal control system and so a push-pull ventilation design was developed as an alternative. Laboratory tests of the system's capture efficiency were carried out using nitrous oxide tracer gas. Capture efficiency was generally greater than 90% with the push airflow operating. However, without the push airflow, capture efficiency decreased sharply with increasing distance from the exhaust hood (between 38 and 58% at 420 mm from the front of the exhaust hood with the same exhaust airflow used by the push-pull system). The push-pull system was found to be relatively insensitive to obstructions placed in the path of the air flow or the influence of cross draughts. The system was tested in five electronics factories and the effectiveness was compared to their existing ventilation systems. Where only a small amount of soldering was carried out both the in-house and push-pull systems seemed to provide adequate control of inhalation exposure to rosin-based solder flux fume measured as total resin acids. However, the push-pull system provided more consistent control than the existing ventilation systems when larger quantities of solder were used. In these situations the mean personal exposure level was reduced to below the UK Maximum Exposure Limit (MEL) of 0.05 mg/m(3) 8-h time weighted average in most instances. The corresponding mean personal exposure level with the in-house systems in operation was about three to four times the long-term MEL. Interpretation of these data is complicated because of high background contribution to exposure from poorly controlled soldering operations elsewhere in the factories. However, this study suggests that the in-house systems were relatively inefficient.

Forty sites were visited during a survey of exposures to diesel engine exhaust emissions. Personal and background exposure to gaseous components, respirable dust, elemental carbon, organic carbon and total carbon were measured and details of control systems were recorded. The results show a wide spread in exposure patterns reflecting the different work practices, job categories of employees and the control methods used. However, sites where fork-lift trucks were in use consistently produced the highest exposures. The survey results suggest that the measurement of elemental carbon could be used as an indicator of exposure to diesel engine exhaust emissions.

Forty sites were visited during a survey of exposures to diesel engine exhaust emissions. Personal and background exposure to gaseous components, respirable dust, elemental carbon, organic carbon and total carbon were measured and details of control systems were recorded. The results show a wide spread in exposure patterns reflecting the different work practices, job categories of employees and the control methods used. However, sites where fork-lift trucks were in use consistently produced the highest exposures. The survey results suggest that the measurement of elemental carbon could be used as an indicator of exposure to diesel engine exhaust emissions.

Airflow visualization in the workplace to assess containment, ventilation, or general air movements is often carried out using smoke tracers. The most prevalent method uses a disposable smoke tube that generates a plume of concentrated sulfuric acid fume. However, use of the smoke tube exposes occupational hygienists to the risk of sulfuric acid exposure through inhalation or dermal contact, as well as injury from sharps. Following concern over the potential health hazard associated with smoke tube usage, alternative flow visualization methods and technologies have been reviewed. Methods of generating smoke or bubbles other than using smoke tubes suitable for visualizing air movements include heated element smoke generators, combustion generators, generation of metallic chlorides and ammonium chloride, generation of neutral density bubbles, and water fog generation. Some of these methods are applicable in specific workplace situations. However, there is no commercially available smoke or bubble generator currently available that matches the smoke tube for cost effectiveness, ease of use, and wide applicability, while also reducing the potential health risks associated with smoke tube usage. Despite this, certain technologies, in particular water/glycerol smoke generation using heated element generators, have the potential to be developed into viable alternatives to the smoke tube. Thus, with further development, an air movement visualization method that poses a significantly lower health hazard than the smoke tube is feasible.

This paper describes the design and fabrication of a soft liner-retained, implant-supported overdenture used in 10 patients over a period of 1 to 6 years. A final complete denture impression is made of the dental arch, including implant abutments extending 5 mm above the gingival tissue. The master cast is fabricated with actual abutments placed in the impression. After the final wax try-in, the denture is flasked in the usual manner with the metal abutments in place. Before packing with acrylic resin, plastic tubing 1 to 2 mm thick is placed around each abutment. The denture is trial packed and allowed to bench cure over night. The plastic tubing is then removed and a soft denture lining material is placed in these areas only. The flask is closed and cured according to the manufacturer's recommendation. The denture is delivered as a conventional overdenture.

Introduction Knitted enteral stents have reduced stent shortening and no axial straightening forces, resulting in better conformability to tortuous anatomy compared to conventional braided stents. The first covered removable oesophageal stent is now available consisting of a knitted Nitinol skeleton with large heads covered in silicone, but the shaft only externally covered by an ePTFE membrane. In vitro it has better conformability but comparable radial force to standard braided stents. We report the first experience world-wide with this type of device. Methods All consecutive patients over a 9-month period referred for oesophageal stenting had an Egis stent (BVM Medical, Hinckley, UK/S&G Biotech, Seoul, Korea) placed under fluoroscopic guidance. Stents with anti-reflux valve were used if the lower end had to be placed in the stomach. Patients were followed up prospectively until death or stent failure. Clinical outcome was compared to the results from the national Registry of Oesophageal Stenting (ROST). The device is CE marked and was used within its license. Institutional review board was nevertheless sought and granted. The manufacturer made 30 stents were available for evaluation free of charge. Results 22 patients with malignant dysphagia and 2 with a benign post-radiation stricture had an EGIS oesophageal stent inserted. Median immediate stent expansion at insertion was 45% (25%–100%) increasing to 100% (60%–100%) after 1 week. Minor complications occurred in 8% compared to 14% in the national audit. No stent migrated from the oesophagus above the cardia, partial migration occurred in 1/15 stents (9.8%) placed across the GO-junction, comparing favourably to a migration rate of 4.3% (mid-oesophagus) and 18% (cardia) from the national audit. Improvement in dysphagia was comparable with a pre-stent median score of 3 (2–4) improving to 2 (0–3) at 48 h and to 1 (1–3) after 1 week. The two stents inserted for benign strictures were removed endoscopically by inversion through capture of the lower purse string. Initial difficulties with the delivery system were identified and corrected by the manufacturer. Conclusion Limited first experience shows the EGIS oesophageal stent to perform at least as good as the large variety of existing oesophageal stents. There may be a benefit in terms of reduced stent migration, particularly if placed across the adverse anatomy of the GO-junction, but more extensive experience is required. Palliation of dysphagia is as good as with conventional stents. The stent should be particularly considered in tortuous anatomy due to the excellent conformability. Competing interests J Cain: None declared, T Westwood: None declared, C Gordon: None declared, R Frost: None declared, H-U Laasch Consultant for: S&G Biotech. Reference 1. British Society of Interventional Radiology (BSIR) . ROST - Registry of Oesophageal Stenting, First Report 2004 . Henley-on-Thames: Dendrite Clinical Systems, 2004.

Introduction A replacement button-gastrostomy has been developed, retained by a mechanical internal fixator formed by loops of the tube shaft. When stretched by the introducer/extractor tool it returns to a completely flat tube profile, avoiding the need for oversizing the stoma, reducing pain on exchange and potentially increasing the tube dwell time beyond the recommended 3 month intervals of balloon tubes. We assessed whether the prototype is applicable to clinical practice. Methods Suitable patients referred for replacement of a conventional gastrostomy were invited to receive a 14Fr prototype instead of a 12Fr balloon gastrostomy requiring a 16Fr track. Gastrostomies were inserted without local anaesthesia, unless required for removal of the existing PEG/RIG. Regular follow-up at increasing periods was performed and difficulties and complications recorded. Informed consent and approval by the institutional review board was given, the device is CE marked. Results All tubes were sited and subsequently exchanged without difficulty and essentially pain-free. Two patients had PEGs removed fluoroscopically under sedation prior to siting the tubes, 14 patients with an existing balloon tube found the exchange from much less painful. Initially the prototypes were changed routinely after 6 months. At present they are left until the patient indicates a need for review. No complications occurred during the insertion of the feeding tubes. No accidental displacements occurred. Seven feeding tubes (47%) are still in situ after a median of 250 days. Of the remaining tubes five were removed due to end of treatment, 4 were changed back to a balloon tube (two patient preference, two for infection and leakage). 14/16 patients indicated a clear preference for the prototype because of lack of balloon-maintenance, reduced number of tube changes and painfree tube removal and insertion. Conclusion The feasibility study proved the mechanical retainer to have sufficient internal fixation with much reduced need for maintenance and applicable to clinical practice. Dwell time can easily exceed 1 year and patient acceptability was much higher than expected. The reduced number of tube changes and lack of pain of these would be particularly important in children. Competing interests J Cain: None declared, T Westwood: None declared, L Wilbraham: None declared, D Edwards consultant for: Vygon, H U Laasch consultant for: Vygon, Kimberley-Clarke.

In 1988, a 54-year-old edentulous patient received a cranial bone onlay graft with the immediate placement of five dental implants. Treatment procedures and early results of restoration are described.

The use of adrenocorticotropin (ACTH) challenges was tested as an indicator of the level of physiological stress response of laying hens in several housing alternatives. Single Comb White Leghorn (SCWL) hens were challenged with intravenous ACTH injections (either .33, 1.0 or 3.0 IU/kg body weight). Plasma corticosterone (CORT) concentrations taken at intervals from 10 to 180 min following ACTH challenges revealed CORT response curves which peaked within 30 min at 34-, 54- and 60-fold increases over pre-challenge CORT levels with doses of .33, 1.0 and 3.0 IU/kg ACTH, respectively. Peak CORT levels for 1.0 and 3.0 IU/kg of ACTH did not differ; however, CORT levels for 1.0 IU/kg ACTH were significantly elevated above the peak for .33 IU/kg ACTH. Laying hens housed in cage and floor management alternatives were challenged with .33 and 1.0 IU/kg of ACTH after 10 months of lay. Cage management treatments were 3, 4 or 5 hens per cage and floor treatments with hens kept at 2 densities. Significant differences in the ACTH-induced CORT response between management alternatives could be detected following injection of .33 IU/kg ACTH, but not with the higher ACTH dose (1.0 IU/kg). These studies demonstrated that the CORT response to the lower dose of ACTH seemed to be more effective in assessing management differences, but further clarification may be necessary before ACTH challenges can be accurately used to evaluate physiological stress responses of laying hens housed in different conditions.

When 23 healthy native Southwestern Colori,oian men were studied to determine the prevalence of Enterobacteniaceae in the jejunal microflora in a sample of thoroughly evaluated tropical inhabitants who were normal by physical examination, chest x-ray, and medical history, 14 of the 23 proved to be Enterobacteniaceae-positive, with counts of l0� to l0� per milliliter ofjejunal aspirate. Thirteen had Escherichia coli, and the fourteenth had Klebsiella pneumoniae. Four had a second species of Enterobacteniaceae associated with E. coli: three were K. pneumoniae, and one was Proteus morganii. Laboratory studies routinely done on all subjects disclosed a total of 18 low biochemical values, 17 of which were associated with 12 of the 14 Enterobacteniaceae-positive subjects: six were low in serum cholesterol, four low in serum vitamin B12, four low in D-xylose excretion, and three low in creatinine coefficient; whereas, the Enterobacteniaceae-negative subjects had normal values for all biochemical tests except for serum vitamin B12 in one case. Nitrogen balance means were significantly different for the two groups: 3.39 g for the Enterobacteniaceae- positive subjects and 1.94 g for the Enterobacteniaceae-negative. No relationship was evident when the histology of the jejunal biopsies was compared with the microbiological or laboratory findings. When the 23 subjects were grouped into those (N = 19) with significant microbial recoveries of any type and those (N = 4) without, the data yielded no meaningful relationships. Am.J. Clin. Nutr. 29: 1397-1403, 1976.

Summary The ultrastructure and carbohydrate chemistry of Glaucosphaera vacuolata Korsh. were studied to clarify the uncertain taxonomic position of this alga. Serial thin sections reveal that the double membrane bounded photosynthetic apparatus of Glaucosphaera, described by previous investigators to consist of many chromatophores or cyanelles, is a single, highly lobed chloroplast without a pyrenoid. Thylakoids are single and bear phycobilisomes. The single nucleus is centrally located and surrounded by Golgi bodies. Starch granules are located outside the chloroplast and are not membrane bounded. Chemical analysis of the solubilized starch granules by butanol precipitation, iodine staining, and enzymatic digestion indicates the presence of both amylose and amylopectin. It is concluded that Glaucosphaera is a red alga and should be assigned to the order Porphyridiales.

SUMMARY An algal assay capable of detecting the carrying capacity of nutrient-poor rivers was developed. In order to eliminate carry-over of nutrients, thus masking the true nutrient condition of the water tested, a new growth medium was developed. This maintenance medium contained less than 4 mg · 1−1 total inorganic salts. With an inoculum of 104 cells-ml−1 the test organism Selenastrum capricornutum Printz was grown in sterile-filtered, river water and transferred daily with a 1:1 dilution. The assay was carried out for 4 or 5 days, at which time cell number was calculated, and the doublings per day were determined. Comparisons are made with similar but less sensitive assays, on the basis of both daily and 5-day readings.

Adrenal involvement in ovulation has been demonstrated for several mammalian species and has recently come under scrutiny in birds. Complete adrenalectomy causes severe system imbalances; therefore, it was decided to evaluate the effect of unilateral adrenalectomy on ovulation in coturnix. Since no mortality occurred among 59 hens recovering from anesthesia following hemiadrenalectomy, systemic imbalances appeared to be tolerable. Hen-day egg production of adrenalectomized hens was significantly (P greater than .05) lower than that of sham operated and unoperated controls. Adrenalectomized birds exhibited their lowest rate of lay (18.7%) on the second day following treatment. The amount of time that hemiadrenalectomy preceded oviposition on the day of treatment influenced the occurrence of an ovulation. When adrenalectomy occurred 5 to 7.5 hr prior to oviposition, 86.7% of the birds failed to ovulate that day, compared with 27.8% of controls. This difference was highly significant. When adrenalectomy occurred less than 2.5 hr prior to oviposition, 92.3% of the birds ovulated on that day, but failed to ovulate on the next day. Subsequent to the period of adrenal insufficiency, hens resumed normal egg production. It was concluded that the adrenals directly influence daily ovulations in Coturnix, exerting an effect on hormonal events leading to ovulation.

n/a

INTRODUCTION Egg position during incubation has been considered an important factor in satisfactory hatchability and one which influences the incidence of certain embryo malpositions (Landauer, 1967). In particular, incubation of eggs in an inverted position, i.e., with the small end up (S.E.U.) has been reported to drastically reduce hatchability and to result in about a 60% incidence of embryos in Malposition 2 (head in small end of the egg) and 5 (feet over head) (Byerly and Olsen, 1931, 1933). Reports in the literature indicate hatchabilities as low as 36.4% (Byerly and Olsen, 1933) although recently El-Ibiary et al. (1966) reported a much less drastic reduction in hatch, using mostly eggs from S.C. White Leghorn pullets. Homma and Shumiya (1964), however, reported that in Japanese quail hatchability was sharply reduced in eggs incubated in an inverted position. We have compared the effects of incubating in the SEU position eggs from three…

INTRODUCTION THE effect of seasonal changes in light and temperature is apparent in the reproductive cycle of birds such as coturnix, also referred to as Japanese quail. The corresponding changes in feed consumption related to gonadal development, however, has been a neglected area of investigation. Light has been considered the prime factor in hastening sexual maturity in coturnix and other bird species, but temperature has also been implicated. The unraveling of this complex relationship of light and temperature effects on reproduction requires a controlled environment facility, and a close examination of reproductive capacity and energy intake. The objectives of these experiments were to determine the effects of light-temperature interactions on the gonadal function and energy consumption of old and young adult coturnix, and further to determine the amount of feed intake associated with egg formation. METHODS Two experiments with very similar protocol were completed in the avian bioclimatic chambers at…

Plasma corticosterone was measured as a stress indicator of laying hens in different management conditions. Laying hens housed in cages and floor pens were sampled repeatedly in the morning and the afternoon. Plasma corticosterone concentrations of afternoon samples of hens from floor treatments were significantly higher than those from cage treatments, but morning values were not different. These results suggest that management systems, producing subtle adverse conditions for laying hens, are associated with elevated baseline corticosterone levels during the nadir of the diurnal response, whereas peak values may not be affected.

n/a

In Texas in 1976 and 1977, Rio Grande turkeys (Meleagris gallopavo intermedia) from seven counties and Eastern turkeys (M. g. silvestris) from one county were tested for antibodies to selected poultry pathogens. Standardized serological tests disclosed reactors to Salmonella pullorum (2.4%), S. typhimurium (2.3%), and Mycoplasma gallisepticum (4.8%). There were no reactors to Newcastle disease virus or Chlamydia psittaci. Prevalence of M. gallisepticum antibody in wild turkeys was significantly higher for counties with commercial turkey operations than for counties lacking domestic turkeys, whereas the incidence of S. pullorum and S. typhimurium did not differ significantly.

The effects of bird density and dietary protein and energy level on growth rate and feather pecking in Ring-Necked pheasants were investigated in two experiments. After brooding, pheasants in Experiment 1 were housed at densities of .19, .38, or .74 m2/bird and fed grower diets containing 16, 19, or 22% protein. Experiment 2 pheasants were housed at .4 m2/bird and fed diets containing 16 or 22% protein with energy levels of 2530, 2750, 2970, or 3190 kcal/kg. Body weight was not affected by bird density differences, but feather pecking was significantly reduced by increasing floor space per bird. Body weight, cannibalism, and feed conversion were poorer in groups fed the 16% protein diet than those fed the 19 or 22% protein diets. Body weight gains, feed efficiency, and feather pecking scores improved as the energy content of grower diets increased. Significant interactions existed between dietary protein and bird density and between dietary protein and energy for feather picking in pheasants. Total performance was best for groups fed a grower diet of 22% protein and 2970 kcal/kg metabolizable energy level with a floor space of .38 m2 or greater per bird.

Bobwhites were fed one of several doses (.01 to 1,000 micrograms/day) of estriol (E3), beta-estradiol-3-benzoate (E2B), diethylstilbestrol (DES), or biochanin-A (BA) during two 10-week trials. The initial 2 weeks of each trial were short day length (10L:14D) followed by 8 weeks of long day length (16L:8D). In addition, female bobwhites were given daily injections containing dosages (.01 to 10 micrograms/day) of E2B, E3, and DES while housed on the same light regimen. Reproductive performance as assessed by onset of lay, egg production, and egg fertility was depressed in a dose-dependent manner and was inhibited by dietary dosages of 1,000 micrograms/day of E3, DES, and E2B. No consistent effects on reproductive performance were observed in bobwhites fed up to 1,000 micrograms/day of the phytoestrogen BA. Injected estrogens appeared approximately 100 times more potent than dietary estrogens. It was concluded that both dietary and parenteral estrogen can inhibit reproduction, but in order for phytoestrogen (BA) in natural feedstuffs to impair reproduction in bobwhites it would have to be consumed in excess of 1 mg/day.

Responses of commercial laying hens to 16 management systems were examined for 10 laying periods of 28 days each. Twelve cage treatments consisted of housing three, four, or five hens in deep and shallow cages of different dimensions which provided .035 and .046 m2/hen. Four floor treatments housed 35 hens or 32 hens and three roosters at densities of .094 or .373 m2/bird, in two replicated pens each. Quantitative data were collected simultaneously for 23 production, physiological, and behavioral characteristics throughout the study. When comparing all caged with floor pen hens, caged hens had better (P less than .05) egg production rates (76.3 vs. 73.9%), gained more weight, had better feed efficiency, and had greater egg and egg shell weights than floor hens. All floor pen hens had higher (P less than .01) viability (98.9 vs. 95.0%), higher (P less than .01) plasma corticosterone levels (595.0 vs. 445.4 pg/ml), a greater (P less than .01) response to adrenocorticotropin (ACTH) challenges, and lower (P less than .01) antibody titers to Salmonella pullorum challenges than all caged hens. Caged hens preened, stood, crouched, and feather pecked more than floor hens, while floor hens drank and moved about more than caged hens. This study attempted to quantify production, physiological, and behavioral traits, all on the same flock of hens, in order to separate stressful from nonstressful management environments. Integration of all measurements indicates that properly managed caged hens were subjected to significantly fewer stressors than laying hens housed in floor pens, although the hens' well-being in the two environments could not be quantitatively compared.

n/a

INTRODUCTION THE use of biotelemetry systems permits the measurement of physiological information from unrestrained subjects. In addition, if the system is automated, then diurnal records may be taken in the absence of an investigator whose very presence will alter the results (Cain and Abbott, 1970; Cain and Wilson, 1971). The importance of telemetry for physiological rhythm studies has been reported by Miles (1962) and Essler and Folk (1961). Telemetry with birds has included respiration of a flying duck (Lord et al., 1962) and the diurnal heart rate pattern of a chicken (Sturkie, 1963). An implanted telemetry system has also been used to relate time of oviposition and ovulation to changes in body temperature in the chicken (Winget et al., 1965). Many applications of telemetry are described in reviews by Mackay (1968), Ko and Neumann (1967) and Slater (1963). A multichannel AM telemetry and multiplexing system for measuring body temperature circadian…

n/a

INTRODUCTION A VARIETY of methods have been used to measure the heart rate of chickens and commonly heart rate has been altered by the measurement process. In general birds have been placed in an unfamiliar environment either restrained or anesthetized. Time of day, comfort of the bird or activity of the investigator have often been contributing factors to the heart rate obtained. We wished to develop a system permitting the heart measurement and comparison of a large number of birds under essentially normal conditions. Such a system would allow valid comparisons of breeds, sexes and ages, any of which may react differently to handling. In this report a measurement system developed to satisfy these criteria and its application is described. APPARATUS A scanning device was developed to automatically survey the electrocardiograms (EKG) of twenty chickens each hour. The multiplexing unit scanned stations, without switching transients to the pen recorder, by…

SummaryA new technique was used to measure the heart rate of developing chick embryos. Ballistocardiography should afford ideal conditions for observing embryonic heartbeats with a minimum of disturbance to the embryo. The same embryos can be measured on each day of incubation. The heart rate increased from day 4 through day 10 and then decreased until hatching time. The average frequency at 10 days was 280 bpm and 263 bpm at 19 days of incubation. Male embryos consistently had slower average heart rates than did females. No significant difference was observed in the average daily heart rate of embryos from 4 different genotypes, even though differences are apparent between adults of these genotypes. Mechanical disturbances or alterations in temperature had a marked effect on the heart rate of the embryo. Brief exposure to room temperature or slight injuries, such as those following insertion of electrodes, usually result in a decreased heart rate.