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PubMed1988

Economic and reproductive consequences of retained placenta in dairy cattle.

The financial losses due to retained placenta in Dutch dairy cattle were estimated by using two different methods of calculation. A data-set containing the birth records of 160,188 Meuse-Rhine-Yssel cows provided data on the reproductive performance of cows with and without retained placenta. The fertility of cows after retention of the placenta appeared to be affected. An economic calculation made by adding the losses due to increased calving interval, increased culling rate, loss of milk production and the costs of veterinary treatment and drugs revealed that the total loss due to retained placenta was 471 pounds per year for a 100-cow farm with an average incidence of the condition (6.6 per cent). For a 'problem' farm with a 30 per cent rate, the loss was 2139 pounds per year. A computer farm simulation model, based on a stochastic determination of events, was used to make calculations for circumstances closely resembling those on farms. A 6.6 per cent rate of retained placenta caused a small but significant decrease in net return on labour and management; however, a 30 per cent rate caused highly significant changes. The economic effects of retained placenta were similar in magnitude in herds of high or low productivity and high or low fertility. Sensitivity analysis showed that the greatest financial losses were caused by loss of milk production, followed by the number of animals suffering from complications. The financial losses in herds with an average rate of retained placenta were thus of limited economic importance and therapeutic measures alone should be adequate.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Husbandry↗
PubMed2004

An evaluation of economics and acceptability of screening for Chlamydia trachomatis infection, in women attending antenatal, abortion, colposcopy and family planning clinics in Scotland, UK.

OBJECTIVE: The aims of this study were to determine cost effectiveness of screening for Chlamydia trachomatis in hospital-based antenatal and gynaecology clinics, and community-based family planning clinics. Additionally, women's views of screening were determined in the hospital-based clinics. DESIGN: Cost effectiveness based on decision model. Model probabilities were generated for a hypothetical sample of 250 women in each age group in each setting, based on prevalence studies, published data and expert opinion. A prospective observational study was used to generate data on prevalence and acceptability. SETTING: Antenatal, gynaecology and family planning clinics in Aberdeen, Edinburgh and Glasgow. SAMPLE: Prevalence was estimated in 2817 women. Acceptability was determined in 484 women. METHODS: An economic evaluation was performed using prevalence data from this and a previous study, and using outcome data from the literature and observational work. Incremental cost effectiveness ratios were estimated for each age group and clinical setting. Sensitivity analyses were performed to determine the robustness of incremental cost effectiveness ratios to changes in the incidence of long term sequelae and costs. The prevalence of infection was determined by nucleic acid amplification of urine samples or endocervical swabs. Knowledge of C. trachomatis and women's views of screening were determined using structured questionnaires. MAIN OUTCOME MEASURES: Direct health service costs of screening, incidence and costs associated with adverse sequelae, women's views of screening and prevalence of infection. RESULTS: The estimated cost of screening 250 women in each age group in each the four sample populations (total population of 3750) is 49,367 UK pounds, while preventing 64 major sequelae. This represents a net cost of 771.36 UK pounds in preventing one major sequela. Selective screening of all women under 20 years and all patients attending abortion clinics were shown to be the most cost effective strategies. These results were relatively insensitive to changes in estimated parameters, such as uptake rate, probabilities and unit costs of all major sequelae averted. Prevalence (95% CI) of infection in the highest risk groups (those aged under 20 in both antenatal and abortion clinics) was 12.1% (8.6-16.7) and 12.7% (7.3-21.2), respectively. The majority (>95%) of women agreed with a policy of regular screening for C. trachomatis, and screening in the settings employed in this study was largely acceptable. CONCLUSIONS: A single episode of screening for C. trachomatis does not result in net cost savings. Currently recommended strategies of screening for C. trachomatis in women under 25 years of age in abortion clinics are supported by our data on prevalence and acceptability. These data also suggest that hospital-based screening strategies should be further extended to include younger women attending antenatal clinics and all women of reproductive age attending colposcopy clinics.

Ambulatory Care↗
PubMed1992

Energy metabolism in potoroine marsupials.

Fasting and fed metabolic rates were measured in three species of potoroine marsupials, the rufous rat-kangaroo (Aepyprymnus rufescens), the long-nosed potoroo (Potorous tridactylus) and the brush-tailed bettong (Bettongia penicillata). There were no significant differences among potoroine species in fasting metabolic rate. The lowest fasting heat production for each species was 11-20% less than the interspecific value of 295 kJ.kg-0.75.day-1 for basal metabolism of mature, non-reproductive eutherian homeotherms. The respiratory quotient of all species was reduced significantly as starvation proceeded, but only for B. penicillata was there a significant effect of starvation duration on fasting heat production. The night-time activity of P. tridactylus and B. penicillata doubled their daytime fasting heat production; the corresponding increase for A. rufescens was only 25%. The calorimetric measurement of fed animals showed no differences in digestible energy or metabolisable energy between species. Nevertheless, P. tridactylus and B. penicillata produced more heat per unit metabolic body mass. The maintenance energy requirements (kJ.kg-0.75.day-1) were 479, 494 and 345 for P. tridactylus, B. penicillata and A. rufescens, respectively. The net availability of metabolisable energy was about 0.70 in the three species. The combined heat production of fed female A. rufescens and their pouch young stayed relatively constant for the first two-thirds of pouch life, after which it rose sharply (20%) in response to the rapid growth of the young. Only during the last week of pouch life did the female enter negative energy balance. There was no indication that the metabolism of the female increased in response to the presence of a pouch young. The presence of pouch young did not alter the efficiency of utilisation of metabolisable energy. The daily energy requirement for maintenance was 0.83 MJ.day-1 or 0.36 MJ.kg-0.75.day-1.

Animals↗
PubMed1980

Canine population dynamics: a study of the Manhattan, Kansas, canine population.

Analysis of the age distribution in the pet population of dogs in the community of Manhattan, Kansas from 1968 to 1979 revealed that the distribution was stationary and the rate of population change (lambda1) was close to 1, which means, that if present conditions do not change, the population probably would remain stable in size in the future. The number of females spayed in the Manhattan population reached a frequency of 66% in 1979. Considering only present age-dependent birth and survival rates, the population could not maintain itself and would decrease rapidly in size. It was found, however, that the population is maintained by a high net rate of immigration, with about 75% of all dogs under 6 months old coming from outside the Manhattan population. The ratio of people to dogs in Manhattan was estimated to be 4.14:1; about 41% of all dogs under 6 months of age were acquired through breeders. Roaming animals in 1 year represented about 12% of the canine population in Manhattan; of those, 36% were stray (not claimed by owner) and the rest were owned and redeemed. The data represented only a portion of the population (dogs with responsible owners) and for a complete understanding of the dynamics of the entire population, one should analyze roaming dogs in a similar way. The methods described in this study should be useful for collecting data to be used by veterinarians and municipal authorities confronted with proposals for regulation dealing with reproduction and pet population.

Age Factors↗
PubMed2003

The effect of feeding frequency on consumption of food, absorption efficiency, and gonad production in the sea urchin Lytechinus variegatus.

The frequency of feeding in the field is variable in sea urchins, ranging from nearly continuous to diel or intermittent. It is essential to know the effect of feeding interval on physiological and metabolic processes to understand the basis for production. Lytechinus variegatus (50 mm horizontal diameter) were collected in January 1999 and held in closed-circuit aquaria at 25 degrees C and 35 per thousand salinity. After 9 days without food, individuals were fed one of three treatments: food available ad libitum, food available for 1 day every 2 days or food available for 1 day every 4 days for 28 days. The rate of food consumption per day of all individuals was high the first week of feeding. It then decreased to a lower, constant rate in those fed ad libitum but remained high in those fed one day every 2 or 4 days. The total amount eaten was directly related to frequency of feeding. The apparent dry matter digestibility (absorption efficiency) did not vary with frequency of feeding. As the total amount of energy absorbed was directly related to the frequency of feeding, the increase in the rate of food consumption does not compensate for a decrease in frequency of feeding. Gonad production efficiency was directly related to frequency of feeding. Gonad gross production (assimilation) efficiencies were 8.4, 3.9 and 3.4% for individuals fed every day, or fed one day every 2 and 4 days, respectively. The corresponding gonad net assimilation efficiencies were 12.5, 5.5, and 4.8%. A decrease in frequency of food availability results in use of a greater proportion of the food consumed for maintenance and less for gonad production.

Animal Feed↗
PubMed2000

Quantitative structure-activity analysis of the algae toxicity of nitroaromatic compounds.

Proliferation toxicity toward the algae Scenedesmus vacuolatus in a 24 h one-generation reproduction assay was determined for nitrobenzene and 18 derivatives, including two phenols. The resultant EC(50) values covering more than 4 orders of magnitude were subjected to a quantitative structure-activity analysis (QSAR) using hydrophobicity in terms of the octanol/water partition coefficient in logarithmic form, log K(ow), and 16 quantum chemical descriptors of molecular reactivity that were calculated with the AM1 scheme. For 13 mononitro derivatives and the highly hydrophobic trifluralin, a narcotic-type mode of action can explain most of the toxicity variation. Correction of log K(ow) for ionization for the phenols and quantification of the molecular susceptibility for one-electron reduction as apparently rate-determining biotransformation step by the energy of the lowest unoccupied molecular orbital, E(LUMO), yields a highly significant QSAR for all 19 compounds (r(adj)(2) = 0.90), which can be further improved when adding the maximum net atomic charge at the nitro nitrogen, q(nitro)(-)(N), as the third descriptor (r(adj)(2) = 0.93). Comparison of the energy of the singly occupied molecular orbital, E(SOMO), of the radical anions as initial metabolites with the E(SOMO) of known redox cyclers suggests that dinitrobenzenes and TFM as well as multiply chlorinated nitrobenzenes may also exert oxidative stress. This is based on an E(SOMO) window of -0.30 to 0. 55 eV as a tentative criterion for molecular structures to have the potential for redox cycling, derived from a set of eight known redox cyclers. The discussion includes a detailed analysis of apparently relevant metabolic pathways and associated modes of toxic action of nitroaromatics.

Cell Division↗
PubMed1984

Characterization of amino Acid efflux from isolated soybean cells.

Cells from reproductive soybean (Glycine max [L.] Merr.) plants were isolated using a mechanical-enzymic technique that produced a high yield of uniform, physiologically active cells. Cells were incubated in a pH 6.0 buffered solution and subjected to various treatments in order to determine the nature of net amino acid efflux. Total net amino acid (ninhydrinreactive substances) efflux was not affected by the following conditions: (a) darkness, (b) aeration, (c) K(+) concentrations of 0.1, 1.0, 10, or 100 millimolar and (d) pH 4, 5, 6, 7, or 8. The Q(10) for net amino acid efflux between 10 degrees C and 30 degrees C was 1.6. Thus, it seems that net amino acid efflux requires neither current photosynthetic energy nor a pH/ion concentration gradient. Amino acid analyses of the intra-and extracellular fractions over time showed that each amino acid was exported linearly for at least 210 minutes, but that export rate was not necessarily related to internal amino acid pools. Amino acids that were exported fastest were alanine, lysine, leucine, and glycine. Addition of the inhibitor p-chloromercuriphenyl sulfonic acid, 3(3,4-dichlorophenyl)-1,1-dimethylurea, or carbonylcyanide p-trifluoromethoxyphenylhydrazone increased the rate of total amino acid efflux but had specific effects on the efflux of certain amino acids. For example, p-chloromercuriphenyl sulfonic acid greatly enhanced efflux of gamma-aminobutyric acid, which is not normally exported rapidly even though a high concentration normally exists within cells. The data suggest that net amino acid efflux is a selective diffusional process. Because net efflux is the result of simultaneous efflux and influx, we propose that efflux is a facilitated diffusion process whereas influx involves energy-dependent carrier proteins.

Journal Article↗
PubMed1994

Pregnancy incidence in high producing dairy cows treated with recombinant bovine somatotropin.

Reproductive performance in cows exposed for two lactations to recombinant bST was measured using unconditional logistic regression. Intramuscular administration of 17.2, 51.6, and 86 mg of recombinant bST/d per cow started at d 70 postpartum and ended at dry-off or 305 d postpartum. Performance was measured as the cumulative incidence of cows becoming pregnant by 305 d post-partum. Within each parity group, cows treated with bST had higher total milk yield. During the first study lactation, the log odds of a cow becoming pregnant decreased linearly as dose increased, following adjustment for serum cholesterol, blood urea N, average daily milk yield, peak milk yield, net energy balance, and body condition score. However, differences in pregnancy incidence between treated and untreated cows were statistically significant only at the higher dose categories, the 51.6 and 86.0 mg of recombinant bST per cow. During the second study lactation, pregnancy rates were similar to those in the first lactation; rates reduced as recombinant bST dose increased. The singular exception was for cows exposed to recombinant bST during the previous lactation but not during the second. In the latter group, previously treated cows had higher pregnancy incidence than did the controls.

Animals↗
PubMed1988

Cost-effectiveness of prenatal screening and immunization for hepatitis B virus.

Perinatal transmission of hepatitis B virus is associated with substantial morbidity and mortality, yet controversy still exists regarding the value of routine screening of pregnant women in the United States and subsequent immunization of their at-risk neonates. To evaluate the cost-effectiveness of such a screening and immunization program, we developed a decision analysis model and obtained data from published reports, chart review, and a Delphi survey to determine outcome probabilities and costs. When considering direct and indirect costs, routine screening and immunization would be cost-effective at a prevalence of 0.06%, significantly lower than the national prevalence of 0.2%. At an annual national birth rate of 3.5 million births, a national policy of routine screening of all pregnant women would result in an annual net savings of more than $105 million. In the high-risk groups, as many as 140 cases of acute neonatal hepatitis and as many as 1400 cases of chronic liver disease would be prevented yearly per 100,000 pregnant women screened, at a net annual savings of as much as $765 million.

Carrier State↗
PubMed1982

Prevalence and socioeconomic correlates of subfecundity and spontaneous abortion in Denmark.

This paper provides an estimate of the prevalence of subfecundity and spontaneous abortion in Denmark, and examines social factors associated with these problems of reproduction. The data of this study were collected by interviewing a stratified random sample of 1.4 women per thousand in Denmark between the ages 25 and 45. The interview generated detailed information on reproductive history and sociodemographic data for 709 women. The survey results indicate that reduced fecundity is a relatively common health problem. The proportion of women that either could not achieve a wanted conception or experienced a delay of one or more years before achieving conception was 0.16 in a first pregnancy and 0.17 in a second or subsequent pregnancy attempt. Four per cent of the women interviewed never produced a desired first child and an additional four per cent reported failure to produce a second or subsequent desired child. Social factors relating to subfecundity and spontaneous abortion were studied using logistic regression. No significant associations were found between the occurrence of subfecundity and family net income, employment status of the 'head of the household', area of residence, type of housing or age at time of interview. Women without a college education were more likely to exhibit primary subfecundity than college-educated women (p less than .05). The rate of spontaneous abortion was not found to be associated with socioeconomic class. A significantly higher rate of abortion was found among women with a history of subfecundity than among women with no such history.

Abortion, Incomplete↗
PubMed1991

Cardiovascular and catecholamine responses to head-up tilt in the diagnosis of recurrent unexplained syncope in elderly patients.

To increase understanding of the mechanisms causing syncope in patients over the age of 60, hemodynamic and hormonal responses to 60 minutes of 60 degree head-up tilt were examined in 10 patients with recurrent syncope of unknown origin and five controls with no history of syncope. Nine of 10 patients and all five controls experienced orthostatic intolerance on the tilt table. Syncope or pre-syncope occurred later in controls than in those syncope patients who had exact reproduction of their clinical symptoms (median time 52 versus 22 minutes, P = 0.05). Three different mechanisms of orthostatic intolerance were identified in the 14 subjects: (1) vasovagal syncope, n = 9 (sudden hypotension +/- bradycardia); (2) dysautonomic syncope, n = 3 (immediate and gradual parallel declines in both systolic and diastolic pressures with blunted increase in heart rate); (3) psychogenic or vestibular reaction, n = 2 (orthostatic intolerance without hemodynamic changes). Vasovagal syncope patients showed a significant increase in plasma norepinephrine from baseline to maximum level during tilt (100 +/- 39% increase, P = 0.03) and a subsequent decrease at the time of syncope (30 +/- 5% decrease, P = 0.01), while plasma epinephrine increased markedly from baseline to the time of syncope (827 +/- 154% increase, P = 0.0003). Dysautonomic syncope patients had lower supine levels of norepinephrine compared to vasovagal syncope patients (182 +/- 30 versus 614 +/- 146 pg/mL, P = 0.008) and no significant change in norepinephrine over time; epinephrine levels increased significantly less than in vasovagal patients (net change 38 +/- 8 versus 189 +/- 56 pg/mL, P = 0.008).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

A fractal model of HIV transmission on complex sociogeographic networks: towards analysis of large data sets.

"A paradigm of HIV (human immunodeficiency virus) transmission along very large 'sociogeographic' networks--spatially focused nets of social interaction--is extended to include fractal (dilationally self-similar) structures upon which a metric of 'sociogeographic' distance can be defined.... Techniques are sketched for determining the sociogeographic structure of a large, geographically centered social network, providing a possible empirical basis for predicting forms and rates of spread of the initial, rapid stages of an HIV outbreak for networks not yet infected, and perhaps greatly expanding the utility of routinely collected small-area administrative data sets in the design of mutually reinforcing, multifactorial disease-control strategies."

Communicable Diseases↗
PubMed1996

Plasma corticosterone concentrations associated with acute captivity stress in wild loggerhead sea turtles (Caretta caretta).

Plasma corticosterone concentrations were measured in wild loggerhead sea turtles (Caretta caretta) in response to acute captivity (capture, serial bleeding, and restraint up to 6 hr). In general, concentrations of corticosterone dramatically increased 1 hr after capture, peaked at 3 hr, and decreased by 6 hr. Initial corticosterone concentrations were significantly lower in animals captured by tangle net than in those captured by trawl and were thought to more closely represent baseline levels. Significant effects of season and size class on corticosterone concentrations were found for turtles captured by trawl. Corticosterone concentrations of small turtles captured in summer were higher than those of large turtles captured in the same season and of all turtles captured during winter. In winter, corticosterone concentrations for small turtles were higher than those for large turtles at 3 hr after capture. Large turtles captured during winter experienced the slowest rate of increase in plasma corticosterone and a decline at 3 hr after capture. Although cloacal temperatures were significantly higher in summer samples, corticosterone concentrations of large turtles did not differ between seasons until 1 hr after capture. In addition, several large turtles during summer did not experience an increase in corticosterone concentrations 1 hr after capture. It is possible that the lower corticosterone response of large turtles captured during summer may be associated with reproductive condition.

Animals↗
PubMed1989

A comparative evaluation of the safety and contraceptive effectiveness of 65 mg and 100 mg of 90-day norethindrone (NET) injectable microspheres: a multicenter study.

The first of a second generation of slow-release injectable contraceptives is the norethindrone (NET) microspheres with a 90-day duration of action. It was evaluated at 65-mg and 100-mg doses for safety and contraceptive effectiveness in two randomized, single-blind trials among 131 women: 94 women for 12 months and 37 women for 6 months. The 6-month trial included additional evaluations of ovarian function and serum NET values. In the 6-month trial, no indication of ovulation was detected in the 100-mg dose group, while 3 of the 19 women in the 65-mg group showed signs of ovulation (progesterone greater than 3 ng/ml). No pregnancies were reported in the 100-mg group and one pregnancy in the 65-mg group resulted in a life-table pregnancy rate for that dose of 2.6 per 100 woman-years (95% confidence interval, 0 to 7.5). Days of vaginal bleeding were analyzed for 30 days before treatment and in 90-day reference periods after treatment. The mean number of vaginal bleeding and spotting days increased initially after the first injection in both dose groups, but decreased to below baseline in both dose groups after 6 months. The two doses appear comparable in clinical safety, side effects, vaginal bleeding patterns, and laboratory measures. With the preliminary estimate of efficacy, the 65-mg dose would be the minimally effective dose for the NET 90-day injectable contraceptive.

Adult↗
PubMed2004

Diet-dependent effects of gut bacteria on their insect host: the symbiosis of Erwinia sp. and western flower thrips.

Studies on bacteria in the gut of insect species are numerous, but their focus is hardly ever on the impact on host performance. We showed earlier that Erwinia bacteria occur in the gut of western flower thrips, most probably acquired during feeding. Here, we investigate whether thrips gain a net benefit or pay a net cost because of these gut bacteria. On a diet of cucumber leaves, the time to maturity is shorter and the oviposition rate is higher in thrips with bacteria than in thrips without (aposymbionts). When fed on cucumber leaves and pollen, aposymbionts develop faster and lay more eggs. So Erwinia bacteria benefit or parasitize their thrips hosts depending on the diet, which is in accordance with theoretical predictions for fitness of organisms engaged in symbiotic interactions. Possibly, the transmission of gut bacteria has not become strictly vertical because of this diet-dependent fitness variability.

Analysis of Variance↗
PubMed2006

Physiology, behaviour and welfare of fish during recreational fishing and after release.

This review investigates how recreational fishing affects the physiology, behaviour, and welfare of fish. Sentience and the capacity of fish to experience pain, suffering and fear are discussed, and practical recommendations for improving the treatment of fish during recreational fishing are provided. Handling procedures used in recreational fishing should match the environment where the fish is caught and the size and strength of the fish. Minimising the number of hooks on lures and baits, and using barbless hooks and circle hooks generally reduce rates of injury and the severity of tissue trauma. Capture time, handling time, and exposure to air play significant roles in the stress responses of fish and should be minimised by anglers. Keep-nets, gaffs, landing-nets, live-wells and other restraining devices should only be used when necessary because each device can prolong or intensify the negative influences of catching fish by hook-and-line. The use of fish as bait is discouraged unless they have been euthanised. Euthanasia of fish used as bait or fish captured recreationally should include a stunning blow to the head, followed by bleeding-out, or pithing the brain and spinal cord. Fish should be euthanised if they are bleeding, injured, deeply-hooked, foul-hooked, or severely exhausted, but local fisheries' regulations must be obeyed. Fish that are released after being caught may be subjected to additional factors that influence their welfare, such as elevated stress, barotrauma, suppressed feeding and growth, impaired reproductive function, increased potential for disease, infection, and delayed mortality.

Animal Welfare↗
PubMed1984

Long-term experience with Norplant implants in international clinical trials.

Norplant subdermal implants containing levonorgestrel were used for contraception and compared with the Copper T, Model T Cu 200, during 42 months of use in an open study in Chile, the Dominican Republic, and Finland. Among 324 women enrolled for the implant regimen, there were no pregnancies in the 1st 2.5 years, and 2 by the end of 42 months. 1st segment net and gross cumulative pregnancy rates were 0.7 and 1.2/100 respectively, at 3.5 years. Cumulative pregnancy rates for the T Cu 200 group were 2.9, net and 3.5/100, gross at 42 months. More than 1/2 of the implant acceptors, 51.6/100 were continuing use at 3.5 years, somewhat above the continuation rate of the T Cu acceptors, 43.5/100, but not significantly so.

Americas↗
PubMed1997

Abortion in the framework of family planning in Estonia.

OBJECTIVE: To analyze the legal status of abortion and trends in childbirth, abortions and contraceptive use in Estonia. DESIGN: National statistical data on induced abortions, spontaneous abortions, births and contraceptive use in Estonia. RESULTS: Even though induced abortion is legal in Estonia, the abortion rate has been declining but is still high and in 1994 was 53.8 per 1000 women of fertile age. Among young women under 20 years of age, abortions decreased slightly in the period 1992-94 (from 55.5 to 41.5 per 1000). The birth rate has been declining rapidly in recent years, resulting in a net population reduction. The use of modern contraceptives is increasing but is still low. CONCLUSION: Survey on abortion and on contraceptive sales and use are needed. To improve family planning and prevent unwanted pregnancies it is important to increase awareness among the entire population--and especially among young people--by information, education and communication. A high standard of counseling, including pre- and postabortion counseling and in the youth services, is essential.

Abortion, Induced↗