scholarly journals IMMUNOLOGICAL AND CHEMICAL INVESTIGATIONS OF VACCINE VIRUS

1936 ◽  
Vol 64 (3) ◽  
pp. 439-452 ◽  
Author(s):  
Robert F. Parker ◽  
Thomas M. Rivers
Keyword(s):  
Coefficient Of Variation ◽  
Vaccine Virus ◽  
Agglutination Reaction ◽  
Test Antigen ◽  
End Point ◽  
Negative Results ◽  
The Mean ◽  
Different Strains ◽  
High Degree ◽  
Infectious Unit

Methods have been described by which the number of elementary bodies present in a suspension can be estimated. It has been shown that by means of replicate counts, in which the Petroff-Hausser chamber was used, a high degree of accuracy can be attained. By means of the Gates densitometer, the number of elementary bodies in a suspension can be determined with a coefficient of variation of about 3.0 per cent. A method has been described by which the accuracy of estimation of the infectious titer of a suspension can be increased without greatly enlarging the number of animals employed. This consists of selecting as the end-point that dilution of virus which on intradermal inoculation in a rabbit would lead theoretically to an equal number of positive and negative results. The statistical advantages of this method have been confirmed by the experiences of other laboratories. By the application of the methods described, there was shown to be a direct correlation between the number of elementary bodies and the number of infectious units of virus present in a given suspension. At the mean of the distribution this ratio is as the logarithms 9.62 to 8.0. To extrapolate this curve, in order to determine the number of elementary bodies present in a single infectious unit, while tempting, is probably not justifiable. It must likewise be remembered that the data given apply to a particular strain of vaccine virus, and that the number of infectious units has been determined by intradermal inoculation of rabbits. It appears also that this method may be of value in studies of the virulence of different strains of vaccine virus, since by its application one may determine not only the infectious liter of a suspension, but its content of elementary bodies. In the agglutination reaction it was found that optimum titers of serum were obtained when the test antigen contained from 2.0 x 109 to 1.05 x 1010 elementary bodies per cc. Approximately 1.95 x 108 particles per cc. of suspension were required for the production of visible agglutination.

scholarly journals Infectivity titrations of myxoma virus in the rabbit and the developing chick embryo

1956 ◽  
Vol 54 (2) ◽  
pp. 246-257 ◽  
Author(s):  
Frank Fenner ◽  
G. A. McIntyre
Keyword(s):  
Chorioallantoic Membrane ◽  
Myxoma Virus ◽  
Close Approximation ◽  
Rabbit Skin ◽  
Maximum Value ◽  
Average Probability ◽  
Proportional Relationship ◽  
The Mean ◽  
Different Strains ◽  
Infectious Unit

Titrations of the same preparations of myxoma virus have been made on the chorioallantoic membranes of developing chick embryos and by the intradermal inoculation of rabbits. Six strains of widely differing virulence for the rabbit were used.No differences were found in the infectivity of different strains for either the rabbit or the egg, even though the severity of the symptoms produced in the rabbit varied greatly with different strains; and although some had never previously been inoculated in eggs and one had been subjected to seventy-five serial passages on the chorioallantoic membrane.The egg was less sensitive than the rabbit, the mean number of infections per dose for rabbits relative to eggs being 2.46, taken over all strains. This ratio did not differ significantly between strains of myxoma virus.There was evidence of some host variation in rabbit susceptibility and a great deal of variation in egg susceptibility. The maximum value for the average probability that an infectious unit would produce a lesion in the rabbit skin was about 0.6, and the maximum value for the average probability that an infectious unit would produce a pock on the chorioallantoic membrane was 0.25.Titration of several closely spaced dilutions of different strains of the virus on the chorioallantoic membrane showed a reasonably close approximation to a proportional relationship between the pock count and the virus dilution. The change with dilution in the proportion of failures to infect rabbits approximated to expectation. Both lines of evidence are consistent with the hypothesis that a pock or skin lesion is initiated by one infective unit of virus, and that the infective unit is stable with dilution.

OXYTOCIN DETERMINATION BY RADIOIMMUNOASSAY IN CATTLE

1979 ◽  
Vol 92 (2) ◽  
pp. 258-270 ◽  
Author(s):  
D. Schams ◽  
B. Schmidt-Polex ◽  
V. Kruse
Keyword(s):  
Coefficient Of Variation ◽  
Radioactive Tracer ◽  
Strong Response ◽  
Assay Sensitivity ◽  
Disappearance Curve ◽  
The Mean ◽  
Milking Machine ◽  
Plasma Disappearance Curve ◽  
High Degree ◽  
Synthetic Oxytocin

ABSTRACT A radioimmunoassay for oxytocin in cow plasma is described. Antisera were raised in rabbits against synthetic oxytocin coupled to bovine thyroglobulin. Iodinated oxytocin free of unlabelled oxytocin and most likely also free of diiodo-oxytocin was used as radioactive tracer. The tracer showed a high degree of purity, and was stable on storage. It could be used in the assay for 2–3 months. The assay showed very little crossreactivity with vasopressin. Acetone was used for the extraction of oxytocin from plasma as well as from standards made of synthetic oxytocin in pooled cow plasma. Inhibition curves obtained with plasma collected from cows at parturition were parallel to those obtained with the oxytocin standard preparation. The mean recovery of oxytocin added to cow plasma was 106 % (sd = 14). The within-assay coefficient of variation (CV) varied from 5.2 to 10.9 %, and the between-assay CV was in the order of 13 %. The assay sensitivity was 1 pg (0.5 μU) per tube, corresponding to 3 pg/ml plasma. Around the time of milking the plasma oxytocin profile showed a strong response to the preparation for milking, and a further effect releated to the attachment of the teat cups of the milking machine. Peak concentrations were in the range of 15–50 pg/ml. During parturition there was a peak of oxytocin (65 pg/ml) coinciding with the expulsion phase. After this peak levels decreased but remained measurably elevated until the expulsion of the placenta. The plasma disappearance curve for immunoreactive oxytocin after the infusion of 100 IU oxytocin over a period of 1 h showed two components with apparent half-lives of 7–9 and 25 min, respectively.

Heparin-Induced Thrombocytopenia from Venous Thromboembolism Treatment.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 908-908
Author(s):  
Susan M. Begelman ◽  
Marcie J. Hursting ◽  
Richard V. Aghababian ◽  
David McCollum
Keyword(s):  
Platelet Count ◽  
Venous Thromboembolism ◽  
Heparin Therapy ◽  
Primary Study ◽  
Heparin Induced Thrombocytopenia ◽  
Mean Values ◽  
End Point ◽  
The Mean ◽  
Platelet Count Monitoring ◽  
High Degree

Abstract Heparin therapy for any indication, including venous thromboembolism (VTE), can be complicated by heparin-induced thrombocytopenia (HIT). The purpose of this retrospective study was to characterize the clinical experience of patients in whom HIT complicated heparin therapy for VTE and who were switched to argatroban therapy. From the previously reported prospective, multicenter, historical-controlled Argatroban-911 and Argatroban-915 studies of argatroban therapy in HIT, we identified all patients who developed HIT while on heparin therapy for pulmonary embolism and/or deep venous thrombosis and in whom heparin was discontinued and argatroban therapy initiated. The primary study end point was a composite of death, amputation, or new thrombosis within 37 days of argatroban initiation; we also evaluated a 37-day composite end point of thrombosis-associated events, including death due to thrombosis, amputation secondary to HIT, or new thrombosis. A total of 145 patients with VTE and HIT were included in our analysis. During heparin therapy before HIT was diagnosed, platelet counts decreased from daily mean values greater than 175x109/L to a mean±SD nadir of 78±67x109/L over the course of 5 days, and new thrombosis developed in 75 (52%) patients. After heparin was discontinued, patients received argatroban (mean dose 2.1±1.2 mcg/kg/min) for 6.8±4.3 days achieving mean activated partial thromboplastin times during therapy of 63±12 s. By day 6 of argatroban therapy, the mean platelet count had risen to >150x109/L. The primary end point occurred in 41 (28.3%) patients, and the thrombotic composite in 23 (15.9%) patients (Table 1). Seventeen (11.7%) patients, including 12 who had also experienced thrombosis while on heparin, developed new thrombosis after argatroban initiation, typically on the day argatroban was discontinued or later (n=10). Death due to thrombosis occurred in only 1 (0.7%) patient. Seven (4.8%) patients experienced major bleeding. We conclude that in heparin-treated patients with VTE, HIT-associated thrombosis often occurs before HIT is recognized, emphasizing the importance of platelet count monitoring and a high degree of suspicion for HIT in this setting. For VTE patients with HIT, argatroban provides effective anticoagulation, with outcomes comparable with those reported for argatroban-treated patients in whom HIT developed following heparin therapy for any indication. New thrombosis occurring after switching to argatroban therapy more typically occurs in patients with existing HIT-associated thrombosis and at/after argatroban discontinuation. Clinical Outcomes n(%) Outcome n=145 Primary (all cause)* Thrombosis-related†,¥ *All-cause death, all-cause amputation, or new thrombosis within 37 days. †Death due to thrombosis, amputation secondary to HIT, or new thrombosis within 37 days. ¥More than 1 outcome may have occurred in a single patient. Composite end point 41 (28.3) 23 (15.9) Individual components Death 19 (13.1) 1 (0.7) Amputation 8 (5.5) 6 (4.1) New thrombosis 17 (11.7) 17 (11.7)

Design and development of manually operated gladiolus planter

2018 ◽  
Vol 5 (01) ◽  
Author(s):  
TAPAN K. KHURA ◽  
H. L. KUSHWAHA ◽  
SATISH D LANDE ◽  
PKSAHOO . ◽  
INDRA L . KUSHWAHA
Keyword(s):  
Coefficient Of Variation ◽  
Field Capacity ◽  
Power Source ◽  
Forward Speed ◽  
Cereal Crop ◽  
Maximum Coefficient ◽  
Coefficient Of Uniformity ◽  
The Mean ◽  
The Cost ◽  
Immense Potential

Floriculture is an age-old farming activity in India having immense potential for generating selfemployment and income to farmers. However, the cost of cultivation of flower is high as compared to cereal crop. Level of mechanization for different field operations is one but foremost reason for the higher cost of cultivation. As most of the Indian farmers are marginal and small, a need for manually operated gladiolus planter was felt. The geometric properties of gladiolus corm were determined for designing the seed metering system and seed hopper of the planter. The planter was evaluated in the field when pulled by two persons as a power source and guided by a person. The coefficient of variation and highest deviation from the mean spacing was observed as 12.93% and 2.65cm respectively. The maximum coefficient of uniformity of 90.59% was observed for a nominal corm spacing of 15cm at 0.56 kmh-1 forward speed. An average MISS percentage was observed as 2.65 and 2.25 for nominal corm spacing of 15 and 20 cm. The multiple index was zero for two levels corm spacing and forward speed of operation. The QFI was found in the range of 97.2 and 97.9 percent. The average field capacity of the planter was observed as 0.02 hah-1.The average draft requirement of the planter was found as 821 ± 50.3 N.

scholarly journals Technical note: Inherent benchmark or not? Comparing Nash–Sutcliffe and Kling–Gupta efficiency scores

2019 ◽  
Vol 23 (10) ◽  
pp. 4323-4331 ◽  
Author(s):  
Wouter J. M. Knoben ◽  
Jim E. Freer ◽  
Ross A. Woods
Keyword(s):  
Time Series ◽  
Coefficient Of Variation ◽  
Ad Hoc ◽  
Model Performance ◽  
Technical Note ◽  
Mean Flow ◽  
Model Adequacy ◽  
Robust Model ◽  
The Mean ◽  
Adequacy Assessment

Abstract. A traditional metric used in hydrology to summarize model performance is the Nash–Sutcliffe efficiency (NSE). Increasingly an alternative metric, the Kling–Gupta efficiency (KGE), is used instead. When NSE is used, NSE = 0 corresponds to using the mean flow as a benchmark predictor. The same reasoning is applied in various studies that use KGE as a metric: negative KGE values are viewed as bad model performance, and only positive values are seen as good model performance. Here we show that using the mean flow as a predictor does not result in KGE = 0, but instead KGE =1-√2≈-0.41. Thus, KGE values greater than −0.41 indicate that a model improves upon the mean flow benchmark – even if the model's KGE value is negative. NSE and KGE values cannot be directly compared, because their relationship is non-unique and depends in part on the coefficient of variation of the observed time series. Therefore, modellers who use the KGE metric should not let their understanding of NSE values guide them in interpreting KGE values and instead develop new understanding based on the constitutive parts of the KGE metric and the explicit use of benchmark values to compare KGE scores against. More generally, a strong case can be made for moving away from ad hoc use of aggregated efficiency metrics and towards a framework based on purpose-dependent evaluation metrics and benchmarks that allows for more robust model adequacy assessment.

scholarly journals Perception of the Online Learning Environment of Nursing Students in Slovenia: Validation of the DREEM Questionnaire

Healthcare ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 998
Author(s):  
Lucija Gosak ◽  
Nino Fijačko ◽  
Carolina Chabrera ◽  
Esther Cabrera ◽  
Gregor Štiglic
Keyword(s):  
Nursing Students ◽  
Nursing Student ◽  
Student Perception ◽  
Psychometric Testing ◽  
Educational Environment ◽  
Educational Process ◽  
Survey Questionnaire ◽  
Self Perception ◽  
The Mean ◽  
High Degree

At the time of the outbreak of the coronavirus pandemic, several measures were in place to limit the spread of the virus, such as lockdown and restriction of social contacts. Many colleges thus had to shift their education from personal to online form overnight. The educational environment itself has a significant influence on students’ learning outcomes, knowledge, and satisfaction. This study aims to validate the tool for assessing the educational environment in the Slovenian nursing student population. To assess the educational environment, we used the DREEM tool distributed among nursing students using an online platform. First, we translated the survey questionnaire from English into Slovenian using the reverse translation technique. We also validated the DREEM survey questionnaire. We performed psychometric testing and content validation. I-CVI and S-CVI are at an acceptable level. A high degree of internal consistency was present, as Cronbach’s alpha was 0.951. The questionnaire was completed by 174 participants, of whom 30 were men and 143 were women. One person did not define gender. The mean age of students was 21.1 years (SD = 3.96). The mean DREEM score was 122.2. The mean grade of student perception of learning was 58.54%, student perception of teachers was 65.68%, student academic self-perception was 61.88%, student perception of the atmosphere was 60.63%, and social self-perception of students was 58.93%. Although coronavirus has affected the educational process, students still perceive the educational environment as positive. Nevertheless, there is still room for improvement in all assessed areas.

Heart rate as a marker of relapse during withdrawal of heart failure therapy in patients with recovered dilated cardiomyopathy: an analysis from TRED-HF

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
B Halliday ◽  
A Vazir ◽  
R Owen ◽  
J Gregson ◽  
R Wassall ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cardiac Function ◽  
Dilated Cardiomyopathy ◽  
Funding Source ◽  
End Point ◽  
Therapy Withdrawal ◽  
The Mean ◽  
Withdrawal Of Therapy ◽  
Continue Therapy

Abstract Introduction In TRED-HF, 40% of patients with recovered dilated cardiomyopathy (DCM) relapsed in the short-term during phased withdrawal of drug therapy. Non-invasive markers of relapse may be used to monitor patients who wish a trial of therapy withdrawal and provide insights into the pathophysiological drivers of relapse. Purpose To investigate the relationship between changes in heart rate (HR) and relapse amongst patients with recovered DCM undergoing therapy withdrawal in TRED-HF. Methods Patients with recovered DCM were randomised to phased withdrawal of therapy or to continue therapy for 6 months. After 6 months of continued therapy, those in the control arm underwent withdrawal of therapy in a single arm crossover phase. HR was measured at each study visit. Mean HR and 95% confidence intervals (CI) were calculated at baseline, 45 days after baseline, 45 days prior to the end of the study or relapse and at the end of the study or relapse. Patients were stratified by treatment arm and the occurrence of the primary relapse end-point. Heart rate at follow-up was compared amongst patients who had therapy withdrawn and relapsed versus those who had therapy withdrawn and did not. ANCOVA was used to adjust for differences in HR at baseline between the two groups. Results Of 51 patients randomised, 26 were assigned to continue therapy and 25 to withdraw therapy. In the randomised and cross-over phases, 20 patients met the primary relapse end-point; one patient withdrew from the study and one patient completed follow-up in the control arm but did not enter the cross-over phase. Mean HR (standard deviation) at baseline and follow-up for (i) patients in the control arm was 69.9 (9.8) & 65.9 (9.1) respectively; (ii) for those who had therapy withdrawn and did not relapse was 64.6 (10.7) & 74.7 (10.4) respectively; and (iii) for those who had therapy withdrawn and relapsed was 68.3 (11.3) & 86.1 (11.8) respectively [all beats per minute]. The mean change in HR between the penultimate visit and the final visit for those who had therapy withdrawn and did not relapse was −2.4 (9.7) compared to 3.1 (15.5) for those who relapsed. After adjusting for differences in HR at baseline, the mean difference in HR measured at follow-up between patients who underwent therapy withdrawal and did, and did not relapse was 10.4bpm (95% CI 4.0–16.8; p=0.002) (Figure 1 & Table 1). Conclusion(s) A larger increase in HR may be a simple and effective marker of relapse for patients with recovered DCM who have insisted on a trial of therapy withdrawal. Whether HR control is crucial to the maintenance of remission amongst patients with improved cardiac function, or is simply a marker of deteriorating cardiac function, warrants further investigation. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): British Heart Foundation

scholarly journals Assessment of costs and insurance policies for referral treatment of equine colic

2019 ◽  
Vol 185 (16) ◽  
pp. 508-508 ◽  
Author(s):  
Isobel Barker ◽  
Sarah L Freeman
Keyword(s):  
Surgical Treatment ◽  
Insurance Companies ◽  
Insurance Policies ◽  
Insurance Cover ◽  
Survey Costs ◽  
The Mean ◽  
High Degree ◽  
Mean Cost ◽  
Monthly Premium ◽  
Equine Colic

Colic is the most common emergency problem in horses. The aims of this study were to survey costs of different referral treatments and to review insurance policies relevant to horses with colic. Data were collected retrospectively from nine equine hospitals for case costs, categorised into four different outcomes: admitted and euthanased; euthanased during or immediately after surgery; medical treatment and survived more than 24 hours; and surgical treatment and survived more than 24 hours. Data from five UK equine insurance companies were extracted and analysed using a standardised case example. Costs were obtained for 108 cases. The mean cost for horses admitted and euthanased was £873.89 (range £459.72–£1471.51), and for surgical treatment and survival more than 24 hours was £6437.80 (range £3178.87–£9100.00). Insurance cover for veterinary fees ranged from £5000 to £7500, and monthly premium rates for a standardised case ranged from £27.06 to £47.06. The terms and conditions for the insurance policies ranged in length from 2098 to 17,701 words; Flesch Kincaid Reading Ease scores ranged from 21.6 to 57.7, indicating a high degree of complexity and low readability. This study highlights the complexity and challenges for decision-making in critical cases of colic.

Responses of the bovine teat to machine milking: measurement of changes in thickness of the teat apex

1988 ◽  
Vol 55 (3) ◽  
pp. 331-338 ◽  
Author(s):  
Jörn Hamann ◽  
Graeme A. Mein
Keyword(s):  
Positive Pressure ◽  
Vacuum Level ◽  
Machine Milking ◽  
Before And After ◽  
The Mean ◽  
High Degree

SummaryChanges in the teat apex before and after different milking treatments were measured with a spring-loaded caliper device known as a cutimeter which could detect changes in thickness of the tissues of the teat end, presumably due to congestion and/or oedema, with a high degree of accuracy (± 2%) and repeatability (r = 0·99). Teat end thickness increased with increasing vacuum level. The mean increase immediately after milking with a conventional cluster was 2% for 24 teats milked at 30 kPa, 8% at 50 kPa and 21% at 70 kPa. At these vacuum levels, the mean increases for the same teats milked with an unconventional (PKME) teatcup were 10, 18 and 25% respectively. Cyclic application of 35 kPa positive pressure to the pulsation chamber of a conventional teatcup operating at 50 kPa reduced teat end thickness by 8% compared with the mean premilking value. Although most teats returned to within ± 2% of their premilking thickness values by 1 h after milking, differences were apparent between different milking systems for up to 4 h postmilking.

Effects of the Fractional Laplacian Order on the Nonlocal Elastic Rod Response

2017 ◽  
Vol 3 (3) ◽  
Author(s):  
Giuseppina Autuori ◽  
Federico Cluni ◽  
Vittorio Gusella ◽  
Patrizia Pucci
Keyword(s):  
Probability Density Function ◽  
Probability Density ◽  
Density Function ◽  
Coefficient Of Variation ◽  
Fractional Laplacian ◽  
Numerical Procedure ◽  
Elastic Rod ◽  
The Mean ◽  
Distributed Forces ◽  
Nonlinear Fashion

In this paper, we yield with a nonlocal elastic rod problem, widely studied in the last decades. The main purpose of the paper is to investigate the effects of the statistic variability of the fractional operator order s on the displacements u of the rod. The rod is supposed to be subjected to external distributed forces, and the displacement field u is obtained by means of numerical procedure. The attention is particularly focused on the parameter s, which influences the response in a nonlinear fashion. The effects of the uncertainty of s on the response at different locations of the rod are investigated by the Monte Carlo simulations. The results obtained highlight the importance of s in the probabilistic feature of the response. In particular, it is found that for a small coefficient of variation of s, the probability density function of the response has a unique well-identifiable mode. On the other hand, for a high coefficient of variation of s, the probability density function of the response decreases monotonically. Finally, the coefficient of variation and, to a small extent, the mean of the response tend to increase as the coefficient of variation of s increases.

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