Scalability of genetic biocontrols for eradicating invasive alien mammals

CRISPR-based gene drives offer novel solutions for controlling invasive alien species, which could ultimately extend eradication efforts to continental scales. Gene drives for suppressing invasive alien vertebrates are now under development. Using a landscape-scale individual-based model, we present the first estimates of times to eradication for long-lived alien mammals. We show that demography and life-history traits interact to determine the scalability of gene drives for vertebrate pest eradication. Notably, optimism around eradicating smaller-bodied pests (rodents and rabbits) with gene-drive technologies does not easily translate into eradication of larger-bodied alien species (cats and foxes).Aysegul Birand, Phillip Cassey, Joshua V. Ross, Paul Q. Thomas, Thomas A. A. Prows

Leveraging a natural murine meiotic drive to suppress invasive populations

Invasive rodents are a major cause of environmental damage and biodiversity loss, particularly on islands. Unlike insects, genetic biocontrol strategies including populationsuppressing gene drives with biased inheritance have not been developed in mice. Here, we demonstrate a gene drive strategy (tCRISPR) that leverages super-Mendelian transmission of the t haplotype to spread inactivating mutations in a haplosufficient female fertility gene (Prl). Using spatially explicit individual-based in silico modeling, we show that tCRISPR can eradicate island populations under a range of realistic field-based parameter values. We also engineer transgenic tCRISPR mice that, crucially, exhibit biased transmission of the modified t haplotype and Prl mutations at levels our modeling predicts would be sufficient for eradication. This is an example of a feasible gene drive system for invasive alien rodent population control.Luke Gierusa, Aysegul Birandc, Mark D. Buntinga, Gelshan I. Godahewa, Sandra G. Piltz Kevin P. Oh, Antoinette J. Piaggio, David W. Threadgill, John Godwin, Owain Edwards, Phillip Cassey, Joshua V. Ross, Thomas A. A. Prowse and Paul Q. Thoma

The effects of cardiac glucoside, digitoxin, on atrial electrocardiogram in healthy persons

Atrial electrocardiograms have been studied in 32 normal subjects both before and after digitalisation, where digitoxin was given for three successive days in a total dose of 1.2 mgr. Following a statistical analysis of the results obtained it has been concluded that the effects of digitoxin on the atrial electrocardiograms of normal subjects are insignificant

Editorial comment: Factors regulating exercise capacity in heart failure and effects of beta- receptor blockers on exercise tolerance [Editöryel Yorum: Kalp Yetersizliginde Egzersiz Kapasitesini Düzenleyen Etkenler ve Beta-Reseptör Blokerlerinin Egzersiz Toleransi Üzerindeki Etkileri]

PubMedID: 14675881[No abstract available

On the behavior and identification of collapsible soils

The objective of this paper is to present research first on the factors that control collapse, which are; the effect of silt content and the surcharge intensity and second, a comparative treatment of major methods of identification

Effects of perindopril on autonomic modulation of the heart and left ventricular function: An open-label study

Background: Heart rate variability (HRV) is depressed and parasympathetic modulation of the heart is attenuated in patients with heart failure (HF). Angiotensin-converting enzyme (ACE) inhibitors are known to reduce the mortality and morbidity associated with HF after acute myocardial infarction, but the mechanism of this activity is not known. Objective: The purpose of this study was to evaluate the effects of the ACE inhibitor perindopril on autonomic modulation of the heart and left ventricular (LV) function in patients with HF after acute myocardial infarction. Methods: Adult patients with HF (New York Heart Association Class II and III) after acute myocardial infarction were enrolled and received 2 mg/d perindopril for 30 days. Autonomic regulation of the heart was assessed at baseline and after 30 days of treatment by analyzing HRV in the frequency domain, and LV function was evaluated by 2-dimensional and Doppler echocardiography. Results: Twenty patients (18 men, 2 women; mean age, 51.5 ± 7.7 years) were enrolled. On day 30 of therapy, there was a significant increase in high-frequency power (P = 0.004), which reflects parasympathetic modulation, and a significant decrease in the low-frequency/high-frequency power ratio (P = 0.02), which is thought to reflect sympathetic modulation of the heart. In addition, significant improvement in LV function was noted on echocardiographic examination. The decrease in LV dimensions (P = 0.007) and end-diastolic (P = 0.003) and end-systolic (P < 0.001) volume indexes, as well as the increase in ejection fraction (P < 0.001), were found to be significant. Conclusions: The results of this open-label, uncontrolled study suggest that therapy with perindopril decreases sympathetic cardiac modulation, increases parasympathetic cardiac modulation, and improves LV function in patients with HF after acute myocardial infarction

Time-Frequency Analysis of Heart Rate Variability: Smoothed Pseudo-Wigner Distribution

Background: The heart rate variability (HRV) signal is mainly analyzed in frequency-domain and the signal's spectrum is estimated using either Fast Fourier Transformation (FFT) or the autoregressive (AR) model. These two methods assume that the HRV signal is stationary and additionally the AR method is based on the assumption that the model is linear and the signal is monocomponent in nature. Qualities of spectral estimates are thus closely related to the validity of the above assumptions. Evidence has accumulated indicating that HRV is a multicomponent, nonlinear and nonstationary signal. Then the spectral representations currently used would yield global, approximate, and smoothed view of HRV dynamics. Methods: We applied time-frequency (TF) analysis methods, smoothed pseudo-Wigner distribution (SPWD), and spectrogram and complemented for validation by FT spectrum to the HRV signal of fifteen apparently healthy volunteers (mean age 27.2 ± 5.6 years). Short-term electrocardiograms (ECG) were recorded during supine and upright tilting positions (baseline recording). After baseline recording we induced parasympathetic, sympathetic, and total autonomic blockade correspondingly to six, nine, and four subjects. In addition, in four patients ECGs were recorded during controlled respiration. Results: SPWD and spectrogram revealed strips in frequency, or TF components, corresponding to FT components. High frequency (HF) components appeared stationary (in wide sense), with slight mean frequency shifts during spontaneous respiration, concurrent with respiratory motions. Low frequency (LF) and very low frequency (VLF) components had a nonstationary character displaying activity burst in time and interrelation in frequency. Upright tilting caused a uniform reduction in intensity and bandwidth of the HF component and enhancement of intensity and burst activity of the LF component. There was a pronounced decline of HF and LF components' intensity and decrease of HF component's bandwidth after parasympathetic blockade and total autonomic blockade, while the VLF component did not change. Sympathetic blockade was accompanied by augmentation of the LF and HF components' intensity associated with an increase in the HF component's bandwidth and the spreading of it in the region between the LF and HF. The LF component exhibited less burst activity during tilting under sympathetic blockade, as compared to baseline recordings during tilt. The VLF component's behavior did not change after sympathetic, parasympathetic, and total autonomic blockades. Conclusion: Application of TF distributions to the HRV signal offers a new representation of HRV dynamics. SPWD unveiled features in the HRV signal not available in separate time- and frequency-domains. TF components display idiosyncratic behavior patterns in time and were effected by physiological and pharmacological interventions

Evaluation of electrocardiographic findings in children with homozygous sickle cell anemia in Cukurova area

[No abstract available

Bispectral analysis of heart rate variability signal

11th European Signal Processing Conference, EUSIPCO 2002 --3 September 2002 through 6 September 2002 -- --This article explores the potential of third-order statistics to analysis of heart rate variability (HRV) signal. Bispectral analysis of short-term HRV signals, obtained from a group of of healthy subjects under various experimental settings, showed the HRV activity to be located on specific bifrequency regions of the magnitude bispectrum. Nine strength measures were defined and were found to respond selectively to induced perturbation of sympathetic-vagal control of heart rate. In general the measures contained the spectral information and provided complementary information. © 2002 EUSIPCO