There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

Flatfi shes are very accessible in the wild and hardy in the laboratory, thus many of the early studies of fi sh growth used fl atfi shes, especially plaice (Pleuronectes platessa) in the Atlantic and a number of species in the Pacifi c. As the science of fi sheries developed, so did the need to quantify the population structure and growth characteristics of the different fl atfi sh species. In fact, the importance of ageing fi shes and determining their growth rate was realised early in the last century (Allen 1916). Much of the early information on the aging and growth of fl atfi shes (primarily plaice) is referenced in Wimpenny (1953), Graham (1956) and Beverton & Holt (1957). Prior to the 1950s researchers had gained a fairly good understanding of the methods. A clear pattern of summer and winter growth was recognised in the otoliths, which were fi rst used in the late 1800s. Other bony structures such as opercular bones, the pectoral girdle and the concave faces of the vertebrae exhibited seasonal growth patterns (Cunningham 1905) but these were not as distinctive as those on the otoliths. The observation that a pair of rings may not delimit 1 year’s growth led to early verifi cation studies based on marginal increment analyses. Experimental work on plaice and fl ounder (Platichthys fl esus) showed that the seasonal pattern on both otoliths and scales was primarily driven by seasonal changes in water temperature rather than by variations in food availability. The use of otoliths for age estimation of fl atfi shes was not universal. Species differences slowly became apparent and methodological refi nements followed. Direct measurements of the growth of fl atfi shes were afforded by series of tagging and transplantation experiments, and laboratory or enclosure experiments (Johnstone et al. 1921). In all cases it was apparent that there was considerable variability in individual growth rates and that growth rates varied between areas. The widespread sexual dimorphism in growth with females growing faster and reaching larger sizes than males was also recognised (e.g. Johnstone et al. 1921; Bigelow & Schroeder 1953; Bagenal, 1955). The effects of gear selectivity and ontogenetic behavioural changes of fl atfi shes on the accurate estimation of age structure and growth rates were recognised, especially with the offshore movement of larger juvenile plaice from the nursery grounds and a general offshore movement with size and age. The possibility that fi shing pressure could make major changes to the age structure and growth of commercially exploited fl atfi sh populations was mentioned by Jones (1958), citing the prevalence of Rosa Lee’s phenomenon in plaice.

https://folk.uib.no/nfiag/nfiag/reprints/chapter7.pdf

Age and Growth

Artificial intelligence (AI) algorithms, particularly deep learning, have demonstrated remarkable progress in image-recognition tasks. Methods ranging from convolutional neural networks to variational autoencoders have found myriad applications in the medical image analysis field, propelling it forward at a rapid pace. Historically, in radiology practice, trained physicians visually assessed medical images for the detection, characterization and monitoring of diseases. AI methods excel at automatically recognizing complex patterns in imaging data and providing quantitative, rather than qualitative, assessments of radiographic characteristics. In this Opinion article, we establish a general understanding of AI methods, particularly those pertaining to image-based tasks. We explore how these methods could impact multiple facets of radiology, with a general focus on applications in oncology, and demonstrate ways in which these methods are advancing the field. Finally, we discuss the challenges facing clinical implementation and provide our perspective on how the domain could be advanced.

/pdf/artificial-intelligence-in-radiology-2c2bdk1z41.pdf

Artificial intelligence in radiology

Hypertension is the major controllable risk factor associated with cardiovascular disease (CVD) events such as myocardial infarction, stroke, heart failure, and end-stage diabetes. A 5 mm Hg decrease in blood pressure has been equated with approximately 16% decrease in CVD. In the U.S. alone current annual antihypertensive drug costs are approximately dollars 15 billion. The renin-angiotensin-aldosterone system is a target for blood pressure control. Cleavage of angiotensinogen by renin produces angiotensin I which is subsequently hydrolyzed by angiotensin-I-converting enzyme (ACE) to angiotensin II (a potent vasoconstrictor). Various side effects are associated with the use of ACE inhibitory drugs in the control of blood pressure including hypotension, increased potassium levels, reduced renal function, cough, angioedema, skin rashes, and fetal abnormalities. Milk proteins, both caseins and whey proteins, are a rich source of ACE inhibitory peptides. Several studies in spontaneously hypertensive rats show that these casokinins and lactokinins can significantly reduce blood pressure. Furthermore, a limited number of human studies have associated milk protein-derived peptides with statistically significant hypotensive effects (i.e., lower systolic and diastolic pressures). The advent of effective milk protein based functional food ingredients/nutraceuticals for the prevention/control of blood pressure therefore has the potential to significantly reduce global healthcare cost.

/pdf/hypotensive-peptides-from-milk-proteins-2zo0q38924.pdf

Hypotensive Peptides from Milk Proteins

Bioactive peptides from marine processing waste and shellfish: A review

Numerous casein and whey protein-derived angiotensin-I-converting enzyme (ACE) inhibitory peptides/hydrolysates have been identified. Clinical trials in hypertensive animals and humans show that these peptides/hydrolysates can bring about a significant reduction in hypertension. These peptides/hydrolysates may be classified as functional food ingredients and nutraceuticals due to their ability to provide health benefits i.e. as functional food ingredients in reducing the risk of developing a disease and as nutraceuticals in the prevention/treatment of disease.

/pdf/milk-protein-derived-peptide-inhibitors-of-angiotensin-i-3omm4yntpa.pdf

Milk protein-derived peptide inhibitors of angiotensin-I-converting enzyme.

Food proteins contain latent biofunctional peptide sequences within their primary structures which may have the ability to exert a physiological response in vivo. A large range of biofunctional peptides have been isolated from food proteins including opioid, immunomodulatory, antimicrobial, mineral binding, growth and muscle stimulating, anti-cancer, proteinase and angiotensin converting enzyme (ACE, EC 3.4.15.1) inhibitory peptides. The biofunctional peptide activity currently most studied in food proteins appears to be those that inhibit ACE. ACE plays a central role in the regulation of blood pressure (BP) through the production of the potent vasoconstrictor, angiotensin (Ang) II , and the degradation of the vasodilator, bradykinin (BK). ACE inhibitory peptides may therefore have the ability to lower BP in vivo by limiting the vasoconstrictory effects of Ang II and by potentiating the vasodilatory effects of BK. These ACE inhibitory peptides can be enzymatically released from intact proteins in vitro and in vivo during food processing and gastrointestinal digestion, respectively. ACE inhibitory peptides may be generated in or incorporated into functional foods in the development of 'natural' beneficial health products. Several products are currently on the market or are in development that contain peptide sequences which have ACE inhibitory properties. Detailed human studies are required in order to demonstrate the efficacy of these bioactive peptides prior to their widespread utilisation as physiologically beneficial functional foods/food ingredients.

Angiotensin converting enzyme inhibitory peptides derived from food proteins: biochemistry, bioactivity and production.

The protein fraction of milk contains many valuable components and biologically active substances. Moreover, milk proteins are precursors of many different biologically active peptides which are inactive within the sequence of the precursor protein but can be released by enzymatic proteolysis. Many milk protein-derived peptides, such as caseinophosphopeptides, reveal multi-functional bioactivities. Caseinophosphopeptides can form soluble organophosphate salts and may function as carriers for different minerals, especially calcium. Furthermore, they have been shown to exert cytomodulatory effects. Cytomodulatory peptides inhibit cancer cell growth or they stimulate the activity of immunocompetent cells and neonatal intestinal cells, respectively. Several bioactive peptides derived from milk proteins are potential modulators of various regulatory processes in the body and thus may exert beneficial physiological effects. Caseinophosphopeptides are already produced on an industrial-scale and as a consequence these peptides have been considered for application as ingredients in both 'functional foods' and pharmaceutical preparations. Although the physiological significance as exogenous regulatory substances is not yet fully understood, both mineral binding and cytomodulatory peptides derived from bovine milk proteins are claimed to be health enhancing components that can be used to reduce the risk of disease or to enhance a certain physiological function.

Richard J. FitzGerald

Papers

Hypotensive Peptides from Milk Proteins

Bioactive peptides from marine processing waste and shellfish: A review

Milk protein-derived peptide inhibitors of angiotensin-I-converting enzyme.

Angiotensin converting enzyme inhibitory peptides derived from food proteins: biochemistry, bioactivity and production.

Biofunctional peptides from milk proteins: mineral binding and cytomodulatory effects.