Impacts of Nile tilapia cage culture on water and bottom sediment quality: The ability of an eutrophic lake to absorb and dilute perturbations

Environmentally sustainable aquaculture depends on accurate understanding of the impacts of aquaculture-derived organic matter (AOM) and the ability of aquaculture systems to absorb and dilute perturbations. To this end, the present study assessed the impacts of AOM from cage culture of Nile tilapia on the ecology of Lake Victoria, Kenya, using fish cages near Anyanga Beach in Siaya County from December 2018 to October 2019. Four locations were surveyed for organic loadings from cage cultures, located 0, 50, 150 and 500 m (as a control site) away from the cages. The cage aquaculture produced increased P and N concentrations near the cages and a decreased N:P molar ratio. These changes stimulated algal growth which, in turn, affected the water quality. The organic material accumulated on the bottom under the cages, increasing the benthic BOD (BOD, >10 mg/g), a sensitive indicator of the ecological footprint of the cage aquaculture. Further, the negative ORP observed in the benthic layer suggested anoxic bacterial metabolism, possibly causing build-up of sulphides and methane. These changes altered the abundance and composition of both limnetic and benthic communities. At the beginning of the study, 22 zoobenthic taxa existed around the cages and 18 at the reference sites. Only 3 saprophilous taxa, chiefly gastropods (Physella spp.), bivalves (Sphaerium spp.) and oligochaetes (Tubifex spp.) were present at the cage site and 17 at the reference site at the end of the culture period. The Shannon diversity index exhibited a declining tendency with the length of culture period at the cage site, signifying a negative impact of aquaculture on biodiversity. The water quality recovery after cage disturbance is rapid (<4 months), noting there was no significant difference in the water quality recorded at the cage site and the other sampling sites after a fallow period of 4 months. However, the recovery of the sediment and meiofauna was far from complete at the end of this period. Moving the cages slightly (50–100 m) away from the former location may allow the benthic communities to recover and alleviate the problem. Further, the fallowing period, particularly for the Anyanga Beach site, should be extended from four to at least 5 months to allow for the environment to recover. With the rapid increase of cage fish farming in the African Great Lakes Region and with the potential for its occurrence in other lakes, there is a need to develop regulations to guide the industry, as well as the need for continuous monitoring of the environment, in order to provide information to guide investments and ensure sustainable cage farming

Arctic charr farming

The Arctic charr (Salvelinus alpinus L.) is a holarctic salmonid fish species with both landlocked and anadromous populations. In Scandinavia it is mainly found in the mountain area, but it also appears in deep and large lake further south, i.e. in the Alps. It is the northernmost freshwater fish and A. charr is generally regarded as the most cold-adapted freshwater fish. A. charr has been commercially farmed since the early 90ths and today, the total production is 3000, 2300 and 700 tonnes/year in Iceland, Sweden and Norway, respectively. Both in Sweden and Iceland, there are selective breeding programs in effect and the bulk of the farming production is conducted using offspring from the national breeding programs in each country. A. charr is renowned for its ability of high growth rate at low temperature and is therefore especially suitable for farming at high latitudes and altitudes. Moreover, due to the success of the breeding programs, the charr used in farms today grow faster and mature at a larger size and age than the original wild charr. Hence, although being a fairly small industry at present, A. charr farming is predicted to grow in all three countries. This booklet summarises up-to-date knowledge on A. charr farming production cycle, from brood stock to juvenile on-growing stage (Fig. 1). It is intended to be useful for people taking their first steps in A. charr culture but also to serve as a farming manual for more experienced farm staff. Therefore, the booklet is divided in to two chapters. The first chapter (Arctic charr farming in practice) provides a straight forward introduction to each production step from brood stock to juveniles. The second chapter (theory and background) presents some details and research data on the background of specific farming practices and procedures

NANS-CDG: Delineation of the Genetic, Biochemical, and Clinical Spectrum.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadBackground: NANS-CDG is a recently described congenital disorder of glycosylation caused by biallelic genetic variants in NANS, encoding an essential enzyme in de novo sialic acid synthesis. Sialic acid at the end of glycoconjugates plays a key role in biological processes such as brain and skeletal development. Here, we present an observational cohort study to delineate the genetic, biochemical, and clinical phenotype and assess possible correlations. Methods: Medical and laboratory records were reviewed with retrospective extraction and analysis of genetic, biochemical, and clinical data (2016-2020). Results: Nine NANS-CDG patients (nine families, six countries) referred to the Radboudumc CDG Center of Expertise were included. Phenotyping confirmed the hallmark features including intellectual developmental disorder (IDD) (n = 9/9; 100%), facial dysmorphisms (n = 9/9; 100%), neurologic impairment (n = 9/9; 100%), short stature (n = 8/9; 89%), skeletal dysplasia (n = 8/9; 89%), and short limbs (n = 8/9; 89%). Newly identified features include ophthalmological abnormalities (n = 6/9; 67%), an abnormal septum pellucidum (n = 6/9; 67%), (progressive) cerebral atrophy and ventricular dilatation (n = 5/9; 56%), gastrointestinal dysfunction (n = 5/9; 56%), thrombocytopenia (n = 5/9; 56%), and hypo-low-density lipoprotein cholesterol (n = 4/9; 44%). Biochemically, elevated urinary excretion of N-acetylmannosamine (ManNAc) is pathognomonic, the concentrations of which show a significant correlation with clinical severity. Genotypically, eight novel NANS variants were identified. Three severely affected patients harbored identical compound heterozygous pathogenic variants, one of whom was initiated on experimental prenatal and postnatal treatment with oral sialic acid. This patient showed markedly better psychomotor development than the other two genotypically identical males. Conclusions: ManNAc screening should be considered in all patients with IDD, short stature with short limbs, facial dysmorphisms, neurologic impairment, and an abnormal septum pellucidum +/- congenital and neurodegenerative lesions on brain imaging, to establish a precise diagnosis and contribute to prognostication. Personalized management includes accurate genetic counseling and access to proper supports and tailored care for gastrointestinal symptoms, thrombocytopenia, and epilepsy, as well as rehabilitation services for cognitive and physical impairments. Motivated by the short-term positive effects of experimental treatment with oral sialic, we have initiated this intervention with protocolized follow-up of neurologic, systemic, and growth outcomes in four patients. Research is ongoing to unravel pathophysiology and identify novel therapeutic targets.European Reference Network for Rare Neurological Disease

Rare variants with large effects provide functional insights into the pathology of migraine subtypes, with and without aura

Publisher Copyright: © 2023, The Author(s).Migraine is a complex neurovascular disease with a range of severity and symptoms, yet mostly studied as one phenotype in genome-wide association studies (GWAS). Here we combine large GWAS datasets from six European populations to study the main migraine subtypes, migraine with aura (MA) and migraine without aura (MO). We identified four new MA-associated variants (in PRRT2, PALMD, ABO and LRRK2) and classified 13 MO-associated variants. Rare variants with large effects highlight three genes. A rare frameshift variant in brain-expressed PRRT2 confers large risk of MA and epilepsy, but not MO. A burden test of rare loss-of-function variants in SCN11A, encoding a neuron-expressed sodium channel with a key role in pain sensation, shows strong protection against migraine. Finally, a rare variant with cis-regulatory effects on KCNK5 confers large protection against migraine and brain aneurysms. Our findings offer new insights with therapeutic potential into the complex biology of migraine and its subtypes.Peer reviewe

Meðfædd bogfrymlasótt : tvö nýgreind sjúkratilfelli

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenTwo girls with congenital toxoplasmosis are described. This is a rare disease in Iceland. The patients both had signs of chorioretinitis and cerebral calcifications and were treated with combination therapy of pyrimethamine, sulfonamide and folinic acid, alternating with spiramycin. The importance of preventive measures against toxoplasma infection is discussed with special emphasis on pregnant women.Greint er frá tveimur stúlkum með meðfædda bogfrymlasótt. Fjallað er um lífsferil og smitleiðir bogfrymla, tíðni, einkenni, greiningu og meðferð sjúkdómsins svo og fyrirbyggjandi aðgerðir. Tilgangurinn með skrifum þessum er að vekja athygli á, að meðfædd bogfrymlasótt (toxoplasmosis congenita) er til á Íslandi. Forvarnir, einkum fræðsla fyrir ófrískar konur, eru einfaldasta og hagkvæmasta leiðin til að stemma stigu við þessum sjúkdómi

Sjúkdómur Menetrier í börnum

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenA 21/2 year old boy with Menetrier's disease is described. Clinical symptoms included fatique, loss of appetite and peripheral edema. Hypoalbuminaemia without proteinuria was present. These findings abated within 2 weeks and X-ray changes (hypertrophy of gastric mucosa) within 3 months. Different presentation and prognosis of Menetrier's disease in children versus adults is discussed.Hér er fjallað urn ungan dreng rneð sjúkdóm Menetrier sem greindur var á barnadeild Landakotsspítala. Drengurinn er, að því best er vitað, fyrsta barnið sem greint er með sjúkdóm Menetrier hér á landi. Árið 1981 var þó annar sjúklingur á sömu deild sterklega grunaður um þennan sjúkdóm. Einkenni, breytingar á röntgenmynd og gangur voru dæmigerð, en stórsætt (macroscopic) og smásætt (microscopic) útlit benti hins vegar ekki til sjúkdóms Menetrier

Meðfædd bogfrymlasótt : tvö nýgreind sjúkratilfelli

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenTwo girls with congenital toxoplasmosis are described. This is a rare disease in Iceland. The patients both had signs of chorioretinitis and cerebral calcifications and were treated with combination therapy of pyrimethamine, sulfonamide and folinic acid, alternating with spiramycin. The importance of preventive measures against toxoplasma infection is discussed with special emphasis on pregnant women.Greint er frá tveimur stúlkum með meðfædda bogfrymlasótt. Fjallað er um lífsferil og smitleiðir bogfrymla, tíðni, einkenni, greiningu og meðferð sjúkdómsins svo og fyrirbyggjandi aðgerðir. Tilgangurinn með skrifum þessum er að vekja athygli á, að meðfædd bogfrymlasótt (toxoplasmosis congenita) er til á Íslandi. Forvarnir, einkum fræðsla fyrir ófrískar konur, eru einfaldasta og hagkvæmasta leiðin til að stemma stigu við þessum sjúkdómi

Nationwide Incidence of Acquired Central Nervous System Demyelination in Icelandic Children.

To access publisher's full text version of this article click on the hyperlink at the bottom of the pageRecognizing acquired demyelinating syndromes and multiple sclerosis is important to commence early treatment. The objective of this study was to describe the incidence of acquired demyelinating syndromes and multiple sclerosis among the entire Icelandic pediatric population according to recently promoted criteria.The study included all children in Iceland (<18 years) with acquired demyelinating syndromes and multiple sclerosis from 1990 to 2009 with a minimum of 5-year follow-up. Clinical data were gathered and radiological images reviewed. The cohort included all patients with acquired demyelinating syndromes and multiple sclerosis in the Icelandic pediatric population.Eighteen patients with acquired demyelinating syndromes and multiple sclerosis were included, the total annual incidence being 1.15/100,000 (acquired demyelinating syndromes 1.02 and multiple sclerosis 0.45/100,000). The median age at diagnosis was 14.25 years (range 1.25-17.5 years). Thirteen patients were initially diagnosed with clinically isolated syndrome, two had acute disseminated encephalomyelitis, two had multiple sclerosis, and one had neuromyelitis optica. Seven children were diagnosed with multiple sclerosis; three patients with clinically isolated syndrome developed multiple sclerosis after the age of 18 and were not included in the multiple sclerosis group. The gender ratio was equal. Of the nine girls, seven were diagnosed with clinically isolated syndrome. Most patients (11 of 18) were diagnosed during the period January through March. Oligoclonal bands in cerebrospinal fluid were exclusively found in patients with multiple sclerosis and clinically isolated syndrome and 13 of 14 available magnetic resonance images revealed clear abnormalities.The annual incidence of acquired demyelinating syndromes and multiple sclerosis in Iceland was 1.15/100,000 children. The risk of progression from clinically isolated syndrome to multiple sclerosis was high. There was no female preponderance

A comparative study of the effects of pelleted and extruded feed on growth, financial revenue and nutrient loading of Nile tilapia (Oreochromis niloticus L.) cage culture in a lacustrine environment

We compared the benefits of using extruded feed (EF), against pelleted feed (PF) to guide cage culture investments in Great Lakes. Three out of six cages in the same farm had fish that were fed EF and the other half, belonging to a different farm had fish that were fed PF. The diets were similar in crude protein, lipid and energy content. However, the fiber content in PF was 4 times higher than that of EF. The fish fed on EF grew better (438.0 ± 7.4 g) than the fish fed on PF (220.8 ± 2.9 g). The cost of production for EF was about 26% lower than for PF, primarily because of better feed utilization. The load of P and N for PF diet was 59% and 29% higher, respectively, than when EF was used. Therefore, EF feed delivered better economic gains with lower environmental impact than PF feed