Skin Cancer Detection and Classification Using Neural Network Algorithms: A Systematic Review.

In recent years, there has been growing interest in the use of computer-assisted technology for early detection of skin cancer through the analysis of dermatoscopic images. However, the accuracy illustrated behind the state-of-the-art approaches depends on several factors, such as the quality of the images and the interpretation of the results by medical experts. This systematic review aims to critically assess the efficacy and challenges of this research field in order to explain the usability and limitations and highlight potential future lines of work for the scientific and clinical community. In this study, the analysis was carried out over 45 contemporary studies extracted from databases such as Web of Science and Scopus. Several computer vision techniques related to image and video processing for early skin cancer diagnosis were identified. In this context, the focus behind the process included the algorithms employed, result accuracy, and validation metrics. Thus, the results yielded significant advancements in cancer detection using deep learning and machine learning algorithms. Lastly, this review establishes a foundation for future research, highlighting potential contributions and opportunities to improve the effectiveness of skin cancer detection through machine learning.

At-sea distribution patterns of the Peruvian diving petrel Pelecanoides garnotii during breeding and non-breeding seasons.

At-sea distributions of seabird species are strongly associated with the distribution patterns of their prey, which are influenced by physical oceanic features. During breeding and non-breeding seasons, seabirds move extraordinary distances among different environments. However, foraging site fidelity by seabirds appears to be high in areas of known high productivity, such as frontal zones and upwellings. Here, we present a tracking study for the Peruvian diving-petrel Pelecanoides garnotii, an endemic seabird of the highly productive Humboldt Current System, to assess whether adults use the same foraging areas throughout the year, combining data from nest monitoring and global location sensors (GLS) deployed on 12 individuals between two breeding seasons (2013-2014 and 2014-2015), in Choros Island (29°15'S; 71°32'W), Chile. Two main foraging areas were registered. During the breeding season, adults moved in the northern direction, between 60 to 144 km away from their colony, foraging in areas with high primary productivity. During the non-breeding period, they moved to southern latitudes (~ 1200 km). Adults spent 37% and 63% of their time in flight/land and on/underwater activities, respectively. We determined that birds move northward from their colony during breeding, where prey availability seems more predictable throughout the year. However, during the non-breeding period, it is likely that other environmental factors influence the distribution pattern of the Peruvian diving-petrel.

The Subantarctic Rayadito (Aphrastura subantarctica), a new bird species on the southernmost islands of the Americas.

We describe a new taxon of terrestrial bird of the genus Aphrastura (rayaditos) inhabiting the Diego Ramírez Archipelago, the southernmost point of the American continent. This archipelago is geographically isolated and lacks terrestrial mammalian predators as well as woody plants, providing a contrasted habitat to the forests inhabited by the other two Aphrastura spp. Individuals of Diego Ramírez differ morphologically from Aphrastura spinicauda, the taxonomic group they were originally attributed to, by their larger beaks, longer tarsi, shorter tails, and larger body mass. These birds move at shorter distances from ground level, and instead of nesting in cavities in trees, they breed in cavities in the ground, reflecting different life-histories. Both taxa are genetically differentiated based on mitochondrial and autosomal markers, with no evidence of current gene flow. Although further research is required to define how far divergence has proceeded along the speciation continuum, we propose A. subantarctica as a new taxonomic unit, given its unique morphological, genetic, and behavioral attributes in a non-forested habitat. The discovery of this endemic passerine highlights the need to monitor and conserve this still-pristine archipelago devoid of exotic species, which is now protected by the recently created Diego Ramírez Islands-Drake Passage Marine Park.

Author Correction: Rapid fabrication of reinforced and cell-laden vascular grafts structurally inspired by human coronary arteries.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Rapid fabrication of reinforced and cell-laden vascular grafts structurally inspired by human coronary arteries.

Design strategies for small diameter vascular grafts are converging toward native-inspired tissue engineered grafts. A new automated technology is presented that combines a dip-spinning methodology for depositioning concentric cell-laden hydrogel layers, with an adapted solution blow spinning (SBS) device for intercalated placement of aligned reinforcement nanofibres. This additive manufacture approach allows the assembly of bio-inspired structural configurations of concentric cell patterns with fibres at specific angles and wavy arrangements. The middle and outer layers were tuned to structurally mimic the media and adventitia layers of native arteries, enabling the fabrication of small bore grafts that exhibit the J-shape mechanical response and compliance of human coronary arteries. This scalable automated system can fabricate cellularized multilayer grafts within 30 min. Grafts were evaluated by hemocompatibility studies and a preliminary in vivo carotid rabbit model. The dip-spinning-SBS technology generates constructs with native mechanical properties and cell-derived biological activities, critical for clinical bypass applications.

Assessing the effects of human activities on the foraging opportunities of migratory shorebirds in Austral high-latitude bays.

Human presence at intertidal areas could impact coastal biodiversity, including migratory waterbird species and the ecosystem services they provide. Assessing this impact is therefore essential to develop management measures compatible with migratory processes and associated biodiversity. Here, we assess the effects of human presence on the foraging opportunities of Hudsonian godwits (Limosa haemastica, a trans-hemispheric migratory shorebird) during their non-breeding season on Chiloé Island, southern Chile. We compared bird density and time spent foraging in two similar bays with contrasting disturbance levels: human presence (mostly seaweed harvesters accompanied by dogs) was on average 0.9±0.4 people per 10 ha in the disturbed bay, whereas it was negligible (95% days absent) in the non-disturbed bay. Although overall abundances were similar between bays, godwit density was higher in the non-disturbed bay throughout the low tide period. Both days after the start of the non-breeding season and tidal height significantly affected godwit density, with different effects in either bay. Time spent foraging was significantly higher in the non-disturbed bay (86.5±1.1%) than in the disturbed one (81.3±1.4%). As expected, godwit density significantly decreased with the number of people and accompanying dogs in the disturbed bay. Our results indicate that even a low density of people and dogs can significantly reduce the foraging opportunities of shorebirds. These constraints, coupled with additional flushing costs, may negatively affect godwits' pre-migratory fattening. Hence, as a first step we suggest limiting human presence within bays on Chiloé to 1 person per 10 ha and banning the presence of accompanying dogs in sensitive conservation areas.

l-NIL prevents the ischemia and reperfusion injury involving TLR-4, GST, clusterin, and NFAT-5 in mice.

On renal ischemia-reperfusion (I/R) injury, recruitment of neutrophils during the inflammatory process promotes local generation of oxygen and nitrogen reactive species, which, in turn, are likely to exacerbate tissue damage. The mechanism by which inducible nitric oxide synthase (iNOS) is involved in I/R has not been elucidated. In this work, the selective iNOS inhibitor l- N6-(1-iminoethyl)lysine (l-NIL) and the NOS substrate l-arginine were employed to understand the role of NOS activity on the expression of particular target genes and the oxidative stress elicited after a 30-min of bilateral renal ischemia, followed by 48-h reperfusion in Balb/c mice. The main findings of the present study were that pharmacological inhibition of iNOS with l-NIL during an I/R challenge of mice kidney decreased renal injury, prevented tissue loss of integrity, and improved renal function. Several novel findings regarding the molecular mechanism by which iNOS inhibition led to these protective effects are as follows: 1) a prevention of the I/R-related increase in expression of Toll-like receptor 4 (TLR-4), and its downstream target, IL-1ß; 2) reduced oxidative stress following the I/R challenge; noteworthy, this study shows the first evidence of glutathione S-transferase (GST) inactivation following kidney I/R, a phenomenon fully prevented by iNOS inhibition; 3) increased expression of clusterin, a survival autophagy component; and 4) increased expression of nuclear factor of activated T cells 5 (NFAT-5) and its target gene aquaporin-1. In conclusion, prevention of renal damage following I/R by the pharmacological inhibition of iNOS with l-NIL was associated with the inactivation of proinflammatory pathway triggered by TLR-4, oxidative stress, renoprotection (autophagy inactivation), and NFAT-5 signaling pathway.

Impaired phosphorylation of JAK2-STAT5b signaling in fibroblasts from uremic children.

BACKGROUND: Chronic kidney disease (CKD) in children is characterized by severe growth failure. The growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis in uremic animals shows a post-receptor impaired phosphorylation of Janus kinase 2/signal transducer and activator of transcription (JAK-STAT) proteins. The objective of our study was to characterize the intracellular phosphorylation of JAK-STAT signaling in fibroblasts from children with CKD on chronic peritoneal dialysis (PD). METHODS: Serum GH-binding protein (GHBP), IGF-1 and IGFBP3 were measured in 15 prepubertal CKD stage-5 children on PD. Cytoplasmic JAK2, cytoplasmic/nuclear STAT5b and nuclear IGFBP3, acid-labile subunit (ALS) and IGF-1 mRNA expression were quantified in fibroblasts obtained from skin biopsies before and after stimulation with 200 ng/ml recombinant human growth hormone (rhGH). Phosphorylation activity at both the cytoplasmic and nuclear level was expressed as the ratio phosphorylated (p)/total (t) abundance of the product (p/t) at 30 and 60 min. Fifteen healthy children were recruited as the control group. Values were expressed in arbitrary units (AU) and normalized for comparison. Significance was defined as p < 0.05. RESULTS: Thirty minutes after rhGH stimulus, the cytoplasmic (p/t) JAK2 ratio was significantly lower in patients than in controls [median and interquartile range (IQR): 7.4 (4.56) vs. 20.5 (50.06) AU]. At 60 min after rhGH stimulation, median JAK2 phosphorylation activity was still significantly lower in the patients [7.14 (IQR 3.8) vs. 10.2 (IQR 29.8) AU; p < 0.05]. The increase in the cytoplasmic (p/t) STAT5b/ß-actin ratio was lower at both measurement points in the patients compared to the controls, without reaching statistical significance between groups. Median IGFBP3 mRNA abundance was significantly decreased in fibroblasts from uremic patients 24 h after rhGH stimulation compared to the healthy controls [1.27 (IQR 0.83) vs. 2.37 (IQR 0.80) AU]. Median ALS and IGF-1 mRNA expression changed in response to rhGH stimuli at 24 and 48 h. CONCLUSION: In this study, children with CKD undergoing PD therapy showed an impaired phosphorylation of JAK2/STAT5b signaling in fibroblasts after GH stimulation, as well as impaired IGFBP3 mRNA abundance. Both impairments may be partially responsible for the observed resistance to the growth-promoting actions of GH in chronic kidney failure.

Intrauterine growth restriction modifies the normal gene expression in kidney from rabbit fetuses.

The aim of this work was to study the effect of intrauterine growth restriction (IUGR) on fetal kidneys. The IUGR was induced by uteroplacental vessels ligature in a model of pregnant rabbit. We centralized the study in the gene expression of essential proteins for fetal kidney development and kidney protection against hypoxia, osmotic stress, and kidney injury. The gene expression of HIF-1α, NFAT5, IL-1ß, NGAL, and ATM were studied by qRT-PCR and Western blot in kidneys from control and IUGR fetuses. Experimental IUGR fetuses were significantly smaller than the control animals (39 vs. 48 g, p<0.05). The number of glomeruli was decreased in IUGR kidneys, without morphological alterations. IUGR increased the gene expression of HIF-1α, NFAT5, IL-1ß, NGAL, and ATM (p<0.05) in kidneys of fetuses undergoing IUGR, suggesting that fetal blood flow restriction produce alterations in gene expression in fetal kidneys.