A survey of shape variation in keratinized labial teeth of anuran larvae as related to phylogeny and ecology

Labial teeth of anuran tadpoles are keratinized structures derived from the activity of a single epidermal cell of the oral labia; they are not homologous with adult anuran teeth, nor with teeth of other vertebrates. The present study comprises a first approach for studying labial tooth shape variation that will be useful for future studies of comparative development and the functional mechanics of feeding structures. We examined interspecific shape variations in the labial teeth of anuran tadpoles and searched for correlations of these variations with ecomorphological guilds and phylogeny. Species ordination shows that important variations at various taxonomic levels are related mainly to the general curvature of the tooth axis, the angle between the labial tooth base and tip, head length and curvature, and sheath width. The teeth of most basal taxa are broad‐based and curved, although some broad‐based teeth also characterize some phthanobatrachian species. Teeth of hyloids and ranoids differ in the oral angle, overall curvature, and sheath width. A phylogenetically independent ecomorphological effect is significant only for lotic suctorial and gastromyzophorous guilds; teeth in these forms have short, thick and curved heads, wide sheaths, and generally acute oral angles. The lack of a significant correlation between labial tooth shape and trophic guilds suggests that labial tooth harvesting ability has a wide latitude that could be particularly functional only under specific circumstances. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 609–625.     

Saturated fatty acids dampen the immunogenicity of cancer by suppressing STING

1. Download : Download high-res image (195KB)
2. Download : Download full-size image

     

Application of radiomics and machine learning in head and neck cancers

With the continuous development of medical image informatics technology, more and more high-throughput quantitative data could be extracted from digital medical images, which has resulted in a new kind of omics-Radiomics. In recent years, in addition to genomics, proteomics and metabolomics, radiomic has attracted the interest of more and more researchers. Compared to other omics, radiomics can be perfectly integrated with clinical data, even with the pathology and molecular biomarker, so that the study can be closer to the clinical reality and more revealing of the tumor development. Mass data will also be generated in this process. Machine learning, due to its own characteristics, has a unique advantage in processing massive radiomic data. By analyzing mass amounts of data with strong clinical relevance, people can construct models that more accurately reflect tumor development and progression, thereby providing the possibility of personalized and sequential treatment of patients. As one of the cancer types whose treatment and diagnosis rely on imaging examination, radiomics has a very broad application prospect in head and neck cancers (HNC). Until now, there have been some notable results in HNC. In this review, we will introduce the concepts and workflow of radiomics and machine learning and their current applications in head and neck cancers, as well as the directions and applications of artificial intelligence in the treatment and diagnosis of HNC.     

Role of helmet in the mechanics of shock wave propagation under blast loading conditions

The effectiveness of helmets in extenuating the primary shock waves generated by the explosions of improvised explosive devices is not clearly understood. In this work, the role of helmet on the overpressurisation and impulse experienced by the head were examined. The shock wave–head interactions were studied under three different cases: (i) unprotected head, (ii) head with helmet but with varying head–helmet gaps and (iii) head covered with helmet and tightly fitting foam pads. The intensification effect was discussed by examining the shock wave flow pattern and verified with experiments. A helmet with a better protection against shock wave is suggested.     

Scanning electron microscopy on Parascaris equorum (Goeze, 1782), Yorke and Maplestone, 1926

Research on Ascaridinae from African zebra and zebra living in Vincennes zoological garden (Paris) and those from horses confirmed that they all belong to the same parasite, Parascaris equorum (Goeze, 1782), Yorke &; Maplestone, 1926. Study by scanning electron microscopy permitted greater precision in investigation of various formations: denticules along the peribuccal groove, sinuses separating eulabium from prelabium, intrabuccal sockets.     

Constructional morphology within the head of hammerhead sharks (sphyrnidae)

The study of functional trade‐offs is important if a structure, such as the cranium, serves multiple biological roles, and is, therefore, shaped by multiple selective pressures. The sphyrnid cephalofoil presents an excellent model for investigating potential trade‐offs among sensory, neural, and feeding structures. In this study, hammerhead shark species were chosen to represent differences in head form through phylogeny. A combination of surface‐based geometric morphometrics, computed tomography (CT) volumetric analysis, and phylogenetic analyses were utilized to investigate potential trade‐offs within the head. Hammerhead sharks display a diversity of cranial morphologies where the position of the eyes and nares vary among species, with only minor changes in shape, position, and volume of the feeding apparatus through phylogeny. The basal winghead shark, Eusphyra blochii, has small anteriorly positioned eyes. Through phylogeny, the relative size and position of the eyes change, such that derived species have larger, more medially positioned eyes. The lateral position of the external nares is highly variable, showing no phylogenetic trend. Mouth size and position are conserved, remaining relatively unchanged. Volumetric CT analyses reveal no trade‐offs between the feeding apparatus and the remaining cranial structures. The few trade‐offs were isolated to the nasal capsule volume's inverse correlation with braincase, chondrocranial, and total cephalofoil volume. Eye volume also decreased as cephalofoil width increased. These data indicate that despite considerable changes in head shape, much of the head is morphologically conserved through sphyrnid phylogeny, particularly the jaw cartilages and their associated feeding muscles, with shape change and morphological trade‐offs being primarily confined to the lateral wings of the cephalofoil and their associated sensory structures. J. Morphol. 276:526–539, 2015. © 2015 Wiley Periodicals, Inc.     

A decimal code describing the developmental stages of head cabbage (Brassica oleracea var. capitata)

The developmental stages of head cabbage (Brassica oleracea var. capitata) as a vegetable have been characterised by a decimal code. Five primary stages are recognised: germination, emergence and establishment, leaf formation, head formation and maturity. Each primary stage is divided into secondary stages, which apply both to single plants and to crops. Maturity is defined as the head having obtained a marketable weight and density. The standing ability is defined as the number of days from 90% of the crop being marketable to 25% of the crop having become unmarketable.     

Assessment of the exposure to WLAN frequencies of a head model with a cochlear implant

In the last few years, significant developments have taken place in the field of Wireless Local Area Networks (WLAN), and the popularity of portable devices supporting Wireless Fidelity (Wi‐Fi) is continuously growing. At the same time, the number of Active Implanted Medical Devices (AIMD) being placed in patients is widely increasing and among them, cochlear implants (CI) are becoming a common aid. The goal of this study is to investigate the effect on the electromagnetic field distribution and the specific absorption rate (SAR) due to the presence of a CI in a head model during far‐field exposure to Wi‐Fi frequencies. The head model was obtained by image segmentation, the implant was modelled as a geometric structure, and the exposure sources were modelled as a uniform plane wave (power density = 10 W/m²) at 2.4, 5.2 and 5.8 GHz. Vertical and horizontal polarizations were simulated. Conditions with and without CI were compared. The findings of that are: (1) local differences in the field distribution close to the CI, comparing the head models with or without the CI; (2) higher field strength and point SAR value in the cochlear region very close to the CI; (3) negligible differences in the field strength and point SAR value in the cochlear region far from the CI; (4) negligible variations in the average SAR values in the cochlea and head due to the presence of the CI. The results of this study conclude that insertion of a CI brings moderate localized differences in the E, H and point SAR distribution when evaluated close to the electrode array in the cochlea, while negligible differences are found in the average SAR values both in the cochlea and head, independent of frequency and wave polarization. Bioelectromagnetics 31:546–555, 2010. © 2010 Wiley‐Liss, Inc.