Hair removal methods: A comparative study for dermoscopy images

Removal and restoration of hair and hair-like regions within skin lesion images is needed so features within lesions can be more effectively analyzed for benign lesions, cancerous lesions, and for cancer discrimination. This paper refers to “melanoma texture” as a rationale for supporting the need for the proposed hair detection and repair techniques, which incompletely represents why hair removal is an important operation for skin lesion analysis. A comparative study of the state-of-the-art hair-repaired methods with a novel algorithm is also proposed by morphological and fast marching schemes. The hair-repaired techniques are evaluated in terms of computational, performance and tumor-disturb patterns (TDP) aspects. The comparisons have been done among (i) linear interpolation, inpainting by (ii) non-linear partial differential equation (PDE) and (iii) exemplar-based repairing techniques. The performance analysis of hair detection quality, was based on the evaluation of the hair detection error (HDE), quantified by statistical metrics and manually used to determine the hair lines from a dermatologist as the ground truth. The results are presented on a set of 100 dermoscopic images. For the two characteristics measured in the experiments the best method is the fast marching hair removal algorithm (HDE: 2.98%, TDP: 4.21%). This proposed algorithm repaired the texture of the melanoma, which becomes consistent with human vision. The comparisons results obtained, indicate that hair-repairing algorithm based on the fast marching method achieve an accurate result.     

A comparative study of preservation and storage of Haemophilus influenzae

The aim of this study was to compare the efficacy of conservation by freezing the strains of Haemophilus influenzae at -20 degrees C and -70 degrees C. Skim milk supplemented with glucose, yeast extract and glycerol allowed highest viability of H. influenzae both at -20 degrees C and -70 degrees C from the media analyzed. Trypticase soy broth and brain heart infusion broth supplemented with glycerol, allowed excellent recovery. Use of cotton swaps as supporting material, with or without addition of cryoprotective agents, did not modify H. influenzae viability after six months of storage. Concentration of the initial inoculum positively affected viability when stored at -20 degrees C. Initial concentration did not influence survival after storage at -70 degrees C. Thawing at room temperature should not exceed 3 h as to get highest survival percentage.     

Numbers and size of sperm storage tubules and the duration of sperm storage in birds: a comparative study

Estimates of the numbers of sperm storage tubules (SSTs) in the utero-vaginal junction of 11 bird species are presented. Numbers of SSTs varied by a factor of 40 between species, and ranged from 500 to 20000. Body mass accounted for over 50% of the variation in SST mumbers. SST length was positively correlated with the length of spermatozoa across species. The duration of sperm storage was not correlated with the number of SSTs or the volume of sperm storage tissue. However, the number of 'active' SSTs appears to vary between species and it was not possible to make allowance for this. Sperm storage duration was weakly, positively correlated wth clutch size, but showed a significant positive relationship with the number of days over which laying occurred. The number of SSTs was also positively correlated with the number of sperm per ejaculate. The best predictor of sperm storage duration was a multiple regression equation using the spread of laying and the length of sperm storage tubules. The duration of sperm storage in birds which remain together during the pre-laying period is such that a single insemination immediately before the start of laying could fertilize the entire clutch.     

Evaluation of texture features in spatial and frequency domain for automatic discrimination of histologic tissue

OBJECTIVE: To investigate the applicability of different texture features in automatic discrimination of microscopic views from benign common nevi and malignant melanoma lesions. STUDY DESIGN: In tissue counter analysis (TCA) the images are dissected into square elements used for feature calculation. The first class of features is based on the histogram, the co-occurrence matrix and the texture moments. The second class is derived from spectral properties of the wavelet Daubechie 4 and the Fourier transform. Square elements from images of a training set are classified by Classification and Regression Trees analysis. RESULTS: Features from the histogram and the co-occurrence matrix enable correct classification of 94.7% of nevi elements and 92.6% of melanoma elements in the training set. Classification results are applied to individual test set cases. Discriminant analysis based on the percentage of "malignant elements" showed correct classification of all nevi cases and 95% of melanoma cases. Features derived from the wavelet and Fourier spectrum showed correct results for 88.8% and 79.3% of nevi and 85.6% and 81.5% of melanoma elements, respectively. CONCLUSION: TCA is a potential diagnostic tool in automatic analysis of melanocytic skin tumors. Histogram and co-occurrence matrix features are superior to the wavelet and the Fourier features.     

A comparative and phylogenetic analysis of the alpha-actinin rod domain

Alpha-actinin is a ubiquitous actin-binding protein, composed of 3 domains; an actin-binding domain and a calcium-binding domain at the termini, connected by a rod domain composed by 1, 2, or 4 spectrin repeats (SRs). To understand how the rod domain has evolved during evolution, we have analyzed and compared the amino acid residue heterogeneity and phylogeny of the SRs of alpha-actinins of vertebrates, invertebrates, fungi, and several protozoa. The repeats of vertebrate alpha-actinins show a high degree of similarity, whereas repeats of invertebrates, fungi, and, in particular, of protozoa are more divergent. In the phylogeny, SR1 of all species were clustered together, independent of the number of repeats in the protein. It was also obvious that the second and last repeat in fungi (SR2) grouped with the fourth and last repeat of vertebrates and invertebrates (SR4). Therefore, the phylogeny implied that the rod domain of the cenancestral alpha-actinin only contained one SR. It was also obvious that SR2 of fungi are related to SR4 of vertebrates and invertebrates, implying that in the second intragenic duplication 2 repeats (i.e., what become SR2 and SR3) were inserted between the initial 2 repeats that become SR1 and SR4.     

A comparative study of convicilin storage protein gene sequences in species of the tribe Vicieae.

Convicilins, a set of seed storage proteins, differ from vicilins, a related group of seed storage proteins, mainly because of the presence of the N-terminal extension, an additional sequence of amino acids in the sequence corresponding to the first exon. Convicilins have been described only in species of the legume tribe Vicieae. One or two genes for convicilins have been identified in most species of this tribe. The genus Pisum is the main exception, since two genes have been identified in most of its species. Thirty-four new convicilin gene sequences from 29 different species (Lathyrus, Lens, Pisum, and Vicia spp.) have been analyzed here. Convicilin gene sequences are generally organized in 6 exons, but in some instances one of the internal introns (2nd or 4th) is lost. In these 29 species, the N-terminal extension is formed by a stretch of 99 to 196 amino acids particularly rich in polar and charged amino acids (on average, it contains 29.43% glutamic acid and 15.38% arginine residues). This N-terminal extension has the characteristics of an intrinsically unstructured region (IUR), one of the categories of protein "degenerate sequences". A comparative analysis indicates that the N-terminal extension sequence has evolved faster than the surrounding sequence, which is common to all vicilins, and it evolved mainly through a series of duplications of short internal sequences and triplet expansions, the predominant one being GAA. This agrees with the evolution of IURs, which is faster than the evolution of surrounding sequences and is mainly due to replication slippage and unequal crossover recombination. Alternative maximum-likelihood trees of phylogenetic relationships among the 29 Vicieae species based on the convicilin exon sequences are presented and discussed.     

A method of nonlinear analysis in the frequency domain.

A method is developed for the analysis of nonlinear biological systems based on an input temporal signal that consists of a sum of a large number of sinusoids. Nonlinear properties of the system are manifest by responses at harmonics and intermodulation frequencies of the input frequencies. The frequency kernels derived from these nonlinear responses are similar to the Fourier transforms of the Wiener kernels. Guidelines for the choice of useful input frequency sets, and examples satisfying these guidelines, are given. A practical algorithm for varying the relative phases of the input sinusoids to separate high-order interactions is presented. The utility of this technique is demonstrated with data obtained from a cat retinal ganglion cell of the Y type. For a high spatial frequency grafting, the entire response is contained in the even-order nonlinear components. Even at low contrast, fourth-order components are detectable. This suggests the presence of an essential nonlinearity in the functional pathway of the Y cell, with its singularity at zero contrast.     

Wildfire spatial pattern analysis in the Zagros Mountains,Iran: A comparative study of decision tree based classifiers

Knowledge of wildfire behavior is of key importance for planning and allocating resources to fire suppression efforts. In this study, we analyzed the spatial pattern of wildfires with five decision tree based classifiers, including alternating decision tree (ADT), classification and regression tree (CART), functional tree (FT), logistic model tree (LMT), and Naïve Bayes tree (NBT). The classifiers were trained using historical fire locations in the Zagros Mountains (Iran) from the years 2007–2014 and a set of fifteen explanatory variables (i.e., slope degree, aspect, altitude, plan curvature, topographic position index (TPI), topographic roughness index (TRI), topographic wetness index (TWI), mean annual temperature and rainfall, wind effect, soil type, land use, and proximity to settlements, roads, and rivers) that were first optimized with a twostep process using multicollinearity analysis and the Gain Ratio variable selection method. The classifiers were then validated using the Kappa index and several statistical index-based evaluators (i.e., accuracy, sensitivity, specificity, precision, and F-measure). The global performance of the classifiers was measured using the ROC-AUC method. In this comparative study, the ADT classifier demonstrated the highest performance both in terms of goodness-of-fit with the training dataset (accuracy = 99.8%, AUC = 0.991) and the capability to predict future wildfires (accuracy = 75.7%, AUC = 0.903). This study contributes to the suite of research that evaluates data mining methods for the prediction of natural hazards.     

A comparative study of the effects of freezing and frozen storage on intact and demembranated bull spermatozoa

The damage caused to bull sperm by freezing and thawing them without cryoprotectants was assessed in both intact and membrane-extracted cells. Preparations of membrane-extracted cells were produced by treating the sperm with 0.1% Triton X-100 and motility was restored with exogenously applied ATP and Mg²⁺. Motile demembranated sperm showed no detectable reduction in motility after freezing and thawing. In contrast, when intact cells where subjected to freezing and thawing they lost all motility. These damaged cells were also restored to motility when exogenous ATP and Mg²⁺ were added to the sperm mixture. Apparently freezing and thawing sperm cells causes damage to the plasma membrane which permits ATP and Mg²⁺ to freely enter or leave the cells, but does not damage the components of the sperm cell which generate motility.The effects of storage temperature on frozen demembranated sperm were also explored. Sperm held at ?20 °C showed marked structural changes and progressively decreased motility after prolonged storage. When sperm were frozen at ?20 °C the mitochondrial structures were completely lost after 48 to 72 hr and ATP caused the disintegration of the flagellum rather than initiating motility. Sperm which were frozen at ?76 °C retained motility after short periods of storage, but showed a significant decline in motility when thawed after 8 days. Demembranated sperm which were kept frozen at ?196 °C showed no significant loss of motility when thawed after 1 year of storage.     

MedataWeb: A shared platform for multimodality medical images and Atlases

Computer-assisted medical interventions and treatment planning have known an increasing interest and research activity in different fields and applications. However, before the routine deployment of these procedures becomes a reality, in vivo and in silico validations must be undertaken. This paper describes a platform containing multimodality medical images and atlases useful for algorithms evaluation, comparison and validation. The platform contains des-identified data (images, contours and atlases) from the ProstateAtlas and ProstateWeb project: the first morphological and zonal atlas of the prostate, and from clinical data of lymphoma PET (PETWeb). Data are available at the URL: http://www.medataweb.U703.net.     

Uncovering interactions in the frequency domain

Oscillatory activity plays a critical role in regulating biological processes at levels ranging from subcellular, cellular, and network to the whole organism, and often involves a large number of interacting elements. We shed light on this issue by introducing a novel approach called partial Granger causality to reliably reveal interaction patterns in multivariate data with exogenous inputs and latent variables in the frequency domain. The method is extensively tested with toy models, and successfully applied to experimental datasets, including (1) gene microarray data of HeLa cell cycle; (2) in vivo multi-electrode array (MEA) local field potentials (LFPs) recorded from the inferotemporal cortex of a sheep; and (3) in vivo LFPs recorded from distributed sites in the right hemisphere of a macaque monkey.     

Predatory behavior in the genusLeptogenys: A comparative study

We studied the predatory behavior of seven species of the genusLeptogenys from Mexico and Cameroon. The ants of this genus are armed with long, thin, curved mandibles articulated at the extreme corners of the anterior margin of the head, permitting them easily to seize oniscoid isopods, the obligate or the principal prey of mostLeptogenys species. Workers hunt these prey, which are able to roll themselves up, solitarily. Foraging behavior comprises sequences of up to eight activities. The prey can be seized by the body (rolled up or not), or alternatively by the edge of the shell, then turned over and stung on the ventral face. A relationship between the mandible size of the workers and the handling method permitted us to established that the phase “seizure by the edge of the shell” (compared to grasping the prey by the body) was more frequent as the prey size increased or the mandible length of the workers decreased. The rate of prey escape followed the same pattern. When a prey escaped, workers reacted by using a local searching or “reserve” behavior: they moved by increasing both sinuosity and speed. Recruitment occurred mainly after a worker found a group of prey or a large prey.L. mexicana are attractive at a distance to the isopods Bathytropidae living in the same natural environment. As a consequence, prey capture is possible without foraging for this species.     

Simultaneous nitrification-denitrification achieved by an innovative internal-loop airlift MBR: comparative study

This study assessed the performance of different single-stage continuous aerated submerged membrane bioreactors (MBR) for nitrogen removal. Almost complete nitrification was achieved in each MBR irrespective of operating mode and biomass system. Denitrification was found to be the rate-limiting step for total nitrogen (T-N) removal. The MBR with internal-loop airlift reactor (ALR) configuration performed better as regards T-N removal compared with continuous stirred-tank reactor (CSTR). It was demonstrated that simultaneous nitrification and denitrification (SND) is the mechanism leading to nitrogen removal and the contribution of microenvironment on SND is more remarkable for the MBRs with hybrid biomass. Macroenvironment analyses showed that gradient distribution of dissolved oxygen (DO) level in airlift MBRs imposed a significant effect on SND. Higher mixed liquor suspended solid (MLSS) concentration led to the improvement in T-N removal by enhancing anoxic microenvironment. Apparent nitrite accumulation coupled with higher nitrogen reduction was accomplished at MLSS concentration exceeded 12.6 g/L.     

Myogenesis and neurogenesis in the chick embryo: A comparative study

Summary An electron microscope study of the comparative development of muscle and nerve tissue in the pectoral and wing regions of the chick embryo has been performed. Neurogenesis in the pectoral region is seen to be about 2 days advanced over that in the wing. Myogenesis proceeds at approximately the same rate in both areas. Myofibril organization and myotube alignment appear to be independent of developing nerve tissue.An incidental finding is that of aggregates of poorly organized myofilaments inserted into otherwise mature myofibres. It is suggested that this may be a method of increase in muscle length.     

Ecdysteroid metabolism: A comparative study

The metabolism of ecdysone and 20-hydroxyecdysone has been investigated in various animal species, including representatives of arthropods, molluscs, annelids and mammals. Some of the major metabolites have been isolated and characterized by mass spectrometry and two-dimensional proton NMR.It appears that metabolic pathways differ strongly between species and that each class has evolved specific reactions.     

Objective response detection in the frequency domain

Several different and related measures have been proposed for objective response detection in the frequency domain. We compared magnitude-squared coherence (MSC) to phase coherence (PC) using simulations with specified signal-to-noise ratios (SNRs) and varying numbers of subaverages; the performance measure was area unde a receiver operating characteristic (ROC) curve. MSC was superior to PC; test time required for equivalent performance is about 3 times greater PC than for MSC. MSC performance for a given final SNR increased with the number of subaverages, but reached a plateau at 16 subaverages. Simulations of noise non-stationarity (high-amplitude noise in some subaverages compared to the others) led to decreased performance advantage for MSC over PC. However, weighted averaging restored this advantage. MSC is shown to be a simple algebraic transform of Victor and Mast's (1991) “circular T²” statistic and of two earlier statistics; all have identical statistical power.     

耕地占补面积时空变化对碳储量的影响测度——以湖北省为例

基于InVEST模型定量评估湖北省2000-2020年耕地占补面积时空变化对陆地生态系统碳储量的影响,在县级行政单元尺度探究由耕地占补导致的碳储量变化量在空间上的集聚程度,并运用PLUS模型模拟区域未来四种发展情景下的土地利用格局及碳储量变化趋势。结果表明：（1）2000年至2020年,湖北省耕地面积净变化率为-3.89%,耕地面积略微下降,基本实现耕地占补数量平衡。（2）2000-2005年、2005-2010年、2010-2015年、2015-2020年耕地占用和补偿导致的碳储量变化值占该时段碳储量变化值的比例分别为68.45%、59.45%、57.86%、55.46%,二十年整体占比为61.38%。耕地碳储量的变化对陆地生态系统碳储量的影响巨大。碳固持的地块面积为1.29×10⁵ hm²,碳损失的地块面积为3.88×10⁵ hm²。（3）2000-2020年,湖北省耕地占补导致的碳储量变化值具有明显的空间集聚性,"高高聚集"区主要分布在西部和西南部山区,"低低聚集"区分布在中南部的江汉平原。（4）2020-2030年,湖北省陆地生态系统碳储量在自然发展情景下减少5.50×10⁶ t,在耕地保护情景下减少1.22×10⁶ t,在城镇开发情景下减少8.89×10⁶ t,在生态保护情景下增加2.43×10⁶ t。与其他三种情景相比,生态保护情景是未来发展的最优情景。研究通过定量评估耕地占补平衡背景下湖北省耕地面积时空变化对区域碳储量的影响为未来的国土空间规划以及增汇政策的制定提供决策依据和科学参考,对于实现土地资源的可持续利用和生态环境保护具有重要意义。     

Color vision in the comb frequency domain

In 1982, Horace Barlow considered the question of human trichromacy in the context of information theory: according to the Sampling Theorem, three types of receptors covering the visible spectrum (400-700 nm) might be sufficient to reconstruct the color signal. Although Barlow was led to reject the direct application of the Sampling Theorem to explain color dimensionality, the theoretical framework offers a fresh point of view for analyzing the color system in conjunction with the physical characteristics of natural color signals. This review aims to illustrate that if the strict mathematical reconstruction (as implied by the Sampling Theorem) is replaced by a pragmatic approximation of color signals, then trichromacy, with its subsequent opponent-color process, could be regarded as an optimization of color constancy abilities in the spectral environment of primates. Higher dimension systems (tetrachromacy) found in other species can also serve the purpose of color constancy optimization in environments where color signals exhibit a finer spectral structure.