probability density function
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Functional diversity (FD) has the potential to address many ecological questions, from impacts of global change on biodiversity to ecological restoration. There are several methods estimating the different components of FD. However, most of these methods can only be computed at limited spatial scales and cannot account for intraspecific trait variability (ITV), despite its significant contribution to FD. Trait probability density (TPD) functions (which explicitly account for ITV) reflect the probabilistic nature of niches. By doing so, the TPD approach reconciles existing methods for estimating FD within a unifying framework, allowing FD to be partitioned seamlessly across multiple scales (from individuals to species, and from local to global scales), and accounting for ITV. We present methods to estimate TPD functions at different spatial scales and probabilistic implementations of several FD concepts, including the primary components of FD (functional richness, evenness, and divergence), functional redundancy, functional rarity, and solutions to decompose beta FD into nested and unique components. The TPD framework has the potential to unify and expand analyses of functional ecology across scales, capturing the probabilistic and multidimensional nature of FD. The R package TPD (https://CRAN.R-project.org/package=TPD) will allow users to achieve more comparative results across regions and case studies.
- MeSH
- biodiverzita * MeSH
- ekologie * MeSH
- fenotyp MeSH
- pravděpodobnostní funkce MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Diagnostika polyneuropatie tenkých nervových vláken (NTV) je v současnosti založena na přítomnosti pozitivních subjektivních senzitivních symptomů a abnormálního nálezu testování termického prahu (TTT). Histologickým korelátem postižení tenkých nervových vláken je redukce intraepidermální inervace, resp. její morfologické abnormality. Nově zaváděnou metodou diagnostiky NTV je kvantifikace intraepidermální hustoty tenkých nervových vláken pomocí kožní biopsie. Cílem práce bylo zavedení metody kožní biopsie, stanovení normativních dat a korelace s nálezy TTT v souboru nemocných s NTV. Kožní biopsie prúbojníkem z oblasti distálního lýtka byla provedena u 17 zdravých kontrol a 76 pacientů s NTV. Intraepidermální tenká nervová vlákna byla vizualizována pomocí nepřímé imunofluorescence s použitím rhodaminem značených protilátek proti panneuronálnímu markeru PGP 9.5. Průměrný počet nervových vláken na mm epidermis byl ve skupině zdravých dobrovolníků významně vyšší oproti pacientům s NTV (11,54 ± 2,87 oproti 5,98 ± 3,81, p< 0,0001). Z hodnot zjištěných ve skupině zdravých dobrovolníků byl stanoven dolní normální limit počtu tenkých nervových vláken na úrovni 6,69/mm epidermis. Redukce počtu intraepidermálních nervových vláken byla prokázána u 69 % pacientů s klinicky a elektrofyziologicky definovanou NTV. Abnormity kožní biopsie odrážejí strukturální postižení tenkých nervových vláken a jsou vhodnou metodou k verifikaci diagnózy NTV založené na subjektivních symptomech a nálezech TTT. Vzhledem k nižší senzitivitě (ve srovnání s TTT) a invazivnímu charakteru je kožní biopsie méně vhodná jako screeningová metoda. Vyšší senzitivita TTT (pravděpodobně podmíněná schopností TTT reflektovat abnormální funkci tenkých nervových vláken dříve než se rozvinou signifikantní strukturální změny) spolu s neinvazivním charakterem předurčuje tuto metodu k použití při screeningu NTV.
The diagnosis of small fiber neuropathy (SEN) is currently based on the presence of positive sensory symptoms and abnormal findings in thermal threshold testing (TTT). Decreased density of intraepidermal innervation (or its structural abnormities) seems to be a morphological correlate of small fiber dysfunction. Therefore, the assessment of intraepidermal nerve fibers (lENFs) density in skin punch biopsies as a new method for SEN diagnosis is introduced in this study. The aim of this work was to adopt a method of skin biopsy, to establish the reference values of lENFs density, and to correlate the skin biopsy results with TTT findings in a group of SEN patients. Methods: Skin punch biopsies were obtained from the distal calf of 17 healthy individuals and 76 SEN patients. lENEs were stained with antibodies to panneuronal marker PGP 9.5. The correlation between the skin biopsy findings and TTT results was calculated. Mean lENFs density was significatly higher in healthy volunteers if compared with SEN patients. Intraepidemal nerve fibers counts per millimeter of epidermis were 11.54 ± 2.87 (mean ± SD) and 5.98 ± 3.81, respectively (p< 0.0001). The reference value for lENFs density was calculated from the healthy volunteers findings and set at a value of 6.69 fibers per millimeter of epidermis (95. percentile). Using this normal limit, decreased intraepidermal nerve fibers density was found in 69% SEN patients. Skin biopsies reflect the structural changes of small sensory fibers and prove to be useful in the algorithm of SEN diagnosis, based on subjective sensitive symptoms and abnormal TTT findings at present. With respect to lower sensitivity (compared to TTT) and invasiveness of this method, the application of skin biopsy as a screening method is not convenient. Higher sensitivity of TTT (probably caused bv the abilitv of TTT to reflect abnormal small fiber neuropathy function before the development of structural changes) together with its noninvasive character predetermine this method for the small fiber neuropathy screening.
- MeSH
- biologické markery MeSH
- biopsie metody MeSH
- dermatochirurgické výkony MeSH
- finanční podpora výzkumu jako téma MeSH
- fluorescenční protilátková technika nepřímá metody MeSH
- kůže MeSH
- lidé MeSH
- nervová vlákna patologie MeSH
- polyneuropatie diagnóza MeSH
- senzorické prahy MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
Cíl studie: Na základě soudobých studií podat přehled o hlavních biologických funkcích lipoproteinů o vysoké hustotě (HDL), zejména ve vztahu k reverznímu transportu cholesterolu a k jejich protizánětlivému působení. Popsat pravděpodobné mechanismy vzniku dysfunkčních prozánětlivých HDL a uvést některé parametry asociované s tímto procesem. Podat přehled o laboratorních metodách stanovení kvantitativních, strukturních a funkčních vlastností HDL, včetně moderních metod založených na hmotové spektrometrii. Typ studie: přehledový článek Závěr: V případě systémového zánětu a/nebo oxidačního stresu dochází ke vzniku dysfunkčních HDL akumulujících oxidanty. Probíhá strukturní modifikace apolipoproteinu AI, což vede mimo jiné k inhibici reverzního transportu cholesterolu a tvorbě prozánětlivých HDL. Na ztrátě příznivých vlastností HDL se podílí modifikace proteinové i lipidové složky HDL. Izolované měření HDL cholesterolu nemusí u některých syndromů bezvýhradně korelovat s mírou kardiovaskulárního rizika a v některých situacích je vhodné stanovit markery mapující strukturu a funkci HDL.
Objective: On the basis of recent studies to make an overview concerning the crucial biological functions of high density lipoproteins (HDL), with emphasis on the role in reverse cholesterol transport and their antiinflammatory traits. The aim was to describe probable mechanisms of dysfunctional proinflammatory HDL formation with introduction some of associated parameters. To present laboratory methods for determination of quantitative, structural and functional qualities of HDL, including advanced mass spectrometry techniques. Study design: review Conclusion: In the case of systemic inflammation and/or oxidative stress, the formation of dysfunctional HDL accumulating oxidants takes place, including apo AI structural modifications. This process can lead to the inhibition of reverse cholesterol transport and proinflammatory HDL generation, among others. Loss of beneficial qualities results from modification of both lipid and protein components of HDL. In some cases, an isolated quantitative measurement of HDL cholesterol may not fully correlate with cardiovascular risk and it is eligible to determine some of structural and/or functional markers of HDL.
- MeSH
- adiponektin analýza terapeutické užití MeSH
- apolipoproteiny analýza MeSH
- aryldialkylfosfatasa analýza terapeutické užití MeSH
- dospělí MeSH
- HDL-cholesterol analýza MeSH
- hmotnostní spektrometrie MeSH
- ischemická choroba srdeční diagnóza prevence a kontrola MeSH
- kardiovaskulární nemoci diagnóza prevence a kontrola MeSH
- klinické laboratorní techniky metody využití MeSH
- lidé MeSH
- lipoproteiny HDL * fyziologie klasifikace MeSH
- peroxidasa analýza terapeutické užití MeSH
- proteomika * MeSH
- senioři MeSH
- transportní proteiny pro estery cholesterolu MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH
The analysis of dermal ridges and their configuration on fingertips has been of considerable interest due to their inimitable, permanent and unique characteristics. The present cross-sectional study is an attempt to assess sex as well as topological differences in fingerprint ridge density among adult population of Nahan, Himachal Pradesh, North India. The data comprised of 240 subjects (120 males and 120 females), aged between 18 to 24 years. The results obtained in the study revealed significantly (p<0.001) higher fingerprint ridge density in females than males at radial, ulnar and proximal topological areas. Both the sexes revealed a disto-proximal gradient of fingerprint ridge density i.e proximal < ulnar < radial in both the hands. In regard to radial area fingerprint ridge density of ≤11 ridges and ≥13 ridges had more possibility of male and female origin respectively. Fingerprint ridge density of ≤11 ridges and ≥12 ridges was more likely of male and female origin respectively in the ulnar regions. In proximal region, fingerprint ridge density of ≤8 ridges and fingerprint ridge density of ≥10 ridges had more probability of being male and female origin respectively. Results of discriminant function analysis further strengthen the conclusion of significant gender differences in the ridge density at all the counting areas, thereby confirming fingerprint ridge density as a potential tool for sex distinction.
The concentration of a drug in the circulatory system is studied under two different elimination strategies. The first strategy--geometric elimination--is the classical one which assumes a constant elimination rate per cycle. The second strategy--Poisson elimination--assumes that the elimination rate changes during the process of elimination. The problem studied here is to find a relationship between the residence-time distribution and the cycle-time distribution for a given rule of elimination. While the presented model gives this relationship in terms of Laplace-Stieltjes transform., the aim here is to determine the shapes of the corresponding probability density functions. From experimental data, we expect positively skewed, gamma-like distributions for the residence time of the drug in the body. Also, as some elimination parameter in the model approaches a limit, the exponential distribution often arises. Therefore, we use Laguerre series expansions, which yield a parsimonious approximation of positively skewed probability densities that are close to a gamma distribution. The coefficients in the expansion are determined by the central moments, which can be obtained from experimental data or as a consequence of theoretical assumptions. The examples presented show that gamma-like densities arise for a diverse set of cycle-time distribution and under both elimination rules.
- MeSH
- biologické modely * MeSH
- farmakokinetika * MeSH
- lidé MeSH
- matematika MeSH
- metabolická clearance MeSH
- stochastické procesy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
In some taxa, males perform multiple ejaculations, which may function in sperm competition or in maintaining a baseline density of spermatozoa in the female reproductive tract to ensure fertilization, a process that has been termed 'topping up'. We investigated the function of multiple ejaculations in two species of bitterling, the European bitterling (Rhodeus amarus) and Chinese rose bitterling (Rhodeus ocellatus). Bitterling oviposit in living freshwater mussels, with fertilization taking place within the mussel gill cavity. Thus, although fertilization is external, the mussel is analogous to the female reproductive tract in an internally fertilizing species. We measured the frequency of ejaculations and mussel inspections by individual males of two bitterling species in 28 replicated mesocosms and examined focal male responses to rival ejaculations and the presence of females in spawning condition. We used a model of ejaculatory behaviour to simulate the temporal abundance of spermatozoa in mussels. Male R. amarus exhibited high rates of ejaculation and inspection of the siphons of mussels and increased their ejaculation rate in response to the presence of females in spawning condition. Rhodeus ocellatus showed lower overall rates of ejaculation, but significantly elevated ejaculation rate in response to rival ejaculations. The ejaculatory strategy of R. amarus is one that maintains a minimum level of spermatozoa in mussels, which is elevated when the probability of oviposition increases. In contrast, R. ocellatus engages more directly in sperm competition with rivals. We discuss these results in the context of the function of multiple ejaculations and male mating tactics.
- MeSH
- biologické modely MeSH
- Cyprinidae fyziologie MeSH
- ejakulace fyziologie MeSH
- kladení vajíček MeSH
- sexuální chování zvířat fyziologie MeSH
- spermie fyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
While androgens generally have been associated with an increased cardiovascular risk, recent studies indicate potential beneficial acute effects of testosterone. However, detailed evaluation of chronic and acute actions of testosterone on the function of cardiac I(Ca,L) and intracellular Ca2+ handling is limited. To clarify this situation we performed whole-cell and single-channel analysis of I(Ca,L), recordings of Ca2+ sparks, measurements of contractility and quantitative real-time RT-PCR in rat cardiomyocytes following testosterone pretreatment and acute testosterone application. Pretreatment with testosterone 100 nM for 24-30 h increased whole-cell I(Ca,L) from 3.8+/-0.8 pA/pF (n=10) to 10.1+/-0.31 pA/pF (n=9) at +10 mV (p<0.001). Increase of I(Ca,L) density was caused by both, increased expression levels of the alpha 1C subunit of L-type calcium channel and a pronounced increment of the single-channel activity (availability 81.8+/-3.15% versus 37.1+/-7.01%; open probability 12.8+/-3.09% versus 1.0+/-0.62%, p<0.01). Moreover, testosterone pretreatment significantly increased the frequency of Ca2+ sparks and improved myocytes contractility without altering SR Ca2+ load. All chronic effects could be inhibited by flutamide. In contrast acute testosterone administration significantly reduced I(Ca,L) density. Indeed, on the single-channel level acute testosterone application completely reversed the chronic testosterone-mediated effects, and antagonized the chronic testosterone effects on Ca2+ spark frequency, which was unaffected by flutamide. Thus, testosterone pretreatment activates I(Ca,L) via nuclear receptor-mediated pathways, while testosterone acutely blocks I(Ca,L) in a direct manner. Thus, testosterone chronically affects the basal level of intracellular Ca2+ handling, which in addition rapidly may be modulated by acute changes of hormone levels.
- MeSH
- financování organizované MeSH
- gating iontového kanálu účinky léků MeSH
- kardiomyocyty metabolismus účinky léků MeSH
- kontrakce myokardu účinky léků MeSH
- krysa rodu rattus MeSH
- kultivované buňky MeSH
- novorozená zvířata MeSH
- potkani Sprague-Dawley MeSH
- testosteron farmakologie MeSH
- vápník metabolismus MeSH
- vápníková signalizace účinky léků MeSH
- vápníkové kanály - typ L metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- ženské pohlaví MeSH
- zvířata MeSH
PURPOSE: Utility of prostate-specific antigen density (PSAd) for risk-stratification to avoid unnecessary biopsy remains unclear due to the lack of standardization of prostate volume estimation. We evaluated the impact of ellipsoidal formula using multiparametric magnetic resonance (MRI) and semi-automated segmentation using tridimensional ultrasound (3D-US) on prostate volume and PSAd estimations as well as the distribution of patients in a risk-adapted table of clinically significant prostate cancer (csPCa). METHODS: In a prospectively maintained database of 4841 patients who underwent MRI-targeted and systematic biopsies, 971 met inclusions criteria. Correlation of volume estimation was assessed by Kendall's correlation coefficient and graphically represented by scatter and Bland-Altman plots. Distribution of csPCa was presented using the Schoots risk-adapted table based on PSAd and PI-RADS score. The model was evaluated using discrimination, calibration plots and decision curve analysis (DCA). RESULTS: Median prostate volume estimation using 3D-US was higher compared to MRI (49cc[IQR 37-68] vs 47cc[IQR 35-66], p < 0.001). Significant correlation between imaging modalities was observed (τ = 0.73[CI 0.7-0.75], p < 0.001). Bland-Altman plot emphasizes the differences in prostate volume estimation. Using the Schoots risk-adapted table, a high risk of csPCa was observed in PI-RADS 2 combined with high PSAd, and in all PI-RADS 4-5. The risk of csPCa was proportional to the PSAd for PI-RADS 3 patients. Good accuracy (AUC of 0.69 and 0.68 using 3D-US and MRI, respectively), adequate calibration and a higher net benefit when using 3D-US for probability thresholds above 25% on DCA. CONCLUSIONS: Prostate volume estimation with semi-automated segmentation using 3D-US should be preferred to the ellipsoidal formula (MRI) when evaluating PSAd and the risk of csPCa.
- MeSH
- hodnocení rizik MeSH
- klinické rozhodování MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie metody MeSH
- multiparametrická magnetická rezonance MeSH
- nádory prostaty * patologie diagnostické zobrazování MeSH
- prospektivní studie MeSH
- prostata * patologie diagnostické zobrazování MeSH
- prostatický specifický antigen * krev MeSH
- senioři MeSH
- ultrazvukem navigovaná biopsie metody MeSH
- velikost orgánu MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
Idiopathic pulmonary fibrosis (IPF), hypersensitivity pneumonitis (HP) and sarcoidosis belong to interstitial lung diseases (ILD) where an imbalance of regulatory, profibrotic and antifibrotic cytokines is hypothesized. The relationship of bronchoalveolar lavage (BAL) fluid (BALF) cytokines, BALF cell profile and ILD course is supposed. The aim of our study was to correlate BALF cytokine and chemokine levels with BALF cellular characteristics and lung function parameters in different ILD. Twenty-two sarcoidosis, seven IPF and 11 HP patients underwent lung function tests and BAL. The BALF differential cell counts and superficial cell markers were characterized, and MCP-1, MIP-1alpha, MIP-1beta, RANTES, epithelial neutrophil-activating protein (ENA)-78, FGF, G-CSF, GM-CSF, IFN-gamma, interleukin (IL)-1alpha, IL-1RA, IL-1beta, -2beta, -4beta, -5beta, -6beta, -8beta, -10beta, -17beta, tumour necrosis factor (TNF)-alpha, thromobopoietin (Tpo) and vascular endothelial growth factor (VEGF) values measured. The BALF VEGF values were highest in sarcoidosis (P = 0.0526). IL-1RA values were higher in IPF and HP compared with sarcoidosis (P = 0.0334). IL-8/ENA-78 ratio positively correlated with BALF neutrophil counts in IPF (r = 0.89, P = 0.04). Vital capacity and TL(CO) values positively correlated with VEGF and negatively with IL-8 BALF levels in all ILDs but the correlations were most significant in sarcoidosis group. We suppose that VEGF plays a role in ILDs' early phases and has rather angiogenic than profibrotic effect. On the contrary, IL-8 is probably upregulated in advanced ILDs with prominent fibrosis and marked lung functions decline. We state that BALF VEGF, IL-8 and ENA-78 levels and IL-8/ENA-78 ratio could become useful markers of ILDs' phase, activity and prognosis. They might also be helpful in treatment modality choice.
- MeSH
- bronchoalveolární laváž MeSH
- bronchoalveolární lavážní tekutina cytologie imunologie MeSH
- cytokiny metabolismus MeSH
- financování organizované MeSH
- intersticiální plicní nemoci imunologie patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- počet buněk MeSH
- respirační funkční testy MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH