Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Nutrients ; 16(3)2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38337638

RESUMEN

The previous literature suggests that regular consumption of edible mushrooms may confer neuroprotective cognitive health benefits. To further investigate the possible association between mushrooms and brain function during ageing, data from a population-based study of diet and chronic disease (EPIC-Norfolk cohort) were analysed. Changes in mushroom intake were measured using a food frequency questionnaire at three health check (HC) points over an 18-year period, with participants categorised based on their consumption frequency. Cognitive performance was assessed at the final health check (3HC) via a battery of validated tests assessing a range of different cognitive domains. The findings revealed a significant reduction in mushroom intake over time, with 4.12% of the cohort giving up mushrooms after previously consuming them. At 3HC, mushroom consumers displayed better cognitive performance than non-consumers across multiple cognitive domains. This relationship was observed to be dose-dependent, with those consuming 1 or more portions per week showing the highest cognitive scores. These findings suggest that regular mushroom consumption may be beneficial for cognitive function during aging. Further randomised controlled trials will be needed to confirm any potential benefits of mushrooms on long-term cognitive health, alongside public health initiatives to promote mushroom consumption in this older-adult demographic.


Asunto(s)
Agaricales , Neoplasias , Adulto , Humanos , Estudios de Cohortes , Estudios Prospectivos , Estudios Epidemiológicos , Neoplasias/epidemiología , Cognición
2.
Neurosci Biobehav Rev ; 158: 105548, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38246232

RESUMEN

Mushrooms contain bioactive compounds with documented antioxidant and anti-inflammatory actions. Here, we present a systematic evaluation of epidemiological and clinical studies that investigate the role of mushrooms, either as a separate or integral dietary component, on neurocognition and mood. Following a search of four databases, a total of 34 human studies examining the effect of different mushrooms across varying age cohorts and health statuses were selected for inclusion. Epidemiological studies included in this review (n = 24) revealed a significant benefit of dietary patterns that included mushrooms of any species on cognition and mood in both healthy and compromised populations. However, the results obtained from intervention studies (n = 10) were mixed. Studies mainly investigated Lion's Mane (Hericium erinaceus), showing some enhancement of mood and cognitive function in middle-aged and older adults. Further acute and chronic human intervention studies are needed, using adequate sample sizes, employing appropriately sensitive neurocognitive tests, and investigating a range of dietary mushrooms, to confirm the effects of mushroom supplementation on neurocognition and mood in humans.


Asunto(s)
Agaricales , Humanos , Persona de Mediana Edad , Anciano , Longevidad , Antioxidantes
3.
J Forensic Sci ; 69(1): 162-181, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37789521

RESUMEN

Early recovery of human bodies from the water requires an understanding of how a body acts in the water. However, there is currently a lack of baseline data surrounding body movement in British Columbian (B.C.) waters. This study aims to assist Canadian response agencies with understanding and predicting body movement in outdoor waterbodies in B.C. One hundred and eighty-six water-related fatalities in B.C. waters, including lakes, rivers, and the coastal Pacific Ocean, were examined to determine the recovery times and displacement patterns of submerged decedents. Cases between 2010 and 2021 were extracted from the Police Records Information Management Environment (PRIME-BC) for analysis. Most deaths were unintentional, followed by suicide and homicide, and most often occurred in rivers, followed by lakes and the ocean. Regardless of waterbody, the first day was the most successful recovery period, with decedents most often recovered close to the incident location. Nearly 16% of individuals in this study were not recovered. Recovery success was greatest in lakes, followed by rivers and the ocean. Body displacement was the least in lakes, while rivers resulted in the furthest and most variable displacement. Low recovery success in the ocean is likely due to decedents being quickly displaced out of the search area, never to be found. The results of this study suggest that knowledge of body movement in outdoor aquatic environments remains incomplete. Further empirical research based on known data is necessary to continue improving prediction of body movement and increase early recovery success.


Asunto(s)
Suicidio , Agua , Humanos , Colombia Británica/epidemiología , Homicidio , Ríos
4.
Genome Res ; 33(4): 622-631, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37072186

RESUMEN

Density separation is a process routinely used to segregate minerals, organic matter, and even microplastics, from soils and sediments. Here we apply density separation to archaeological bone powders before DNA extraction to increase endogenous DNA recovery relative to a standard control extraction of the same powders. Using nontoxic heavy liquid solutions, we separated powders from the petrous bones of 10 individuals of similar archaeological preservation into eight density intervals (2.15 to 2.45 g/cm3, in 0.05 increments). We found that the 2.30 to 2.35 g/cm3 and 2.35 to 2.40 g/cm3 intervals yielded up to 5.28-fold more endogenous unique DNA than the corresponding standard extraction (and up to 8.53-fold before duplicate read removal), while maintaining signals of ancient DNA authenticity and not reducing library complexity. Although small 0.05 g/cm3 intervals may maximally optimize yields, a single separation to remove materials with a density above 2.40 g/cm3 yielded up to 2.57-fold more endogenous DNA on average, which enables the simultaneous separation of samples that vary in preservation or in the type of material analyzed. While requiring no new ancient DNA laboratory equipment and fewer than 30 min of extra laboratory work, the implementation of density separation before DNA extraction can substantially boost endogenous DNA yields without decreasing library complexity. Although subsequent studies are required, we present theoretical and practical foundations that may prove useful when applied to other ancient DNA substrates such as teeth, other bones, and sediments.


Asunto(s)
ADN Antiguo , Hueso Petroso , Humanos , Polvos , Plásticos , ADN/genética
5.
Am J Clin Nutr ; 117(6): 1306-1319, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36972800

RESUMEN

BACKGROUND: Evidence suggests that the intake of blueberry (poly)phenols is associated with improvements in vascular function and cognitive performance. Whether these cognitive effects are linked to increases in cerebral and vascular blood flow or changes in the gut microbiota is currently unknown. METHODS: A double-blind, parallel randomized controlled trial was conducted in 61 healthy older individuals aged 65-80 y. Participants received either 26 g of freeze-dried wild blueberry (WBB) powder (302 mg anthocyanins) or a matched placebo (0 mg anthocyanins). Endothelial function measured by flow-mediated dilation (FMD), cognitive function, arterial stiffness, blood pressure (BP), cerebral blood flow (CBF), gut microbiome, and blood parameters were measured at baseline and 12 wk following daily consumption. Plasma and urinary (poly)phenol metabolites were analyzed using microelution solid-phase extraction coupled with liquid chromatography-mass spectrometry. RESULTS: A significant increase in FMD and reduction in 24 h ambulatory systolic BP were found in the WBB group compared with the placebo group (0.86%; 95% CI: 0.56, 1.17, P < 0.001; -3.59 mmHg; 95% CI: -6.95, -0.23, P = 0.037; respectively). Enhanced immediate recall on the auditory verbal learning task, alongside better accuracy on a task-switch task was also found following WBB treatment compared with placebo (P < 0.05). Total 24 h urinary (poly)phenol excretion increased significantly in the WBB group compared with placebo. No changes in the CBF or gut microbiota composition were found. CONCLUSIONS: Daily intake of WBB powder, equivalent to 178 g fresh weight, improves vascular and cognitive function and decreases 24 h ambulatory systolic BP in healthy older individuals. This suggests that WBB (poly)phenols may reduce future CVD risk in an older population and may improve episodic memory processes and executive functioning in older adults at risk for cognitive decline. Clinical Trial Registration number in clinicaltrials.gov: NCT04084457.


Asunto(s)
Antocianinas , Arándanos Azules (Planta) , Humanos , Anciano , Fenoles , Fenol/análisis , Fenol/farmacología , Polvos/análisis , Polvos/farmacología , Frutas/química , Cognición , Memoria a Corto Plazo , Método Doble Ciego
6.
J Forensic Sci ; 68(2): 382-398, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36734276

RESUMEN

Stable carbon isotope analysis has proven utility for reconstructing dietary information in humans in past populations. The usefulness of stable carbon for forensic geolocation has been little investigated, largely because of the globalization of the human diet seemingly rendering it inconsequential. This study queried this assumption at a country-wide level on a known sample group. Stable carbon isotope values were obtained from human enamel with known biographical and geographical information to determine whether stable carbon, when paired with stable oxygen isotope values, could differentiate Canadians from non-Canadians. Samples originating outside of Canada were separated into three regions, and a linear discriminant analysis was used to generate discriminant functions that best separate the regions according to the stable carbon and oxygen isotope values. The results revealed two functions, where the first function explained 92.1% and the second 7.9% of the variance. Although some overlap in stable carbon and oxygen values was observed for individuals from both the United States and Canada, differences were observed between those from Canada and other geographical regions. This study demonstrated that pairing the dietary isotope carbon with the geolocator stable oxygen isotope, produced an interesting separation geographically, one that might well be helpful when attempting a geolocation query on unknown human remains.


Asunto(s)
Carbono , Medicina Legal , Humanos , Estados Unidos , Isótopos de Oxígeno/análisis , Carbono/análisis , Isótopos de Carbono/análisis , Dieta
7.
Sci Rep ; 12(1): 21169, 2022 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-36477390

RESUMEN

The utility of stable hydrogen and oxygen isotope analysis of human tissues for geolocation is an important area of study within forensic science. This study aimed to first validate the latitudinal relationship between stable hydrogen and oxygen isotopes in drinking water and human keratinous tissues through the analysis of human samples with known geographical origin. And secondly, to explore the use of classification and regression tree (CART) models to geographically classify individuals based on the stable isotope values of tissues themselves. Human hair and toenails were collected from four distinct study sites across Canada. The comparison of stable isotope values in drinking water and human tissues produced low R2 values indicating that linear models may not fully explain the variation observed for both hydrogen and oxygen values. Additionally, large intrapopulation variations were observed for Canadian cities and highlights the importance of understanding the regional isotopic spread of human values. Further, this study demonstrated that a closed group of unknown individuals known to have originated from a limited number of geographically distinct regions may be classified into their respective groups through the use of CART models. The potential for the CART model approach for human geolocation presents a promising new tool.


Asunto(s)
Agua Potable , Hidrógeno , Humanos , Isótopos de Oxígeno , Canadá , Medicina Legal
8.
Mol Nutr Food Res ; 66(21): e2100976, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35333451

RESUMEN

Improving cognition is important in all age groups, from performance in school examinations to prevention of cognitive decline in later life. Dietary polyphenols, in particular flavonoids, have been examined for their benefits to cognitive outcomes. This meta-analysis evaluates the effects of dietary flavonoids on cognition across the lifespan. In January 2020 databases were searched for randomized controlled trials investigating flavonoid effects on human cognition. Eighty studies, comprising 5519 participants, were included in the final meta-analysis. The global analysis indicates dietary flavonoids induced significant benefit to cognitive performance (g = 0.148, p < 0.001), with subgroup analyses revealing that cocoa (g = 0.224, p = 0.036), ginkgo (g = 0.187, p ≤ 0.001), and berries (g = 0.149, p = 0.009) yielded the most notable improvements. Significant benefits were observed from chronic studies, in middle-aged and older adults, and with low and medium doses. The domains of long-term memory, processing speed, and mood showed sensitivity to flavonoid intervention. This meta-analysis provides evidence for the positive effects of flavonoids on cognition and highlights several moderating factors. Flavonoid-based dietary interventions therefore potentially offer a highly accessible, safe, and cost-effective treatment to help tackle the burden of cognitive decline.


Asunto(s)
Disfunción Cognitiva , Polifenoles , Persona de Mediana Edad , Humanos , Anciano , Polifenoles/farmacología , Cognición , Disfunción Cognitiva/prevención & control , Frutas , Flavonoides/farmacología
9.
Eur J Nutr ; 61(1): 413-428, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34396468

RESUMEN

PURPOSE: Cereboost®, an American ginseng extract, has shown improved short-term memory and attention/alertness in healthy young and middle-aged individuals, potentially via modulation of the gut microbiome and upregulation of neurotransmitters such as acetylcholine. Here, we explored the effects of Cereboost® on cognition and mood in the first 6 h post intervention (acute), after 2 weeks daily supplementation (chronic), and whether 2 weeks daily supplementation altered the response to a single acute dose (acute-on-chronic). A concurrent in vitro study evaluated effects of repeated Cereboost® administration on human gut microbiota. METHODS: Cognitive effects of Cereboost® were assessed using a double-blind, randomized, placebo-controlled clinical trial, with 61 healthy young adults. Modulation of the gut microbiome was concurrently modelled using the Simulator of the Human Microbial Ecosystem (SHIME®), using a young adult donor. RESULTS: Consistent with previous findings, Cereboost® improved working memory and attention during the immediate postprandial period; effects that were amplified following two weeks' treatment (acute-on-chronic) compared to acute testing alone. Chronic supplementation improved cognition on an acetylcholine-sensitive attention task and improved mental fatigue and self-assurance aspects of mood. The parallel in vitro study revealed significantly increased acetate, propionate, and butyrate levels in simulated proximal and distal colon regions, linked with observed increases in Akkermansia muciniphila and Lactobacillus. CONCLUSION: This study confirmed the promising effects of Cereboost® on cognitive function and mood, while suggesting a possible link to alterations of the gut microbiome and modulation of acetylcholine. Further studies will be required to unravel the underlying mechanisms that are involved. REGISTRATION: The study was pre-registered at ClinicalTrials.gov on 6th July 2018 (Identifier: NCT03579095).


Asunto(s)
Microbioma Gastrointestinal , Panax , Cognición , Método Doble Ciego , Ecosistema , Humanos , Persona de Mediana Edad , Extractos Vegetales/farmacología , Adulto Joven
10.
Nutr Neurosci ; 25(1): 54-63, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31942838

RESUMEN

Grapes are polyphenol-rich, and grape juice intake has shown cognitive benefits in middle-aged females and older adults with mild cognitive impairment. Extracts obtained from grape seeds have similarly been associated with cognitive benefits in older adults. The aim of this research was to investigate whether a highly purified grape seed-derived polyphenol extract was associated with cognitive benefits in healthy young adults following a single acute dose, and chronically following repeated daily dosage over 12 weeks. Following an acute-on-chronic, parallel groups, randomised, double-blind, placebo-controlled design, sixty adults aged 18-30 consumed either a 400 mg grape seed polyphenol extract (GSPE, n = 30) or a placebo (n = 30). Cognitive function was assessed acutely at baseline and 2, 4 and 6 h post consumption, and chronically at 6 and 12 twelve weeks with a computerised battery of multiple cognitive tests. Mood was assessed with the Positive and Negative Affect Schedule. Linear marginal model analysis with baseline included as a covariate did not reveal a consistent pattern of cognitive benefits following the GSPE relative to the placebo either acutely or chronically when considering all outcome measures. GSPE was associated with some improvements in reaction time (acutely) and psychomotor skill (chronically), however the placebo was also associated with some benefits to reaction time and memory. Therefore, a 400 mg GSPE did not consistently improve cognitive function in healthy young adults. These findings suggest that younger, healthy populations are perhaps less sensitive to polyphenol extract doses <400mg relative to older, or cognitively compromised populations.


Asunto(s)
Cognición/efectos de los fármacos , Extracto de Semillas de Uva/administración & dosificación , Extracto de Semillas de Uva/química , Polifenoles/administración & dosificación , Adolescente , Adulto , Afecto , Método Doble Ciego , Humanos , Memoria/efectos de los fármacos , Tiempo de Reacción/efectos de los fármacos , Adulto Joven
11.
Sci Justice ; 61(5): 459-466, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34482926

RESUMEN

Experimental knowledge of human body decomposition in the deep ocean is very limited, partly due to the logistical challenges of deep-sea research. The literature on ecological responses to the arrival of naturally sunk and implanted whale carcasses on the seafloor represents a potential source of information relevant to questions of human body survival and recovery in the deep ocean. Whale falls trigger the formation of complex, localized, and dense biological communities that have become a point of interest for marine biologists for the past 2-3 decades. Researchers have documented whale falls by whale type, size, geographic location, water depth and water chemistry, and there have been some comparative analyses of decomposition rates and faunal presence on carcasses. We undertook a review and meta-analysis of the whale-fall literature to identify and statistically model trends relevant to human forensics. Results from studies using deep-sea cameras baited with pig carcasses and simulated carrion provided further validation of noted trends. The stages of whale carcass decomposition most relevant to human forensics are those characterised by mobile scavengers that strip the soft tissues from carcasses, and to a lesser degree, other biota that degrade skeletal material. Our statistical models used the number of faunal taxa attracted to the whale carcasses as a measure of the ecological response and the potential rate of decomposition. Negative binomial models identified significant influences of carcass age and dissolved oxygen concentration on the ecological response (taxon numbers). The strongest environmental effects were identified in data from experimental studies that implanted whale carcasses across a broad range of dissolved-oxygen conditions. We propose directions for further experimental research to refine models of environmental controls on decomposition in the deep sea. Our results also highlight the potential use of publicly available global databases on environmental conditions in the deep ocean for informing body scavenging activity and thus body survival. Applying a forensic lens to whale-fall studies provides a window into an otherwise unseen world from the standpoint of human forensic taphonomy.


Asunto(s)
Oxígeno , Ballenas , Animales , Humanos , Porcinos , Agua
12.
Sci Rep ; 11(1): 15645, 2021 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-34341459

RESUMEN

Stable isotope analysis of human tissues has become a valuable tool for mapping human geolocation. This study adds to the existing knowledge of the relationship between oxygen stable isotopes in human enamel and drinking water by presenting enamel oxygen values in clinic-extracted human dental enamel with known provenance. The results from this study indicate that the theoretical isotopic relationship between enamel and drinking water oxygen is weak at the city and country-level. Differences of up to 15‰ were observed between predicted drinking water oxygen values using existing models and observed values, highlighting the complexity of using water/enamel conversion equations. The lower isotopic boundary of enamel oxygen values is now understood for Metro Vancouver at δ18Oc(VPDB) = - 11.0‰ and presents the possibility of using stable isotope analysis as an exclusionary tool where individuals falling below threshold value can be identified as non-local. Overall, this study's results support the development of geographical reference maps for human enamel oxygen.


Asunto(s)
Diente , Agua , Humanos
13.
Eur J Nutr ; 60(3): 1521-1536, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32747995

RESUMEN

PURPOSE: Research has demonstrated cognitive benefits following acute polyphenol-rich berry consumption in children and young adults. Berry intake also has been associated with metabolic benefits. No study has yet examined cognitive performance in middle-aged adults. We investigated the relationships among cognitive and metabolic outcomes in middle-aged adults following wild blueberry (WBB) consumption. METHODS: Thirty-five individuals aged 40-65 years participated in a randomized, double blind, cross-over study. Participants consumed a breakfast meal and 1-cup equivalent WBB drink or matched placebo beverage on two occasions. Participants completed cognitive tasks and had blood drawn before and at regular intervals for 8 h after each meal/treatment. Changes in episodic memory and executive function (EF) were assessed alongside plasma levels of glucose, insulin, and triglyceride. RESULTS: Analysis of the memory-related Auditory Verbal Learning Task (AVLT) word recognition measure revealed a decrease in performance over the test day after placebo intake, whereas performance after WBB was maintained. For the AVLT word rejection measure, participants identified more foils following WBB in comparison to placebo. Benefits were also observed for EF on the Go/No-Go task with fewer errors following WBB intake on cognitively demanding invalid No-Go trials in comparison to placebo. Furthermore, in comparison to placebo, response times were faster for the Go/No-Go task, specifically at 4 h and 8 h following WBB treatment. We also observed reduced post-meal glucose and insulin, but not triglyceride, concentrations in comparison to placebo over the first 2 h following ingestion. Though the addition of Age, BMI, glucose and insulin as covariates to the analysis reduced the significant effect of beverage for AVLT word rejection, metabolic outcomes did not interact with treatment to predict cognitive performance with the exception of one isolated trend. CONCLUSIONS: This study indicated acute cognitive benefits of WBB intake in cognitively healthy middle-aged individuals, particularly in the context of demanding tasks and cognitive fatigue. WBB improved glucose and insulin responses to a meal. Further research is required to elucidate the underlying mechanism by which WBB improves cognitive function.


Asunto(s)
Arándanos Azules (Planta) , Niño , Cognición , Estudios Cruzados , Método Doble Ciego , Función Ejecutiva , Frutas , Humanos , Persona de Mediana Edad , Adulto Joven
14.
Int J Food Sci Nutr ; 72(5): 650-652, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33249925

RESUMEN

It is well known that what we eat can influence our physical wellbeing, but interest is also increasing in the relationship between our diet and cognitive health. In recent years, blueberries have risen from relative obscurity to superfood status following a number of published epidemiological studies, rodent trials, and human RCTs, that suggest blueberries may convey benefits to cognition and mood. This commentary explores some of the evidence in humans, particularly during periods of cognitive development in the young and cognitive decline in the elderly. Evidence for possible mechanisms of action are also described. There is little doubt that blueberries convey a small, but tangible, benefit to cognitive function. Effects are seen following dose sizes easily achievable within a normal diet. Nevertheless, further research is needed on the cognitive domains influenced, additional benefits of longer-term supplementation, mechanisms of action responsible, and the real-world relevance of the cognitive benefits attained.


Asunto(s)
Arándanos Azules (Planta) , Cognición , Dieta , Frutas , Longevidad , Humanos
15.
Front Psychol ; 11: 1546, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32714258

RESUMEN

It is estimated that more than half of all online transactions are abandoned before completion. This paper investigates the psychological factors that influence online shopping behavior, with a view to improving transactional success rates. Through a review of the literature, we identify a range of factors which predict abandonment of online shopping, highlighting affective and motivational dimensions in addition to processing style and characteristics of the consumer, device, and product. We conclude that online purchasing and payment systems that boost consumers' motivation to buy and prevent or attenuate negative affective states will demonstrate the greatest rates of transactional success. However, with rapid advancement in technology, continued research is needed to fully understand the potential impact on future online purchasing behavior.

16.
Genome Res ; 30(3): 427-436, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32098773

RESUMEN

DNA recovery from ancient human remains has revolutionized our ability to reconstruct the genetic landscape of the past. Ancient DNA research has benefited from the identification of skeletal elements, such as the cochlear part of the osseous inner ear, that provides optimal contexts for DNA preservation; however, the rich genetic information obtained from the cochlea must be counterbalanced against the loss of morphological information caused by its sampling. Motivated by similarities in developmental processes and histological properties between the cochlea and auditory ossicles, we evaluate the ossicles as an alternative source of ancient DNA. We show that ossicles perform comparably to the cochlea in terms of DNA recovery, finding no substantial reduction in data quantity and minimal differences in data quality across preservation conditions. Ossicles can be sampled from intact skulls or disarticulated petrous bones without damage to surrounding bone, and we argue that they should be used when available to reduce damage to human remains. Our results identify another optimal skeletal element for ancient DNA analysis and add to a growing toolkit of sampling methods that help to better preserve skeletal remains for future research while maximizing the likelihood that ancient DNA analysis will produce useable results.


Asunto(s)
ADN Antiguo/análisis , Osículos del Oído/química , Cóclea/química , Osículos del Oído/anatomía & histología , Osículos del Oído/embriología , Humanos , Análisis de Secuencia de ADN
17.
J Forensic Sci ; 65(4): 1247-1259, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32092159

RESUMEN

Aging adult skeletal material is a crucial component of building the biological profile of unknown skeletal remains, but many macro- and microscopic methods have challenges regarding accuracy, precision, and replicability. This study developed a volumetric method to visualize and quantify histological remodeling events in three dimensions, using a two-dimensional serialized approach that applied circular polarizing microscopy and geographic information systems protocols. This approach was designed as a tool to extend current histological aging methodologies. Three serial transverse sections were obtained from a human femoral midshaft. A total sample size of 6847 complete osteons from the three sections was identified; 1229 osteons connected between all sections. The volume of all connected osteons was interpolated using ArcGIS area calculations and truncated cone geometric functions. Each section was divided into octants, and two random samples of 100 and of 30 connected osteons from each octant were generated. Osteon volume was compared between the octants for each random sample using ANOVA. Results indicated that the medial aspect had relative uniformity in osteon volume, whereas the lateral aspect showed high variability. The anterolateral-lateral octant had significantly smaller osteon volume, whereas the posterior-posterolateral octant had significantly larger osteon volume. Results also indicated that a minimum of 100 osteons is statistically more robust and more representative of normal osteon distribution and volume; the use of 30 osteons is insufficient. This research has demonstrated that osteon volume can be interpolated using spatial geometry and GIS applications and may be a tool to incorporate into adult age-at-death estimation techniques.


Asunto(s)
Determinación de la Edad por el Esqueleto/métodos , Remodelación Ósea , Fémur/ultraestructura , Osteón/ultraestructura , Antropología Forense , Sistemas de Información Geográfica , Humanos , Procesamiento de Imagen Asistido por Computador , Microscopía
19.
Rapid Commun Mass Spectrom ; 33(18): 1475-1480, 2019 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-31148277

RESUMEN

RATIONALE: The stable isotope ratios of carbon (δ13 C values), nitrogen (δ15 N values) and sulfur (δ34 S values) in bear hair can be used to obtain information on dietary history. Sample protocols often require hair sampling from multiple anatomical locations; however, there remains a question as to whether this is necessary for isotopic studies of hair. The purpose of this study was to determine whether significant differences can be observed for the δ13 C, δ15 N and δ34 S values between paired hair samples taken from the rump and shoulder of grizzly bears (Ursus arctos). METHODS: Paired hair samples were collected from the rump and the shoulder of 81 grizzly bears in the Yukon, Canada. Hair samples were analyzed using a thermal combustion elemental analyzer coupled with a continuous flow isotope ratio mass spectrometer. RESULTS: Statistical comparisons of paired hair samples for both males and females showed no meaningful differences in δ13 C, δ15 N and δ34 S values in hair taken from the rump and shoulder, and any observed differences fell within the instrumental error. CONCLUSIONS: Based on these results, hair may be safely sampled on either the rump or the shoulder without loss of isotopic information and thus this finding allows for refinement of sampling.


Asunto(s)
Isótopos de Carbono/análisis , Cabello/química , Isótopos de Nitrógeno/análisis , Isótopos de Azufre/análisis , Ursidae , Animales , Femenino , Masculino , Hombro , El Yukón
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...