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1.
Glob Chang Biol ; 29(12): 3271-3284, 2023 06.
Article in English | MEDLINE | ID: mdl-36924241

ABSTRACT

At large scales, the mechanisms underpinning stability in natural communities may vary in importance due to changes in species composition, mean abundance, and species richness. Here we link species characteristics (niche positions) and community characteristics (richness and abundance) to evaluate the importance of stability mechanisms in 156 butterfly communities monitored across three European countries and spanning five bioclimatic regions. We construct niche-based hierarchical structural Bayesian models to explain first differences in abundance, population stability, and species richness between the countries, and then explore how these factors impact community stability both directly and indirectly (via synchrony and population stability). Species richness was partially explained by the position of a site relative to the niches of the species pool, and species near the centre of their niche had higher average population stability. The differences in mean abundance, population stability, and species richness then influenced how much variation in community stability they explained across the countries. We found, using variance partitioning, that community stability in Finnish communities was most influenced by community abundance, whereas this aspect was unimportant in Spain with species synchrony explaining most variation; the UK was somewhat intermediate with both factors explaining variation. Across all countries, the diversity-stability relationship was indirect with species richness reducing synchrony which increased community stability, with no direct effects of species richness. Our results suggest that in natural communities, biogeographical variation observed in key drivers of stability, such as population abundance and species richness, leads to community stability being limited by different factors and that this can partially be explained due to the niche characteristics of the European butterfly assemblage.


Subject(s)
Butterflies , Ecosystem , Animals , Biodiversity , Bayes Theorem , Europe
2.
J Anim Ecol ; 92(1): 158-170, 2023 01.
Article in English | MEDLINE | ID: mdl-36398379

ABSTRACT

Dispersal is a key life-history trait for most species and is essential to ensure connectivity and gene flow between populations and facilitate population viability in variable environments. Despite the increasing importance of range shifts due to global change, dispersal has proved difficult to quantify, limiting empirical understanding of this phenotypic trait and wider synthesis. Here, we introduce a statistical framework to estimate standardised dispersal kernels from biased data. Based on this, we compare empirical dispersal kernels for European breeding birds considering age (average dispersal; natal, before first breeding; and breeding dispersal, between subsequent breeding attempts) and sex (females and males) and test whether different dispersal properties are phylogenetically conserved. We standardised and analysed data from an extensive volunteer-based bird ring-recoveries database in Europe (EURING) by accounting for biases related to different censoring thresholds in reporting between countries and to migratory movements. Then, we fitted four widely used probability density functions in a Bayesian framework to compare and provide the best statistical descriptions of the different age and sex-specific dispersal kernels for each bird species. The dispersal movements of the 234 European bird species analysed were statistically best explained by heavy-tailed kernels, meaning that while most individuals disperse over short distances, long-distance dispersal is a prevalent phenomenon in almost all bird species. The phylogenetic signal in both median and long dispersal distances estimated from the best-fitted kernel was low (Pagel's λ < 0.25), while it reached high values (Pagel's λ >0.7) when comparing dispersal distance estimates for fat-tailed dispersal kernels. As expected in birds, natal dispersal was on average 5 km greater than breeding dispersal, but sex-biased dispersal was not detected. Our robust analytical framework allows sound use of widely available mark-recapture data in standardised dispersal estimates. We found strong evidence that long-distance dispersal is common among European breeding bird species and across life stages. The dispersal estimates offer a first guide to selecting appropriate dispersal kernels in range expansion studies and provide new avenues to improve our understanding of the mechanisms and rules underlying dispersal events.


La dispersión es un rasgo clave del ciclo vital de la mayoría de las especies y es esencial para garantizar la conectividad y el flujo genético entre poblaciones y contribuir a la viabilidad de la población en contextos de ambiente variable. A pesar de que la dispersión es clave para estudiar los cambios en el área de distribución de las especies debido al cambio global, la dispersión es difícil de cuantificar, lo que limita la comprensión empírica de este rasgo fenotípico y su síntesis más amplia. Aquí introducimos un marco de trabajo estadístico para estimar de manera estandarizada los kernels de dispersión a partir de datos sesgados. Basándonos en este marco, comparamos los kernels de dispersión empíricos para las aves reproductoras europeas considerando la edad (dispersión media vital; natal, antes de la primera reproducción; y dispersión reproductora, entre los intentos de reproducción posteriores) y el sexo (hembras y machos), además de explorar si las diferentes propiedades de dispersión se conservan filogenéticamente. Estandarizamos y analizamos los datos de una extensa base de datos de anillamiento de aves en Europa (EURING), basada en voluntarios, teniendo en cuenta los sesgos relacionados con los diferentes umbrales de comunicación de las anillas entre países y con los movimientos migratorios. A continuación, ajustamos, en un marco bayesiano, cuatro funciones de probabilidad ampliamente utilizadas para comparar y proporcionar las mejores descripciones estadísticas de los diferentes kernels de dispersión por edad y sexo para cada especie de ave. Los movimientos de dispersión de las 234 especies de aves europeas analizadas se explicaron estadísticamente mejor mediante kernels de cola pesada, lo que significa que, aunque la mayoría de los individuos se dispersan en distancias cortas, la dispersión a larga distancia es un fenómeno prevalente en casi todas las especies de aves. La señal filogenética tanto en las distancias de dispersión medias como en las largas estimadas a partir del kernel mejor ajustado fue baja (λ de Pagel < 0,25), mientras que alcanzó valores altos (λ de Pagel >0,7) al comparar las estimas de distancia de dispersión para los kernels de cola pesada. Como se esperaba en las aves, la dispersión natal fue en promedio 5 km mayor que la dispersión reproductiva, pero no se detectó una dispersión sesgada por sexo. Nuestro robusto marco analítico permite un buen uso de los datos de marcaje y recaptura disponibles para la estimación estandarizada de las distancias de dispersión. Hemos encontrado pruebas sólidas de que la dispersión a larga distancia es común entre las especies de aves reproductoras europeas y en todas las etapas de la vida. Las estimas de dispersión ofrecen un primer paso para seleccionar los kernels de dispersión adecuados para los estudios de expansión del rango de distribución y proporcionar nuevas vías de investigación para mejorar nuestra comprensión de los mecanismos y procesos que subyacen a los eventos de dispersión.


Subject(s)
Animal Migration , Birds , Female , Male , Animals , Phylogeny , Bayes Theorem , Europe
3.
J Anim Ecol ; 92(1): 97-111, 2023 01.
Article in English | MEDLINE | ID: mdl-36321197

ABSTRACT

Many migratory species are in decline across their geographical ranges. Single-population studies can provide important insights into drivers at a local scale, but effective conservation requires multi-population perspectives. This is challenging because relevant data are often hard to consolidate, and state-of-the-art analytical tools are typically tailored to specific datasets. We capitalized on a recent data harmonization initiative (SPI-Birds) and linked it to a generalized modelling framework to identify the demographic and environmental drivers of large-scale population decline in migratory pied flycatchers (Ficedula hypoleuca) breeding across Britain. We implemented a generalized integrated population model (IPM) to estimate age-specific vital rates, including their dependency on environmental conditions, and total and breeding population size of pied flycatchers using long-term (34-64 years) monitoring data from seven locations representative of the British breeding range. We then quantified the relative contributions of different vital rates and population structure to changes in short- and long-term population growth rate using transient life table response experiments (LTREs). Substantial covariation in population sizes across breeding locations suggested that change was the result of large-scale drivers. This was supported by LTRE analyses, which attributed past changes in short-term population growth rates and long-term population trends primarily to variation in annual survival and dispersal dynamics, which largely act during migration and/or nonbreeding season. Contributions of variation in local reproductive parameters were small in comparison, despite sensitivity to local temperature and rainfall within the breeding period. We show that both short- and long-term population changes of British breeding pied flycatchers are likely linked to factors acting during migration and in nonbreeding areas, where future research should be prioritized. We illustrate the potential of multi-population analyses for informing management at (inter)national scales and highlight the importance of data standardization, generalized and accessible analytical tools, and reproducible workflows to achieve them.


Subject(s)
Songbirds , Animals , Population Dynamics , Songbirds/physiology , Seasons , Population Growth , Temperature , Animal Migration
4.
Biol Lett ; 18(8): 20220186, 2022 08.
Article in English | MEDLINE | ID: mdl-36043306

ABSTRACT

Climate change affects the phenology of annual life cycle events of organisms, such as reproduction and migration. Shifts in the timing of these events could have important population implications directly, or provide information about the mechanisms driving population trajectories, especially if they differ between life cycle event. We examine if such shifts occur in a declining migratory passerine bird (willow warbler, Phylloscopus trochilus), which exhibits latitudinally diverging population trajectories. We find evidence of phenological shifts in breeding initiation, breeding progression and moult that differ across geographic and spring temperature gradients. Moult initiation following warmer springs advances faster in the south than in the north, resulting in proportionally shorter breeding seasons, reflecting higher nest failure rates in the south and in warmer years. Tracking shifts in multiple life cycle events allowed us to identify points of failure in the breeding cycle in regions where the species has negative population trends, thereby demonstrating the utility of phenology analyses for illuminating mechanistic pathways underlying observed population trajectories.


Subject(s)
Animal Migration , Passeriformes , Animals , Climate Change , Life Cycle Stages , Reproduction , Seasons
5.
Proc Biol Sci ; 288(1946): 20202955, 2021 03 10.
Article in English | MEDLINE | ID: mdl-33653129

ABSTRACT

Wildlife conservation policies directed at common and widespread, but declining, species are difficult to design and implement effectively, as multiple environmental changes are likely to contribute to population declines. Conservation actions ultimately aim to influence demographic rates, but targeting actions towards feasible improvements in these is challenging in widespread species with ranges that encompass a wide range of environmental conditions. Across Europe, sharp declines in the abundance of migratory landbirds have driven international calls for action, but actions that could feasibly contribute to population recovery have yet to be identified. Targeted actions to improve conditions on poor-quality sites could be an effective approach, but only if local conditions consistently influence local demography and hence population trends. Using long-term measures of abundance and demography of breeding birds at survey sites across Europe, we show that co-occurring species with differing migration behaviours have similar directions of local population trends and magnitudes of productivity, but not survival rates. Targeted actions to boost local productivity within Europe, alongside large-scale (non-targeted) environmental protection across non-breeding ranges, could therefore help address the urgent need to halt migrant landbird declines. Such demographic routes to recovery are likely to be increasingly needed to address global wildlife declines.


Subject(s)
Animal Migration , Birds , Animals , Conservation of Natural Resources , Europe , Population Dynamics
6.
Int J Gynecol Pathol ; 40(3): 301-304, 2021 May 01.
Article in English | MEDLINE | ID: mdl-32187084

ABSTRACT

Primary ovarian carcinoid tumors are uncommon neoplasms that typically arise in the context of a mature cystic teratoma. Pure primary ovarian carcinoid tumors (PPOCTs) are rare and present as a solid ovarian mass in which, by definition, elements of an associated teratoma or other neoplasm are absent. We report a case of a middle-aged woman who presented with abdominal distension. Computed tomography identified a 20 cm abdominopelvic mass. The patient underwent exploratory laparotomy, hysterectomy, and bilateral salpingo-oophorectomy. A large, solid, yellow-tan ovarian mass was resected and diagnosed as a PPOCT. Para-aortic lymph node metastases were identified. This case highlights the gross and microscopic findings characteristic of PPOCTs. In addition, the large number of differential considerations for an insular PPOCT at intraoperative evaluation are discussed.


Subject(s)
Carcinoid Tumor/diagnostic imaging , Ovarian Neoplasms/diagnostic imaging , Teratoma/diagnostic imaging , Carcinoid Tumor/pathology , Carcinoid Tumor/surgery , Disease-Free Survival , Female , Humans , Hysterectomy , Laparotomy , Lymph Nodes/diagnostic imaging , Lymph Nodes/pathology , Middle Aged , Ovarian Neoplasms/pathology , Ovarian Neoplasms/surgery , Salpingo-oophorectomy , Teratoma/pathology , Teratoma/surgery , Tomography, X-Ray Computed
7.
J Anim Ecol ; 89(9): 2111-2121, 2020 09.
Article in English | MEDLINE | ID: mdl-32383289

ABSTRACT

Migratory species form an important component of biodiversity; they link ecosystems across the globe, but are increasingly threatened by global environmental change. Understanding and mitigating threats requires knowledge of how demographic processes operate throughout the annual cycle, but this can be difficult to achieve when breeding and non-breeding grounds are widely separated. Our goal is to quantify the importance of variability in survival during the breeding and non-breeding seasons in determining variation in annual survival using a single population and, more broadly, the extent to which annual survival across species reflects variation in probability of surviving the migratory period. We use a 25-year dataset in which individuals of a long-distance migratory bird, the alpine swift Tachymarptis melba, were captured towards the beginning and end of each breeding season to estimate age- and season-specific survival probabilities and incorporate explicit estimation of the correlations in survival between age-classes and seasons. Monthly survival was higher during the breeding period than during the rest of the year and strongly affected by conditions in the breeding season; effects that remained apparent in the following non-breeding season, but not subsequently. Recruitment of juveniles was dependent on the timing of breeding, being higher if egg-laying commenced before the median date, and substantially lower if not. Across migratory bird species, variation in annual survival largely reflects variation in the probability of surviving the migratory period. Using a double-capture approach, even within a single season, provides valuable insights into the demography of migratory species, which will help understand the extent and impacts of the threats they face in a changing world.


Subject(s)
Animal Migration , Ecosystem , Animals , Biodiversity , Birds , Seasons
8.
BJU Int ; 124(3): 532-544, 2019 09.
Article in English | MEDLINE | ID: mdl-31077629

ABSTRACT

OBJECTIVES: To develop a focused panel of somatic mutations (SMs) present in the majority of urothelial bladder cancers (UBCs), to investigate the diagnostic and prognostic utility of this panel, and to compare the identification of SMs in urinary cell-pellet (cp)DNA and cell-free (cf)DNA as part of the development of a non-invasive clinical assay. PATIENTS AND METHODS: A panel of SMs was validated by targeted deep-sequencing of tumour DNA from 956 patients with UBC. In addition, amplicon and capture-based targeted sequencing measured mutant allele frequencies (MAFs) of SMs in 314 urine cpDNAs and 153 urine cfDNAs. The association of SMs with grade, stage, and clinical outcomes was investigated by univariate and multivariate Cox models. Concordance between SMs detected in tumour tissue and cpDNA and cfDNA was assessed. RESULTS: The panel comprised SMs in 23 genes: TERT (promoter), FGFR3, PIK3CA, TP53, ERCC2, RHOB, ERBB2, HRAS, RXRA, ELF3, CDKN1A, KRAS, KDM6A, AKT1, FBXW7, ERBB3, SF3B1, CTNNB1, BRAF, C3orf70, CREBBP, CDKN2A, and NRAS; 93.5-98.3% of UBCs of all grades and stages harboured ≥1 SM (mean: 2.5 SMs/tumour). RAS mutations were associated with better overall survival (P = 0.04). Mutations in RXRA, RHOB and TERT (promoter) were associated with shorter time to recurrence (P < 0.05). MAFs in urinary cfDNA and cpDNA were highly correlated; using a capture-based approach, >94% of tumour SMs were detected in both cpDNA and cfDNA. CONCLUSIONS: SMs are reliably detected in urinary cpDNA and cfDNA. The technical capability to identify very low MAFs is essential to reliably detect UBC, regardless of the use of cpDNA or cfDNA. This 23-gene panel shows promise for the non-invasive diagnosis and risk stratification of UBC.


Subject(s)
DNA, Neoplasm/urine , High-Throughput Nucleotide Sequencing/methods , Mutation/genetics , Urinary Bladder Neoplasms/diagnosis , Urinary Bladder Neoplasms/genetics , Adult , Aged , Aged, 80 and over , Databases, Genetic , Female , Humans , Male , Middle Aged , Prognosis , Risk Assessment , Sequence Analysis, DNA
9.
Mod Pathol ; 30(s1): S96-S103, 2017 01.
Article in English | MEDLINE | ID: mdl-28060370

ABSTRACT

Odontogenic cysts and osseous lesions are often seen as challenging diagnostic lesions but the majority of them are easily classified. This article outlines the diagnostic features required for separating the most common of odontogenic cysts and select osseous lesions of the jaws. Clinical and radiographic findings of these jaw lesions often lead to a differential diagnosis that only the histologic findings will clarify. Dentigerous cyst, keratocystic odontogenic tumor, and certain ameloblastomas that have cystic change, may have identical radiographic findings, with only separation by their specific histologic features leading to the significantly different treatments required for each. Conversely, some cystic lesions can appear histologically identical and cannot be diagnosed without the radiographic findings. Certain osseous lesions of the jaws are particularly problematic for diagnosis without the appropriate radiographic findings, and the diagnosis should probably not be attempted on the histologic findings alone. This article will integrate the necessary clinical, radiographic, and histologic findings required to address the most common odontogenic lesions.


Subject(s)
Jaw Cysts/diagnosis , Jaw Neoplasms/diagnosis , Odontogenic Tumors/diagnosis , Diagnosis, Differential , Humans , Jaw Cysts/diagnostic imaging , Jaw Cysts/pathology , Jaw Neoplasms/diagnostic imaging , Jaw Neoplasms/pathology , Odontogenic Tumors/diagnostic imaging , Odontogenic Tumors/pathology
10.
Ecology ; 98(1): 175-186, 2017 Jan.
Article in English | MEDLINE | ID: mdl-28052398

ABSTRACT

Many factors may affect daily nest survival. We present a novel multi-state, multi-stage model to estimate daily survival for each nest stage, daily hatching probability and probability that a failed nest died during a specific stage when stage of failure is unknown. The model does not require that hatching date be known. We used data from a large citizen science dataset to demonstrate the application of this approach, exploring the impact of laying dates, weather conditions, conserved soil moisture, soil carbon, habitat type and urbanization on failure rates of common blackbird (Turdus merula) nests. Models selected and estimates of nest success were similar to those of the simpler logistic exposure method, but accounted for additional uncertainty. Simulations suggest the multi-state approach performs better when incubation mortality is affected by nest age, but not when incubation mortality is assumed constant. Both approaches worked best when date of incubation initiation was known for all nests first visited during the incubation stage. Daily blackbird survival probabilities were higher in human rural habitat than in urban or countryside habitats supporting the hypothesis that these intermediate habitats offer a better balance between low food availability in urban areas and high predation rates in the wider countryside. Nest success was influenced more by recent precipitation in urban habitats, but by a longer-term measure of water availability, soil moisture, in non-human dominated habitats, indicating that climatic change is likely to alter relationships between habitat and breeding success (and their temporal scale) by influencing the trade-off between food availability and predation rates. The multi-state, multi-stage model developed here may be helpful to other researchers modelling ecological processes in which transition probabilities between multiple stages are of interest.


Subject(s)
Birds/physiology , Ecosystem , Models, Theoretical , Weather , Animals , Ecology , Nesting Behavior , Predatory Behavior
11.
J Oral Pathol Med ; 46(9): 798-802, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28727172

ABSTRACT

BACKGROUND: Basal cell predominant salivary gland neoplasms can be difficult to separate histologically. One of the most aggressive of basaloid salivary gland neoplasms is adenoid cystic carcinoma. MYB expression by immunohistochemistry has been documented in adenoid cystic carcinoma. Some investigators have suggested that using this expression can help in establishing the diagnosis of adenoid cystic carcinoma. Utilizing tissue microarrays, we studied a group of basal cell adenocarcinomas and basal cell adenomas to determine: (i) whether either tumor expressed MYB and (ii) the frequency of any expression in either tumors. METHODS: Seventeen salivary gland basal cell adenocarcinomas and 30 salivary gland basal cell adenomas were used to construct microarrays. These tissue microarrays were used to assess for immunohistochemical MYB expression. RESULTS: Fifty-three percent (nine of 17) of salivary gland basal cell adenocarcinomas and 57% (17 of 30) of salivary gland basal cell adenomas showed MYB overexpression. For comparison, we studied 11 adenoid cystic carcinomas for MYB expression and found that 64% (seven of 11) overexpressed MYB. We found no relation to clinical course for basal adenomas or basal cell adenocarcinomas that overexpressed MYB vs those that did not. CONCLUSIONS: MYB expression does not help separate basal cell adenocarcinomas from basal cell adenomas, and our data suggest it does not differentiate between either of these neoplasms and adenoid cystic carcinoma.


Subject(s)
Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Adenoma/metabolism , Adenoma/pathology , Oncogene Proteins v-myb/biosynthesis , Salivary Gland Neoplasms/metabolism , Salivary Gland Neoplasms/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Immunohistochemistry , Male , Middle Aged , Young Adult
12.
J Environ Manage ; 201: 163-171, 2017 Oct 01.
Article in English | MEDLINE | ID: mdl-28658643

ABSTRACT

Assessing the potential impact of additional mortality from anthropogenic causes on animal populations requires detailed demographic information. However, these data are frequently lacking, making simple algorithms, which require little data, appealing. Because of their simplicity, these algorithms often rely on implicit assumptions, some of which may be quite restrictive. Potential Biological Removal (PBR) is a simple harvest model that estimates the number of additional mortalities that a population can theoretically sustain without causing population extinction. However, PBR relies on a number of implicit assumptions, particularly around density dependence and population trajectory that limit its applicability in many situations. Among several uses, it has been widely employed in Europe in Environmental Impact Assessments (EIA), to examine the acceptability of potential effects of offshore wind farms on marine bird populations. As a case study, we use PBR to estimate the number of additional mortalities that a population with characteristics typical of a seabird population can theoretically sustain. We incorporated this level of additional mortality within Leslie matrix models to test assumptions within the PBR algorithm about density dependence and current population trajectory. Our analyses suggest that the PBR algorithm identifies levels of mortality which cause population declines for most population trajectories and forms of population regulation. Consequently, we recommend that practitioners do not use PBR in an EIA context for offshore wind energy developments. Rather than using simple algorithms that rely on potentially invalid implicit assumptions, we recommend use of Leslie matrix models for assessing the impact of additional mortality on a population, enabling the user to explicitly define assumptions and test their importance.


Subject(s)
Algorithms , Birds , Energy-Generating Resources , Wind , Animals , Europe , Mortality , Population Dynamics
13.
Proc Biol Sci ; 283(1842)2016 11 16.
Article in English | MEDLINE | ID: mdl-27807267

ABSTRACT

Across Europe, rapid population declines are ongoing in many Afro-Palaearctic migratory bird species, but the development of appropriate conservation actions across such large migratory ranges is severely constrained by lack of understanding of the demographic drivers of these declines. By constructing regional integrated population models (IPMs) for one of the suite of migratory species that is declining in the southeast of Britain but increasing in the northwest, we show that, while annual population growth rates in both regions vary with adult survival, the divergent regional trajectories are primarily a consequence of differences in productivity. Between 1994 and 2012, annual survival and productivity rates ranged over similar levels in both regions, but high productivity rates were rarer in the declining southeast population and never coincided with high survival rates. By contrast, population growth in the northwest was fuelled by several years in which higher productivity coincided with high survival rates. Simulated population trajectories suggest that realistic improvements in productivity could have reversed the decline (i.e. recovery of the population index to more than or equal to 1) in the southeast. Consequently, actions to improve productivity on European breeding grounds are likely to be a more fruitful and achievable means of reversing migrant declines than actions to improve survival on breeding, passage or sub-Saharan wintering grounds.


Subject(s)
Animal Migration , Birds , Africa South of the Sahara , Animals , Conservation of Natural Resources , Population Dynamics , Seasons , United Kingdom
14.
J Anim Ecol ; 85(5): 1298-306, 2016 09.
Article in English | MEDLINE | ID: mdl-27390034

ABSTRACT

Male-biased sex ratios occur in many bird species, particularly in those with small or declining populations, but the causes of these skews and their consequences for local population demography are rarely known. Within-species variation in sex ratios can help to identify the demographic and behavioural processes associated with such biases. Small populations may be more likely to have skewed sex ratios if sex differences in survival, recruitment or dispersal vary with local abundance. Analyses of species with highly variable local abundances can help to identify these mechanisms and the implications for spatial variation in demography. Many migratory bird species are currently undergoing rapid and severe declines in abundance in parts of their breeding ranges and thus have sufficient spatial variation in abundance to explore the extent of sex ratio biases, their causes and implications. Using national-scale bird ringing data for one such species (willow warbler, Phylloscopus trochilus), we show that sex ratios vary greatly across Britain and that male-biased sites are more frequent in areas of low abundance, which are now widespread across much of south and east England. These sex ratio biases are sufficient to impact local productivity, as the relative number of juveniles caught at survey sites declines significantly with increasing sex ratio skew. Sex differences in survival could influence this sex ratio variation, but we find little evidence for sex differences in survival increasing with sex ratio skew. In addition, sex ratios have become male-biased over the last two decades, but there are no such trends in adult survival rates for males or females. This suggests that lower female recruitment into low abundance sites is contributing to these skews. These findings suggest that male-biased sex ratios in small and declining populations can arise through local-scale sex differences in survival and dispersal, with females recruiting disproportionately into larger populations. Given the high level of spatial variation in population declines and abundance of many migratory bird species across Europe at present, male-biased small populations may be increasingly common. As singing males are the primary records used in surveys of these species, and as unpaired males often sing throughout the breeding season, local sex ratio biases could also be masking the true extent of these population declines.


Subject(s)
Longevity , Reproduction , Sex Ratio , Songbirds/physiology , Animal Migration , Animals , Female , Geography , Male , Population Density , Seasons
15.
Int J Gynecol Pathol ; 35(5): 442-7, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27258816

ABSTRACT

Struma ovarii accounts for 5% of ovarian teratomas. Malignant transformation occurs in <0.3%, however, the underlying molecular mechanism is unknown. We report a patient with follicular variant and tall cell variant of papillary thyroid carcinoma (PTC) arising from struma ovarii and coexisting incidental PTC in the thyroid. Mutation analysis by next-generation sequencing identified a novel germline mutation, KIT p.V530I mutation in the tumors and normal ovarian and thyroid tissue. Immunohistochemical staining showed loss of KIT expression in the PTCs. Activating mutations in KIT play an important role in diagnosis and prognosis of multiple malignancies including mastocytosis, gastrointestinal stromal tumors, and a subset of melanoma and acute myeloid leukemia. The p.V530I mutation has only been reported in 3 previous cases: acute myeloid leukemia, aggressive fibromatosis, and adenocarcinoma of the colon. In the case of aggressive fibromatosis, the patient responded well to imatinib treatment. KIT mutations have never been reported in thyroid carcinomas. This is the first case of PTC-harboring KIT mutation. Although more work needs to be done to elucidate the significance of this germline mutation, the response of the fibromatosis patient to imatinib may shed light on targeted therapy in PTC harboring this mutation.


Subject(s)
Antineoplastic Agents/therapeutic use , Carcinoma/genetics , Imatinib Mesylate/therapeutic use , Ovarian Neoplasms/genetics , Proto-Oncogene Proteins c-kit/genetics , Teratoma/genetics , Thyroid Neoplasms/genetics , Carcinoma/diagnosis , Carcinoma/drug therapy , Carcinoma/pathology , Carcinoma, Papillary , DNA Mutational Analysis , Female , Germ-Line Mutation , Humans , Middle Aged , Ovarian Neoplasms/diagnosis , Ovarian Neoplasms/pathology , Prognosis , Struma Ovarii/pathology , Teratoma/diagnosis , Teratoma/pathology , Thyroid Cancer, Papillary , Thyroid Neoplasms/diagnosis , Thyroid Neoplasms/drug therapy , Thyroid Neoplasms/pathology
16.
Yale J Biol Med ; 88(4): 351-8, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26604858

ABSTRACT

Fine-needle aspiration (FNA) is commonly used for primary evaluation of thyroid nodules. Twenty to 30 percent of thyroid nodules remain indeterminate after FNA evaluation. Studies show the BRAF p.V600E to be highly specific for papillary thyroid carcinoma (PTC), while RAS mutations carry up to 88 percent positive predictive value for malignancy. We developed a two-tube multiplexed PCR assay followed by single-nucleotide primer extension assay for simultaneous detection of 50 mutations in the BRAF (p.V600E, p.K601E/Q) and RAS genes (KRAS and NRAS codons 12, 13, 19, 61 and HRAS 61) using FNA smears of thyroid nodules. Forty-two FNAs and 27 paired formalin-fixed, paraffin-embedded (FFPE) tissues were tested. All BRAF p.V600E-positive FNA smears (five) carried a final diagnosis of PTC on resection. RAS mutations were found in benign as well as malignant lesions. Ninety-two percent concordance was observed between FNA and FFPE tissues. In conclusion, our assay is sensitive and reliable for simultaneous detection of multiple BRAF/RAS mutations in FNA smears of thyroid nodules.


Subject(s)
Multiplex Polymerase Chain Reaction/methods , Polymorphism, Single Nucleotide/genetics , Proto-Oncogene Proteins B-raf/genetics , Thyroid Nodule/genetics , ras Guanine Nucleotide Exchange Factors/genetics , Biopsy, Fine-Needle , Genetic Predisposition to Disease/genetics , Humans , Thyroid Gland/pathology , Thyroid Nodule/diagnosis , Thyroid Nodule/pathology
17.
J Surg Case Rep ; 2024(3): rjae138, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38495046

ABSTRACT

Leiomyosarcoma of the prostate is a rare and aggressive tumor, with a quarter of the patients harboring metastatic disease, commonly in the lung. It usually presents with urinary obstruction in a relatively younger patient group. A 29-year-old male presented with lower urinary tract symptoms to the urologist. Computed tomography scan revealed a large pelvic mass involving the prostate. Biopsy on two occasions yielded leiomyoma. Instead of conventional radical surgery, en-bloc resection of the mass was done while preserving the remaining portion of the prostate, seminal vesicles, and ejaculatory duct. Histopathology revealed a high-grade leiomyosarcoma with negative margins. The patient had excellent recovery of defecation, erectile, and ejaculatory functions within 2 months after adjuvant radiotherapy. At the 24-month follow-up there was no evidence of disease. En-bloc resection of the tumor can be considered in select cases to improve functional outcomes and sustain a higher quality of life in patients.

18.
Lab Invest ; 93(6): 711-9, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23608756

ABSTRACT

We previously identified a novel mutant mouse strain on the C3HeB/FeJ background named Justy. This strain bears a recessive mutation in the Gon4l gene that greatly reduces expression of the encoded protein, a nuclear factor implicated in transcriptional regulation. Here, we report that Justy mutant mice aged 6 months or older spontaneously developed carcinomas with myoepithelial and basaloid differentiation in salivary glands with an incidence of ∼25%. Tumors developed proximate to submandibular glands and to a lesser extent in the sublingual and parotid glands. Histologically, tumors often had central cavitary lesions filled with necrotic debris that were lined by tumor cells, and had spindle and epithelioid cell differentiation with lesser basaloid to clear cell features. Tumor tissue often had variable evidence of a high mitotic rate, pleomorphism, and invasion into adjacent salivary glands. Neoplastic cells had diffuse immunoreactivity for pancytokeratin (AE1/AE3) and p63. Although CK5/6 immunostaining was seen in the much of the tumor cells, it was often lacking in pleomorphic areas. Tumor cells lacked immunoreactivity for alpha-smooth muscle actin, S100, c-Kit, and glial fibrillary acid protein. In addition, tumors had immunoreactivity for phosphorylated and total epidermal growth factor receptor, suggesting that EGFR signaling may participate in growth regulation of these tumors. These findings indicate that the salivary gland carcinomas occur spontaneously in Justy mice, and that these tumors may offer a valuable model for study of EGFR regulation. In combination, our data suggest that Justy mice warrant further investigation for use as a mouse model for human salivary gland neoplasia.


Subject(s)
Carcinoma, Basal Cell/pathology , Myoepithelioma/pathology , Neoplasms, Experimental , Nuclear Proteins/genetics , Salivary Gland Neoplasms/pathology , Animals , Cell Transformation, Neoplastic , Co-Repressor Proteins , DNA-Binding Proteins , Immunohistochemistry , Mice , Mice, Inbred C3H , Mice, Inbred Strains , Salivary Gland Neoplasms/genetics
19.
PLoS One ; 18(4): e0282069, 2023.
Article in English | MEDLINE | ID: mdl-37011064

ABSTRACT

Large-scale declines in terrestrial insects have been reported over much of Europe and across the world, however, population change assessments of other key invertebrate groups, such as soil invertebrates, have been largely neglected through a lack of available monitoring data. This study collates historic data from previously published studies to assess whether it is possible to infer previously undocumented long-term changes in soil invertebrate abundance. Earthworm and tipulid data were collated from over 100 studies across the UK, spanning almost 100 years. Analyses suggested long-term declines in earthworm abundance of between 1.6 to 2.1% per annum, equivalent to a 33% to 41% decline over 25 years. These appeared greatest in broadleaved woodlands and farmland habitats, and were greater in pasture than arable farmland. Significant differences in earthworm abundance between habitats varied between models but appeared to be highest in urban greenspaces and agricultural pasture. More limited data were available on tipulid abundance, which showed no significant change over time or variation between enclosed farmland and unenclosed habitats. Declines in earthworm populations could be contributing to overall declines in ecosystem function and biodiversity as they are vital for a range of ecosystem services and are keystone prey for many vertebrate species. If robust, our results identify a previously undetected biodiversity decline that would be a significant conservation and economic issue in the UK, and if replicated elsewhere, internationally. We highlight the need for long-term and large-scale soil invertebrate monitoring, which potentially could be carried out by citizen/community scientists.


Subject(s)
Oligochaeta , Soil , Animals , Ecosystem , Biodiversity , Agriculture/methods
20.
R Soc Open Sci ; 10(5): 230521, 2023 May.
Article in English | MEDLINE | ID: mdl-37234500

ABSTRACT

Human activity has modified the availability of natural resources and the abundance of species that rely on them, potentially changing interspecific competition dynamics. Here, we use large-scale automated data collection to quantify spatio-temporal competition among species with contrasting population trends. We focus on the spatial and temporal foraging behaviour of subordinate marsh tits Poecile palustris among groups of socially and numerically dominant blue tits Cyanistes caeruleus and great tits Parus major. The three species exploit similar food resources in mixed groups during autumn-winter. Using 421 077 winter recordings of individually marked birds at 65 automated feeding stations in Wytham Woods (Oxfordshire, UK), we found that marsh tits were less likely to join larger groups of heterospecifics, and they accessed food less frequently in larger groups than in smaller ones. Marsh tit numbers within groups declined throughout the diurnal and winter periods, while the number of blue and great tits increased. However, sites that attracted larger groups of these heterospecifics also attracted more marsh tits. The results suggest that subordinate species exhibit temporal avoidance of socially and numerically dominant heterospecifics, but have limited ability for spatial avoidance, indicating that behavioural plasticity enables only a partial reduction of interspecific competition.

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