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1.
Clin Epigenetics ; 16(1): 50, 2024 04 01.
Article in English | MEDLINE | ID: mdl-38561804

ABSTRACT

BACKGROUND: Nucleosome repositioning in cancer is believed to cause many changes in genome organisation and gene expression. Understanding these changes is important to elucidate fundamental aspects of cancer. It is also important for medical diagnostics based on cell-free DNA (cfDNA), which originates from genomic DNA regions protected from digestion by nucleosomes. RESULTS: We have generated high-resolution nucleosome maps in paired tumour and normal tissues from the same breast cancer patients using MNase-assisted histone H3 ChIP-seq and compared them with the corresponding cfDNA from blood plasma. This analysis has detected single-nucleosome repositioning at key regulatory regions in a patient-specific manner and common cancer-specific patterns across patients. The nucleosomes gained in tumour versus normal tissue were particularly informative of cancer pathways, with ~ 20-fold enrichment at CpG islands, a large fraction of which marked promoters of genes encoding DNA-binding proteins. The tumour tissues were characterised by a 5-10 bp decrease in the average distance between nucleosomes (nucleosome repeat length, NRL), which is qualitatively similar to the differences between pluripotent and differentiated cells. This effect was correlated with gene activity, differential DNA methylation and changes in local occupancy of linker histone variants H1.4 and H1X. CONCLUSIONS: Our study offers a novel resource of high-resolution nucleosome maps in breast cancer patients and reports for the first time the effect of systematic decrease of NRL in paired tumour versus normal breast tissues from the same patient. Our findings provide a new mechanistic understanding of nucleosome repositioning in tumour tissues that can be valuable for patient diagnostics, stratification and monitoring.


Subject(s)
Breast Neoplasms , Cell-Free Nucleic Acids , Humans , Female , Nucleosomes/genetics , Breast Neoplasms/genetics , DNA Methylation , Histones/genetics , Histones/metabolism , DNA/metabolism , Cell-Free Nucleic Acids/metabolism , Chromatin
2.
Mol Cancer ; 22(1): 133, 2023 08 12.
Article in English | MEDLINE | ID: mdl-37573301

ABSTRACT

Prostate cancer (PCa) is a common and fatal type of cancer in men. Metastatic PCa (mPCa) is a major factor contributing to its lethality, although the mechanisms remain poorly understood. PTEN is one of the most frequently deleted genes in mPCa. Here we show a frequent genomic co-deletion of PTEN and STAT3 in liquid biopsies of patients with mPCa. Loss of Stat3 in a Pten-null mouse prostate model leads to a reduction of LKB1/pAMPK with simultaneous activation of mTOR/CREB, resulting in metastatic disease. However, constitutive activation of Stat3 led to high LKB1/pAMPK levels and suppressed mTORC1/CREB pathway, preventing mPCa development. Metformin, one of the most widely prescribed therapeutics against type 2 diabetes, inhibits mTORC1 in liver and requires LKB1 to mediate glucose homeostasis. We find that metformin treatment of STAT3/AR-expressing PCa xenografts resulted in significantly reduced tumor growth accompanied by diminished mTORC1/CREB, AR and PSA levels. PCa xenografts with deletion of STAT3/AR nearly completely abrogated mTORC1/CREB inhibition mediated by metformin. Moreover, metformin treatment of PCa patients with high Gleason grade and type 2 diabetes resulted in undetectable mTORC1 levels and upregulated STAT3 expression. Furthermore, PCa patients with high CREB expression have worse clinical outcomes and a significantly increased risk of PCa relapse and metastatic recurrence. In summary, we have shown that STAT3 controls mPCa via LKB1/pAMPK/mTORC1/CREB signaling, which we have identified as a promising novel downstream target for the treatment of lethal mPCa.


Subject(s)
Diabetes Mellitus, Type 2 , Metformin , Prostatic Neoplasms , Animals , Humans , Male , Mice , AMP-Activated Protein Kinases/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism , Metformin/pharmacology , Neoplasm Recurrence, Local , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolism
4.
Conserv Biol ; 37(2): e14018, 2023 04.
Article in English | MEDLINE | ID: mdl-36178020

ABSTRACT

Opportunity costs can represent a significant portion of the costs associated with conservation projects and frequently outstrip other kinds of cost. They are typically understood to refer to the benefits someone would have obtained if conservation projects had not required them to give up current activities, such as farming or hunting or if the land had been available for uses other than conservation. This familiar way of identifying opportunity costs is flawed, however, because it threatens to condone, or take advantage of, the injustices that many people face that affect their opportunities. I integrated ideas from the political theory of global justice to examine how the analysis of opportunity costs illustrates the importance of considering conservation and issues of global justice together, rather than thinking about them in isolation. I distinguish four baselines for defining opportunity costs. A status quo baseline defines opportunity costs by asking what people would have earned had a conservation project not happened. A willingness to accept baseline defines them by asking people what it would take to make them indifferent to whether a conservation project takes place or not. An antipoverty baseline suggests that opportunity costs have been met when people affected by a project are not left in poverty. An egalitarian baseline suggests opportunity costs have been met when people are not left in relative disadvantage, with worse than average opportunities. I argue that the egalitarian baseline is the most acceptable from the point of view of justice. Such a baseline would suggest that, in practice, many of the world's poor are being unjustly treated, or even exploited, as a result of conservation activities.


Los costos de oportunidad pueden representar una porción significativa de los costos asociados con los proyectos de conservación y con frecuencia superan otros tipos de costos. Comúnmente se entiende que estos costos se refieren a los beneficios que alguien habría obtenido si los proyectos de conservación no los hubieran requerido para renunciar a ciertas actividades, como la agricultura o la cacería, o si la tierra hubiera estado disponible para otros usos además de la conservación. Sin embargo, esta manera familiar de identificar los costos de oportunidad es defectuosa ya que amenaza con perdonar, o aprovechar, las injusticias que muchas personas enfrentan y que afectan sus oportunidades. Integré ideas de la teoría política de la justicia global para examinar cómo el análisis de los costos de oportunidad ilustra la importancia de considerar en conjunto la conservación y los temas de justicia global, en lugar de considerarlos de manera aislada. Distingo cuatro líneas base para definir los costos de oportunidad. Una línea base de orden establecido define los costos de oportunidad al preguntar a las personas lo que habrían obtenido de no haberse realizado un proyecto de conservación. Una línea base de la voluntad de aceptación las define al preguntar a las personas qué necesitarían para volverse indiferentes a si se realiza o no un proyecto de conservación. Una línea base de antipobreza sugiere que los costos de oportunidad se han cumplido cuando las personas afectadas por un proyecto no quedan en la pobreza. Una línea base igualitaria sugiere que los costos de oportunidad se han cumplido cuando las personas no quedan en una desventaja relativa, con peores oportunidades al promedio. Argumento que la línea base igualitaria es la más aceptable desde el punto de vista de la justicia. Dicha línea base sugeriría que, en la práctica, muchas de las personas que viven en pobreza son tratadas injustamente, o incluso explotadas, como resultado de las actividades de conservación.


Subject(s)
Agriculture , Conservation of Natural Resources , Humans , Social Justice
5.
Database (Oxford) ; 20212021 03 30.
Article in English | MEDLINE | ID: mdl-33784373

ABSTRACT

Developments in high-throughput sequencing (HTS) result in an exponential increase in the amount of data generated by sequencing experiments, an increase in the complexity of bioinformatics analysis reporting and an increase in the types of data generated. These increases in volume, diversity and complexity of the data generated and their analysis expose the necessity of a structured and standardized reporting template. BioCompute Objects (BCOs) provide the requisite support for communication of HTS data analysis that includes support for workflow, as well as data, curation, accessibility and reproducibility of communication. BCOs standardize how researchers report provenance and the established verification and validation protocols used in workflows while also being robust enough to convey content integration or curation in knowledge bases. BCOs that encapsulate tools, platforms, datasets and workflows are FAIR (findable, accessible, interoperable and reusable) compliant. Providing operational workflow and data information facilitates interoperability between platforms and incorporation of future dataset within an HTS analysis for use within industrial, academic and regulatory settings. Cloud-based platforms, including High-performance Integrated Virtual Environment (HIVE), Cancer Genomics Cloud (CGC) and Galaxy, support BCO generation for users. Given the 100K+ userbase between these platforms, BioCompute can be leveraged for workflow documentation. In this paper, we report the availability of platform-dependent and platform-independent BCO tools: HIVE BCO App, CGC BCO App, Galaxy BCO API Extension and BCO Portal. Community engagement was utilized to evaluate tool efficacy. We demonstrate that these tools further advance BCO creation from text editing approaches used in earlier releases of the standard. Moreover, we demonstrate that integrating BCO generation within existing analysis platforms greatly streamlines BCO creation while capturing granular workflow details. We also demonstrate that the BCO tools described in the paper provide an approach to solve the long-standing challenge of standardizing workflow descriptions that are both human and machine readable while accommodating manual and automated curation with evidence tagging. Database URL:  https://www.biocomputeobject.org/resources.


Subject(s)
Computational Biology , Genomics , High-Throughput Nucleotide Sequencing , Humans , Reproducibility of Results , Software , Workflow
6.
NAR Cancer ; 2(3): zcaa012, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32743555

ABSTRACT

Functional impairment of the tumour suppressor PTEN is common in primary prostate cancer and has been linked to relapse post-radiotherapy (post-RT). Pre-clinical modelling supports elevated CXC chemokine signalling as a critical mediator of PTEN-depleted disease progression and therapeutic resistance. We assessed the correlation of PTEN deficiency with CXC chemokine signalling and its association with clinical outcomes. Gene expression analysis characterized a PTEN LOW/CXCR1HIGH/CXCR2HIGH cluster of tumours that associates with earlier time to biochemical recurrence [hazard ratio (HR) 5.87 and 2.65, respectively] and development of systemic metastasis (HR 3.51). In vitro, CXCL signalling was further amplified following exposure of PTEN-deficient prostate cancer cell lines to ionizing radiation (IR). Inhibition of CXCR1/2 signalling in PTEN-depleted cell-based models increased IR sensitivity. In vivo, administration of a CXCR1/2-targeted pepducin (x1/2pal-i3), or CXCR2-specific antagonist (AZD5069), in combination with IR to PTEN-deficient xenografts attenuated tumour growth and progression compared to control or IR alone. Post-mortem analysis confirmed that x1/2pal-i3 administration attenuated IR-induced CXCL signalling and anti-apoptotic protein expression. Interventions targeting CXC chemokine signalling may provide an effective strategy to combine with RT in locally advanced prostate cancer patients with known presence of PTEN-deficient foci.

7.
Proc Natl Acad Sci U S A ; 116(10): 3994-3999, 2019 Mar 05.
Article in English | MEDLINE | ID: mdl-30760584

ABSTRACT

Ultrahigh-power terahertz (THz) radiation sources are essential for many applications, for example, THz-wave-based compact accelerators and THz control over matter. However, to date none of the THz sources reported, whether based upon large-scale accelerators or high-power lasers, have produced THz pulses with energies above the millijoule (mJ) level. Here, we report a substantial increase in THz pulse energy, as high as tens of mJ, generated by a high-intensity, picosecond laser pulse irradiating a metal foil. A further up-scaling of THz energy by a factor of ∼4 is observed when introducing preplasmas at the target-rear side. Experimental measurements and theoretical models identify the dominant THz generation mechanism to be coherent transition radiation, induced by the laser-accelerated energetic electron bunch escaping the target. Observation of THz-field-induced carrier multiplication in high-resistivity silicon is presented as a proof-of-concept application demonstration. Such an extremely high THz energy not only triggers various nonlinear dynamics in matter, but also opens up the research era of relativistic THz optics.

8.
Conserv Biol ; 33(3): 554-560, 2019 06.
Article in English | MEDLINE | ID: mdl-30569477

ABSTRACT

We examined how, from the point of view of justice, the burdens of paying for conservation should be shared. I resisted simple answers to the question of who should pay for conservation that lean on a single moral principle. I identified 3 relevant principles that relate to who causes conservation challenges, who has greater capacity to carry burdens, and who stands to benefit from conservation. I argue for a distinctive pluralist framework for allocating conservation burdens that grants a proper role to all 3 principles. A multistep process can be used to put the framework into practice. First, identify cases in which conservation is necessary. Second, consider whether people knew or could have been expected to anticipate the consequences of their activities and whether they had reasonable alternatives to acting the way they did. Third, turn to facts about benefits; when no culprit for conservation challenges can be found, ask who benefits from acts of conservation. In the second and third stages, consideration must also be given to ability to pay.


Reparto Equitativo de las Responsabilidades de Conservación Resumen Examinamos cómo, desde el punto de vista de la justicia, se deberían repartir las responsabilidades del pago por conservación. Me resistí a las respuestas para la pregunta de quién debería pagar por la conservación que fueron simples y que se inclinaban por un solo principio moral. Identifiqué tres principios relevantes que se relacionan con quién genera obstáculos para la conservación, quién tiene una mayor capacidad para cargar con las responsabilidades, y quién se beneficiará con la conservación. Abogo por un marco de trabajo distintivo y pluralista para la asignación de responsabilidades de la conservación que otorgue un papel adecuado para los tres principios. Un proceso con múltiples pasos puede usarse para poner en práctica el marco de trabajo. Primero, se deben identificar los casos en los cuales la conservación es necesaria. Segundo, se debe considerar si las personas conocían o podrían haber esperado las consecuencias de sus acciones y si tenían alternativas razonables a las acciones que realizaron. Tercero, ver hacia los hechos sobre los beneficios; cuando no se puede hallar a un culpable de los retos para la conservación, se debe preguntar quién se beneficia con los actos de conservación. En los pasos dos y tres también se debe considerar la habilidad para pagar.


Subject(s)
Conservation of Natural Resources , Social Justice , Morals
9.
Cell Death Dis ; 9(11): 1081, 2018 10 22.
Article in English | MEDLINE | ID: mdl-30349042

ABSTRACT

Expression of tumor necrosis factor-α (TNFα) in the serum of prostate cancer patients is associated with poorer outcome and progression to castrate-resistant (CRPC) disease. TNFα promotes the activity of NFκB, which regulates a number of anti-apoptotic and proinflammatory genes, including those encoding the inhibitor of apoptosis proteins (IAPs); however, in the presence of IAP antagonists, TNFα can induce cell death. In the presence of recombinant or macrophage-derived TNFα, we found that IAP antagonists triggered degradation of cIAP1 and induced formation of Complex-IIb, consisting of caspase-8, FADD and RIPK1 in CRPC models; however, no, or modest levels of apoptosis were induced. This resistance was found to be mediated by both the long (L) and short (S) splice forms of the caspase-8 inhibitor, FLIP, another NFκB-regulated protein frequently overexpressed in CRPC. By decreasing FLIP expression at the post-transcriptional level in PC3 and DU145 cells (but not VCaP), the Class-I histone deacetylase (HDAC) inhibitor Entinostat promoted IAP antagonist-induced cell death in these models in a manner dependent on RIPK1, FADD and Caspase-8. Of note, Entinostat primarily targeted the nuclear rather than cytoplasmic pool of FLIP(L). While the cytoplasmic pool of FLIP(L) was highly stable, the nuclear pool was more labile and regulated by the Class-I HDAC target Ku70, which we have previously shown regulates FLIP stability. The efficacy of IAP antagonist (TL32711) and Entinostat combination and their effects on cIAP1 and FLIP respectively were confirmed in vivo, highlighting the therapeutic potential for targeting IAPs and FLIP in proinflammatory CRPC.


Subject(s)
Apoptosis/drug effects , CASP8 and FADD-Like Apoptosis Regulating Protein/metabolism , Cell Nucleus/drug effects , Cytoplasm/drug effects , Drug Resistance, Neoplasm/drug effects , Histone Deacetylase Inhibitors/pharmacology , Inhibitor of Apoptosis Proteins/antagonists & inhibitors , Prostatic Neoplasms, Castration-Resistant/drug therapy , Animals , Caspase 8/metabolism , Cell Line, Tumor , Cell Nucleus/metabolism , Cytoplasm/metabolism , Histone Deacetylases/metabolism , Humans , Male , Mice , Mice, Inbred BALB C , Mice, SCID , NF-kappa B/metabolism , PC-3 Cells , Prostatic Neoplasms, Castration-Resistant/metabolism , THP-1 Cells , Tumor Necrosis Factor-alpha/metabolism
10.
Methods Mol Biol ; 1786: 195-206, 2018.
Article in English | MEDLINE | ID: mdl-29786794

ABSTRACT

Cancer studies have entered an era that is heavily focused on the contribution of the tumor microenvironment. For this reason, in vivo experimentation in an immunodeficient model system is no longer fit for purpose. As a consequence, numerous genetically engineered mouse models (GEMMs) which self-develop tumors have been developed to allow experiments to be performed in a fully immunocompetent setting. One of the most commonly used technologies is Cre-loxP recombination due to its unique ability to control target gene expression in a specified tissue type. However, the major limitation of these models remains the inability to generate sufficient numbers of age-matched mice for a synchronized experimental start date. For this reason, the derivation of cell lines from genetically modified murine prostate tissue is desirable and allows for the generation of syngeneic models via subcutaneous or orthotopic injection.


Subject(s)
Disease Models, Animal , Mice, Transgenic , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Animals , Breeding , Cell Line, Tumor , Gene Knockout Techniques , Gene Targeting , Genotype , Humans , Male , Mice , Recombination, Genetic , Transplantation, Isogeneic
11.
Environ Toxicol Chem ; 37(2): 336-344, 2018 02.
Article in English | MEDLINE | ID: mdl-28940243

ABSTRACT

Provisional molecular weights and chemical formulas were assigned to 4 significant previously unidentified contaminants present during active fish kills in the Red River region of Oklahoma. The provisional identifications of these contaminants were determined using high-resolution liquid chromatography-time-of-flight mass spectrometry (LC-TOFMS), LC-Fourier transform ion cyclotron resonance mass spectrometry (LC-FTICRMS), and LC-ion trap mass spectrometry (LC-ITMS). Environmental water samples were extracted using a solid-phase extraction (SPE) method, and sediment samples were extracted using a modified sonication liquid extraction method. During screening of the samples, 2 major unknown chromatographic peaks were detected at m/z 624.3 and m/z 639.3. The peak at m/z 639.3 was firmly identified, through the use of an authentic standard, as a porphyrin, specifically chlorin-e6-trimethyl ester, with m/z 639.31735 (M + H)+ and molecular formula C37 H43 N4 O6 . The other major peak, at m/z 624.3 (M + H)+ , was identified as an amide-containing porphyrin. It was discovered that the amide compound was an artifact created during the SPE process by reaction of ammonium hydroxide at 1 of 3 potential reaction sites on chlorin-e6-trimethyl ester. Other unique nontargeted chemicals were also detected and the importance of their identification is discussed. Environ Toxicol Chem 2018;37:336-344. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.


Subject(s)
Fishes/physiology , Rivers/chemistry , Water Pollutants, Chemical/analysis , Animals , Chlorophyllides , Chromatography, Liquid , Geography , Geologic Sediments/chemistry , Oklahoma , Porphyrins/chemistry , Porphyrins/toxicity , Tandem Mass Spectrometry
12.
J Hazard Mater ; 318: 694-701, 2016 Nov 15.
Article in English | MEDLINE | ID: mdl-27484945

ABSTRACT

A small scale sample nuclear waste package, consisting of a 28mm diameter uranium penny encased in grout, was imaged by absorption contrast radiography using a single pulse exposure from an X-ray source driven by a high-power laser. The Vulcan laser was used to deliver a focused pulse of photons to a tantalum foil, in order to generate a bright burst of highly penetrating X-rays (with energy >500keV), with a source size of <0.5mm. BAS-TR and BAS-SR image plates were used for image capture, alongside a newly developed Thalium doped Caesium Iodide scintillator-based detector coupled to CCD chips. The uranium penny was clearly resolved to sub-mm accuracy over a 30cm(2) scan area from a single shot acquisition. In addition, neutron generation was demonstrated in situ with the X-ray beam, with a single shot, thus demonstrating the potential for multi-modal criticality testing of waste materials. This feasibility study successfully demonstrated non-destructive radiography of encapsulated, high density, nuclear material. With recent developments of high-power laser systems, to 10Hz operation, a laser-driven multi-modal beamline for waste monitoring applications is envisioned.

13.
Oncotarget ; 7(7): 7885-98, 2016 Feb 16.
Article in English | MEDLINE | ID: mdl-26799286

ABSTRACT

PTEN loss is prognostic for patient relapse post-radiotherapy in prostate cancer (CaP). Infiltration of tumor-associated macrophages (TAMs) is associated with reduced disease-free survival following radical prostatectomy. However, the association between PTEN loss, TAM infiltration and radiotherapy response of CaP cells remains to be evaluated. Immunohistochemical and molecular analysis of surgically-resected Gleason 7 tumors confirmed that PTEN loss correlated with increased CXCL8 expression and macrophage infiltration. However PTEN status had no discernable correlation with expression of other inflammatory markers by CaP cells, including TNF-α. In vitro, exposure to conditioned media harvested from irradiated PTEN null CaP cells induced chemotaxis of macrophage-like THP-1 cells, a response partially attenuated by CXCL8 inhibition. Co-culture with THP-1 cells resulted in a modest reduction in the radio-sensitivity of DU145 cells. Cytokine profiling revealed constitutive secretion of TNF-α from CaP cells irrespective of PTEN status and IR-induced TNF-α secretion from THP-1 cells. THP-1-derived TNF-α increased NFκB pro-survival activity and elevated expression of anti-apoptotic proteins including cellular inhibitor of apoptosis protein-1 (cIAP-1) in CaP cells, which could be attenuated by pre-treatment with a TNF-α neutralizing antibody. Treatment with a novel IAP antagonist, AT-IAP, decreased basal and TNF-α-induced cIAP-1 expression in CaP cells, switched TNF-α signaling from pro-survival to pro-apoptotic and increased radiation sensitivity of CaP cells in co-culture with THP-1 cells. We conclude that targeting cIAP-1 can overcome apoptosis resistance of CaP cells and is an ideal approach to exploit high TNF-α signals within the TAM-rich microenvironment of PTEN-deficient CaP cells to enhance response to radiotherapy.


Subject(s)
Chemoradiotherapy , Inhibitor of Apoptosis Proteins/antagonists & inhibitors , Macrophages/pathology , PTEN Phosphohydrolase/metabolism , Prostatic Neoplasms/radiotherapy , Radiation-Sensitizing Agents/pharmacology , Apoptosis/drug effects , Apoptosis/radiation effects , Blotting, Western , Cell Proliferation/drug effects , Cell Proliferation/radiation effects , Cells, Cultured , Chemotaxis/drug effects , Chemotaxis/radiation effects , DNA Methylation/drug effects , DNA Methylation/radiation effects , Flow Cytometry , Humans , Immunoenzyme Techniques , Inhibitor of Apoptosis Proteins/drug effects , Inhibitor of Apoptosis Proteins/metabolism , Interleukin-8/metabolism , Macrophages/drug effects , Macrophages/radiation effects , Male , Neoplasm Grading , Prognosis , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/pathology , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Tumor Necrosis Factor-alpha/metabolism , X-Rays
14.
Biol Lett ; 10(1): 20130885, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24451267

ABSTRACT

Observations of the flight paths of pigeons navigating from familiar locations have shown that these birds are able to learn and subsequently follow habitual routes home. It has been suggested that navigation along these routes is based on the recognition of memorized visual landmarks. Previous research has identified the effect of landmarks on flight path structure, and thus the locations of potentially salient sites. Pigeons have also been observed to be particularly attracted to strong linear features in the landscape, such as roads and rivers. However, a more general understanding of the specific characteristics of the landscape that facilitate route learning has remained out of reach. In this study, we identify landscape complexity as a key predictor of the fidelity to the habitual route, and thus conclude that pigeons form route memories most strongly in regions where the landscape complexity is neither too great nor too low. Our results imply that pigeons process their visual environment on a characteristic spatial scale while navigating and can explain the different degrees of success in reproducing route learning in different geographical locations.


Subject(s)
Animal Migration , Columbidae/physiology , Memory , Animals , Humans
15.
Anim Cogn ; 17(1): 33-43, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23604691

ABSTRACT

When homing from familiar areas, homing pigeons are able to exploit previously acquired topographical information, but the mechanisms behind this ability are still poorly understood. One possibility is that they recall the familiar release site topographical features in association with the home direction (site-specific compass orientation strategy), another that the spatial relationships among landmarks guide their route home (piloting strategy), without relying on the compass mechanism. The two strategies can be put in conflict by releasing clock-shifted birds at familiar locations, in order to highlight which is preferred. We analysed GPS tracks of clock-shifted pigeons, with familiarity controlled at each of three different release sites, and we observed that pigeons can display individual preferences for one of the two orientation strategies and that some characteristic features of the release site have an important role in determining the level of landmark-based homeward orientation.


Subject(s)
Columbidae , Homing Behavior , Animals , Circadian Rhythm , Columbidae/physiology , Geographic Information Systems , Recognition, Psychology
16.
Am Surg ; 79(10): 1017-21, 2013 Oct.
Article in English | MEDLINE | ID: mdl-24160791

ABSTRACT

The use of mesh in laparoscopic paraesophageal hiatal hernia repair (LHR) may reduce the risk of late hernia recurrence. The aim of this study was to evaluate initial outcomes and recurrence rate of 92 patients who underwent LHR reinforced with a synthetic bioabsorbable mesh. Surgical approaches included LHR and Nissen fundoplication (n = 64), LHR without fundoplication (n = 10), reoperative LHR (n = 9), LHR with a bariatric operation (n = 6), and emergent LHR (n = 3). The mean length of hospital stay was 2 ± 3 days (range, 1 to 30 days). There were no conversions to open laparotomy and no intraoperative complications. One of 92 patients (1.1%) required intensive care unit stay. The 90-day mortality was zero. Minor complications occurred in 3.3 per cent, major complications in 2.2 per cent, and late complications in 5.5 per cent of patients. There were no perforations or early hernia recurrence. The 30-day reoperation rate was 1.1 per cent. For patients with available 1-year follow-up, the overall recurrence rate was 18.5 per cent with a mean follow-up of 30 months (range, 12 to 51 months). LHR repair with mesh is associated with low perioperative morbidity and no mortality. The use of bioabsorbable mesh appears to be safe with no early hiatal hernia recurrence or late mesh erosion. Longer follow-up is needed to determine the long-term rate of hernia recurrence associated with LHR with mesh.


Subject(s)
Absorbable Implants , Hernia, Hiatal/surgery , Herniorrhaphy/instrumentation , Laparoscopy , Surgical Mesh , Adolescent , Adult , Aged , Aged, 80 and over , Female , Follow-Up Studies , Hernia, Hiatal/prevention & control , Herniorrhaphy/methods , Humans , Length of Stay/statistics & numerical data , Male , Middle Aged , Postoperative Complications/epidemiology , Reoperation/statistics & numerical data , Retrospective Studies , Secondary Prevention , Treatment Outcome , Young Adult
17.
PLoS One ; 8(5): e63130, 2013.
Article in English | MEDLINE | ID: mdl-23717401

ABSTRACT

The sun has long been thought to guide bird navigation as the second step in a two-stage process, in which determining position using a map is followed by course setting using a compass, both over unfamiliar and familiar terrain. The animal's endogenous clock time-compensates the solar compass for the sun's apparent movement throughout the day, and this allows predictable deflections in orientation to test for the compass' influence using clock-shift manipulations. To examine the influence of the solar compass during a highly familiar navigational task, 24 clock-shifted homing pigeons were precision-tracked from a release site close to and in sight of their final goal, the colony loft. The resulting trajectories displayed significant partial deflection from the loft direction as predicted by either fast or slow clock-shift treatments. The partial deflection was also found to be stable along the entire trajectory indicating regular updating of orientation via input from the solar compass throughout the final approach flight to the loft. Our results demonstrate that time-compensated solar cues are deeply embedded in the way birds orient during homing flight, are accessed throughout the journey and on a remarkably fine-grained scale, and may be combined effectively simultaneously with direct guidance from familiar landmarks, even when birds are flying towards a directly visible goal.


Subject(s)
Columbidae/physiology , Homing Behavior , Animals , Cues , Flight, Animal , Housing, Animal , Orientation , Sunlight , Time Factors
18.
J R Soc Interface ; 8(55): 210-9, 2011 Feb 06.
Article in English | MEDLINE | ID: mdl-20656739

ABSTRACT

Pigeons home along idiosyncratic habitual routes from familiar locations. It has been suggested that memorized visual landmarks underpin this route learning. However, the inability to experimentally alter the landscape on large scales has hindered the discovery of the particular features to which birds attend. Here, we present a method for objectively classifying the most informative regions of animal paths. We apply this method to flight trajectories from homing pigeons to identify probable locations of salient visual landmarks. We construct and apply a Gaussian process model of flight trajectory generation for pigeons trained to home from specific release sites. The model shows increasing predictive power as the birds become familiar with the sites, mirroring the animal's learning process. We subsequently find that the most informative elements of the flight trajectories coincide with landscape features that have previously been suggested as important components of the homing task.


Subject(s)
Columbidae/physiology , Cues , Flight, Animal/physiology , Homing Behavior/physiology , Models, Theoretical , Orientation/physiology , Animals , England , Normal Distribution
19.
Am J Geriatr Cardiol ; 16(1): 15-23, 2007.
Article in English | MEDLINE | ID: mdl-17215638

ABSTRACT

There are limited data regarding the diagnosis and treatment of hypercholesterolemia in elderly patients with acute myocardial infarction (AMI). The authors describe the in-hospital and discharge prescription patterns of lipid-lowering agents in patients hospitalized with an AMI, and identify factors associated with low rates of utilization of these therapies. The authors analyzed the Minnesota Heart Survey, a population-based surveillance project that retrospectively abstracted the medical records of patients hospitalized with AMI in 2001-2002 from 21 hospitals in the Minneapolis-St Paul metropolitan area. They identified 2773 patients 30 years and older with an AMI. The mean total cholesterol was 175+/-45 mg/dL, the mean low-density lipoprotein cholesterol was 104+/-38 mg/dL, and the mean high-density lipoprotein cholesterol was 44+/-14 mg/dL. Statins were prescribed at discharge to 74.6%, 63.2%, and 38.5% of patients younger than 65, 65-74, and 75 years and older, respectively (P<.0001). The utilization of statins was highly correlated with the administration of other standard AMI therapies-aspirin, beta-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and reperfusion therapy-and was more prevalent among patients undergoing percutaneous coronary intervention than among those undergoing coronary artery bypass surgery. Elderly patients remain less likely to receive lipid-lowering therapy following an AMI. Greater attention is required to ensure that elderly AMI patients without contraindications are appropriately treated with lipid-lowering therapy.


Subject(s)
Anticholesteremic Agents/therapeutic use , Drug Utilization Review/statistics & numerical data , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Hypercholesterolemia/drug therapy , Myocardial Infarction/physiopathology , Patient Discharge , Practice Patterns, Physicians'/statistics & numerical data , Acute Disease , Adult , Aged , Aged, 80 and over , Anticholesteremic Agents/pharmacology , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Female , Health Care Surveys , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Hypercholesterolemia/diagnosis , Male , Middle Aged , Minnesota , Myocardial Infarction/surgery , Program Evaluation , Retrospective Studies
20.
Med Sci Sports Exerc ; 38(10): 1716-23, 2006 Oct.
Article in English | MEDLINE | ID: mdl-17019292

ABSTRACT

PURPOSE: Twenty-year trends in lifestyle (leisure, household, and transportation related) physical activity and leisure-time physical activity (LTPA) were evaluated in the Minnesota Heart Survey (MHS), a population-based surveillance study to monitor trends in cardiovascular risk factor levels among residents of the Minneapolis-St. Paul metropolitan area. METHODS: The Minnesota LTPA questionnaire was administered to adult participants in one of five cross-sectional MHS surveys conducted in 1980 (N = 1626), 1985 (N = 2292), 1990 (N = 2552), 1995 (N = 2432), and 2000 (N = 3089). Occupational activity was queried in 1980, 1995, and 2000. Age-adjusted, gender-specific geometric means of lifestyle physical activity and LTPA and of light-, moderate-, and vigorous-intensity activities were calculated for each survey. The proportion of adults participating in regular physical activity for 30 and 60 min x d(-1) was reported. RESULTS: Male gender, younger age, higher educational status, and employment were characteristic of greater participation in physical activity. Daily energy expenditure from lifestyle physical activity and LTPA increased between 1980 and 2000 in both genders, and workplace activity decreased. Using direct questions, the prevalence of men and women participating in 30 or more minutes of physical activity at least five times per week ranged from 8 to 12%, with no time trend. Only 1% of participants participated 60 min daily. Overall, BMI was 1-2 kg x m(-2) lower among individuals who participated regularly in physical activity. CONCLUSIONS: Although energy expenditure was lower than national recommendations, greater physical activity was associated with lower body mass. Public health strategies are needed to facilitate participation in physical activity, especially for women, elderly, and less educated individuals.


Subject(s)
Cardiovascular Diseases/epidemiology , Exercise/physiology , Health Surveys , Leisure Activities , Motor Activity/physiology , Adult , Cardiovascular Diseases/physiopathology , Cross-Sectional Studies , Female , Humans , Life Style , Male , Middle Aged , Minnesota/epidemiology , Population Surveillance , Risk Assessment , Risk Factors , Surveys and Questionnaires , Urban Health
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