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1.
Neurobiol Learn Mem ; 157: 41-47, 2019 01.
Article in English | MEDLINE | ID: mdl-30471346

ABSTRACT

Midlife obesity is a risk factor for cognitive decline and is associated with the earlier onset of Alzheimer's disease (AD). Diets high in saturated fat potentiate the onset of obesity, microglial activation, and neuroinflammation. Signaling deficiencies in the hypothalamic peptide orexin and/or orexin fiber loss are linked to neurodegeneration, cognitive impairment, and neuroinflammation. Prior studies show that orexin is neuroprotective, suppresses neuroinflammation, and that treatment with orexin improves cognitive processes in orexin/ataxin-3 (O/A3) mice, a transgenic mouse model of orexin neurodegeneration. Our overall hypothesis is that loss of orexin contributes to high fat diet (HFD)-induced hippocampal neuroinflammation and cognitive decline. To examine this, we tested male O/A3 mice (7-8 mo. of age) in a two-way active avoidance (TWAA) hippocampus-dependent memory task. We tested whether (1) orexin loss impaired cognitive function; (2) HFD worsened cognitive impairment; and (3) HFD increased microglial activation and neuroinflammation. O/A3 mice showed significant impairments in TWAA task learning vs. wild type (WT) mice (increased escapes p < 0.05, reduced avoidances p < 0.0001). Mice were then placed on HFD (45% total fat, 31.4% saturated fat) or remained on normal chow (NC; 4% total fat and 1% saturated fat), and TWAA was retested at 2 and 4 weeks. Learning impairment was evident at both 2 and 4 weeks in O/A3 mice fed HFD for following diet exposure vs. WT mice on normal chow or HFD (increased escapes, reduced avoidances p < 0.05). Additionally, O/A3 mice had increased gene expression of the microglial activation marker Iba-1 (measured via qRT-PCR, p < 0.001). Further characterization of the microglial immune response genes in hippocampal tissue revealed a significant increase in CX3 chemokine receptor 1 (CX3CR1), tumor necrosis factor-alpha (TNF-α) and the mitochondria-associated enzyme immune responsive gene-1 (Irg1). Collectively, our results indicate that orexin loss impairs memory, and that HFD accelerates hippocampus-dependent learning deficits and the onset of neuroinflammation.


Subject(s)
Ataxin-3/physiology , Cognitive Dysfunction/physiopathology , Diet, High-Fat , Encephalitis/physiopathology , Obesity/physiopathology , Orexins/physiology , Animals , Ataxin-3/genetics , Cognitive Dysfunction/etiology , Encephalitis/etiology , Hippocampus/physiopathology , Male , Memory/physiology , Mice, Inbred C57BL , Mice, Transgenic , Obesity/complications , Orexin Receptors/metabolism , Orexins/genetics
2.
BJOG ; 126(8): 1008-1013, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30739400

ABSTRACT

BACKGROUND: As more women are presenting with three previous caesarean deliveries (CD), providers may suggest early term delivery as a means to avoid the risk of spontaneous labour and associated maternal morbidity. OBJECTIVE: To determine whether early term delivery is associated with lower maternal and neonatal morbidity for women with three previous CD. STUDY DESIGN: Secondary analysis of a prospective registry of CD at 19 US academic centres from 1999 to 2002. POPULATION: Women with three previous CD undergoing scheduled or emergent delivery with live, singleton gestations 37-41+ weeks of gestation were included. Women with non-low transverse incisions, antepartum stillbirth, previous myomectomy, fetal anomalies, more or fewer than three previous CD or attempting trial of labour after caesarean section were excluded. METHODS: Gestational age was categorised by week. We fitted logistic regression models to adjust for clinically relevant or statistically significant confounders. MAIN OUTCOME MEASURES: The primary and secondary outcomes were composites, respectively, of maternal and neonatal morbidity. RESULTS: In all, 821 women met the inclusion criteria; maternal morbidity composite occurred in 9.86% and neonatal morbidity occurred in 10.5%. After adjusting for confounding variables, maternal and neonatal morbidity occurred least frequently at 39 weeks. CONCLUSIONS: In women with three previous CDs, adverse maternal outcomes do not increase with increasing gestational age beyond 37 weeks but early term elective repeat CDs are associated with higher neonatal morbidity. Elective delivery of women with three previous CD at 39 weeks of gestation is safe in the absence of maternal or fetal indications for early term delivery. TWEETABLE ABSTRACT: Delivery of women with three previous caesarean deliveries at 39 weeks, in the absence of maternal or fetal indications for early term delivery, is associated with decreased maternal morbidity.


Subject(s)
Cesarean Section, Repeat/adverse effects , Elective Surgical Procedures/adverse effects , Infant, Newborn, Diseases/etiology , Pregnancy Complications/etiology , Time Factors , Adult , Delivery, Obstetric/adverse effects , Female , Gestational Age , Humans , Infant, Newborn , Logistic Models , Pregnancy , Prospective Studies , Registries , United States
4.
Diabet Med ; 35(12): 1686-1692, 2018 12.
Article in English | MEDLINE | ID: mdl-30175547

ABSTRACT

AIM: Attending routine outpatient clinic appointments is a central self-management behaviour of individuals living with Type 1 diabetes. A large number of young adults with Type 1 diabetes disengage from diabetes services, which may contribute to poor psychosocial and diabetes outcomes. The aim of this study is to elicit preferences from young adults with Type 1 diabetes regarding clinic-related services to inform service delivery. METHODS: A discrete choice experiment was developed to understand the preferences of young adults with Type 1 diabetes for clinic-related services. RESULTS: Young adults recruited from young adult Type 1 diabetes clinics in 2016 completed the experiment (n = 105). Young adults with Type 1 diabetes showed a preference for shorter waiting times, seeing a nurse and a consultant, relative to a nurse alone, and a flexible booking system compared with fixed appointment times. Results suggest no preference for a nurse and a doctor, relative to a nurse alone, or other optional services (e.g. seeing dietitians or psychologists), type of HbA1c test and digital blood glucose diaries over paper-based diaries. CONCLUSION: This study highlights aspects of routine clinic appointments that are valued by young adults living with Type 1 diabetes, namely shorter waiting times at clinic, the option to see both a nurse and consultant at each visit and a flexible clinic appointment booking system. These findings suggest young adults with Type 1 diabetes value convenience and should help services to restructure their clinics to be more responsive to the needs of young adults.


Subject(s)
Choice Behavior , Diabetes Mellitus, Type 1/therapy , Patient Preference , Adolescent , Adult , Ambulatory Care Facilities , Blood Glucose/analysis , Blood Glucose Self-Monitoring/instrumentation , Blood Glucose Self-Monitoring/methods , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/epidemiology , Diabetes Mellitus, Type 1/psychology , Female , Focus Groups , Humans , Male , Patient Preference/psychology , Patient Preference/statistics & numerical data , Patient Satisfaction/statistics & numerical data , Professional-Patient Relations , Surveys and Questionnaires , Time Factors , Waiting Lists , Young Adult
6.
BJOG ; 126(7): 915, 2019 06.
Article in English | MEDLINE | ID: mdl-30801941
7.
J Fish Biol ; 85(5): 1739-45, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25130757

ABSTRACT

This study assessed the levels of relatedness of Galeorhinus galeus of progeny arrays using six microsatellite DNA markers. A parentage analysis from five families (mother and litter) from the North Island of New Zealand suggested the occurrence of genetic polyandry in G. galeus with two of the five litters showing multiple sires involved in the progeny arrays. This finding may be consistent with the reproductive characteristics of G. galeus, in which females can potentially store sperm for long periods of time after the mating season.


Subject(s)
Microsatellite Repeats , Sharks/genetics , Alleles , Animals , Embryo, Nonmammalian , Female , Genotype , Male , New Zealand , Sequence Analysis, DNA
8.
Nat Commun ; 15(1): 8406, 2024 Sep 27.
Article in English | MEDLINE | ID: mdl-39333487

ABSTRACT

The signature feature of the 'strange metal' state of high-Tc cuprates-its linear-in-temperature resistivity-has a coefficient α1 that correlates with Tc, as expected were α1 derived from scattering off the same bosonic fluctuations that mediate pairing. Recently, an anomalous linear-in-field magnetoresistance (=γ1H) has also been observed, but only over a narrow doping range, leaving its relation to the strange metal state and to the superconductivity unclear. Here, we report in-plane magnetoresistance measurements on three hole-doped cuprate families spanning a wide range of temperatures, magnetic field strengths and doping. In contrast to expectations from Boltzmann transport theory, γ1 is found to correlate universally with α1. A phenomenological model incorporating real-space inhomogeneity is proposed to explain this correlation. Within this picture, superconductivity in hole-doped cuprates is governed not by the strength of quasiparticle interactions with a bosonic bath, but by the concentration of strange metallic carriers.

9.
Sci Rep ; 14(1): 19467, 2024 08 22.
Article in English | MEDLINE | ID: mdl-39174569

ABSTRACT

Nailfold capillary density is lower in patients with pulmonary arterial hypertension (PAH). It is unclear whether this observation signifies a unique systemic manifestation of PAH, or reflects microcirculatory dysfunction secondary to pulmonary hypertension (PH). Capillary density and loop dimensions were measured by nailfold-capillaroscopy (NC) in 30 PAH (23 idiopathic, or iPAH, 7 hereditary, or hPAH), 17 chronic thromboembolic PH (CTEPH) patients and 48 controls. NC-Measurements were repeated after pulmonary endarterectomy (PEA) or balloon pulmonary angioplasty (BPA) in CTEPH patients. We examined whether NC-measurements were related to markers of disease severity and predictive of time to clinical worsening (TTCW) as tested by univariate linear/logistic regression and cox-regression analysis, respectively. Capillary density was significantly lower in PAH (7.5 ± 1.1, p < 0.001) and in CTEPH (8.4 ± 1.5, p < 0.001) compared to asymptomatic controls (10.3 ± 1.0 capillaries/mm). Capillary density was similar in iPAH and hPAH and unrelated to hemodynamics in either PAH or CTEPH. A lower capillary density was predictive of clinical worsening in PAH (p 0.05). After normalization of pulmonary artery pressures by PEA or BPA, capillary density remained reduced in CTEPH patients. Capillary loop apex, capillary and venous- and arterial limb diameter were increased in patients with PAH and CTEPH compared to controls. Nailfold capillary density is reduced to a similar extent in iPAH, hPAH and CTEPH. Normalization of hemodynamics by PEA or BPA does not lead to a restoration of capillary density in CTEPH. Capillary dimensions were increased in both patients with PAH and CTEPH. Lower capillary density was predictive of clinical worsening in PAH. Our findings indicate that a loss of peripheral capillaries is not specific to PAH and is not related to the hemodynamic disturbance per se, but that shared mechanisms may account for a simultaneous development of a systemic microangiopathy and pulmonary vascular remodeling.


Subject(s)
Capillaries , Hypertension, Pulmonary , Humans , Female , Male , Middle Aged , Capillaries/pathology , Capillaries/physiopathology , Hypertension, Pulmonary/physiopathology , Hypertension, Pulmonary/etiology , Aged , Biomarkers , Pulmonary Embolism/physiopathology , Pulmonary Embolism/complications , Microscopic Angioscopy/methods , Adult , Pulmonary Arterial Hypertension/physiopathology , Pulmonary Arterial Hypertension/surgery , Endarterectomy/methods , Microvascular Density , Chronic Disease , Nails/blood supply , Case-Control Studies
10.
Phys Chem Chem Phys ; 15(43): 18752-70, 2013 Nov 21.
Article in English | MEDLINE | ID: mdl-23868502

ABSTRACT

We present our perspective on the theoretical basis of light-harvesting within the photosynthetic membrane. Far from being a static structure, the photosynthetic membrane is a highly dynamic system, with protein mobility playing an important role in the damage/repair cycle of photosystem II (PSII), in balancing the input of energy between PSI and PSII, and in the photoprotection of PSII in response to a sudden excess of illumination. The concept of a photosynthetic antenna is illustrated and the state transition phenomenon is discussed as an example of purposeful antenna mobility. We discuss fluorescence recovery after photo-bleaching as a technique for visualising membrane mobility, before introducing light-induced grana membrane reorganisation as an integral part of the rapid photoprotective switch in plants. We then discuss current theoretical approaches to modelling the energy transfer dynamics of the PSII antenna: the atomistic models of intra-complex transfer and the coarse-grained approach to the inter-complex dynamics. Finally we discuss the future prospect of extending these methods, beyond the static picture of the membrane, to the dynamic PSII photosynthetic antenna.


Subject(s)
Photosynthesis , Photosystem II Protein Complex/metabolism , Energy Transfer , Light-Harvesting Protein Complexes/chemistry , Light-Harvesting Protein Complexes/metabolism , Models, Molecular , Photobleaching , Photosystem II Protein Complex/chemistry , Plants/metabolism , Thylakoids/metabolism
11.
J Musculoskelet Neuronal Interact ; 13(4): 480-6, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24292618

ABSTRACT

Muscle function can be assessed through jumping mechanography, where portable ground reaction force plates collect dynamic information as a subject jumps. The aim of this study was to assess both intra- and inter- rater reliability of jumping mechanography. Ten healthy adults underwent 3 sets of testing (collected by 3 different raters) at two separate sessions, one week apart. They performed a number of tests in each session: multiple one-legged hopping (M1LH; on right and left legs) and single two-legged jumps (S2LJ; with or without arm swing). The S2LJ assessed variables of power per body mass, jump height, velocity and efficiency; whereas, M1LH assessed maximum force per body mass and stiffness. Inter-rater coefficients of variation (CV) were less than 0.6% and 2.6% for the S2LJ and M1LH, respectively, for the primary outcome variables of power/body mass and force/body mass. Analyzing intra-rater results also produced CVs less than 5.3% for all variables. The present study reports that the Leonardo ground reaction force plate system yields reproducible results between sessions, without significant contribution of variability from the test operator. Jumping mechanography is an easy, safe and reliable method for the assessment of lower limb musculoskeletal function.


Subject(s)
Exercise/physiology , Leg/physiology , Movement/physiology , Muscle, Skeletal/physiology , Adult , Biomechanical Phenomena/physiology , Female , Humans , Male , Reproducibility of Results
12.
Science ; 382(6672): 792-796, 2023 Nov 17.
Article in English | MEDLINE | ID: mdl-37972183

ABSTRACT

Upon cooling, condensed-matter systems typically transition into states of lower symmetry. The converse-i.e., the emergence of higher symmetry at lower temperatures-is extremely rare. In this work, we show how an unusually isotropic magnetoresistance in the highly anisotropic, one-dimensional conductor Li0.9Mo6O17 and its temperature dependence can be interpreted as a renormalization group (RG) flow toward a so-called separatrix. This approach is equivalent to an emergent symmetry in the system. The existence of two distinct ground states, Mott insulator and superconductor, can then be traced back to two opposing RG trajectories. By establishing a direct link between quantum field theory and an experimentally measurable quantity, we uncover a path through which emergent symmetry might be identified in other candidate materials.

13.
Science ; 376(6588): 77-80, 2022 04.
Article in English | MEDLINE | ID: mdl-35271303

ABSTRACT

Recurrent novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated when ejected material slams into the companion star's wind can accelerate particles. We report very-high-energy (VHE; [Formula: see text]) gamma rays from the recurrent nova RS Ophiuchi, up to 1 month after its 2021 outburst, observed using the High Energy Stereoscopic System (H.E.S.S.). The temporal profile of VHE emission is similar to that of lower-energy giga-electron volt emission, indicating a common origin, with a 2-day delay in peak flux. These observations constrain models of time-dependent particle energization, favoring a hadronic emission scenario over the leptonic alternative. Shocks in dense winds provide favorable environments for efficient acceleration of cosmic rays to very high energies.

14.
Arch Virol ; 156(12): 2157-62, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21947503

ABSTRACT

The production, preliminary characterisation and applications of monoclonal antibodies (mAbs) against two novel swine bocaviruses isolated in cell culture from swine in Northern Ireland are described. Of the 17 stable final clones produced, four were characterised. All were of the IgG2a isotype and showed no cross-reactivity with either bocavirus strain. Partial neutralisation was observed with PBoV4 mAbs and homologous virus. The two mAbs selected for use in antigen-detecting ELISAs were successful in highlighting those fractions containing infectious virus within sucrose gradients. This is the first report of the production of specific reagents that will prove useful in the study of the biology of these viruses and swine bocavirus-associated diseases.


Subject(s)
Antibodies, Monoclonal/biosynthesis , Antibodies, Viral/biosynthesis , Bocavirus/immunology , Bocavirus/isolation & purification , Sus scrofa/virology , Animals , Antigens, Viral/analysis , Bocavirus/pathogenicity , Cross Reactions , Enzyme-Linked Immunosorbent Assay , Immunoglobulin G/biosynthesis , Mice , Mice, Inbred BALB C , Neutralization Tests , Northern Ireland , Parvoviridae Infections/veterinary , Parvoviridae Infections/virology , Swine , Swine Diseases/virology
15.
Science ; 372(6546): 1081-1085, 2021 06 04.
Article in English | MEDLINE | ID: mdl-34083487

ABSTRACT

Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera-electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.

17.
Science ; 212(4499): 1148-51, 1981 Jun 05.
Article in English | MEDLINE | ID: mdl-7233208

ABSTRACT

Long-term potentiation of the hippocampal slice preparation results in an increase in the incorporation of labeled valine into the proteins destined for secretion into the extracellular medium. Double-labeling methods established that the increased secretion of the labeled proteins was limited to the potentiated region of a slice; incorporation of labeled valine was increased in the hippocampus if potentiation was through the Schaffer collaterals and in the dentate if potentiation was through the perforant path. Controls for nonspecific stimulation showed no changes. There appears to be a link between long-term potentiation and the metabolic processes that lead to protein synthesis in the hippocampal slice system.


Subject(s)
Hippocampus/metabolism , Nerve Tissue Proteins/biosynthesis , Animals , Carbon Radioisotopes , Electric Stimulation , Hippocampus/physiology , In Vitro Techniques , Kinetics , Nerve Tissue Proteins/metabolism , Rats , Tritium , Valine
18.
Nanotechnology ; 20(2): 025203, 2009 Jan 14.
Article in English | MEDLINE | ID: mdl-19417265

ABSTRACT

We have used scanning Kelvin probe microscopy (SKPM) as a local probe to study charge trapping in zone-cast pentacene field effect transistors on both SiO(2) and benzocyclobutene (BCB) substrates. Annealing at 130 degrees C was found to reduce the threshold voltage, susceptibility to negative gate bias stress and trapping of positive charges within single pentacene grains. We conclude that oxygen is able to penetrate and disassociatively incorporate into crystalline pentacene, chemically creating electrically active defect states. Screening of a positive gate bias caused by electron injection from Au into pentacene was directly observed with SKPM. The rate of screening was found to change significantly after annealing of the film and depended on the choice of gate dielectric.

19.
Cardiol Young ; 19 Suppl 2: 96-9, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19857356

ABSTRACT

BACKGROUND: The so-called Gerbode ventriculo-atrial defect is a rare defect that permits shunting from the left ventricle to the right atrium. It takes 2 forms, either a deficiency of the atrioventricular membranous septum, or shunting initially through a ventricular septal defect, with atrial shunting occurring through a deficiency in the septal leaflet of the tricuspid valve. In this review, we describe the natural history and outcomes of surgical repair for the variant with shunting through a deficiency at the site of the atrioventricular membranous septum. METHODS: From 1990 to 2008, we identified 6 patients from our departmental database who had undergone surgical closure of a congenital defect of the atrioventricular component of the membranous septum. Median age at repair was 1.6 years, with a range, from 0.4 to 19 years. All patients were symptomatic, with 3 having congestive cardiac failure, 2 failing to thrive, and 2 having intolerance to exercise. All had a dilated right atrium demonstrated by echocardiogram, with a mean preoperative gradient measured by echocardiogram to be 109 millimetres of mercury, with a range from 65 to 150 millimetres of mercury. RESULTS: There was no operative or late mortality. The mean size of the defect was 6.2 +/- 2.0 millimetres, with a range from 4 to 8 millimetres. All were closed by insertion of a patch. The mean period of cardiopulmonary bypass was 90.5 +/- 11.3 minutes, the mean time of aortic cross-clamping 54.8 +/- 6.9 minutes, and the mean length of stay in hospital 4.3 +/- 1.0 days. No patient had a residual defect, and only trivial regurgitation of the tricuspid valve was evident by postoperative echocardiography. There were no complications or reoperations. CONCLUSION: The membranous ventriculo-atrial defect can be recognized echocardiographically on the basis of dilation of the right atrium in the setting of an unusually high Doppler echocardiogram gradient compared to the ventricular septal defect with shunting only at ventricular level. Since all patients in our series were symptomatic, we recommend surgical closure of all these defects.


Subject(s)
Cardiopulmonary Bypass/methods , Heart Septal Defects/surgery , Adolescent , Cardiomegaly/etiology , Child , Child, Preschool , Female , Heart Atria/abnormalities , Heart Atria/diagnostic imaging , Heart Atria/surgery , Heart Septal Defects/complications , Heart Ventricles/abnormalities , Heart Ventricles/diagnostic imaging , Heart Ventricles/surgery , Humans , Infant , Male , Retrospective Studies , Treatment Outcome , Ultrasonography , Young Adult
20.
Sci Rep ; 8(1): 2661, 2018 02 08.
Article in English | MEDLINE | ID: mdl-29422513

ABSTRACT

Conservation concerns exist for many sharks but robust estimates of abundance are often lacking. Improving population status is a performance measure for species under conservation or recovery plans, yet the lack of data permitting estimation of population size means the efficacy of management actions can be difficult to assess, and achieving the goal of removing species from conservation listing challenging. For potentially dangerous species, like the white shark, balancing conservation and public safety demands is politically and socially complex, often leading to vigorous debate about their population status. This increases the need for robust information to inform policy decisions. We developed a novel method for estimating the total abundance of white sharks in eastern Australia and New Zealand using the genetic-relatedness of juveniles and applying a close-kin mark-recapture framework and demographic model. Estimated numbers of adults are small (ca. 280-650), as is total population size (ca. 2,500-6,750). However, estimates of survival probability are high for adults (over 90%), and fairly high for juveniles (around 73%). This represents the first direct estimate of total white shark abundance and survival calculated from data across both the spatial and temporal life-history of the animal and provides a pathway to estimate population trend.


Subject(s)
Sharks/genetics , Animals , Australia , Conservation of Natural Resources/methods , Demography , Ecosystem , Genetics, Population , New Zealand , Population Density
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