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1.
Neurosci Res ; 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37992997

RESUMEN

Childhood and adolescent affiliations guide how individuals engage in social relationships throughout their lifetime and adverse experiences can promote biological alterations that facilitate behavioral maladaptation. Indeed, childhood victims of abuse are more likely to be diagnosed with conduct or mood disorders which are both characterized by altered social engagement. A key domain particularly deserving of attention is aggressive behavior, a hallmark of many disorders characterized by deficits in reward processing. Animal models have been integral in identifying both the short- and long-term consequences of stress exposure and suggest that whether it is disruption to parental care or social isolation, chronic exposure to early life stress increases corticosterone, changes the expression of neurotransmitters and neuromodulators, and facilitates structural alterations to the hypothalamus, hippocampus, and amygdala, influencing how these brain regions communicate with other reward-related substrates. Herein, we describe how adverse early life experiences influence social behavioral outcomes across a wide range of species and highlight the long-term biological mechanisms that are most relevant to maladaptive aggressive behavior.

2.
Neuron ; 111(18): 2899-2917.e6, 2023 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-37442130

RESUMEN

Motivated behaviors are often studied in isolation to assess labeled lines of neural connections underlying innate actions. However, in nature, multiple systems compete for expression of goal-directed behaviors via complex neural networks. Here, we examined flexible survival decisions in animals tasked with food seeking under predation threat. We found that predator exposure rapidly induced physiological, neuronal, and behavioral adaptations in mice highlighted by reduced food seeking and consumption contingent on current threat level. Diminishing conflict via internal state or external environment perturbations shifted feeding strategies. Predator introduction and/or selective manipulation of danger-responsive cholecystokinin (Cck) cells of the dorsal premammilary nucleus (PMd) suppressed hunger-sensitive Agouti-related peptide (AgRP) neurons, providing a mechanism for threat-evoked hypophagia. Increased caloric need enhanced food seeking under duress through AgRP pathways to the bed nucleus of the stria terminalis (BNST) and/or lateral hypothalamus (LH). Our results suggest oscillating interactions between systems underlying self-preservation and food seeking to promote optimal behavior.


Asunto(s)
Hipotálamo , Neuronas , Ratones , Animales , Proteína Relacionada con Agouti/metabolismo , Hipotálamo/metabolismo , Neuronas/fisiología , Hambre/fisiología , Área Hipotalámica Lateral/fisiología
3.
Res Sq ; 2023 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-37461537

RESUMEN

Aggression is an evolutionarily conserved behavior that controls social hierarchies and protects valuable resources like mates, food, and territory. In mice, aggressive behaviour can be broken down into an appetitive phase, which involves approach and investigation, and a consummatory phase, which involves biting, kicking, and wrestling. By performing an unsupervised weighted correlation network analysis on whole-brain c-Fos expression, we identified a cluster of brain regions including hypothalamic and amygdalar sub-regions and olfactory cortical regions highly co-activated in male, but not female aggressors (AGG). The posterolateral cortical amygdala (COApl), an extended olfactory structure, was found to be a hub region based on the number and strength of correlations with other regions in the cluster. Our data further show that estrogen receptor 1 (ESR1)-expressing cells in the COApl exhibit increased activity during attack behaviour, and during bouts of investigation which precede an attack, in male mice only. Chemogenetic or optogenetic inhibition of COApl ESR1 cells in AGG males reduces aggression and increases pro-social investigation without affecting social reward/reinforcement behavior. We further confirmed that COApl ESR1 projections to the ventrolateral portion of the ventromedial hypothalamus and central amygdala are necessary for these behaviours. Collectively, these data suggest that in aggressive males, COApl ESR1 cells respond specifically to social stimuli, thereby enhancing their salience and promoting attack behaviour.

4.
Radiography (Lond) ; 29(3): 653-660, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37141686

RESUMEN

INTRODUCTION: Engaging with patients when designing a clinical or research project is beneficial; feedback from the intended audience provides invaluable insight form the patients' perspective. Working with patients can result in developing successful research grants and interventions. The benefit of including the voice of the patient in the Yorkshire Cancer Research funded PREHABS study is described in this article. METHODS: Patients were included in the PREHABS study from inception to completion. The Theory of Change methodology was used to provide a framework to implement patient feedback to refine the study intervention. RESULTS: In total, 69 patients engaged with the PREHABS project. Two patients were recruited as co-applicants on the grant and were members on the Trial Management Group. Six patients attended the pre application workshop and provided feedback on their lived experiences of being a lung cancer patient. Commentary from the patients influenced the interventions selected and the design of the prehabs study. Following ethical approval (21/EE/0048) and informed written consent, 61 patients were recruited into the PREHABS study between October 2021 and November 2022. The breakdown of recruited patients was 19 males: mean age 69.1 years (SD 8.91) and 41 females; mean age 74.9 years (SD 8.9). CONCLUSION: It is practicable and beneficial to include patients at all stages of designing and delivering a research study. Patient feedback can help refine the study interventions to allow for maximum acceptance, recruitment and retention. IMPLICATIONS FOR PRACTICE: Including patients in the design of radiotherapy research studies can provide invaluable insight that can support the selection and delivery of interventions that are acceptable to the patient cohort.


Asunto(s)
Neoplasias , Proyectos de Investigación , Masculino , Femenino , Humanos , Anciano , Neoplasias/radioterapia
5.
Nature ; 613(7945): 696-703, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36450985

RESUMEN

In humans, traumatic social experiences can contribute to psychiatric disorders1. It is suggested that social trauma impairs brain reward function such that social behaviour is no longer rewarding, leading to severe social avoidance2,3. In rodents, the chronic social defeat stress (CSDS) model has been used to understand the neurobiology underlying stress susceptibility versus resilience following social trauma, yet little is known regarding its impact on social reward4,5. Here we show that, following CSDS, a subset of male and female mice, termed susceptible (SUS), avoid social interaction with non-aggressive, same-sex juvenile C57BL/6J mice and do not develop context-dependent social reward following encounters with them. Non-social stressors have no effect on social reward in either sex. Next, using whole-brain Fos mapping, in vivo Ca2+ imaging and whole-cell recordings, we identified a population of stress/threat-responsive lateral septum neurotensin (NTLS) neurons that are activated by juvenile social interactions only in SUS mice, but not in resilient or unstressed control mice. Optogenetic or chemogenetic manipulation of NTLS neurons and their downstream connections modulates social interaction and social reward. Together, these data suggest that previously rewarding social targets are possibly perceived as social threats in SUS mice, resulting from hyperactive NTLS neurons that occlude social reward processing.


Asunto(s)
Vías Nerviosas , Trauma Psicológico , Recompensa , Núcleos Septales , Conducta Social , Estrés Psicológico , Animales , Femenino , Masculino , Ratones , Encéfalo/patología , Encéfalo/fisiopatología , Calcio/análisis , Calcio/metabolismo , Ratones Endogámicos C57BL , Neuronas/metabolismo , Neurotensina/metabolismo , Optogenética , Trauma Psicológico/patología , Trauma Psicológico/fisiopatología , Núcleos Septales/patología , Núcleos Septales/fisiopatología , Estrés Psicológico/patología , Estrés Psicológico/fisiopatología
6.
Clin Oncol (R Coll Radiol) ; 34(11): 724-732, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36088168

RESUMEN

Lung cancer is the third most common type of cancer in the UK, with nearly 50 000 new cases diagnosed a year. Treatments for lung cancer have improved in recent years with the advent of new surgical and radiotherapy techniques and the increased use of immunotherapies. These advances have resulted in increasing numbers of patients surviving beyond the completion of their treatment. Lung cancer patients are now not dying from their cancer diagnosis, but from other co-existing pathologies. Lung cancer patients commonly present with multiple comorbidities. Mitigating the effects of poor lifestyles and changing behaviours may improve the efficacy of treatments, reduce side-effects and improve the quality of life for lung cancer patients. Published evidence supports the use of interventions to manage behavioural habits, to optimise the health of patients. There is no consensus as to what, when or how to embed these into the patient pathway. Supporting patients before, during and after their cancer treatments to increase activity, eat well and stop smoking have been seen to decrease side-effects and improve patient outcomes and wellbeing. The challenge is to provide a package of interventions that is acceptable to patients and fits within the patient pathway so as not to conflict with diagnostic and therapeutic activities. This article reviews where we are today with providing behavioural support to optimise the health of lung cancer patients undergoing treatment.


Asunto(s)
Neoplasias Pulmonares , Ejercicio Preoperatorio , Humanos , Calidad de Vida
7.
Neuropsychopharmacology ; 47(10): 1746-1754, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35810200

RESUMEN

Aggression is an evolutionarily conserved, adaptive component of social behavior. Studies in male mice illustrate that aggression is influenced by numerous factors including the degree to which an individual finds aggression rewarding and will work for access to attack and subordinate mice. While such studies have expanded our understanding of the molecular and circuit mechanisms of male aggression very little is known about female aggression, within these established contexts. Here we use an ethologically relevant model of male vs. female aggression by pair housing adult male and female outbred CFW mice with opposite sex cage mates. We assess reactive (defensive) aggression in the resident intruder (RI) test and appetitive (rewarding) aggression in the aggression conditioned place preference (CPP) and operant self-administration (SA) tests. Our results show dramatic sex differences in both qualitative and quantitative aspects of reactive vs. appetitive aggression. Males exhibit more wrestling and less investigative behavior during RI, find aggression rewarding, and will work for access to a subordinate to attack. Females exhibit more bites, alternate between aggressive behaviors and investigative behaviors more readily during RI, however, they do not find aggression to be rewarding or reinforcing. These results establish sex differences in aggression in mice, providing an important resource for the field to better understand the circuit and molecular mechanisms of aggression in both sexes.


Asunto(s)
Agresión , Caracteres Sexuales , Animales , Femenino , Masculino , Ratones , Recompensa , Autoadministración , Conducta Social
8.
Nurse Educ Today ; 115: 105407, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35660165

RESUMEN

Introducing best practice approaches to help nursing students identify and respond to patients who are/have been exposed to intimate partner violence (IPV) is instrumental to their professional development. The objectives of this study are to gather preliminary data from the American Association for the Colleges of Nursing (AACN) affiliated schools of nursing to determine 1) if they offer any training of students at the undergraduate or graduate level in identifying and responding to IPV; 2) if so, what are the components of that training, outcomes, and satisfaction with the existing approach; 3) if not, what are the individual and institutional level barriers to offering this training; and 4) if schools are interested in incorporating best practice, IPV training content into their curriculum. DESIGN AND METHODS: A total of 836 AACN affiliated nursing schools across the US were surveyed using a 64-item electronic survey. RESULTS: Of the 95 (11%) schools that completed at least 40% of the survey, approximately 60% offer IPV training once at the undergraduate level and only 30% offered such preparation at the graduate level. We found that most IPV education took place as embedded material within an existing course. Those nursing schools not providing any IPV education identified that they would like to at both levels and the 50% of nursing schools already providing this education said they wanted to provide more. The greatest barriers to offering IPV education were lack of faculty expertise and time constraints, yet about 70% of the participants stated that IPV education should be an essential part of undergraduate and graduate nursing school. CONCLUSION: This study provides useful insights to inform IPV curriculum development by identifying common gaps in IPV education experienced by participating schools and strategies for addressing them.


Asunto(s)
Educación en Enfermería , Violencia de Pareja , Estudiantes de Enfermería , Curriculum , Humanos , Facultades de Enfermería
9.
Mol Psychiatry ; 27(5): 2563-2579, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-33931727

RESUMEN

Heightened aggressive behavior is considered as one of the central symptoms of many neuropsychiatric disorders including autism, schizophrenia, and dementia. The consequences of aggression pose a heavy burden on patients and their families and clinicians. Unfortunately, we have limited treatment options for aggression and lack mechanistic insight into the causes of aggression needed to inform new efforts in drug discovery and development. Levels of proinflammatory cytokines in the periphery or cerebrospinal fluid were previously reported to correlate with aggressive traits in humans. However, it is still unknown whether cytokines affect brain circuits to modulate aggression. Here, we examined the functional role of interleukin 1ß (IL-1ß) in mediating individual differences in aggression using a resident-intruder mouse model. We found that nonaggressive mice exhibit higher levels of IL-1ß in the dorsal raphe nucleus (DRN), the major source of forebrain serotonin (5-HT), compared to aggressive mice. We then examined the effect of pharmacological antagonism and viral-mediated gene knockdown of the receptors for IL-1 within the DRN and found that both treatments consistently increased aggressive behavior of male mice. Aggressive mice also exhibited higher c-Fos expression in 5-HT neurons in the DRN compared to nonaggressive mice. In line with these findings, deletion of IL-1 receptor in the DRN enhanced c-Fos expression in 5-HT neurons during aggressive encounters, suggesting that modulation of 5-HT neuronal activity by IL-1ß signaling in the DRN controls expression of aggressive behavior.


Asunto(s)
Agresión , Núcleo Dorsal del Rafe , Interleucina-1beta , Serotonina , Agresión/fisiología , Animales , Núcleo Dorsal del Rafe/metabolismo , Humanos , Individualidad , Interleucina-1beta/metabolismo , Masculino , Ratones , Serotonina/metabolismo
10.
Front Behav Neurosci ; 15: 735387, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34630052

RESUMEN

The reproducibility crisis (or replication crisis) in biomedical research is a particularly existential and under-addressed issue in the field of behavioral neuroscience, where, in spite of efforts to standardize testing and assay protocols, several known and unknown sources of confounding environmental factors add to variance. Human interference is a major contributor to variability both within and across laboratories, as well as novelty-induced anxiety. Attempts to reduce human interference and to measure more "natural" behaviors in subjects has led to the development of automated home-cage monitoring systems. These systems enable prolonged and longitudinal recordings, and provide large continuous measures of spontaneous behavior that can be analyzed across multiple time scales. In this review, a diverse team of neuroscientists and product developers share their experiences using such an automated monitoring system that combines Noldus PhenoTyper® home-cages and the video-based tracking software, EthoVision® XT, to extract digital biomarkers of motor, emotional, social and cognitive behavior. After presenting our working definition of a "home-cage", we compare home-cage testing with more conventional out-of-cage tests (e.g., the open field) and outline the various advantages of the former, including opportunities for within-subject analyses and assessments of circadian and ultradian activity. Next, we address technical issues pertaining to the acquisition of behavioral data, such as the fine-tuning of the tracking software and the potential for integration with biotelemetry and optogenetics. Finally, we provide guidance on which behavioral measures to emphasize, how to filter, segment, and analyze behavior, and how to use analysis scripts. We summarize how the PhenoTyper has applications to study neuropharmacology as well as animal models of neurodegenerative and neuropsychiatric illness. Looking forward, we examine current challenges and the impact of new developments. Examples include the automated recognition of specific behaviors, unambiguous tracking of individuals in a social context, the development of more animal-centered measures of behavior and ways of dealing with large datasets. Together, we advocate that by embracing standardized home-cage monitoring platforms like the PhenoTyper, we are poised to directly assess issues pertaining to reproducibility, and more importantly, measure features of rodent behavior under more ethologically relevant scenarios.

11.
Radiography (Lond) ; 27 Suppl 1: S14-S19, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34274226

RESUMEN

OBJECTIVES: To explain what a clinical academic career can be, what it can lead to for the individual, profession and most importantly the patient, and why these roles are so important to radiography. KEY FINDINGS: Multiple challenges to the adoption of clinical academic careers exist, including achievable measurable outcomes, visibility & senior support, and balancing different time demands. Equally the rewards are wide ranging and can advance both the individual and profession through role extension opportunities, increased career progression, patient benefits, and academic and research skills. CONCLUSION: Clinical academic careers can provide advantages for the individual, department, profession and most importantly the patient with advanced clinical practice through evidenced based research. IMPLICATIONS FOR PRACTICE: Improving clinical academic careers within Radiography will promote research participation and increase radiographic roles in patient-centred research delivery and development. Combining evidenced based research with academic skills will lead to improved patient care and better clinical outcomes.


Asunto(s)
Técnicos Medios en Salud , Recompensa , Humanos
12.
Nat Neurosci ; 23(5): 638-650, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32284606

RESUMEN

Heightened aggression is characteristic of multiple neuropsychiatric disorders and can have various negative effects on patients, their families and the public. Recent studies in humans and animals have implicated brain reward circuits in aggression and suggest that, in subsets of aggressive individuals, domination of subordinate social targets is reinforcing. In this study, we showed that, in male mice, orexin neurons in the lateral hypothalamus activated a small population of glutamic acid decarboxylase 2 (GAD2)-expressing neurons in the lateral habenula (LHb) via orexin receptor 2 (OxR2) and that activation of these GAD2 neurons promoted male-male aggression and conditioned place preference for aggression-paired contexts. Moreover, LHb GAD2 neurons were inhibitory within the LHb and dampened the activity of the LHb as a whole. These results suggest that the orexin system is important for the regulation of inter-male aggressive behavior and provide the first functional evidence of a local inhibitory circuit within the LHb.


Asunto(s)
Agresión/fisiología , Neuronas GABAérgicas/metabolismo , Habénula/metabolismo , Orexinas/metabolismo , Animales , Masculino , Ratones , Transducción de Señal/fisiología
13.
Anim Reprod Sci ; 207: 73-82, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31208851

RESUMEN

A dopamine type-2 receptor (DRD2) SNP, previously found to be correlated with serum prolactin (PRL) concentrations in cattle, was evaluated for impact on growth traits, serum prolactin concentration, and semen quality. Over a four-year period, yearling beef bulls were allowed diets containing or lacking ergot alkaloids (EA). Every 21 or 28 d semen was collected for semen motility and morphology assessment and blood samples were collected to measure serum PRL concentrations. In addition, body condition score and scrotal circumference were evaluated. Serum PRL concentrations were assessed using a radioimmunoassay. In the first year, all bulls were sacrificed at the end of a 126-day study. Testicles and epididymis were collected at the end of the study or 60 days after removal from treatment. Immunohistochemistry was performed on testis, epididymis, and sperm cells, incubated with or without a primary antibody for DRD2 and counterstained with DAPI. Isolation of DNA was performed on sperm pellets using DNAzol (Thermo Fisher Scientific, Waltham, MA, USA) methods. Polymerase chain reaction was performed to amplify the region of the DRD2 gene containing the SNP of interest. The products were subjected to restriction fragment length polymorphism analysis. Further, all samples were subjected to genotyping using a custom Taqman genotyping assay (Applied Biosystems, Foster city, CA, USA). The presence of DRD2 was detected in the testis, epididymis, and sperm cells. The DRD2 genotype was not associated with semen quality, serum PRL, or growth traits. Consumption of EA resulted in lesser PRL serum concentrations but had no effect on values for other variable examined.


Asunto(s)
Bovinos , Agonistas de Dopamina/farmacología , Crecimiento y Desarrollo , Polimorfismo de Nucleótido Simple , Prolactina/sangre , Receptores de Dopamina D2/genética , Semen/efectos de los fármacos , Animales , Constitución Corporal/genética , Bovinos/sangre , Bovinos/genética , Bovinos/crecimiento & desarrollo , Dopamina/sangre , Genotipo , Crecimiento y Desarrollo/efectos de los fármacos , Crecimiento y Desarrollo/genética , Masculino , Semen/metabolismo , Semen/fisiología , Análisis de Semen/veterinaria , Motilidad Espermática/efectos de los fármacos , Motilidad Espermática/genética
14.
Elife ; 82019 03 25.
Artículo en Inglés | MEDLINE | ID: mdl-30907726

RESUMEN

When presented with a choice, organisms need to assimilate internal information with external stimuli and past experiences to rapidly and flexibly optimize decisions on a moment-to-moment basis. We hypothesized that increasing hunger intensity would curb expression of social behaviors such as mating or territorial aggression; we further hypothesized social interactions, reciprocally, would influence food consumption. We assessed competition between these motivations from both perspectives of mice within a resident-intruder paradigm. We found that as hunger state escalated, resident animal social interactions with either a female or male intruder decreased. Furthermore, intense hunger states, especially those evoked via AgRP photoactivation, fundamentally altered sequences of behavioral choice; effects dependent on food availibility. Additionally, female, but not male, intrusion attenuated resident mouse feeding. Lastly, we noted environmental context-dependent gating of food intake in intruding mice, suggesting a dynamic influence of context cues on the expression of feeding behaviors.


Asunto(s)
Toma de Decisiones , Conducta Alimentaria , Hambre , Conducta Social , Animales , Femenino , Masculino , Ratones , Motivación
15.
Radiography (Lond) ; 24(4): 283-288, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30292495

RESUMEN

INTRODUCTION: To measure the range of T1 values of synovitis using three Tesla (3 T) magnetic resonance imaging (MRI) in patients with osteoarthritis to assess the potential of T1 mapping for identifying synovitis from other features in the knee on unenhanced magnetic resonance scans. METHODS: After receiving institutional ethical approval, 83 patients who met the American College of Rheumatology criteria for diagnosis of osteoarthritis of the knee were scanned using a 3 T Magnetic Resonance Imaging scanner. T1 maps were calculated from spoiled gradient echo images acquired with five different flip angles of 5°-25°. Mean values for the T1 measurements were calculated and compared to existing data from the published literature for anatomical and pathological structures of the knee. RESULTS: T1 values recorded in patients suffering from osteoarthritis demonstrated that T1 values for synovitis (confirmed on gadolinium enhanced images) fall in a narrow range (849-1277 ms, mean 1005 ms SD 91) delineating this from other structures of the knee such as muscle (T1 value range 1305-2638 ms, mean 1785 ms SD 304) and synovial fluid (T1 value range 3867-4129 ms, mean 3915 SD 899) at 3 T. CONCLUSION: T1 values measured in synovitis in patients with osteoarthritis of the knee demonstrated a range of values distinct to those measured in muscle and synovial fluid at 3 T. This offers potential for the use of T1 maps to delineate or quantify synovitis in patients who are unwilling or unable to receive injectable contrast agents.


Asunto(s)
Imagen por Resonancia Magnética , Osteoartritis de la Rodilla/diagnóstico por imagen , Sinovitis/diagnóstico por imagen , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Articulación de la Rodilla/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
16.
Theriogenology ; 118: 219-224, 2018 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-29945053

RESUMEN

The objective of this study was to evaluate semen quality and fertility in beef bulls grazing the ergot alkaloid (EA) producing tall fescue cultivar, Kentucky 31 (KY31), compared to a novel endophyte (NE) cultivar lacking EA. Two studies were conducted over a 3-year period. In studies 1 (n = 10; ages ≥ 24 mo) and 2 (n = 53 over two years; ages 12-16 mo), Angus (AN) bulls were stratified by body weight (BW), body condition score (BCS), and scrotal circumference (SC), and then allotted to graze either KY31 or NE for 56 days. Semen samples were collected, and BW, BCS, and SC were evaluated at the start of treatment (TRT) on day (d) 0 and every 28 days to the end of each study. In addition, blood samples were collected on d 0 and every 28 days for assessment of circulating prolactin (PRL) levels in study 2. On d 56, for both studies, semen from bulls (n = 2 per treatment in study 1 and n = 4 per treatment in study 2) with similar and acceptable quality were extended, kept at 19° C, and used for timed artificial insemination (TAI) of primi- and multiparous AN and AN- crossbred females. Pregnancy was evaluated at 35 and 90 days post-TAI via transrectal ultrasonography to determine pregnancy rates. Serum PRL concentrations showed a TRT by d effect (P ≤ 0.05), with values for bulls grazing KY31 decreased on d 28 and d 56 of grazing compared to NE. In studies 1 and 2, bull BW and BCS were affected by d (P ≤ 0.05), but not by TRT. No TRT or TRT by d effect on semen quality was observed in either study; however, d impacted both velocity and concentration in study 2 (P ≤ 0.05). In study 1, TAI pregnancy rates at 35 days post-TAI were lower (P ≤ 0.05) in the group inseminated with semen from bulls grazing KY31; however, in study 2, pregnancy rates did not differ due to treatment 35 post-TAI (P > 0.05). Grazing KY31 negatively impacted serum PRL concentrations, supporting previous observations; however, consumption of KY31 had no effect on growth or semen quality of AN bulls ranging from 12 to ≥24 mo of age. Furthermore, fertility data is inconsistent between studies and requires further investigation.


Asunto(s)
Alcaloides de Claviceps/efectos adversos , Fertilidad/efectos de los fármacos , Análisis de Semen/veterinaria , Semen/efectos de los fármacos , Envejecimiento , Alimentación Animal/análisis , Animales , Bovinos , Alcaloides de Claviceps/metabolismo , Femenino , Festuca/metabolismo , Inseminación Artificial/veterinaria , Masculino , Embarazo , Índice de Embarazo , Prolactina/sangre , Escroto/anatomía & histología
17.
J Mater Chem B ; 6(22): 3665-3673, 2018 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-32254829

RESUMEN

Iron oxide nanoparticles (IONs) are being actively researched and experimented with as contrast agents for Magnetic Resonance Imaging (MRI), as well as image-directed delivery of therapeutics. The efficiency of an MRI contrast agent can be described by its longitudinal and transverse relaxivities, r1 and r2. γ-Fe2O3 nanoparticles - doped with fluoride in a controlled manner and functionalised with citric acid - showed a 3-fold increase in r1 and a 17-fold increase in r2 in a magnetic field of 3 T and almost 6-fold increase in r1 and a 14-fold increase in r2 at 11 T. Following fluorination, PXRD shows that the crystal structure of γ-Fe2O3 is maintained, Mössbauer spectroscopy shows that the oxidation state of the Fe cation is unchanged and HREM shows that the particle size does not vary. However, magnetisation curves show a large increase in the coercive field, pointing towards a large increase in the magnetic anisotropy for the fluorinated nanoparticles compared to the un-doped γ-Fe2O3 nanoparticles. Therefore, a chemically induced increase in magnetic anisotropy appears to be the most relevant parameter responsible for the large increase in relaxivity for γ-Fe2O3 nanoparticles.

18.
Anim Reprod Sci ; 181: 24-29, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28392308

RESUMEN

There are many positive agronomic traits that make tall fescue a desirable forage, however, reduced fertility rates are reported for beef cattle grazing pasture containing the ergot alkaloid-producing endophyte, Epichloë coenophiala. The objective of this study was to assess the influence of consuming tall fescue containing ergot alkaloids on sperm physiology, as measured by survival of sperm following cryopreservation. Yearling Angus bulls (n=25), having passed a breeding soundness exam (BSE), were assigned to one of two treatments accounting for body weight (BW) and body condition score (BCS). Bulls were allotted to one of two treatments on day (d) 0, grazing toxic Kentucky 31 (KY31) or a novel endophyte-containing cultivar, Texoma Max Q II (NE; AR584 Ag Research) that does not produce ergot alkaloids, for 112 days. On d 112, all bulls were placed on NE pasture to the end of test (d 168) to evaluate recovery from grazing KY31. Blood, urine, and semen samples were collected every 28 days. Semen collected on d 28, 84, 112, 140, and 168 was extended, frozen, thawed 48h later, and subjected to analyses. There were significant treatment by day interactions for serum prolactin (PRL) concentrations, verifying the effectiveness of treatment (P<0.05). Serum PRL concentrations were less in the bulls pastured on KY31 compared to NE on d 28, 84, and 112. Urinary alkaloid concentrations were affected by treatment by day interactions, confirming ergot alkaloids were present in animal systems (P<0.05). Bulls in the NE treatment group had lesser urinary alkaloid concentrations than those pastured on KY31 on d 28, 84, and 112. Post-thaw sperm analyses revealed that the percentage of progressively motile sperm was less in bulls pastured on KY31 when compared to NE (P<0.05). There were treatment by day interactions for sperm concentration, percent motile sperm, percent motile sperm concentration, and percent progressively motile sperm concentration post-thawing (P<0.05). The KY31 treatment group had a lesser sperm 1) concentration than the NE group on d 84; 2) percent motility on d 28, 84, and 168; 3) motile concentration on d 28, 84, and 168; and 4) progressively motile concentration on d 28 and 84. Sperm motility was affected post-thawing for at least 56 d following removal from the KY31 pasture.


Asunto(s)
Criopreservación/veterinaria , Epichloe/metabolismo , Alcaloides de Claviceps/toxicidad , Festuca/microbiología , Preservación de Semen/veterinaria , Alimentación Animal , Animales , Bovinos , Alcaloides de Claviceps/metabolismo , Alcaloides de Claviceps/orina , Masculino , Espermatozoides/efectos de los fármacos , Espermatozoides/fisiología
19.
Risk Anal ; 37(2): 206-218, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28230267

RESUMEN

Space weather describes the way in which the Sun, and conditions in space more generally, impact human activity and technology both in space and on the ground. It is now well understood that space weather represents a significant threat to infrastructure resilience, and is a source of risk that is wide-ranging in its impact and the pathways by which this impact may occur. Although space weather is growing rapidly as a field, work rigorously assessing the overall economic cost of space weather appears to be in its infancy. Here, we provide an initial literature review to gather and assess the quality of any published assessments of space weather impacts and socioeconomic studies. Generally speaking, there is a good volume of scientific peer-reviewed literature detailing the likelihood and statistics of different types of space weather phenomena. These phenomena all typically exhibit "power-law" behavior in their severity. The literature on documented impacts is not as extensive, with many case studies, but few statistical studies. The literature on the economic impacts of space weather is rather sparse and not as well developed when compared to the other sections, most probably due to the somewhat limited data that are available from end-users. The major risk is attached to power distribution systems and there is disagreement as to the severity of the technological footprint. This strongly controls the economic impact. Consequently, urgent work is required to better quantify the risk of future space weather events.

20.
Neuron ; 92(1): 187-201, 2016 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-27693254

RESUMEN

Behavioral choice is ubiquitous in the animal kingdom and is central to goal-oriented behavior. Hypothalamic Agouti-related peptide (AgRP) neurons are critical regulators of appetite. Hungry animals, bombarded by multiple sensory stimuli, are known to modify their behavior during times of caloric need, rapidly adapting to a consistently changing environment. Utilizing ARCAgRP neurons as an entry point, we analyzed the hierarchical position of hunger related to rival drive states. Employing a battery of behavioral assays, we found that hunger significantly increases its capacity to suppress competing motivational systems, such as thirst, anxiety-related behavior, innate fear, and social interactions, often only when food is accessible. Furthermore, real-time monitoring of ARCAgRP activity revealed time-locked responses to conspecific investigation in addition to food presentation, further establishing that, even at the level of ARCAgRP neurons, choices are remarkably flexible computations, integrating internal state, external factors, and anticipated yield. VIDEO ABSTRACT.


Asunto(s)
Núcleo Arqueado del Hipotálamo/fisiología , Hambre/fisiología , Motivación/fisiología , Neuronas/fisiología , Proteína Relacionada con Agouti/genética , Proteína Relacionada con Agouti/fisiología , Animales , Conducta Animal/fisiología , Señales (Psicología) , Ingestión de Alimentos/fisiología , Ratones , Ratones Transgénicos , Proteínas del Transporte Vesicular de Aminoácidos Inhibidores/genética , Proteínas del Transporte Vesicular de Aminoácidos Inhibidores/fisiología
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