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1.
Osteoarthritis Cartilage ; 30(6): 875-885, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35307533

RESUMEN

OBJECTIVE: In light of the role of immune cells in OA pathogenesis, the development of sophisticated animal models closely mimicking the immune dysregulation during the disease development and progression could be instrumental for the preclinical evaluation of novel treatments. Among these models, immunologically humanized mice may represent a relevant system, particularly for testing immune-interacting DMOADs or cell therapies before their transfer to the clinic. Our objective, therefore, was to develop an experimental model of OA by destabilization of the medial meniscus (DMM) in humanized mice. METHOD: Irradiated 5-week-old NOD/LtSz-scid IL2Rγnull (NSG) mice were humanized by intravenous injection of CD34+ human hematopoietic stem cells. The engraftment efficiency was evaluated by flow cytometry 17 weeks after the humanization procedure. Humanized and non-humanized NSG mice underwent DMM or sham surgery and OA development was assessed 1, 6, and 12 weeks after the surgery. RESULTS: 120 days after the humanization, human T and B lymphocytes, macrophages and NK cells, were present in the blood and spleen of the humanized NSG mice. The DMM surgery induced articular cartilage and meniscal alterations associated with an increase in OA and the meniscal score. Moreover, the surgery triggered an inflammatory response that was sustained at a low grade in the DMM group. CONCLUSIONS: Our study shows for the first time the feasibility of inducing OA by DMM in humanized mice. This novel OA model could constitute a useful tool to bridge the gap between the preclinical and clinical evaluation of immune interacting DMOADs and cell-based therapies.


Asunto(s)
Cartílago Articular , Osteoartritis , Animales , Cartílago Articular/patología , Modelos Animales de Enfermedad , Meniscos Tibiales/patología , Meniscos Tibiales/cirugía , Ratones , Ratones Endogámicos NOD , Osteoartritis/patología
2.
Toxicol In Vitro ; 78: 105258, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34653646

RESUMEN

Air pollution has significant health effects worldwide, and airborne particles play a significant role in these effects. Ultrafine particles (UFPs) have an aerodynamic diameter of 0.1 µm or less, can penetrate deep into the respiratory tree, and are more toxic due to their large specific surface area, which should adsorb organic compounds. The aim of this study is to show the toxicological effects of UFPs with high organic content at low dose on BEAS-2B cells through at air-liquid interface (ALI) exposure using a Vitrocell® technology and a miniCAST (Combustion Aerosol Standard) generator. In conjunction with this approach, chemical analysis of particles and gas phase was performed to evaluate the presence of polycyclic aromatic hydrocarbons (PAHs). Chemical analyses confirmed the presence of PAHs in UFPs. With this experimental setup, exposure of the BEAS-2B cells induced neither cytotoxicity nor mitochondrial dysfunction. However, an increase of oxidative stress was observed, as assessed through Nrf2, NQO1, HO-1, CuZnSOD, MnSOD, and Catalase gene expression, together with significant induction of genes related to xenobiotic metabolism CYP1A1 and CYP1B1. Negative regulation of inflammatory genes expression (IL-6 and IL-8) was present three hours after the exposition to the UFPs. Taken together, this experimental approach, using repeatable conditions, should help to clarify the mechanisms by which organic UFPs induce toxicological effects.


Asunto(s)
Material Particulado/toxicidad , Hidrocarburos Policíclicos Aromáticos/análisis , Hollín/toxicidad , Línea Celular , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1B1/genética , Citocromo P-450 CYP1B1/metabolismo , Humanos , Interleucinas/genética , Interleucinas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Material Particulado/química , Hollín/química
3.
J Econ Entomol ; 115(1): 371-380, 2022 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-34970979

RESUMEN

Tennessee and Texas cow-calf producers were surveyed to assess their 2016 expenses for horn fly control methods. Cattle producers who were members of the Texas and Southwestern Cattle Raisers Association and Tennessee cattle producers who have participated in the Tennessee Agricultural Enhancement Program participated in the survey. Average horn fly management costs in Tennessee and Texas were $9.50/head and $12.40/head, respectively. An ordinary least squares regression and quantile regression were estimated to examine how horn fly costs are influenced by producer and farm demographics, seasonality of horn flies, producer horn fly perceptions, and management practices. When controlling for these variables, Tennessee and Texas cattle producers did not spend significantly different amounts on horn fly control methods. Horn fly costs were associated with producer and farm demographics, producer perceptions of horn flies, and management practices. For example, results indicate that horn fly management costs vary depending on a producer's level of education and income. Having Angus cattle and larger herd sizes were associated with lower costs per head spent on horn fly management. Producers who did not consider horn flies to be a problem until greater quantities of flies were present on the animal spent 15% less per head on managing horn flies. In terms of horn fly control methods, feedthrough insecticides increased horn fly costs the most, followed by using ear tags. This is the first known research to estimate horn fly management costs among cattle producers.


Asunto(s)
Enfermedades de los Bovinos , Muscidae , Animales , Bovinos , Femenino , Control de Insectos/métodos , Tennessee , Texas
4.
Stem Cell Res ; 37: 101421, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30933723

RESUMEN

Ischemia-reperfusion injury (I/RI), produced by an initial interruption of organ blood flow and its subsequent restoration, contributes significantly to the pathophysiologies of stroke, myocardial infarction, renal I/RI, intestinal I/RI and liver I/RI, which are major causes of disability (including transplant failure) and even mortality. While the restoration of blood flow is required to restore oxygen and nutrient requirements, reperfusion often triggers local and systemic inflammatory responses and subsequently elevate the ischemic insult where the duration of ischemia determines the magnitude of I/RI damage. I/RI increases vascular leakage, changes transcriptional and cell death programs, drives leukocyte entrapment and inflammation and oxidative stress in tissues. Therapeutic approaches which reduce complications associated with I/RI are desperately needed to address the clinical and economic burden created by I/RI. Stem cells (SC) represent ubiquitous and uncommitted cell populations with the ability to self-renew and differentiate into one or more developmental 'fates'. Like immune cells, stem cells can home to and penetrate I/R-injured tissues, where they can differentiate into target tissues and induce trophic paracrine signaling which suppress injury and maintain tissue functions perturbed by ischemia-reperfusion. This review article summarizes the present use and possible protective mechanisms underlying stem cell protection in diverse forms of ischemia-reperfusion.


Asunto(s)
Daño por Reperfusión/terapia , Trasplante de Células Madre/métodos , Células Madre/citología , Animales , Humanos
5.
J Radiol Prot ; 38(3): 1037-1052, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29871999

RESUMEN

Thermal neutrons are found in reactor, radiotherapy, aircraft, and space environments. The purpose of this study was to characterise the dosimetry and microdosimetry of thermal neutron exposures, using three simulation codes, as a precursor to quantitative radiobiological studies using blood samples. An irradiation line was designed employing a pyrolytic graphite crystal or-alternatively-a super mirror to expose blood samples to thermal neutrons from the National Research Universal reactor to determine radiobiological parameters. The crystal was used when assessing the relative biological effectiveness for dicentric chromosome aberrations, and other biomarkers, in lymphocytes over a low absorbed dose range of 1.2-14 mGy. Higher exposures using a super mirror will allow the additional quantification of mitochondrial responses. The physical size of the thermal neutron fields and their respective wavelength distribution was determined using the McStas Monte Carlo code. Spinning the blood samples produced a spatially uniform absorbed dose as determined from Monte Carlo N-Particle version 6 simulations. The major part (71%) of the total absorbed dose to blood was determined to be from the 14N(n,p)14C reaction and the remainder from the 1H(n,γ)2H reaction. Previous radiobiological experiments at Canadian Nuclear Laboratories involving thermal neutron irradiation of blood yielded a relative biological effectiveness of 26 ± 7. Using the Particle and Heavy Ion Transport Code System, a similar value of ∼19 for the quality factor of thermal neutrons initiating the 14N(n,p)14C reaction in soft tissue was determined by microdosimetric simulations. This calculated quality factor is of similar high value to the experimentally-derived relative biological effectiveness, and indicates the potential of thermal neutrons to induce deleterious health effects in superficial organs such as cataracts of the eye lens.


Asunto(s)
Sangre/efectos de la radiación , Neutrones , Reactores Nucleares , Radiometría , Humanos , Cristalino/efectos de la radiación , Transferencia Lineal de Energía , Método de Montecarlo
6.
Med Devices (Auckl) ; 11: 123-137, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29713206

RESUMEN

INTRODUCTION: Invasive medical devices are used in treating millions of patients each day. Bacterial adherence to their surface is an early step in biofilm formation that may lead to infection, health complications, longer hospital stays, and death. Prevention of bacterial adherence and biofilm development continues to be a major healthcare challenge. Accordingly, there is a pressing need to improve the anti-microbial properties of medical devices. MATERIALS AND METHODS: Polydimethylsiloxane (PDMS) was doped with halloysite nanotubes (HNTs), and the PDMS-HNT composite surfaces were coated with PDMS-b-polyethylene oxide (PEO) and antibacterials. The composite material properties were examined using SEM, energy dispersive spectroscopy, water contact angle measurements, tensile testing, UV-Vis spectroscopy, and thermal gravimetric analysis. The antibacterial potential of the PDMS-HNT composites was compared to commercial urinary catheters using cultures of E. coli and S. aureus. Fibrinogen adsorption studies were also performed on the PDMS-HNT-PEO composites. RESULTS: HNT addition increased drug load during solvent swelling without reducing material strength. The hydrophilic properties provided by PEO were maintained after HNT addition, and the composites displayed protein-repelling properties. Additionally, composites showed superiority over commercial catheters at inhibiting bacterial growth. CONCLUSION: PDMS-HNT composites showed superiority regarding their efficacy at inhibiting bacterial growth, in comparison to commercial antibacterial catheters. Our data suggest that PDMS-HNT composites have potential as a coating material for anti-bacterial invasive devices and in the prevention of institutional-acquired infections.

7.
J Homosex ; 65(9): 1138-1151, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29144852

RESUMEN

The present study investigates microaggressions toward individuals in lesbian, gay, bisexual, transgender, and queer (LGBTQ) families. Microaggressions are subtle forms of discrimination experienced on a daily basis as verbal or behavioral slights against individuals in oppressed groups. LGBTQ microaggressions are often studied at an individual level and understood as being directed toward an individual based on perceived identity. The present study allows for an understanding of bias directed at the family system level. Participants included 46 adults who identified as being part of an LGBTQ family. Participants completed an online questionnaire and described their experiences of LGBTQ family microaggressions. Thematic analysis revealed that LGBTQ family microaggressions were salient to individuals across multiple family roles. Three specific themes emerged: family legitimacy, conflicts with family values, and gender violation within family. These findings highlight the way LGBTQ microaggressions are influenced by cultural notions of family and impact the family system.


Asunto(s)
Familia , Minorías Sexuales y de Género , Discriminación Social , Adolescente , Adulto , Agresión , Femenino , Identidad de Género , Homofobia , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Adulto Joven
8.
J Phys Condens Matter ; 29(49): 495804, 2017 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-29091590

RESUMEN

We have determined the magnetic structures of GdCuSn, GdAgSn and GdAuSn using a combination of [Formula: see text]Gd Mössbauer spectroscopy and neutron powder diffraction. Each compound shows the same antiferromagnetic ordering of the Gd sublattice. The magnetic cell is doubled along the crystallographic a-axis (propagation vector [Formula: see text]) with the moments aligned along the hexagonal c-axis, forming alternating ferromagnetic sheets of up/down Gd moments along the a-axis.

9.
Sci Rep ; 7(1): 646, 2017 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-28381825

RESUMEN

Neutron powder diffraction patterns measured above T C have been used to determine the location of the excess Mn in MnxGa (1.15 ≤ x ≤ 1.8). This information has then been used to constrain the fits to neutron powder diffraction patterns measured at ambient temperature and so determine unambiguously the Mn moments in this system. We find that Mn randomly occupies the two Ga sites (2a and 2b) in the I4/mmm structure and propose that it is more appropriate to use a simpler structure based on the P4/mmm space group with a reduced unit cell. In this structure the two Ga sites are formally equivalent (they occupy the 1a site while Mn occupies the 1d site). Our experimental observations are supported by DFT calculations. Below T C we find that the Mn(1d) moment is constant at 2.45(3) µ B , while Mn on the 1a site carries a slightly larger moment (~3 µ B ) that is coupled antiparallel to the Mn(1d) moments, leading to the observed drop in magnetisation with increasing Mn content in MnxGa.

10.
Prog Urol ; 27(6): 337-344, 2017 May.
Artículo en Francés | MEDLINE | ID: mdl-28392433

RESUMEN

INTRODUCTION: Since 2003, fight against cancer was structured by 3 national cancer programs (CP). The objective of this study is to evaluate the application of these measures in the case of surgical prostate cancer (PCa) treatment in a geographically isolated center. MATERIAL: Monocentric retrospective study carried in a 100-bed clinic located 2hours away from a Cancer Regional Reference Center. Between August 2009 and December 2014, 251 consecutive patients were treated by total laparoscopic prostatectomy (TLP). Fifty-seven patients (22.7 %) received a secondary treatment after TLP. The study focused on the delay between prostate biopsies and PTL, the traceability of AD elements, the return of active patients, inclusion in clinical trials (GETUG 17, GETUG 20 and GETUG 22). Data were collected in September 2016. The follow-up defined by the time between the date of the last visit and the prostate biopsy allows a median follow-up of 43.1 months (2.4-80.5). RESULTS: All elements of the CAP are totally gathered on 45 % of the patients (113/251). Thirty-four (13.5 %) patients were active at the time of the intervention. Thirty-one (91.2 %) will return to an identical activity after a median work stoppage of 1.7 month (0.25-6). Fourteen percent (35/251) of the patients are eligible to a clinical trial. Seventeen percent (6/35) of them were proposed to one of a trial after multidisciplinary meeting and 5.7 % (2/35) are eventually included in one trial. CONCLUSION: CP define a course of high quality care. A better transparency of the founding of the enforceable measures and a better consideration for the local specificities should facilitate their application. The TLP treat the PCa with the reasonable objective of a return to an identical professional activity. The multidisciplinary meeting does not guarantee the participation to clinical trial, which depends mainly on distance from the Cancer Regional Reference Center and the vigilance of the Urologist. LEVEL OF EVIDENCE: 4.


Asunto(s)
Prostatectomía , Neoplasias de la Próstata/cirugía , Anciano , Instituciones Oncológicas , Francia , Humanos , Laparoscopía , Masculino , Planificación de Atención al Paciente , Prostatectomía/métodos , Estudios Retrospectivos
11.
Mol Ecol ; 26(7): 2131-2149, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28101896

RESUMEN

Copper-based antimicrobial compounds are widely used to control plant bacterial pathogens. Pathogens have adapted in response to this selective pressure. Xanthomonas citri pv. citri, a major citrus pathogen causing Asiatic citrus canker, was first reported to carry plasmid-encoded copper resistance in Argentina. This phenotype was conferred by the copLAB gene system. The emergence of resistant strains has since been reported in Réunion and Martinique. Using microsatellite-based genotyping and copLAB PCR, we demonstrated that the genetic structure of the copper-resistant strains from these three regions was made up of two distant clusters and varied for the detection of copLAB amplicons. In order to investigate this pattern more closely, we sequenced six copper-resistant X. citri pv. citri strains from Argentina, Martinique and Réunion, together with reference copper-resistant Xanthomonas and Stenotrophomonas strains using long-read sequencing technology. Genes involved in copper resistance were found to be strain dependent with the novel identification in X. citri pv. citri of copABCD and a cus heavy metal efflux resistance-nodulation-division system. The genes providing the adaptive trait were part of a mobile genetic element similar to Tn3-like transposons and included in a conjugative plasmid. This indicates the system's great versatility. The mining of all available bacterial genomes suggested that, within the bacterial community, the spread of copper resistance associated with mobile elements and their plasmid environments was primarily restricted to the Xanthomonadaceae family.


Asunto(s)
Cobre/farmacología , Farmacorresistencia Bacteriana/genética , Transferencia de Gen Horizontal , Secuencias Repetitivas Esparcidas , Xanthomonas/genética , Adaptación Fisiológica/genética , Argentina , Citrus/microbiología , ADN Bacteriano/genética , Genes Bacterianos , Genética de Población , Genotipo , Martinica , Repeticiones de Microsatélite , Enfermedades de las Plantas/microbiología , Reunión , Xanthomonas/efectos de los fármacos
12.
J Sports Sci ; 35(6): 517-524, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27103499

RESUMEN

Accelerometry is the gold standard for field-based physical activity assessment in children; however, the plethora of devices, data reduction procedures, and cut-points available limits comparability between studies. This study aimed to compare physical activity variables from the ActiGraph GT3X+ and Actical accelerometers in children under free-living conditions. A cross-sectional study of 379 children aged 9-11 years from Ottawa (Canada) was conducted. Children wore the ActiGraph GT3X+ and Actical accelerometers on the hip simultaneously for 7 consecutive days (24-h protocol). Moderate-to-vigorous (MVPA), vigorous (VPA), moderate (MPA), and light (LPA) physical activity, as well as sedentary time, (SED) were derived using established data reduction protocols. Excellent agreement between devices was observed for MVPA (ICC = 0.73-0.80), with fair to good agreement for MPA, LPA and SED, and poor agreement for VPA. Bland-Altman plots showed excellent agreement for MVPA, LPA, and SED, adequate agreement for MPA, and poor agreement for VPA. MVPA derived from the Actical was 11.7% lower than the ActiGraph GT3X+. The ActiGraph GT3X+ and Actical are comparable for measuring children's MVPA. However, comparison between devices for VPA, MPA, LPA, and SED are highly dependent on data reduction procedures and cut-points, and should be interpreted with caution.


Asunto(s)
Actigrafía/instrumentación , Ejercicio Físico , Actigrafía/métodos , Canadá , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Conducta Sedentaria , Factores de Tiempo
13.
Arch Pediatr ; 23(12): 1260-1263, 2016 Dec.
Artículo en Francés | MEDLINE | ID: mdl-27743763

RESUMEN

Intracerebral hemorrhage (ICH) remains a cause of death in hematologic malignancies. Asparaginase represents a key agent in the treatment of acute lymphoblastic leukemia (ALL). The toxicity of asparaginase includes coagulopathy such as thrombotic or bleeding tendency. We report a case of fatal cerebral hemorrhage in a 12-year-old girl treated for ALL. Cerebral hemorrhage occurred after three injections of L-asparaginase. The patient presented with hypofibrinogenemia (0.36g/L), associated with thrombocytopenia (24,000/mm3). Despite maximal medical and surgical treatment (platelets and fresh-frozen plasma transfusions, red blood cells transfusion, fibrinogen replacement therapy, and craniotomy discharge), the patient died. L-asparaginase is well known for its prothrombotic action. By inhibiting the synthesis of fibrinogen and factors V, VII, VIII, and IX, it causes an increased risk of bleeding, including intracranial bleeding. Predictive scores for ICH onset have been established but there is no consensus on the management of coagulation disorders induced by L-asparaginase. It is recommended to check fibrinogen and antithrombin (AT) blood values in order to substitute them if they drop to < 1 g/L for fibrinogen and < 60% for AT. The management of asparaginase-induced ICH does not differ from that of ICH of other origin. The risk of death is high, and surgical treatment has not proven superior to medical therapy in terms of mortality rates and 6-month survival. Further studies are needed to define consensus guidelines for coagulation disorders induced by asparaginase and also to define the specific management in cases of ICH in childhood hematological malignancies.


Asunto(s)
Antineoplásicos/efectos adversos , Asparagina/efectos adversos , Hemorragias Intracraneales/inducido químicamente , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Antineoplásicos/administración & dosificación , Asparagina/administración & dosificación , Niño , Resultado Fatal , Femenino , Humanos
14.
Environ Health ; 15(1): 74, 2016 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-27412149

RESUMEN

BACKGROUND: The issue of endocrine disrupting chemicals (EDCs) is receiving wide attention from both the scientific and regulatory communities. Recent analyses of the EDC literature have been criticized for failing to use transparent and objective approaches to draw conclusions about the strength of evidence linking EDC exposures to adverse health or environmental outcomes. Systematic review methodologies are ideal for addressing this issue as they provide transparent and consistent approaches to study selection and evaluation. Objective methods are needed for integrating the multiple streams of evidence (epidemiology, wildlife, laboratory animal, in vitro, and in silico data) that are relevant in assessing EDCs. METHODS: We have developed a framework for the systematic review and integrated assessment (SYRINA) of EDC studies. The framework was designed for use with the International Program on Chemical Safety (IPCS) and World Health Organization (WHO) definition of an EDC, which requires appraisal of evidence regarding 1) association between exposure and an adverse effect, 2) association between exposure and endocrine disrupting activity, and 3) a plausible link between the adverse effect and the endocrine disrupting activity. RESULTS: Building from existing methodologies for evaluating and synthesizing evidence, the SYRINA framework includes seven steps: 1) Formulate the problem; 2) Develop the review protocol; 3) Identify relevant evidence; 4) Evaluate evidence from individual studies; 5) Summarize and evaluate each stream of evidence; 6) Integrate evidence across all streams; 7) Draw conclusions, make recommendations, and evaluate uncertainties. The proposed method is tailored to the IPCS/WHO definition of an EDC but offers flexibility for use in the context of other definitions of EDCs. CONCLUSIONS: When using the SYRINA framework, the overall objective is to provide the evidence base needed to support decision making, including any action to avoid/minimise potential adverse effects of exposures. This framework allows for the evaluation and synthesis of evidence from multiple evidence streams. Finally, a decision regarding regulatory action is not only dependent on the strength of evidence, but also the consequences of action/inaction, e.g. limited or weak evidence may be sufficient to justify action if consequences are serious or irreversible.


Asunto(s)
Disruptores Endocrinos/toxicidad , Contaminantes Ambientales/toxicidad , Medición de Riesgo/métodos , Animales , Exposición a Riesgos Ambientales , Humanos , Modelos Teóricos , Pruebas de Toxicidad
15.
Intensive Crit Care Nurs ; 36: 8-16, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27283117

RESUMEN

OBJECTIVES: To explore factors perceived to contribute to 'a good death' and the quality of end of life care in two countries with differing legal and cultural contexts. DESIGN AND METHODS: Multi-centre study consisting of focus group and individual interviews with intensive care nurses. Data were analysed using qualitative thematic analysis; emotional content was analysed using specialist linguistic software. SETTINGS/PARTICIPANTS: Fifty five Registered Nurses in intensive care units in Israel (n=4) and England (n=3), purposively sampled across age, ICU experience and seniority. FINDINGS: Four themes and eleven sub-themes were identified that were similar in both countries. Participants identified themes of: (i) timing of communication, (ii) accommodating individual behaviours, (iii) appropriate care environment and (iv) achieving closure, which they perceive prevent, and contribute to, a good death and good quality of end of life care. Emotional content showed significant amount of 'sadness talk' and 'discrepancy talk', using words such as 'could and 'should' when participants were talking about the actions of clinicians. CONCLUSIONS: The qualities of a good death were more similar than different across cultures and legal systems. Themes identified by participants may provide a framework for guiding end of life discussions in the intensive care unit.


Asunto(s)
Actitud Frente a la Muerte , Enfermeras y Enfermeros/psicología , Cuidado Terminal/normas , Adulto , Comunicación , Inglaterra , Femenino , Grupos Focales , Humanos , Unidades de Cuidados Intensivos/organización & administración , Israel , Masculino , Persona de Mediana Edad , Percepción , Relaciones Profesional-Familia , Investigación Cualitativa
16.
J Phys Condens Matter ; 28(26): 266001, 2016 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-27173847

RESUMEN

(151)Eu Mössbauer spectroscopy and neutron powder diffraction are combined to show that the tetragonal (I4mm #107) compound EuNiGe3 orders magnetically below [Formula: see text] K and adopts a complex incommensurate helicoidal magnetic structure at 3.6 K, with a propagation vector [Formula: see text] and a Eu moment of 7.1(2) [Formula: see text]. On warming through 6 K an incommensurate sinusoidal modulation develops and dominates the magnetic order by 12 K.

17.
J Phys Condens Matter ; 28(16): 166003, 2016 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-27009349

RESUMEN

The antiferromagnetic structures of both the manganese and europium sublattices in EuMn2Ge2 have been determined using thermal neutron diffraction. T(N)(Mn) = 714(5) K with the 3.35(5) µ(B) (at 285 K) Mn moments ordering according to the I4'/m'm'm space group. The Eu order is incommensurate with the 6.1(2) µ(B) (at 3.6 K) Eu moments oriented parallel to the c-axis with a propagation vector of k = [0.153(2) 0 0]. Both neutron diffraction and (151)Eu Mössbauer spectroscopy reveal evidence of magnetic short-range ordering of the Eu sublattice around and above T(N)(Eu) ∼ 10 K. The ordering temperature of the Eu sublattice is strongly affected by the sample's thermal history and rapid quenching from the melting point may lead to a complete suppression of that ordering.

18.
J Dairy Sci ; 99(1): 634-43, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26506548

RESUMEN

Heifer rearing is one of the largest production expenses for dairy cattle operations, which is one reason milking operations outsource heifer rearing to custom developers. The cost of harvested feedstuffs is a major expense in heifer rearing. A possible way to lower feed costs is to graze dairy heifers, but little research exists on this topic in the mid-south United States. The objectives of this research were to determine the cost of feeding bred dairy heifers grazing native warm-season grasses (NWSG), with and without legumes, and compare the cost of grazing with the cost of rearing heifers using 3 traditional rations. The 3 rations were corn silage with soybean meal, corn silage with dry distillers grain, and a wet distillers grain-based ration. Bred Holstein heifers between 15- and 20-mo-old continuously grazed switchgrass (SG), SG with red clover (SG+RC), a big bluestem and Indiangrass mixture (BBIG), and BBIG with red clover (BBIG+RC) in Tennessee during the summer months. Total grazing days were calculated for each NWSG to determine the average cost/animal per grazing day. The average daily gain (ADG) was calculated for each NWSG to develop 3 harvested feed rations that would result in the same ADG over the same number of grazing day as each NWSG treatment. The average cost/animal per grazing day was lowest for SG ($0.48/animal/grazing d) and highest for BBIG+RC ($1.10/animal/grazing d). For both BBIG and SG, legumes increased the average cost/animal per grazing day because grazing days did not increase enough to account for the additional cost of the legumes. No difference was observed in ADG for heifers grazing BBIG (0.85 kg/d) and BBIG+RC (0.94 kg/d), and no difference was observed in ADG for heifers grazing SG (0.71 kg/d) and SG+RC (0.70 kg/d). However, the ADG for heifers grazing SG and SG+RC was lower than the ADG for heifers grazing either BBIG or BBIG+RC. The average cost/animal per grazing day was lower for all NWSG treatments than the average cost/animal per day for all comparable feed rations at a low, average, and high yardage fee. Results of this study suggest that SG was the most cost-effective NWSG alternative to harvested feeds for bred dairy heifer rearing.


Asunto(s)
Bovinos/fisiología , Industria Lechera/economía , Ensilaje/economía , Animales , Cruzamiento , Costos y Análisis de Costo , Fabaceae , Femenino , Panicum , Tennessee , Trifolium , Zea mays
19.
Plant Dis ; 100(4): 718-723, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30688624

RESUMEN

Xanthomonas citri pv. mangiferaeindicae is the causal agent of bacterial canker of mango (Mangifera indica, Anacardiaceae), a disease of international importance. Since the original description of the bacterium in the 1940s, the status of cashew (Anacardium occidentale, Anacardiaceae) as a host species has been unclear. Here, we report the first outbreak of a cashew bacterial disease in Burkina Faso (Western Africa) where X. citri pv. mangiferaeindicae recently emerged on mango. A comprehensive molecular characterization, based on multilocus sequence analysis, supplemented with pathogenicity assays of isolates obtained during the outbreak, indicated that the causal agent on cashew in Burkina Faso is X. citri pv. mangiferaeindicae and not X. citri pv. anacardii, which was previously reported as the causal agent of a cashew bacterial leaf spot in Brazil. Pathogenicity data supported by population biology in Burkina Faso suggest a lack of host specialization. Therefore, the inoculum from each crop is potentially harmful to both host species. Symptoms induced on cashew leaves and fruit by X. citri pv. mangiferaeindicae and nonpigmented strains of X. citri pv. anacardii are similar, although the causative bacteria are genetically different. Thus, xanthomonads pathogenic on cashew may represent a new example of pathological convergence in this bacterial genus.

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