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1.
Phys Rev Lett ; 133(12): 121004, 2024 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-39373410

RESUMEN

We report results from an analysis aimed at detecting the trispectrum of the kinematic Sunyaev-Zel'dovich (kSZ) effect by combining data from the South Pole Telescope (SPT) and Herschel-SPIRE experiments over a 100 deg^{2} field. The SPT observations combine data from the previous and current surveys, namely SPTpol and SPT-3G, to achieve depths of 4.5, 3, and 16 µK-arcmin in bands centered at 95, 150, and 220 GHz. For SPIRE, we include data from the 600 and 857 GHz bands. We reconstruct the velocity-induced large-scale correlation of the small-scale kSZ signal with a quadratic estimator that uses two cosmic microwave background (CMB) temperature maps, constructed by optimally combining data from all the frequency bands. We reject the null hypothesis of a zero trispectrum at 10.3σ level. However, the measured trispectrum contains contributions from both the kSZ and other undesired components, such as CMB lensing and astrophysical foregrounds, with kSZ being sub-dominant. We use the agora simulations to estimate the expected signal from CMB lensing and astrophysical foregrounds. After accounting for the contributions from CMB lensing and foreground signals, we do not detect an excess kSZ-only trispectrum and use this nondetection to set constraints on reionization. By applying a prior based on observations of the Gunn-Peterson trough, we obtain an upper limit on the duration of reionization of Δz_{re,50}<4.5 (95% confidence level). We find these constraints are fairly robust to foregrounds assumptions. This trispectrum measurement is independent of, but consistent with, Planck's optical depth measurement. This result is the first constraint on the epoch of reionization using the non-Gaussian nature of the kSZ signal.

2.
J Nutr ; 153(4): 970-978, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36796480

RESUMEN

BACKGROUND: Early growth and body composition may influence the risk of obesity and health in adulthood. Few studies have examined how undernutrition is associated with body composition in early life. OBJECTIVES: We assessed stunting and wasting as correlates of body composition in young Kenyan children. METHODS: Nested in a randomized controlled nutrition trial, this longitudinal study assessed fat and fat-free mass (FM, FFM) using deuterium dilution technique among children at age 6 and 15 months. This trial was registered at http://controlled-trials.com/ (ISRCTN30012997). Cross-sectional and longitudinal associations between z-score categories of length-for-age (LAZ) or weight-for-length (WLZ) and FM, FFM, fat mass index (FMI), fat-free mass index (FFMI), triceps, and subscapular skinfolds were analyzed by linear mixed models. RESULTS: Among the 499 children enrolled, breastfeeding declined from 99% to 87%, stunting increased from 13% to 32%, and wasting remained at 2% to 3% between 6 and 15 mo. Compared with LAZ >0, stunted children had a 1.12 kg (95% CI: 0.88, 1.36; P < 0.001) lower FFM at 6 mo and increased to 1.59 kg (95% CI: 1.25, 1.94; P < 0.001) at 15 mo, corresponding to differences of 18% and 17%, respectively. When analyzing FFMI, the deficit in FFM tended to be less than proportional to children's height at 6 mo (P ≤ 0.060) but not at 15 mo (P > 0.40). Stunting was associated with 0.28 kg (95% CI: 0.09, 0.47; P = 0.004) lower FM at 6 mo. However, this association was not significant at 15 mo, and stunting was not associated with FMI at any time point. A lower WLZ was generally associated with lower FM, FFM, FMI, and FFMI at 6 and 15 mo. Differences in FFM, but not FM, increased with time, whereas FFMI differences did not change, and FMI differences generally decreased with time. CONCLUSIONS: Overall, low LAZ and WLZ among young Kenyan children were associated with reduced lean tissue, which may have long-term health consequences.


Asunto(s)
Tejido Adiposo , Composición Corporal , Femenino , Humanos , Niño , Lactante , Kenia/epidemiología , Índice de Masa Corporal , Estudios Longitudinales , Tejido Adiposo/metabolismo , Estudios Transversales , Caquexia/metabolismo , Trastornos del Crecimiento/epidemiología , Trastornos del Crecimiento/metabolismo
3.
Appl Opt ; 59(10): 3285-3295, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32400613

RESUMEN

We present two prescriptions for broadband ($ {\sim} 77 - 252\;{\rm GHz} $), millimeter-wave antireflection coatings for cryogenic, sintered polycrystalline aluminum oxide optics: one for large-format (700 mm diameter) planar and plano-convex elements, the other for densely packed arrays of quasi-optical elements-in our case, 5 mm diameter half-spheres (called "lenslets"). The coatings comprise three layers of commercially available, polytetrafluoroethylene-based, dielectric sheet material. The lenslet coating is molded to fit the 150 mm diameter arrays directly, while the large-diameter lenses are coated using a tiled approach. We review the fabrication processes for both prescriptions, then discuss laboratory measurements of their transmittance and reflectance. In addition, we present the inferred refractive indices and loss tangents for the coating materials and the aluminum oxide substrate. We find that at 150 GHz and 300 K the large-format coating sample achieves $ (97 \pm 2)\% $ transmittance, and the lenslet coating sample achieves $ (94 \pm 3)\% $ transmittance.

4.
Phys Rev Lett ; 123(18): 181301, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31763885

RESUMEN

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500 deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×10^{14}M_{⊙} which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.

5.
Nature ; 495(7441): 344-7, 2013 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-23485967

RESUMEN

In the past decade, our understanding of galaxy evolution has been revolutionized by the discovery that luminous, dusty starburst galaxies were 1,000 times more abundant in the early Universe than at present. It has, however, been difficult to measure the complete redshift distribution of these objects, especially at the highest redshifts (z > 4). Here we report a redshift survey at a wavelength of three millimetres, targeting carbon monoxide line emission from the star-forming molecular gas in the direction of extraordinarily bright millimetre-wave-selected sources. High-resolution imaging demonstrates that these sources are strongly gravitationally lensed by foreground galaxies. We detect spectral lines in 23 out of 26 sources and multiple lines in 12 of those 23 sources, from which we obtain robust, unambiguous redshifts. At least 10 of the sources are found to lie at z > 4, indicating that the fraction of dusty starburst galaxies at high redshifts is greater than previously thought. Models of lens geometries in the sample indicate that the background objects are ultra-luminous infrared galaxies, powered by extreme bursts of star formation.

6.
Matern Child Nutr ; 15(4): e12836, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31045329

RESUMEN

The impact of quality complementary food products on infant growth and body composition has not been adequately investigated. This study evaluated the effect on fat-free mass (FFM) accrual, linear growth, and iron status of locally produced complementary food products comparing to a standard product. In a randomized, double-blind trial, 499 infants at 6 months received nine monthly rations of (a) WinFood Classic (WFC) comprising germinated amaranth (71%), maize (10.4%), small fish (3%), and edible termites (10%); (b) WinFood Lite (WFL) comprising germinated amaranth (82.5%), maize (10.2%), and multimicronutrient premix; or (c) fortified corn-soy blend plus (CSB+). Primary outcomes were changes in FFM, length, and plasma ferritin and transferrin receptors (TfR). FFM was determined using deuterium dilution. Analysis was by intention to treat, based on available cases. Compared with CSB+, there were no differences in change from 6 to 15 months in FFM for WFC 0.0 kg (95% CI [-0.30, 0.29]) and WFL 0.03 kg (95% CI [-0.25, 0.32]) and length change for WFC -0.3 cm (95% CI [-0.9, 0.4]) and WFL -0.3 cm (95% CI [-0.9, 0.3]). TfR increased in WFC group 3.3 mg L-1 (95% CI [1.7, 4.9]) and WFL group 1.7 mg L-1 (95% CI [0.1, 3.4]) compared with CSB+. Compared with the increase in Hb in CSB+ group, there was a reduction in Hb in WFC of -0.9 g dl-1 (95% CI [-1.3, -0.5]) and a lower increase in WFL -0.4 g dl-1 (95% CI [-0.8, 0.0]). In conclusion, the tested WinFoods had the same effect on FFM and length as CSB+, whereas Hb and iron status decreased, suggesting inhibited iron bioavailability from the amaranth-based WinFoods.


Asunto(s)
Composición Corporal/fisiología , Estatura/fisiología , Alimentos Fortificados , Hierro/sangre , Dieta , Método Doble Ciego , Ferritinas/sangre , Humanos , Lactante , Hierro/administración & dosificación , Kenia , Micronutrientes/administración & dosificación
7.
Nature ; 488(7411): 349-52, 2012 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-22895340

RESUMEN

In the cores of some clusters of galaxies the hot intracluster plasma is dense enough that it should cool radiatively in the cluster's lifetime, leading to continuous 'cooling flows' of gas sinking towards the cluster centre, yet no such cooling flow has been observed. The low observed star-formation rates and cool gas masses for these 'cool-core' clusters suggest that much of the cooling must be offset by feedback to prevent the formation of a runaway cooling flow. Here we report X-ray, optical and infrared observations of the galaxy cluster SPT-CLJ2344-4243 (ref. 11) at redshift z = 0.596. These observations reveal an exceptionally luminous (8.2 × 10(45) erg s(-1)) galaxy cluster that hosts an extremely strong cooling flow (around 3,820 solar masses a year). Further, the central galaxy in this cluster appears to be experiencing a massive starburst (formation of around 740 solar masses a year), which suggests that the feedback source responsible for preventing runaway cooling in nearby cool-core clusters may not yet be fully established in SPT-CLJ2344-4243. This large star-formation rate implies that a significant fraction of the stars in the central galaxy of this cluster may form through accretion of the intracluster medium, rather than (as is currently thought) assembling entirely via mergers.

8.
BMC Public Health ; 18(1): 609, 2018 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-29743062

RESUMEN

BACKGROUND: The decline in global malaria cases is attributed to intensified utilization of primary vector control interventions and artemisinin-based combination therapies (ACTs). These strategies are inadequate in many rural areas, thus adopting locally appropriate integrated malaria control strategies is imperative in these heterogeneous settings. This study aimed at investigating trends and local knowledge on malaria and to develop a framework for malaria control for communities in Baringo, Kenya. METHODS: Clinical malaria cases obtained from four health facilities in the riverine and lowland zones were used to analyse malaria trends for the 2005-2014 period. A mixed method approach integrating eight focus group discussions, 12 key informant interviews, 300 survey questionnaires and two stakeholders' consultative forums were used to assess local knowledge on malaria risk and develop a framework for malaria reduction. RESULTS: Malaria cases increased significantly during the 2005-2014 period (tau = 0.352; p < 0.001) in the riverine zone. March, April, May, June and October showed significant increases compared to other months. Misconceptions about the cause and mode of malaria transmission existed. Gender-segregated outdoor occupation such as social drinking, farm activities, herding, and circumcision events increased the risk of mosquito bites. A positive relationship occurred between education level and opinion on exposure to malaria risk after dusk (χ2 = 2.70, p < 0.05). There was over-reliance on bed nets, yet only 68% (204/300) of respondents owned at least one net. Complementary malaria control measures were under-utilized, with 90% of respondents denying having used either sprays, repellents or burnt cow dung or plant leaves over the last one year before the study was conducted. Baraza, radios, and mobile phone messages were identified as effective media for malaria information exchange. Supplementary strategies identified included unblocking canals, clearing Prosopis bushes, and use of community volunteers and school clubs to promote social behaviour change. CONCLUSIONS: The knowledge gap on malaria transmission should be addressed to minimize the impacts and enhance uptake of appropriate malaria management mechanisms. Implementing community-based framework can support significant reductions in malaria prevalence by minimizing both indoor and outdoor malaria transmissions.


Asunto(s)
Participación de la Comunidad , Conocimientos, Actitudes y Práctica en Salud , Malaria/prevención & control , Control de Mosquitos/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Grupos Focales , Humanos , Kenia/epidemiología , Malaria/epidemiología , Masculino , Persona de Mediana Edad , Medición de Riesgo , Encuestas y Cuestionarios , Adulto Joven
9.
J Intellect Disabil Res ; 62(11): 941-951, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30125044

RESUMEN

BACKGROUND: This study explored the role of demographic, psychosocial, stress and life event-related risk factors for psychopathology and challenging behaviour in a clinical sample of adults with Down syndrome. METHOD: A convenience sample of adults with Down syndrome seen through a specialised clinic was assessed through interviews and questionnaires specifically designed for use in people with intellectual disabilities. RESULTS: Recent negative life events and stressors were significantly correlated with mental and behavioural health, and significantly predicted irritability, lethargy and depressed mood. Social avoidance was predicted by stress related to anticipation and social-environmental stressors, and negatively predicted by verbal ability. Ritual-related stress predicted obsessive-compulsive behaviour. Participants who did not have a job or vocational placement were significantly more depressed than participants who did. CONCLUSIONS: Adults with Down syndrome should be provided increased supports for coping with negative life events and stressors. Interventions should also emphasise community engagement, such as employment, and access to psychosocial supports that teach coping and self-regulation skills when faced with stressors and negative life events.


Asunto(s)
Síntomas Afectivos , Depresión , Síndrome de Down , Trastornos Mentales , Problema de Conducta , Estrés Psicológico , Adolescente , Adulto , Síntomas Afectivos/epidemiología , Síntomas Afectivos/etiología , Síntomas Afectivos/fisiopatología , Anciano , Anciano de 80 o más Años , Depresión/complicaciones , Depresión/etiología , Depresión/fisiopatología , Síndrome de Down/epidemiología , Síndrome de Down/fisiopatología , Femenino , Humanos , Masculino , Trastornos Mentales/epidemiología , Trastornos Mentales/etiología , Trastornos Mentales/fisiopatología , Persona de Mediana Edad , Factores de Riesgo , Estrés Psicológico/complicaciones , Estrés Psicológico/epidemiología , Estrés Psicológico/fisiopatología , Adulto Joven
10.
Malar J ; 16(1): 220, 2017 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-28545590

RESUMEN

BACKGROUND: Malaria transmission in arid and semi-arid regions of Kenya such as Baringo County, is seasonal and often influenced by climatic factors. Unravelling the relationship between climate variables and malaria transmission dynamics is therefore instrumental in developing effective malaria control strategies. The main aim of this study was to describe the effects of variability of rainfall, maximum temperature and vegetation indices on seasonal trends of malaria in selected health facilities within Baringo County, Kenya. METHODS: Climate variables sourced from the International Research Institute (IRI)/Lamont-Doherty Earth Observatory (LDEO) climate database and malaria cases reported in 10 health facilities spread across four ecological zones (riverine, lowland, mid-altitude and highland) between 2004 and 2014 were subjected to a time series analysis. A negative binomial regression model with lagged climate variables was used to model long-term monthly malaria cases. The seasonal Mann-Kendall trend test was then used to detect overall monotonic trends in malaria cases. RESULTS: Malaria cases increased significantly in the highland and midland zones over the study period. Changes in malaria prevalence corresponded to variations in rainfall and maximum temperature. Rainfall at a time lag of 2 months resulted in an increase in malaria transmission across the four zones while an increase in temperature at time lags of 0 and 1 month resulted in an increase in malaria cases in the riverine and highland zones, respectively. CONCLUSION: Given the existence of a time lag between climatic variables more so rainfall and peak malaria transmission, appropriate control measures can be initiated at the onset of short and after long rains seasons.


Asunto(s)
Cambio Climático , Malaria/epidemiología , Ecosistema , Humanos , Kenia/epidemiología , Malaria/parasitología , Malaria/transmisión , Modelos Estadísticos , Modelos Teóricos , Prevalencia , Estaciones del Año
11.
BMC Infect Dis ; 16: 57, 2016 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-26842961

RESUMEN

BACKGROUND: Schistosomes and soil-transmitted helminths (STH) (hookworm, Trichuris trichiura and Ascaris lumbricoides) are widely distributed in developing countries where they infect over 230 million and 1.5 billion people, respectively. The parasites are frequently co-endemic and many individuals are co-infected with two or more of the species, but information on how the parasites interact in co-infected individuals is scarce. The present study assessed Schistosoma haematobium and STH infection and morbidity patterns among school children in a hyper-endemic focus in the Tana River delta of coastal Kenya. METHODS: Two hundred and sixty-two children aged 5-12 years from two primary schools were enrolled in the study. For each child, urine was examined for S. haematobium eggs and haematuria, stool was examined for STH eggs, peripheral blood was examined for eosinophilia and haemoglobin level, the urinary tract was ultrasound-examined for S. haematobium-related pathology, and the height and weight was measured and used to calculate the body mass index (BMI). RESULTS: Prevalences of S. haematobium, hookworm, T. trichiura and A. lumbricoides infection were 94, 81, 88 and 46 %, respectively. There was no significant association between S. haematobium and STH infection but intensity of hookworm infection significantly increased with that of T. trichiura. Lower BMI scores were associated with high intensity of S. haematobium (difference =-0.48, p > 0.05) and A. lumbricoides (difference =-0.67, p < 0.05). Haematuria (both macro and micro) was common and associated with S. haematobium infection, while anaemia was associated with high intensity of S. haematobium (OR = 2.08, p < 0.05) and high hookworm infections OR = 4.75; p < 0.001). The majority of children had eosinophilia, which was significantly associated with high intensity of hookworm infection (OR = 5.34, p < 0.05). Overall 38 % of the children had ultrasound-detectable urinary tract morbidity, which was associated with high intensity of S. haematobium infection (OR = 3.13, p < 0.05). CONCLUSION: Prevalences of S. haematobium and STH infections among the primary school children were high and the parasites were responsible for significant morbidity. A clear synergistic interaction was observed between hookworm and T. trichiura infections. Increased coverage in administration of praziquantel and albendazole in the area is recommended to control morbidity due to these infections.


Asunto(s)
Antihelmínticos/uso terapéutico , Helmintiasis/epidemiología , Schistosoma haematobium/aislamiento & purificación , Esquistosomiasis Urinaria/epidemiología , Albendazol/uso terapéutico , Ancylostomatoidea/aislamiento & purificación , Anemia , Animales , Ascaris lumbricoides/aislamiento & purificación , Niño , Preescolar , Coinfección , Heces/parasitología , Femenino , Helmintiasis/tratamiento farmacológico , Humanos , Kenia/epidemiología , Masculino , Praziquantel/uso terapéutico , Prevalencia , Esquistosomiasis Urinaria/tratamiento farmacológico , Instituciones Académicas , Suelo/parasitología , Trichuris/aislamiento & purificación
12.
BMC Infect Dis ; 14: 501, 2014 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-25223302

RESUMEN

BACKGROUND: Pathological changes due to infection with Schistosoma haematobium include cytokine-mediated urinary tract inflammation. The involved cytokines may be excreted in urine and their presence in urine may therefore reflect S. haematobium-related urinary tract pathology. The present study, for the first time, reports on the relationship between selected cytokines in urine and infection with S. haematobium in children from an area highly affected by this parasite. METHODS: Children aged 5-12 years from two primary schools in Tana Delta District of Kenya were examined for S. haematobium eggs using urine filtration technique, for haematuria using dipstix and for eosinophil cationic protein (ECP), IL-6, IFN- γ, TNF-α and IL-10 levels using ELISA, and for S. haematobium-related urinary tract pathology using ultrasonography. In addition, venous blood was examined for serum IL-6, IFN- γ, TNF-α and IL-10 levels using ELISA. RESULTS: There was no significant correlation between urinary and serum levels of IL-6, IFN- γ, TNF-α or IL-10. There was no significant difference in geometric mean intensity (GMI) in any of the serum cytokines, or in urinary TNF-α or IFN-γ, between children with light and heavy S. haematobium infections. However, children with heavy S. haematobium infections had significantly higher GMI of urinary IL-6 (p < 0.001) and lower GMI of urinary IL-10 (p = 0.002) than children with light infections. There was also a significant positive correlation between urinary IL-6 and urinary ECP (p < 0.001) and a significant negative correlation between urinary IL-10 and urinary ECP (p = 0.012). CONCLUSION: Urinary IL-6 was positively correlated to and IL-10 was negatively correlated to infection intensity and urinary tract inflammation in S. haematobium-infected children. Urinary IL-6 and IL-10 ELISA may be a useful non-invasive tool to complement the already available tools for studying S. haematobium-related urinary tract pathology in children.


Asunto(s)
Citocinas/orina , Esquistosomiasis Urinaria/orina , Adolescente , Animales , Niño , Preescolar , Estudios Transversales , Citocinas/sangre , Ensayo de Inmunoadsorción Enzimática , Femenino , Hematuria/sangre , Humanos , Inflamación , Interleucina-10/sangre , Interleucina-10/orina , Interleucina-6/sangre , Interleucina-6/orina , Kenia , Masculino , Recuento de Huevos de Parásitos , Schistosoma haematobium , Esquistosomiasis Urinaria/parasitología , Factor de Necrosis Tumoral alfa/sangre , Factor de Necrosis Tumoral alfa/orina
13.
Brain Cogn ; 89: 51-60, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24485273

RESUMEN

Adolescent risk-taking behavior has been associated with age-related changes in striatal activation to incentives. Previous cross-sectional studies have shown both increased and decreased striatal activation to incentives for adolescents compared to adults. The monetary incentive delay (MID) task, designed to assess functional brain activation in anticipation of reward, has been used extensively to examine striatal activation in both adult and adolescent populations. The current study used this task with a longitudinal approach across mid-adolescence and late adolescence/early adulthood. Twenty-two participants (13 male) were studied using the MID task at two time-points, once in mid-adolescence (mean age=16.11; SD=1.44) and a second time in late adolescence/early adulthood (mean age=20.14; SD=.67). Results revealed greater striatal activation with increased age in high- compared to low-incentive contexts (incentive magnitude), for gain as well as for loss trials (incentive valence). Results extend cross-sectional findings and show reduced striatal engagement in adolescence compared to adulthood during preparation for action in an incentive context.


Asunto(s)
Anticipación Psicológica/fisiología , Cuerpo Estriado/fisiología , Recompensa , Adolescente , Adulto , Factores de Edad , Mapeo Encefálico , Cuerpo Estriado/crecimiento & desarrollo , Femenino , Humanos , Estudios Longitudinales , Imagen por Resonancia Magnética , Masculino , Motivación/fisiología , Tiempo de Reacción , Adulto Joven
14.
Phys Rev Lett ; 111(14): 141301, 2013 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-24138230

RESUMEN

Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "B-mode" signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a nonzero correlation at 7.7σ significance. The correlation has an amplitude and scale dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable.

15.
BMC Infect Dis ; 13: 263, 2013 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-23734875

RESUMEN

BACKGROUND: HIV-1-related inflammation is associated with increased levels of biomarkers of vascular adhesion and endothelial activation, and may increase production of the inflammatory protein angiopoietin-2 (ANG-2), an adverse prognostic biomarker in severe systemic infection. We hypothesized that antiretroviral therapy (ART) initiation would decrease endothelial activation, reducing plasma levels of ANG-2. METHODS: Antiretroviral-naïve Kenyan women with advanced HIV infection were followed prospectively. Endothelial activation biomarkers including soluble intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), and E-selectin, and plasma ANG-2 and angiopoietin-1 (ANG-1) were tested in stored plasma samples from 0, 6, and 12 months after ART initiation. We used Wilcoxon matched-pairs signed rank tests to compare endothelial activation biomarkers across time-points, generalized estimating equations to analyze associations with change in log10-transformed biomarkers after ART initiation, and Cox proportional-hazards regression to analyze associations with mortality. RESULTS: The 102 HIV-1-seropositive women studied had advanced infection (median CD4 count, 124 cells/µL). Soluble ICAM-1 and plasma ANG-2 levels decreased at both time-points after ART initiation, with concomitant increases in the beneficial protein ANG-1. Higher ANG-2 levels after ART initiation were associated with higher plasma HIV-1 RNA, oral contraceptive pill use, pregnancy, severe malnutrition, and tuberculosis. Baseline ANG-2 levels were higher among five women who died after ART initiation than among women who did not (median 2.85 ng/mL [inter-quartile range (IQR) 2.47-5.74 ng/mL] versus median 1.32 ng/mL [IQR 0.35-2.18 ng/mL], p = 0.01). Both soluble ICAM-1 and plasma ANG-2 levels predicted mortality after ART initiation. CONCLUSIONS: Biomarkers of endothelial activation decreased after ART initiation in women with advanced HIV-1 infection. Changes in plasma ANG-2 were associated with HIV-1 RNA levels over 12 months of follow-up. Soluble ICAM-1 and plasma ANG-2 levels represent potential biomarkers for adverse outcomes in advanced HIV-1 infection.


Asunto(s)
Angiopoyetina 1/sangre , Angiopoyetina 2/sangre , Antirretrovirales/uso terapéutico , Infecciones por VIH/sangre , Infecciones por VIH/tratamiento farmacológico , VIH-1/aislamiento & purificación , Adulto , Terapia Antirretroviral Altamente Activa , Biomarcadores/sangre , Moléculas de Adhesión Celular/sangre , Femenino , Humanos , Kenia , Masculino , Embarazo , Estudios Prospectivos
16.
Heliyon ; 9(11): e21354, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37954294

RESUMEN

Biodiesel has several environmental benefits, such as biodegradability, renewability and lower soot emissions. However, biodiesel has undesirable properties such as higher viscosity and density and low calorific value compared to petroleum diesel, resulting in high Brake Specific Fuel Consumption (BSFC), reduced Brake Power (BP) and increased NOX emissions creating an environmental concerns in biodiesel development. This study investigated the effects of synthesizing transesterification catalysts (CaO and NaOH) with Citric Acid (CA) on the quality of biodiesel and biodiesel blends produced from Black Soldier Fly Larvae (BSFL) (Hermetia Illucens). The quality of biodiesel and blends was determined based on fuel properties, engine performance and emission composition characteristics. The tests were performed on a single-cylinder, four-stroke, Compression Ignition (CI) diesel engine at five loads at a constant speed of 1500 rpm. The results showed that synthesizing the catalysts with CA significantly affected the fatty acid profile of the biodiesel compared to physical fuel properties. B100 (pure BSFL biodiesel) exhibited higher BSFC by 10.57-13.97 % and lower BP by 4.21-7.83 % than diesel fuel. However, the Brake Thermal Efficiency (BTE) of biodiesel was higher than that of diesel fuel by 0.82-4.34 % at maximum load. Synthesizing catalysts with CA improved the viscosity of biodiesel by 0.93-2.81 % and effectively reduced NOX, HC and Smoke opacity by 2.23-3.16 %, 4.95-5.83 % and 20.51-41.15 %, respectively.

17.
Gynecol Obstet Fertil Senol ; 50(3): 266-271, 2022 Mar.
Artículo en Francés | MEDLINE | ID: mdl-34481099

RESUMEN

Peripartum cardiomyopathy is a rare and unpredictable pregnancy-related pathology. Idiopathic cardiomyopathy is characterized by a heart failure secondary to left ventricular systolic dysfunction appearing towards the end of pregnancy or in the months following delivery with a non-specific clinic presentation. Through reviewing previous research, our critical literature review wishes to bring a concise and objective summarize for a better understanding of physiopathology, evocative symptoms and knowing of factors influencing prognosis in order to standardize peripartum management. The treatment remains mainly symptomatic but other promising treatments are still in development. In conclusion, early detection and treatment allow a better cardiac function recovery reducing cardiac transplantation.


Asunto(s)
Cardiomiopatías , Complicaciones Cardiovasculares del Embarazo , Trastornos Puerperales , Disfunción Ventricular Izquierda , Cardiomiopatías/complicaciones , Cardiomiopatías/diagnóstico , Cardiomiopatías/terapia , Femenino , Humanos , Periodo Periparto , Embarazo , Complicaciones Cardiovasculares del Embarazo/diagnóstico , Complicaciones Cardiovasculares del Embarazo/terapia , Trastornos Puerperales/diagnóstico , Trastornos Puerperales/etiología , Trastornos Puerperales/terapia , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/terapia
18.
Vet Surg ; 39(8): 942-8, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21077917

RESUMEN

OBJECTIVE: To (1) assess upper airway function by videoendoscopy in horses performing poorly after laryngoplasty and (2) establish whether dynamic collapse of the left arytenoid can be predicted by the degree of resting postsurgical abduction. STUDY DESIGN: Case series. ANIMALS: Horses that had left laryngoplasty (n=45). METHODS: Medical records (June 1993-December 2007) of horses evaluated for abnormal respiratory noise and/or poor performance after laryngoplasty were reviewed. Horses with video recordings of resting and exercising upper airway endoscopy were included and postsurgical abduction categorized. Horses with immediate postoperative endoscopy recordings were also evaluated and postsurgical abduction categorized. Relationships between resting postsurgical abduction and historical information with exercising endoscopic findings were examined. RESULTS: Dynamic collapse of the left arytenoid cartilage was probable in horses with no postsurgical abduction and could not be predicted in horses with grade 3 or 4 postsurgical abduction. Respiratory noise was associated with upper airway obstruction but was not specific for arytenoid collapse. Most horses with a left vocal fold had billowing of the fold during exercise. Other forms of dynamic collapse involved the right vocal fold, aryepiglottic folds, corniculate process of left arytenoid cartilage, dorsal displacement of soft palate, and pharyngeal collapse. Complex obstructions were observed in most examinations and in all horses with exercising collapse of the left arytenoid cartilage. CONCLUSIONS: There was no relationship between exercising collapse of the left arytenoid cartilage and grade 3 or 4 postsurgical abduction but was likely in horses with no abduction.


Asunto(s)
Enfermedades de los Caballos/diagnóstico , Laringoscopía/veterinaria , Complicaciones Posoperatorias/veterinaria , Trastornos Respiratorios/veterinaria , Ruidos Respiratorios/veterinaria , Animales , Cartílago Aritenoides/fisiopatología , Prueba de Esfuerzo/veterinaria , Femenino , Enfermedades de los Caballos/fisiopatología , Enfermedades de los Caballos/cirugía , Caballos , Laringoplastia/efectos adversos , Laringoplastia/veterinaria , Laringoscopía/métodos , Masculino , Condicionamiento Físico Animal , Complicaciones Posoperatorias/diagnóstico , Trastornos Respiratorios/diagnóstico , Trastornos Respiratorios/cirugía , Ruidos Respiratorios/diagnóstico , Sistema Respiratorio/fisiopatología , Sistema Respiratorio/cirugía , Grabación en Video
19.
Vector Borne Zoonotic Dis ; 20(5): 348-357, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31928511

RESUMEN

Data on pathogen prevalence is crucial for informing exposure and disease risk. We evaluated serological evidence of tick-borne encephalitis (TBE), West Nile (WN), Hepatitis E virus (HEV), Crimean-Congo Hemorrhagic Fever (CCHF), Yersiniosis, Lyme Disease (LD), and brucellosis in 1033 patients presenting with acute febrile illness at 9 health care facilities from diverse ecological zones of Kenya: arid and semiarid (Garissa District Hospital, Lodwar District Hospital, Marigat District Hospital, Gilgil District Hospital), Lake Victoria basin (Kisumu District Hospital, Alupe District Hospital, Kombewa Sub-County Hospital), Kisii highland (Kisii District Hospital), and coastal (Malindi District Hospital). Epidemiological information of the patients such as geography, age, gender, and keeping animals were analyzed as potential risk factors. Of the 1033 samples, 619 (59.9%) were seropositive to at least one pathogen by IgM (current exposure), IgG/IgM (recent exposure), and IgG (past exposure). Collective seroprevalence for current, recent, and past to the pathogens was 9.4%, 5.1%, and 21.1% for LD; 3.6%, 0.5%, and 12.4% for WN; 0.9%, 0.5%, and 16.9% for HEV; 5.8%, 1.3%, and 3.9% for brucellosis; 5.7%, 0.2%, and 2.3% for yersiniosis; 1.7%, 0%, and 6.2% for TBE; and 0.4%, 0%, and 1.9% for CCHF. Brucellosis risk was higher in patients recruited at Garissa District Hospital (odds ratio [OR] = 3.41), HEV (OR = 2.45) and CCHF (OR = 5.46) in Lodwar District Hospital, LD in Alupe District Hospital (OR = 5.73), Kombewa Sub-district hospital (OR = 8.17), and Malindi District hospital (OR = 3.3). Exposure to LD was highest in the younger age group, whereas yersiniosis did not vary with age. Age was a significant risk for WN, brucellosis, CCHF, TBE, and HEV and in those aged >14 years there was an increased risk to WN (OR = 2.30, p < 0.0001), brucellosis (OR = 1.84, p = 0.005), CCHF (OR = 4.35, p = 0.001), TBE (OR = 2.78, p < 0.0001), and HEV (OR = 1.94, p = 0.0001). We conclude that LD is pervasive and constitutes a significant health burden to the study population, whereas yersiniosis and CCHF are not significant threats. Going forward, community-based studies will be needed to capture the true seroprevalence rates and the associated risk factors.


Asunto(s)
Infecciones Bacterianas/epidemiología , Infecciones Bacterianas/microbiología , Virosis/epidemiología , Virosis/virología , Adolescente , Adulto , Anticuerpos Antibacterianos/sangre , Anticuerpos Antivirales/sangre , Brucelosis/epidemiología , Niño , Preescolar , Encefalitis Transmitida por Garrapatas/epidemiología , Femenino , Fiebre Hemorrágica de Crimea/epidemiología , Hepatitis E/epidemiología , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Lactante , Kenia/epidemiología , Enfermedad de Lyme/epidemiología , Masculino , Estudios Seroepidemiológicos , Fiebre del Nilo Occidental/epidemiología , Yersiniosis/epidemiología , Adulto Joven
20.
Science ; 291(5501): 134-7, 2001 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-11141566

RESUMEN

Most traditional cytotoxic anticancer agents ablate the rapidly dividing epithelium of the hair follicle and induce alopecia (hair loss). Inhibition of cyclin-dependent kinase 2 (CDK2), a positive regulator of eukaryotic cell cycle progression, may represent a therapeutic strategy for prevention of chemotherapy-induced alopecia (CIA) by arresting the cell cycle and reducing the sensitivity of the epithelium to many cell cycle-active antitumor agents. Potent small-molecule inhibitors of CDK2 were developed using structure-based methods. Topical application of these compounds in a neonatal rat model of CIA reduced hair loss at the site of application in 33 to 50% of the animals. Thus, inhibition of CDK2 represents a potentially useful approach for the prevention of CIA in cancer patients.


Asunto(s)
Alopecia/inducido químicamente , Alopecia/prevención & control , Antineoplásicos/toxicidad , Quinasas CDC2-CDC28 , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Folículo Piloso/efectos de los fármacos , Indoles/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Sulfonamidas/farmacología , Animales , Animales Recién Nacidos , Protocolos de Quimioterapia Combinada Antineoplásica/toxicidad , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular , Quinasa 2 Dependiente de la Ciclina , Quinasas Ciclina-Dependientes/metabolismo , Ciclofosfamida/toxicidad , Citoprotección/efectos de los fármacos , ADN/biosíntesis , Doxorrubicina/toxicidad , Diseño de Fármacos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Epitelio/efectos de los fármacos , Etopósido/toxicidad , Folículo Piloso/citología , Humanos , Indoles/síntesis química , Indoles/química , Ratones , Ratones SCID , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Ratas , Proteína de Retinoblastoma/metabolismo , Cuero Cabelludo/trasplante , Sulfonamidas/síntesis química , Sulfonamidas/química , Trasplante Heterólogo
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