Increased baseline ECG R-R dispersion predicts improvement in systolic function after atrial fibrillation ablation.

BackgroundAtrial fibrillation (AF) is associated with left ventricular (LV) systolic dysfunction which may improve after AF ablation. We hypothesised that increased ventricular irregularity, as measured by R-R dispersion on the baseline ECG, would predict improvement in the left ventricular ejection fraction (LVEF) after AF ablation.MethodsPatients with LVEF <50% at two US centres (2007-2016), having both a preablation and postablation echocardiogram or cardiac MRI, were included. LVEF improvement was defined as absolute increase in LVEF by >7.5%. Multivariable logistic regression (restricted to echocardiographic/ECG variables) was performed to evaluate predictors of LVEF improvement.ResultsFifty-two patients were included in this study. LVEF improved in 30 patients (58%) and was unchanged/worsened in 22 patients (42%). Those with versus without LVEF improvement had an increased baseline R-R dispersion (645±155 ms vs 537±154 ms, p=0.02, respectively). The average baseline heart rate in all patients was 93 beats per minute. After multivariable logistic regression, increased R-R dispersion (OR 1.59, 95% CI 1.00 to 2.55, p=0.03) predicted LVEF improvement.ConclusionsIncreased R-R dispersion on ECG was independently associated with improved systolic function after AF ablation. This broadens the existing knowledge of arrhythmia-induced cardiomyopathy, demonstrating that irregular electrical activation (as measured by increased R-R dispersion on ECG) is associated with a cardiomyopathy capable of improving after AF ablation

Keeping Adolescent Orphans in School to Prevent Human Immunodeficiency Virus Infection: Evidence From a Randomized Controlled Trial in Kenya

We report findings from a pilot study in western Kenya, using an experimental design to test whether comprehensive support to keep adolescent orphans in school can reduce HIV risk factors

Use of HIV and HSV-2 Biomarkers in Sub-Saharan Adolescent Prevention Research: A Comparison of Two Approaches

Self-report of sexual behavior among adolescents is notoriously inconsistent, yet such measures are commonly used as outcomes for human immunodeficiency virus (HIV) prevention intervention trials. There has been a growing interest in the use of HIV and other sexually transmitted disease biomarkers as more valid measures of intervention impact in high HIV prevalence areas, particularly in sub-Saharan Africa. We examine the challenges, benefits, and feasibility of including HIV and herpes simplex virus type 2 (HSV-2) biomarker data, with details about different data collection and disclosure methods from two adolescent prevention trials in Kenya and Zimbabwe. In Kenya, whole blood samples were collected using venipuncture; adult guardians were present during biomarker procedures and test results were disclosed to participants and their guardians. In contrast, in Zimbabwe, samples were collected using finger pricks for dried blood spots (DBS); guardians were not present during biomarker procedures, and results were not disclosed to participants and/or their guardians. In both countries, prevalence in the study samples was low. Although the standard of care for testing for HIV and other sexually transmitted infections includes disclosure in the presence of a guardian for adolescents under age 18, we conclude that more research about the risks and benefits of disclosure to adolescents in the context of a clinical trial is needed. Notably, current serological diagnosis for HSV-2 has a low positive predictive value when prevalence is low, resulting in an unacceptable proportion of false positives and serious concerns about disclosing test results to adolescents within a trial. We also conclude that the DBS approach is more convenient and efficient than venipuncture for field research, although both approaches are feasible. Manufacturer validation studies using DBS for HSV-2, however, are needed for widespread use

Letters and ViewpointsSome Factors Influencing Natural Regeneration of Selected Tree Species in Kakamega Forest, Kenya

Poor regeneration of valuable timber species under closed forest canopy is a major problem affecting regeneration of tree species in Kenyan moist and Afromontane natural forests. This study was conducted in 1998 – 1999 to investigate the influence of shade tolerance, seed sources and insect herbivory on the regeneration of selected heavily exploited timber species (Maesopsis eminii, Zanthoxylum gilletii, Polyscias fulva, and Prunus africana) in Kakamega forest. 58 woody species were recorded in the sample area, most of which occurred at low densities. Twenty species contributed 81.5% of the total stocking. Shade tolerance, seed source, and insect herbivory had influence on the regeneration of the species in varying degrees. Regeneration of Maesopsis eminii and Polyscias fulva appeared to be more influenced by shading (light regime) than insect herbivory. The latter species also seemed to regenerate from seeds stored in soil seed bank. Phytophagous insects seemed to play more significant role in the regeneration of Zanthoxylum gilletii and Prunus africana than that of Maesopsis eminii and Polyscias fulva. As a recommendation, natural forest management should involve creation of “regeneration gaps” to enhance the regeneration of shade intolerant species like Prunus africana and Zanthoxylum gilletii. Sustainable selective logging of valuable timber species is suggested as a way of creating the gaps. Key Words: Natural forest, regeneration, Insect herbivory, Maesopsis eminii, Zanthoxylum gilletii, Polyscias fulva, and Prunus africana Résumé La régénération pauvre des espèces à bois de valeur sous une canopie forestière fermée constitue un problème majeur pour la régénération des espèces d\' arbres dans les forêts humides montagneuses au Kenya. Cette étude, conduite en 1998-1999, a examiné l\'influence de l\'ombrage, de l\'origine des graines et des insectes herbivores sur la régénération des espèces d\'arbres les plus exploitées (Maesopsis eminii, Zanthoxylum giletii, Polyscias fulva et Prunus africana) dans la forêts de Kakamega. Cinquante huit (58) espèces de plantes ligneuses ont été enregistrées, la plupart à faible densité dans les endroits échantillons; 20 espèces constituaient 81.5% du stockage total. Les trois facteurs éxaminés influencent la régénération des espèces étudieés mais á des degrés variés. La régénération de Maesopsis eminii et Polyscias fulva est plus sensible á l\'ombre qu‘à l\'attaque par des insectes. Polyscias fulva se développe aussi à partir des graines enfuies dans le sous sol. Des insectes phytophages influencent plus significativement la régénération de Zanthoxylum giletii et Prunus africana que celle de Maesopsis eminii et Polyscias fulva. Ainsi, l\'aménagement des forêts naturelles doit considérer la création des \"trous de régénération\" pour favoriser des espèces d\'arbres hostiles à l\'ombrage comme Prunus africana et Zanthoxylum giletii. L\'exploitation séléctive soutenue des arbres de valeur est proposée comme moyen de création des ouvertures dans la canopie forestière. Mots clés: Forêt naturelle, régénération, insectes herbivores, Maesopsis eminii, Zanthoxylum giletii, Polyscias fulva, Prunus africanaDiscovery and Innovation Vol 16 (3&4) 2004: 117-12

Geochemical and palaeoenvironmental characteristics of Missole I iron duricrusts of the Douala sub-basin (Western Cameroon)

Major and trace element composition of iron duricrusts including clayey material samples and biostratigraphy of the Missole I outcrop from the Paleocene-Eocene N'Kapa Formation in the Douala sub-basin of Cameroon were used to infer the palaeoenvironment and relative age of the iron duricrusts. Iron duricrusts and clayey materials are essentially kaolinitic and smectitic and are generally siliceous and ferruginous (iron duricrusts) or siliceous and aluminous (clayey materials). These materials have high Chemical Indices of Alteration (CIA=86.6-99.33%). The negative Eu anomalies with high (La/Yb)(N) shown by iron duricrusts and clayey sediments are essentially derived from silicic or felsic parent rocks when fractionated chondrite-normalized REE patterns also indicate felsic or silicic parent rocks. The Missole I iron duricrusts have a post-Thanetian age according to the relative age of claystones (Thanetian) and were formed after the deposition of sedimentary materials in an anoxic low-depth marine environment with eutrophication of surface water, and may have been exhumed and oxidized under arid climate

Increased baseline ECG R-R dispersion predicts improvement in systolic function after atrial fibrillation ablation.

BackgroundAtrial fibrillation (AF) is associated with left ventricular (LV) systolic dysfunction which may improve after AF ablation. We hypothesised that increased ventricular irregularity, as measured by R-R dispersion on the baseline ECG, would predict improvement in the left ventricular ejection fraction (LVEF) after AF ablation.MethodsPatients with LVEF <50% at two US centres (2007-2016), having both a preablation and postablation echocardiogram or cardiac MRI, were included. LVEF improvement was defined as absolute increase in LVEF by >7.5%. Multivariable logistic regression (restricted to echocardiographic/ECG variables) was performed to evaluate predictors of LVEF improvement.ResultsFifty-two patients were included in this study. LVEF improved in 30 patients (58%) and was unchanged/worsened in 22 patients (42%). Those with versus without LVEF improvement had an increased baseline R-R dispersion (645±155 ms vs 537±154 ms, p=0.02, respectively). The average baseline heart rate in all patients was 93 beats per minute. After multivariable logistic regression, increased R-R dispersion (OR 1.59, 95% CI 1.00 to 2.55, p=0.03) predicted LVEF improvement.ConclusionsIncreased R-R dispersion on ECG was independently associated with improved systolic function after AF ablation. This broadens the existing knowledge of arrhythmia-induced cardiomyopathy, demonstrating that irregular electrical activation (as measured by increased R-R dispersion on ECG) is associated with a cardiomyopathy capable of improving after AF ablation

Fertility of Zero-Grazed Dairy Cattle following Hormone Treatment and Fixed-Time Artificial Insemination

Reproduction is important to dairy herds and achievement of economically optimal performance still remains a substantial multifactorial challenge in many herds. Poor estrus expression and detection, repeat breeding, prolonged postpartum anestrus and delayed onset of puberty are some of the limiting factors to attainment of optimum reproductive efficiency in zero-grazed herds. This study investigated the fertility of anestrous and repeat breeder zerograzed dairy animals following induction of ovarian cyclicity, synchronization of ovulation, and fixed time insemination. The following three categories of animals were recruited into the study: 1) Delayed puberty or anestrus in heifers (n=26), 2) Prolonged postpartum anestrus (n=23), and 3) Repeat breeding cows and heifers (n=28). The seventy seven animals (69 Friesians, 7 Ayrshires and 1 Guernsey) were all zero-grazed and had a median age and parity of 5.0 years and 2.5 respectively, and a body condition score of at least 2.5 on a scale of 1 to 5. All study animals were intramuscularly injected with Gonadotropin Releasing Hormone (GnRH) on Day 0, Prostaglandin F2α (PGF2α) on Day 7, and GnRH on Day 9. Treated animals had timed artificial insemination (AI) 8-24 hours after the last injection. Pregnancy diagnosis was performed by rectal palpation 60 days post-AI. The pregnancy rate for anestrous cows (6/23) was 26.1%, repeat breeder cows (5/14) 35.7%, anestrous heifers (16/26) 61.5% and repeat breeder heifers (5/14) 35.7%. This treatment protocol may improve fertility outcomes in zero-grazed units where anestrus is a problem, reproductive skills are deficient, there is scarcity of labor or where there is an inability to commit the required time for estrus detection. Kenya Veterinarian Vol. 30 (2) 2006: pp. 68-7

Risk factors of anaemia and iron deficiency in Somali children and women: Findings from the 2019 Somalia Micronutrient Survey

There are limited data on the prevalence of anaemia and iron deficiency (ID) in Somalia. To address this data gap, Somalia's 2019 micronutrient survey assessed the prevalence of anaemia and ID in children (6-59 months) and non-pregnant women of reproductive age (15-49 years). The survey also collected data on vitamin A deficiency, inflammation, malaria and other potential risk factors for anaemia and ID. Multivariable Poisson regressions models were used to identify the risk factors for anaemia and ID in children and women. Among children, the prevalence of anaemia and ID were 43.4% and 47.2%, respectively. Approximately 36% and 6% of anaemia were attributable to iron and vitamin A deficiencies, respectively, whereas household possession of soap was associated with approximately 11% fewer cases of anaemia. ID in children was associated with vitamin A deficiency and stunting, whereas inflammation was associated with iron sufficiency. Among women, 40.3% were anaemic, and 49.7% were iron deficient. In women, ID and number of births were significantly associated with anaemia in multivariate models, and approximately 42% of anaemia in women was attributable to ID. Increased parity was associated with ID, and incubation and early convalescent inflammation was associated with ID, whereas late convalescent inflammation was associated with iron sufficiency. ID is the main risk factor of anaemia in both women and children and contributed to a substantial portion of the anaemia cases. To tackle both anaemia and ID in Somalia, food assistance and micronutrient-specific programmes (e.g. micronutrient powders and iron supplements) should be enhanced