Mosquito Larvicidal Constituents from Lantana Viburnoides SP Viburnoides Var Kisi (A. rich) Verdc (Verbenaceae).

\ud \ud Lantana viburnoides sp viburnoides var kisi is used in Tanzania ethnobotanically to repel mosquitoes as well as in traditional medicine for stomach ache relief. Bioassay-guided fractionation and subtraction bioassays of the dichloromethane extract of the root barks were carried out in order to identify the bioactive components for controlling Anopheles gambiae s.s. mosquito larvae. Twenty late III or early IV instar larvae of An. gambiae s.s. were exposed to various concentrations of the plant extracts, fractions, blends and pure compounds, and were assayed in the laboratory by using the protocol of WHO 1996. Mean mortalities were compared using Dunnett's test (p < 0.05) and lethal concentration calculated by Lackfit Inversel of the SAS programme. The crude extract (LC50 = 7.70 ppm in 72 h) and fractions exhibited different level of mosquito larvicidal activity with subtraction of some fractions resulting in activity enhancement. The active fractions contained furanonaphthaquinones regio-isomers (LC50 = 5.48-5.70 ppm in 72 h) and the lantadene triterpenoid camaric acid (LC50 = 6.19 ppm in 72 h) as active principles while the lupane triterpenoid betulinic acid (LC50 < 10 ppm in 72 h) was obtained from the least active fraction. Crude extracts and some fractions had higher or comparable larvicidal activity to the pure compounds. These results demonstrate that L. viburnoides sp viburnoides var kisi extracts may serve as larvicides for managing various mosquito habitats even in their semi-purified form. The isolated compounds can be used as distinct markers in the active extracts or plant materials belonging to the genus Lantana

Topography and distribution of ostia venae hepatica in the retrohepatic inferior vena cava

Background : Openings of hepatic veins into the retrohepatic surface of the inferior vena cava (ostia venae hepatica) play a part in controlling hepatic circulation by acting as collateral channels in obstruction. Their topography and distribution must be taken into account during catheterization and liver transplantation. This anatomy is however little known among Kenyans. Objectives: To study the position, number and distribution of ostia venae hepatica in a selected Kenyan population Materials and methods: Eighty fresh postmortem liver specimens were obtained from the Chiromo Mortuary. The hepatic IVC was isolated from the lower border of caudate lobe to the diaphragmatic opening, with the liver in position. The vein was opened posteriorly by a vertical incision along its whole length and the lateral flaps reflected laterally. The topography of the ostia was studied using the Sahni model. The number and patterns of the ostia were also studied. The patterns of openings of the left, right and middle hepatic veins were studied as well as the distances between them. Results : A total of 584 ostia were identified, an average of 7.3 per liver. The ostia were distributed on the lateral portions of the vein, with an avascular plane at the centre. Major veins terminated in the upper third of the hepatic inferior vena cava, with little extraparenchymal course. The mean distance between the right hepatic vein and middle hepatic vein was 1.7cm Conclusion : The numerous ostia venae hepatica identified in these subjects offer collateral flow channels during hepatic venous obstruction in Budd-Chiari syndrome. The topography and patterns of distribution of the openings suggest the advantage of an avascular virtual plane, which is a safe dissecting path for hepatovascular surgeons

Morphometric parameters of Kenyan adult mandibles

Background: The mandible has a horizontal U-shaped body which is continuous at it posterior end with a pair of vertical rami forming the lower part of the facial skeleton. Knowledge of mandibular dimension is an important consideration during the selection of appropriate reconstruction techniques.Objectives: To determine the morphometric parameters in Kenyan adult mandible and to relate them to those of a sample of reconstruction plate and screw.Design: A descriptive cross-sectional study.Setting: The National Museums of Kenya, Nairobi and the Department of Human Anatomy, University of Nairobi.Subjects: Intact whole adult mandibles (n=82) were obtained from the National Museums of Kenya, Nairobi and the Department of Human Anatomy, University of Nairobi.                                                    Results: The average length of the mandible in males for the right and left sides was 98.6 mm and 100.5 mm respectively while for the females this was 92.2 mm and 94.5 mm respectively. The average height of the rumus of the mandible in male for the right and left sides was 57.40 mm and 58.07 mm respectively while for female this was 51 .81 and 52.20 respectively. Significant differences were noted among the curved length and heights of the mandible between male and females (p&lt;0.05). Significant difference between the right and left side of the mandible were noted (p&lt;0.05) as well as between the length of the mandible and the length of the reconstruction plate (p&lt;0.05). There were no significant difference in the thickness of the mandible between males and females and; between the left and right sides of the mandible with averages of 13.94 mm at the symphysis, 11.00 mm at the canine 10.33 at the mental foramen 11.06 at the bifurcation of the first molar, 12.36 mm at the bifurcation of the secend molar 8.62 mm at the level of the anterior ramus, 5.41 mm at gonion and 5.89 mm at the midpoint of the rums (p&gt;0.05) with strong positive correlations. Significant differences were,however noted between the thicknesses of the body and ramus of the mandible and the sizes of the screws (p&lt;0.05).Conclusion: The baseline parameters of the mandibles for Kenyans can be used in the selection of appropriate reconstruction plates and screws

Ab Initio Quality NMR Parameters in Solid-State Materials Using a High-Dimensional Neural-Network Representation.

Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful experimental tools to probe the local atomic order of a wide range of solid-state compounds. However, due to the complexity of the related spectra, in particular for amorphous materials, their interpretation in terms of structural information is often challenging. These difficulties can be overcome by combining molecular dynamics simulations to generate realistic structural models with an ab initio evaluation of the corresponding chemical shift and quadrupolar coupling tensors. However, due to computational constraints, this approach is limited to relatively small system sizes which, for amorphous materials, prevents an adequate statistical sampling of the distribution of the local environments that is required to quantitatively describe the system. In this work, we present an approach to efficiently and accurately predict the NMR parameters of very large systems. This is achieved by using a high-dimensional neural-network representation of NMR parameters that are calculated using an ab initio formalism. To illustrate the potential of this approach, we applied this neural-network NMR (NN-NMR) method on the (17)O and (29)Si quadrupolar coupling and chemical shift parameters of various crystalline silica polymorphs and silica glasses. This approach is, in principal, general and has the potential to be applied to predict the NMR properties of various materials.This is the author accepted manuscript. The final version is available from ACS via http://dx.doi.org/10.1021/acs.jctc.5b0100

Age changes in the structure of human Atrioventricular annuli

Atrioventricular annuli are important in hemodynamic stability and support to tricuspid and mitral valves. Anatomical features of the annuli such as circumference, organization of connective tissue fibers, myocardium and cellularity may predispose to annular insufficiency and valvular incompetence. These pathologies increase with age and are more common in females, although the anatomical basis for this disparity remains unclear. This study therefore aimed to investigate age-related changes in the structure of human atrioventricular annuli. One hundred and one hearts (48males, 53 females) from subjects (15 to 60 years) were studied in three age groups (≤ 20 yrs, 21-39 yrs and 40-60 yrs). Annular circumferences were measured and corrected for heart weight. Routine histology was carried out on 21 hearts. Differences in annular circumference between the age groups were determined using one-way ANOVA while gender differences were determined using independent Students’t-test. Overall, females had significantly larger annular circumference than males after correcting for heart weight (p ≤0.05). The annular circumference generally increased with age however there was a significant increase in the 21-39 year age group (p ≤0.05). Microscopically, myocardium was consistently present in males but absent in females except in one specimen. The collagen fiber density increased with age in both gender as the fibers became more irregular. The annular cellularity, elasticity and myocardial content also declined with increasing age. The significantly wider annular circumference in the 21-39 year age group is clinically important as wider circumference is associated with decreased heart valve co-aptation and valvular incompetence. This may suggest an earlier predisposition to this pathology in the study population. The age-related decrease in annular cellularity, elasticity and myocardial content may explain the higher incidence of valvular incompetence with increasing age.Key words: Atrioventricular annuli; Age changes; Valve incompetence

Sternal foramina and variant xiphoid morphology in a Kenyan population

Sternal foramina may pose a great hazard during sternal puncture, due to inadvertent cardiac or great vessel injury. They can also be misinterpreted as osteolytic lesions in cross-sectional imaging of the sternum. On the other hand, variant xiphoid morphology such as bifid, duplicated, or trifurcated may be mistaken for fractures during imaging. The distribution of these anomalies differs between populations, but data from Africans is scarcely reported. This study therefore aimed to investigate the distribution and frequency of sternal foramina and variant xiphoid morphology in a Kenyan population. Eighty formalin-fixed adult sterna (42 males [M], 38 females [F]) of age range 18&#8211;45 years were studied during dissection at the Department of Human Anatomy, University of Nairobi. Soft tissues were removed from the macerated sterna by blunt dissection and foramina recorded in the manubrium, body, and xiphoid process. The xiphisternal ending was classified as single, bifurcated (2 xiphoid processes with a common stem), or duplicated (2 xiphoid processes with separate stems). Results were analysed using SPSS version 17.0. Foramina were present in 11 specimens (13.8%): 7 M, 4 F. The highest frequency was in the sternal body (n = 9), where they predominantly occurred at the 5th intercostal segment. Xiphoid foramina were present in 2 specimens (both males) (2.5%), while manubrial foramen was not encountered. The xiphisternum ended as a single process in 64 cases (34 M, 30 F) (80%). It bifurcated in 10 cases (5 M, 5 F) (12.5%), and duplicated in 6 cases (4 M, 2 F) (7.5%). There were no cases of trifurcation. Sternal foramina in Kenyans vary in distribution and show higher frequency than in other populations. These variations may complicate sternal puncture, and due caution is recommended. The variant xiphisternal morphology may raise alarm for xiphoid fractures and may therefore be considered a differential

Presenting symptoms of acute coronary syndrome in older and younger adults in Trinidad & Tobago

BACKGROUND AND AIM: Acute Coronary Syndrome (ACS) is a major cause of mortality in Trinidad and Tobago. As life expectancy increases, Emergency Departments in Trinidad and Tobago are admitting more older patients (age ≥ 65). Previous studies have demonstrated differences in the presenting symptoms between older and younger patients with ACS. However, to our knowledge, no such work has been done on older patients in the developing world. The aim of this study was to determine the differences in the reported symptoms of ACS between the older patients (age ≥ 65) and younger adults (age 18 – 64) in the ED. The primary objective was to compare the differences in frequency of symptoms of ACS between the older and younger adults. A secondary objective was to determine if differences in reported symptoms also exist between older men and older women. CONCLUSIONS: This study demonstrates significant differences in symptoms between older and younger patients as well as between older men and women. Clinical assessment of older patients with ACS should be tailored to their common presenting features. Further work is needed to develop a clinical assessment tool for older patients with ACS that accounts for differences in presentation

New antitrypanosomal tetranotriterpenoids from Azadirachta Indica

Organic extracts of the leaves of Azadirachta indica A. Juss. yielded ten antitrypanosomal terpenoids. Three of these (1 – 3), are novel and are derivatives of nimbolide and nimbin. They were extracted from chloroformfraction of methanol extract. These compounds were found to exhibit strong antitrypanosomal activities against Trypanosoma brucei rhodesiense with MIC values ranging of 6.9, 15.6 and 7.8 μg/ml respectively and were more active than Cymerlarsan ( a standard drug), which had an MIC value of 187.5 μg/ml when tested against T. b. rhodesiense The structures were elucidated by spectroscopic methods including; NMR, MS, UV and IR.Key words: Meliaceae, limonoids, Trypanosoma brucei rhodesiense, Azadirachta indica, antitrypanosomal activity

Forecasting the dry bulk freight market in 2011 and 2012

Dry Bulk market is the largest sector of world shipping market. The analysis of this market and the assessment of dry bulk freight rate, market behavior, policy making in this field, transportation policies and fleet development, and also research in dry bulk shipping industry is inevitable. The main aim of this study is to analyze and forecast the future of dry bulk freight market in 2011 and 2012. Since the shipping industry is known to be a volatile industry; therefore, understanding the characteristics of this market and forecasting its volatilities have been of prime interest in operational and financial decision makings. To achieve this aim, linear regression, multiple regression and time series analyses (winer’s exponential smoothing) methods is used. Results of the study show that the Baltic Dry Index in 2011 and 2012 may decrease in relation to 2010, but this drop in 2011 will be drastic and in 2012 modest

Squeezing Oil into Water under Pressure: Inverting the Hydrophobic Effect

The molecular structure of dense homogeneous fluid water-methane mixtures has been determined for the first time using high-pressure neutron-scattering techniques at 1.7 and 2.2 GPa. A mixed state with a fully H-bonded water network is revealed. The hydration shell of the methane molecules is, however, revealed to be pressure-dependent with an increase in the water coordination between 1.7 and 2.2 GPa. In parallel, ab initio molecular dynamics simulations have been performed to provide insight into the microscopic mechanisms associated with the phenomenon of mixing. These calculations reproduce the observed phase change from phase separation to mixing with increasing pressure. The calculations also reproduce the experimentally observed structural properties. Unexpectedly, the simulations show mixing is accompanied by a subtle enhancement of the polarization of methane. Our results highlight the key role played by fine electronic effects on miscibility and the need to readjust our fundamental understanding of hydrophobicity to account for these