bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the Nutritional Status of Children Living in Orphanages in the City of Douala, Cameroon
Authors: Okalla Cécile Ebongue , Koum Daniele Kedy , Penda Calixte Ida , Mefo’o Jean-Pierre Nda , Wanye Fanta , Eloumou Servais Albert , Temfack Elvis , Luma Henry Name
Published: April 2019

Introduction: Malnutrition is characterised by metabolic disturbances identified by measurement of anthropometric and biological parameters. The purpose of this study was to determine the nutritional profile of children living in orphanages and to investigate the factors associated with malnutrition in these institutions.
Methods: A cross-sectional study was conducted on subjects aged 0 to 18, living in 13 orphanages in Douala. Socio-demographic data, anthropometric and biological parameters were collected. The diagnosis of malnutrition at the clinical level was based on Z score <-2 for the different index and >2 for Weight-for-Height and Body Mass Index for Age. A blood sample permits the photometric assay of albumin, pre-albumin, and C Reactive Protein. The results were interpreted according to reference values for age.
Results: Among the 176 children included, the average age was 10±4 years with a male predominance. The majority of children (51.1%) were placed in orphanages for lack of financial resources, and one or both parents orphaned were 42.1%. The wasting, underweight and stunting rates were 5.6%, 4.7%, and 18.2%, respectively. Hypo-pre-albuminemia and hypo-albuminemia were observed in 42.6% and 34.7% of children respectively. CRP was increased in 5.1% of cases. Stunting and orphanages with one caregiver for more than 5 children were predictive factors for hypo-albuminemia and Hypo-pre-albuminemia.
Conclusion: Rates of wasting, stunting and underweight were high. Several children had sub-clinical malnutrition despite normal anthropometric index. These results recall the importance of biology for screening, in order to prevent the occurrence of clinical malnutrition.
Syndicats et responsabilité sociétale de l’entreprise : analyse longitudinale des stratégies des Confédérations françaises
Authors: Havard Christelle , Sobczak André
Published: April 2019

Au cours des vingt dernières années, la responsabilité sociétale de l’entreprise (RSE) est devenue une préoccupation majeure du débat public et de la recherche en sciences sociales. La multiplication des démarches RSE a nécessairement un impact sur les organisations syndicales qui sont amenés à s’adapter et à réagir ou qui peuvent se saisir des opportunités offertes par la RSE. L’objectif de cet article est d’apporter un éclairage sur la manière dont les stratégies des centrales syndicales en matière de RSE se construisent.

Deux types de travaux sont mobilisés pour analyser ces stratégies et la manière dont elles se sont construites : les travaux de Boxall (2008) en relations industrielles et ceux de Whittington (2006) du courant de la « stratégie comme pratique » (strategy as practice, en anglais). Une grille d’analyse est proposée pour étudier la construction de la stratégie en matière de RSE de cinq Confédérations syndicales représentatives en France au cours de la période 2006-2016.

Les résultats de l’étude longitudinale révèlent trois catégories de stratégies : 1- des Confédérations syndicales qui ont formulé assez tôt une stratégie favorable à la RSE ; 2- des Confédérations qui se sont engagés dans une stratégie plus récemment ; et, 3- une Confédération qui reste critique à l’égard de la RSE. Les éléments déterminants de ces stratégies sont, d’une part, les relations externes que ces Confédérations ont nouées avec les ONG et les pouvoirs publics, et, d’autre part, les ressources affectées à la RSE et les actions engagées. Sur le plan théorique, l’article permet d’élargir le potentiel des courants théoriques retenus et d’ouvrir de futures perspectives de recherche. Sur le plan pratique, il permet de mieux comprendre ces stratégies et, le cas échéant, de mieux s’y adapter, voire de les influencer.
Producción de eventos: puesta en escena de la creatividad
Authors: Riera Creus Míriam
Published: April 2019

¿Cuáles son las claves de un evento exitoso? ¿Una idea creativa original? ¿Un buen hilo conductor? ¿Un ritmo adecuado? ¿El factor Wow? Míriam Riera Creus, professora colaboradora del Máster universitario de Comunicación Corporativa, Protocolo y Eventos de la UOC, reflexiona sobre los elementos que marcan la diferencia en la producción de eventos.
El cuerpo herido o la expulsión de la diversidad
Authors: Ruiz Benedicto Ainhoa , Aranda Dani
Published: April 2019

El biopoder, ese término acuñado por Foucault, define el control que se ejerce desde los gobiernos y las instituciones políticas sobre la vida y en concreto sobre los cuerpos. Es desde los espacios de poder desde donde se ejerce la mutilación social del cuerpo. ¿Cómo y por qué agredimos nuestros cuerpos?
Feminismo colaborativo
Authors: Sanz Martos Sandra
Published: April 2019

El pasado 31 de enero la mayoría de los medios se hicieron eco de la noticia de que se había elaborado un mapa del acoso a las mujeres en Madrid. El resultado obtenido es del fruto del trabajo colaborativo de las propias jóvenes de hasta 30 años que han ido marcando 850 localizaciones. Pero no es, ni mucho menos, el único caso de colaboración entorno al tema del feminismo. Distintas iniciativas de la Fundación Mujeres o las movilizaciones que se dieron entorno al 8 de marzo de 2018, entre otros, son algunos ejemplos.
¿Qué es el periodismo de calidad?
Authors: Cavaller Víctor
Published: April 2019

La irrupción tecnológica de nuevos medios, formas y fuentes de información y de comunicación, la ampliación y crecimiento de su alcance y participación, así como la necesaria inmediatez que implica la actividad profesional periodística están introduciendo una categoría diferenciada en el ámbito que se ha venido a definir como periodismo de calidad. La diferencia presupone la existencia de un periodismo de baja calidad, y por lo tanto hace referencia a un estándar deseable, lo que obliga a redefinirlo. Este artículo se pregunta sobre las características que garantizan la excelencia en el periodismo que permiten valorarlo respecto de otras formas.
Memorias de 'Africa'
Authors: Roig Antoni
Published: April 2019

Éste podría parecer un artículo tardío sobre los Premios Oscar. Pero no. Ciertamente, en 1986, el film Memorias de África se llevaba varios Premios Oscar en medio de cierta polémica acerca sus méritos reales. Como este año, vamos. Pero me interesa ir algo más atrás, hasta 1982, momento en que triunfaba en las listas de todo el mundo una canción denominada Africa, interpretada por la banda norteamericana Toto. Más de tres décadas después, quizás no nos acordamos mucho de Memorias de África, pero Africa se ha convertido en algo así como la canción de Internet, a golpe de memes y versiones. Esta es ─una parte─ de la historia.
'Press': ¿cuáles han de ser habilidades del periodista contemporáneo?
Authors: Herrera Raquel
Published: April 2019

Una de las principales preocupaciones de los nuevos periodistas actuales es el dominio de las herramientas tecnológicas que permitan el desarrollo de su trabajo en entornos complejos y cambiantes donde la multimedialidad y el multiformato acaparan la atención. No obstante, ¿qué otras habilidades, digamos blandas, o mejor, llamémoslas humanas, hay que seguir puliendo? La serie televisiva Press, que acaba de estrenarse en Filmin, lo pone de manifiesto con polos opuestos de la práctica periodística.
Stiffness and tension gradients of the hair cell’s tip-link complex in the mammalian cochlea
Authors: Tobin Mélanie , Chaiyasitdhi Atitheb , Michel Vincent , Michalski Nicolas , Martin Pascal
Published: April 2019

Sound analysis by the cochlea relies on frequency tuning of mechanosensory hair cells along a tonotopic axis. To clarify the underlying biophysical mechanism, we have investigated the micromechanical properties of the hair cell’s mechanoreceptive hair bundle within the apical half of the rat cochlea. We studied both inner and outer hair cells, which send nervous signals to the brain and amplify cochlear vibrations, respectively. We find that tonotopy is associated with gradients of stiffness and resting mechanical tension, with steeper gradients for outer hair cells, emphasizing the division of labor between the two hair-cell types. We demonstrate that tension in the tip links that convey force to the mechano-electrical transduction channels increases at reduced Ca2+. Finally, we reveal gradients in stiffness and tension at the level of a single tip link. We conclude that mechanical gradients of the tip-link complex may help specify the characteristic frequency of the hair cell.
Low wnt/β-catenin signaling determines leaky vessels in the subfornical organ and affects water homeostasis in mice
Authors: Benz Fabienne , Wichitnaowarat Viraya , Lehmann Martin , Germano Raoul FV , Mihova Diana , Macas Jadranka , Adams Ralf H , Taketo M Mark , Plate Karl-Heinz , Guérit Sylvaine , Vanhollebeke Benoit , Liebner Stefan
Published: April 2019

The circumventricular organs (CVOs) in the central nervous system (CNS) lack a vascular blood-brain barrier (BBB), creating communication sites for sensory or secretory neurons, involved in body homeostasis. Wnt/β-catenin signaling is essential for BBB development and maintenance in endothelial cells (ECs) in most CNS vessels. Here we show that in mouse development, as well as in adult mouse and zebrafish, CVO ECs rendered Wnt-reporter negative, suggesting low level pathway activity. Characterization of the subfornical organ (SFO) vasculature revealed heterogenous claudin-5 (Cldn5) and Plvap/Meca32 expression indicative for tight and leaky vessels, respectively. Dominant, EC-specific β-catenin transcription in mice, converted phenotypically leaky into BBB-like vessels, by augmenting Cldn5+vessels, stabilizing junctions and by reducing Plvap/Meca32+ and fenestrated vessels, resulting in decreased tracer permeability. Endothelial tightening augmented neuronal activity in the SFO of water restricted mice. Hence, regulating the SFO vessel barrier may influence neuronal function in the context of water homeostasis.
Influence of long term nitrogen limitation on lipid, protein and pigment production ofEuglena gracilisin photoheterotrophic cultures
Authors: Tossavainen Marika , Ilyass Usman , Ollilainen Velimatti , Valkonen Kalle , Ojala Anne , Romantschuk Martin
Published: April 2019

Nitrogen limitation is considered a good strategy for enhancement of algal lipid production while conversely N repletion has been shown to result in biomass rich in proteins. In this study, the influence of long-term N limitation onEuglena gracilisfatty acid (FA), protein, chlorophylla, and carotenoid concentrations was studied in N limited cultures. Biomass composition was analyzed from three-time points from N starved late stationary phase cultures, exposed to three different initial N concentrations in the growth medium. Total lipid content increased under N limitation in ageing cultures, but the low N content and prolonged cultivation time resulted in the formation of a high proportion of saturated FAs. Furthermore, growth as well as the production of proteins, chlorophyllaand carotenoids were enhanced in higher N concentrations and metabolism of these cellular components stayed stable during the stationary growth phase. Our findings showed that a higher N availability and a shorter cultivation time is a good strategy for efficientE. gracilisbiomass production, regardless of whether the produced biomass is intended for maximal recovery of polyunsaturated FAs, proteins, or photosynthetic pigments. Additionally, we showed an increase of neoxanthin, β-carotene, and diadinoxanthin as a response to higher N availability.
Obstetric and perinatal outcomes of dizygotic twin pregnancies resulting from in vitro fertilization versus spontaneous conception: a retrospective study
Authors: Chen Hua , Wan Ying , Xi Haitao , Su Weijue , Cheng Jing , Zhu Chunfang , Lv Jieqiang , Wu Xinmei , Zhao Junzhao
Published: April 2019

This study was designed to to assess perinatal and neonatal outcomes of dizygotic twin pregnancies conceived naturally or by in vitro fertilization (IVF). After strict selection, the study included 470 dizygotic twin pregnancies. There were 249 resulting from IVF treatments and 221 conceiving spontaneously. After adjusting maternal age and primiparity, the results showed that there were no significant differences between the two groups (P > 0.05) in terms of maternal antenatal complications and neonatal outcomes. In conclusion, our study does not reveal increased risks for pregnancy-related complications and adverse neonatal outcomes in dizygotic twin pregnancies following IVF treatments. With these fundamental data, this study could provide a reference for perinatal care and clinical assisted reproductive technology (ART) treatment and help to inform infertile parents about the potential risks of IVF treatments.
Microfluidic chip combined with magnetic-activated cell sorting technology for tumor antigen-independent sorting of circulating hepatocellular carcinoma cells
Authors: Wang Xuebin , Sun Liying , Zhang Haiming , Wei Lin , Qu Wei , Zeng Zhigui , Liu Ying , Zhu Zhijun
Published: April 2019

Purpose

We aimed to generate a capture platform that integrates a deterministic lateral displacement (DLD) microfluidic structure with magnetic-activated cell sorting (MACS) technology for miniaturized, efficient, tumor antigen-independent circulating tumor cell (CTC) separation.

Methods

The microfluidic structure was based on the theory of DLD and was designed to remove most red blood cells and platelets. Whole Blood CD45 MicroBeads and a MACS separator were then used to remove bead-labeled white blood cells. We established HepG2 human liver cancer cells overexpressing green fluorescent protein by lentiviral transfection to simulate CTCs in blood, and these cells were then used to determine the CTC isolation efficiency of the device. The performance and clinical value of our platform were evaluated by comparison with the Abnova CytoQuest™ CR system in the separating of blood samples from 12 hepatocellular carcinoma patients undergoing liver transplantation in a clinical follow-up experiment. The isolated cells were stained and analyzed by confocal laser scanning microscopy.

Results

Using our integrated platform at the optimal flow rates for the specimen (60 µl/min) and buffer (100 µl/min per chip), we achieved an CTC yield of 85.1% ± 3.2%. In our follow-up of metastatic patients, CTCs that underwent epithelial–mesenchymal transition were found. These CTCs were missed by the CytoQuest™ CR bulk sorting approach, whereas our platform displayed increased sensitivity to EpCAMlow CTCs.

Conclusions

Our platform, which integrates microfluidic and MACS technology, is an attractive method for high-efficiency CTC isolation regardless of surface epitopes.
Identification of the GRAS gene family in the Brassica juncea genome provides insight into its role in stem swelling in stem mustard
Authors: Li Mengyao , Sun Bo , Xie Fangjie , Gong Ronggao , Luo Ya , Zhang Fen , Yan Zesheng , Tang Haoru
Published: April 2019

GRAS transcription factors are known to play important roles in plant signal transduction and development. A comprehensive study was conducted to explore the GRAS family in the Brassica juncea genome. A total of 88 GRAS genes were identified which were categorized into nine groups according to the phylogenetic analysis. Gene structure analysis showed a high group-specificity, which corroborated the gene grouping results. The chromosome distribution and sequence analysis suggested that gene duplication events are vital for the expansion of GRAS genes in the B. juncea genome. The changes in evolution rates and amino acid properties among groups might be responsible for their functional divergence. Interaction networks and cis-regulatory elements were analyzed including DELLA and eight interaction proteins (including four GID1, two SLY1, and two PIF3 proteins) that are primarily involved in light and hormone signaling. To understand their regulatory role in growth and development, the expression profiles of BjuGRASs and interaction genes were examined based on transcriptome data and qRT-PCR, and selected genes (BjuGRAS3, 5, 7, 8, 10, BjuB006276, BjuB037910, and BjuA021658) had distinct temporal expression patterns during stem swelling, indicating that they possessed diverse regulatory functions during the developmental process. These results contribute to our understanding on the GRAS gene family and provide the basis for further investigations on the evolution and functional characterization of GRAS genes.
Health Hazards Associated with Operations of Medium-Scale Dual Purpose Kerosene Vendors Using Motorized Pumps with Aboveground Storage Tanks in Ilorin Metropolis, Kwara State, Nigeria
Authors: Ibrahim Moshood Liman , Sawyerr Henry Olawale , Isiaku Aliyu Nda
Published: April 2019

Introduction: The use of Dual Purpose Kerosene (DPK) as a means of cooking and power supply in Nigeria cannot be overemphasized especially among the over 70% of Nigerians living in poverty. It is a highly hazardous product and the adverse environmental health effects from the use of this product remain widespread. Thus, due to the scarcity of epidemiological studies, potential harm and risks of kerosene, the present study was carried out.

Aim and Objectives: This study aimed at evaluating the environmental health hazards associated with operations of medium-scale DPK vendors using motorized pumps with aboveground storage tanks (ASTs) in Ilorin metropolis and as such estimate the numbers of medium-scale DPK vendors, identify their locations using the Geographic Information System (GIS) tool and assess the likely environmental health hazards associated with the operations of these DPK vendors.

Methodology: Purposive sampling technique was deployed in this study and data was collected using a structured questionnaire and handheld Germin (GPSmap® 78) GPS.

Results: The study revealed that about 76 medium-scale DPK vendors with ASTs are found in Ilorin metropolis with 48(63.2%) found in Ilorin West LGA, 18(23.6%) in Ilorin South and 10(13.2%) in Ilorin East. Over 80% of the DPK vendors have their ASTs in close proximity to major roads, 68.4% in close proximity to residential buildings, 30.3% in close proximity to a water source and 7% reported the incidence of kerosene spillage. The test of association between the operations of medium-scale DPK vendors and associated environmental health hazards was found to be significant at (p<0.05); while ArcGIS 10.4 software was employed in showing the spatial distribution of the DPK vendors within Ilorin metropolis.

Conclusion: Conclusively, this study shows the activities of the DPK vendors causes high environmental health hazards which directly impact both environmental health and health of the population

Recommendations: Stringent enforcement activities by the Environmental Health Officers (EHO's) on adherence to stipulated setbacks from buildings and major roads; massive enlightenment on the various health hazards associated with DPK vendors operations; and government, through the state assembly, should enact laws to curb the uncontrolled proliferation of medium-scale DPK vendors in Ilorin metropolis and storage of toxic and flammable substances.
Developments of an Emerging Infectious Agent: Norovirus
Authors: Tripathi Manikant , Kumar Shailendra
Published: April 2019

Norovirus, a member of calciviruses family is the leading cause of community-acquired and nosocomial acute gastroenteritis or inflammation of the stomach and intestine. This pathogenic virus is highly communicable and found in the stools and vomit of infected persons. The symptoms of infection include sudden vomiting, diarrhea, abdominal cramp, headache, low grade fever, nausea, chills, etc. This RNA virus spreads through contaminated foods or liquids, sharing norovirus loaded objects and contact with infection individual. There is neither a specific medicine nor vaccination available for norovirus infection. Some vaccines are under pre-clinical trials. However, the virus can be controlled by following good personal hygiene practices such as hand washing, eating properly washed fruits and vegetables, properly cooked foods, and cleaning of the area occupied by patient. Norovirus infection can be regulated through public awareness and dissemination of proper knowledge about this viral infection. The present review summarizes the biology of infections caused by norovirus and their control measures.
Costs and Returns Analysis of Maize Wholesaling in Gombe Metropolis, Nigeria
Authors: Mohammeda Suleiman , Sani R. M. , Idi S. , Abubakar Nasiru
Published: April 2019

The study examined the costs and returns of maize wholesaling in Gombe metropolis, Nigeria. Using questionnaire, a time series data were collected from 120 randomly sampled traders and the data were analyzed using descriptive statistics, correlation and net farm income analyses. Results showed that 99.1%, 98.2% and 65.4% of sampled traders were male, married and farmers respectively. Similarly, their average age, marketing experience, household size and capital level were 39.5 years, 12.6 years, 9 persons and N 422, 500.00 respectively. Further, it was found that respondents’ socioeconomic characteristics were significantly correlated with one another except between education and capital level. Furthermore, the marketing margin, net income and return per each Naira invested were found to be N503.84, N227.00 per 100 Kg and 0.06 respectively, while the efficiency value was 181.99%. Finally, while maize marketing in the study area was found to be profitable and efficient, there is need for further improvement, such as in the area of female involvement.
Antidiabetic and Haematological Effects of Chrysophyllum albidum Supplemented Diet on Streptozotocin Induced Diabetic Rats
Authors: Ibrahim H. O. , Osilesi O. , Adebawo O. O. , Onajobi F. D. , Karigidi K. O. , Muhammad L. B.
Published: April 2019

Background: The use of food in the management of diseases is an established art of science. It is essentially important in the management of chronic diseases such as diabetes mellitus where cure is not certain.

Objective: This study investigated the anti-diabetic and heamatological effects of Chrysophyllum albidum fruit-skin (CAFS) supplemented diet on streptozotocin induced diabetic rats.

Methods: Diabetes mellitus was induced by a single intraperitoneal injection of 50 mg/kg streptozotocin (STZ) and 70g/kg CAFS supplemented diet was used on STZ-induced diabetic rats to test its antidiabetic efficacy with some biochemical parameters and histological evaluation of liver and pancreatic tissues for a treatment period of twenty-eight days.

Results: The diabetic untreated rats exhibited hyperglycaemia accompanied with increases in glycosylated haemoglobin, plasma and liver lipid profile except high density lipoprotein-cholesterol (HDL-c) and white blood cell count while decreasing the body weight, insulin, hepatic glycogen and red blood cell levels. CAFS was significantly (p<0.05) effective in inhibiting hyperglycemia by 68%, decreased glycosylated haemoglobin by 20%, plasma and liver lipid profile except HDL-c and white blood cell count but increased the body weight by 17%, insulin, hepatic glycogen and  red blood cell levels in comparison with diabetic untreated group. The results were comparable to glibenclamide (standard-drug). Histopathological studies on liver and pancreas of CAFS-treated rats showed regenerative effects.

Conclusion: This study has indicated that CAFS possesses antihyperglycemic, antihyperlipidemic and ameliorative effect on diabetic induced abnormalities in haematological parameters, β-cell and liver tissue. The findings suggest that CAFS may be used as therapeutic adjunct in the management of diabetes.
Kamal Adomian Decomposition Method for Solving Nonlinear Wave-Like Equation with Variable Coefficients
Authors: Ahmad Azhari
Published: April 2019

In this paper, we applied a new method for solving nonlinear wave-like equation with variable coefficients , when  the exact solution has a closed form. This method is Kamal Adomian De-composition Method (KADM). The Kamal decomposition method is a combined form of the Kamal transform method and the Adomian decomposition method [1,2,3]. The nonlinear term can easily be handled with the help of Adomian polynomials which is considered to be a significant advantage of this technique over the other methods. The results reveal that the Kamal decomposition method is very efficient, simple and can be applied to other nonlinear problems.
Factors Related to Deaths of under 5 Years Old Children in Dar Alsalam Area-Khartoum-Sudan
Authors: Abdalla Asma Abdelaal , Milad Christina Nagi , Balla Siham Ahmed , Mohamed Haieder Abuahmed , Awad Elkarim Mohamed Ali
Published: April 2019

Aims: This study is done to identify factors affecting under five mortality in Dar Alsalam area, Khartoum.

Study Design: This is a community based cross-sectional study.

Place and Duration of Study: The study was carried out in block 25 in Dar Alsalam area in Khartoum State during March- April 2012.

Methodology: A total of 240 women in reproductive age who had an experience of child death were interviewed. The data was collected by semi-final medical students using structured questionnaire.  Two stage cluster sampling was used to select the households. Data was summarized using descriptive statistics and logistic regression analysis was carried out to identify factors associated with under-five mortality.

Results: Age of 156 (65%) of the deceased children was less than one year, while the age of 84 (35%) was between one and five years. The age of (25%) of the mother at the time of their child birth was below 18 years.  The majority of the mothers (70.8%) were illiterate, 74.2% were working and 80% were married.  Of the children 51.7 were males and for 74.2% of them the birth interval was less than 2 years.  Only 16.7% were breast fed for more than two years while the rest (83.3%) were breast fed up to 2years. Only 34.2% of the deceased children had completed their vaccination, and 68.3% had been admitted to hospital more than once before death.

Half of the families have piped water in their houses, in 75.8% of the houses there are pit latrines and in 68.3% there is electricity supply.

Logistic regression analysis identified incomplete vaccination, not employed mothers and having no latrines in the house as the factors related to the death of children between 1-5 years than those below one year.

Conclusion: Under-five mortality in low socioeconomic areas is associated with Low family income, mother’s illiteracy, early marriage and absence of latrines in the houses.
The Effectiveness of Transmission Mechanisms of Monetary Policy in Sierra Leone
Authors: Lavally Mohamed , Nyambe Jacob M.
Published: April 2019

Studies on the effectiveness of transmission mechanisms of monetary policy are crucial for an economy. It is essential to understand how effective are the channels of monetary transmission in directing economic activities in Sierra Leone. In this case, particular focus is on the interest rate, exchange rate, and credit channels. The analytical methods used are unit root tests, cointegration test, Granger causality test, impulse responses and variance decomposition. Central to this investigation is the use of the Vector Autoregression (VAR) approach to estimate time series annual data from 1980 to 2012. The cointegration test result revealed that cointegration exists. The Granger causality test showed that gross capital formation Granger causes exchange rate and real interest rate. The impulse response function showed that output responded positively to monetary shocks, as interest rate increased. For exchange rate and private domestic credit, output showed that even in the long run, the effects of the shocks might not be transitory in order to converge towards a steady state. The variance decomposition indicated that fluctuations in gross domestic product per capita (GDPPC) were attributed to itself. While the total contribution of the real interest rate (RIR) and exchange rate (ER) was relatively insignificant. The error forecast of RIR was attributed by itself with an insignificant contribution of GDPPC and none by ER and private domestic credit (PDC). Fluctuations in forecasting ER were greatly attributed to itself and trivial contributions by the other variables. As the trend fell, there was a slight increase in the contribution of the other variables. The results provided evidence of ineffective channels in the Sierra Leone economy.
Colonial History and Geography have been the Main Determinants of Africa’s Poor Economic Growth: An Experience of Lost Decades (1980-2000)
Authors: Rai Jeetesh
Published: April 2019

Many states in Africa have experienced particularly painful growth trajectories and transitions to post-independence democracy. In particular many writers have noted the ‘lost decades’ for democratic consolidation and economic growth in Africa between 1980 and 2000. Current perceptions of Africa are framed by high levels of absolute poverty and low levels of life expectancy, and significant national debt burdens. Many countries have experienced extended periods of devastating political and military conflict, as well as unsuccessful attempts with Marxist- Leninist and free market economic policy, further exacerbating the painful nature of post-independence development. The development paths of many African countries have also been significantly conditioned by regional militarism as well as international geopolitical developments, furthering conflict and development trauma. This paper therefore seeks to identify some of the root causes of the poor economic growth that many post-independence African nations have experienced, specifically between 1980 to 2000. It argues that colonial (and neo-colonial) history and geography have played a significant role in Africa’s lagging growth rate and peripheral regional status in a hostile and competitive global economy.
Assessing the feasibility of single target radiosurgery quality assurance with portal dosimetry
Authors: Covington Elizabeth L. , Snyder Jesse D. , Wu Xingen , Cardan Rex A. , Popple Richard A.
Published: April 2019

Purpose

To assess the feasibility of using portal dosimetry (PD) for pre‐treatment quality assurance of single target, flattening filter free (FFF), volumetric arc therapy intracranial radiosurgery plans.

Methods

A PD algorithm was created for a 10X FFF beam on a Varian Edge linear accelerator (Varian Inc, Palo Alto, CA, USA). Treatment plans that were previously evaluated with Gafchromic EBT‐XD (Ashland, Bridgewater, NJ, USA) film were measured via PD and analyzed with the ARIA Portal Dosimetry workspace. Absolute dose evaluation for film and PD was done by computing the mean dose in the region receiving greater than or equal to 90% of the max dose and comparing to the mean dose in the same region calculated by the treatment planning system (TPS). Gamma analysis with 10% threshold and 3%/2 mm passing criteria was performed on film and portal images.

Results

Thirty‐six PD verification plans were delivered and analyzed. The average PD to TPS dose was 0.989 ± 0.01 while film to TPS dose was 1.026 ± 0.01. All PD plans passed the gamma analysis with 100% of points having gamma <1. Overall, PD to TPS dose agreement was found to be target size dependent. As target size decreases, PD to TPS dose ratio decreased from 1.004 for targets with diameters between 15–31 mm and 0.978 for targets with diameters less than 15 mm.

Conclusion

The agreement of PD to TPS mean dose in the high dose region was found to be dependent on target size. Film measurements did not exhibit size dependence. All PD plans passed the 3%/2 mm gamma analysis, but caution should be used when using PD to assess overall dosimetric accuracy of the treatment plan for small targets.
Working memory and second language accent acquisition
Authors: Mattys Sven L. , Baddeley Alan
Published: April 2019

We explored the proposal that overt repetition of verbal information improves the acquisition of a native accent in a second language. Mandarin‐speaking Chinese learners of English were recorded while repeating and reading out English sentences before and after one of three treatments: (a) repeating native English sentences subvocally, “covert repetition,” (b) repeating sentences out loud, “overt repetition,” and (c) unfilled time of comparable duration. The sentences were rated by English speakers for their nativeness, fluency, and intelligibility. Overt repetition improved accent rating for readout sentences. Covert repetition did not. Neither condition improved accent rating for repeated sentences, suggesting that immediate repetition depends on temporary rather than long‐term representations. Our results provide some support for the use of overt repetition in accent learning. From a theoretical perspective, an interpretation is proposed in terms of a separation between phonological and articulatory coding within the phonological loop component of working memory.
Determinants of Positive Temporal Artery Biopsies in the Veterans Health Administration National Database Cohort
Authors: Chung Sarah H. , Morcos Meredith B. , Ng Bernard
Published: April 2019

Objective

This study sought to determine the effect of temporal artery biopsy (TAB) postfixation length, laterality, age, and prior prednisone exposure on TAB positivity utilizing the Veterans Health Administration national database.

Methods

Subjects with procedure code for TAB between 1999 and 2017 were queried, and pathology reports were reviewed manually. Demographic, laboratory, and prescription data were extracted. Multivariate analyses and logistic regression were run using Stata, version 13.0.

Results

A total of 3,057 pathology reports were reviewed; 306 biopsies (10%) were designated positive. The likelihood of a positive TAB significantly correlated with TAB postfixation length of >3.0 cm (odds ratio [OR] 1.58 [95% confidence interval (95% CI) 1.06, 2.36], P < 0.05) as well as with bilateral biopsy in 1 sitting (OR 1.83 [95% CI 1.29, 2.59], P < 0.01). Positive TAB also significantly correlated with age >71 years. Prednisone administration up to and beyond 42 days prior to TAB did not influence TAB result.

Conclusion

This retrospective study examined predictors of TAB positivity and utilized national data collected on US veterans over the span of 18 years. The results suggest consideration of pursuing initial bilateral TAB or achieving a TAB postfixation length of at least 3 cm to improve yield. The results also agree with prior studies showing that pre‐TAB steroid exposure does not appear to affect yield even up to and beyond 42 days prior to biopsy.
Pushing the Envelope: Innovation and Collaboration at Bloomberg's New European Headquarters
Authors: Jones Michael
Published: April 2019

Foster + Partners’ European headquarters building for the global financial information and technology company Bloomberg is exceptional not just for the sheer volume of models and prototypes that were constructed, but also for the level of research that went into it. Several significant elements – notably the innovative breathing facades – were modelled at various scales and in different materials, both physically and virtually, allowing the team to refine them throughout the design process. Michael Jones, the project architect, describes how it was done and sets out the added value the method brought to the studio, client and users.
Building Practices: The Infrastructure of Materials Research
Authors: Hall Jane
Published: April 2019

Materials testing is fundamental to multidisciplinary collective Assemble's practice. Trialling large‐scale prototypes in the South London workshop space which they share with various other craft makers and artists allows further cross‐disciplinary pollination of ideas through mutual observation. Assemble member Jane Hall sets out how they achieve innovation at low cost through mixing standard components with bespoke elements. Their recent project for the facade cladding of the nearby Goldsmiths Centre for Contemporary Art serves as an example.
Cytoskeletal and Actin‐Based Polymerization Motors and Their Role in Minimal Cell Design
Authors: Hürtgen Daniel , Vogel Sven Kenjiro , Schwille Petra
Published: April 2019

Life implies motion. In cells, protein‐based active molecular machines drive cell locomotion and intracellular transport, control cell shape, segregate genetic material, and split a cell in two parts. Key players among molecular machines driving these various cell functions are the cytoskeleton and motor proteins that convert chemical bound energy into mechanical work. Findings over the last decades in the field of in vitro reconstitutions of cytoskeletal and motor proteins have elucidated mechanistic details of these active protein systems. For example, a complex spatial and temporal interplay between the cytoskeleton and motor proteins is responsible for the translation of chemically bound energy into (directed) movement and force generation, which eventually governs the emergence of complex cellular functions. Understanding these mechanisms and the design principles of the cytoskeleton and motor proteins builds the basis for mimicking fundamental life processes. Here, a brief overview of actin, prokaryotic actin analogs, and motor proteins and their potential role in the design of a minimal cell from the bottom‐up is provided.
Electrohydrodynamic Jet Printing Driven by a Triboelectric Nanogenerator
Authors: Wu Changsheng , Tetik Halil , Cheng Jia , Ding Wenbo , Guo Hengyu , Tao Xingtian , Zhou Nanjia , Zi Yunlong , Wu Zhiyi , Wu Huixuan , Lin Dong , Wang Zhong Lin
Published: April 2019

Electrohydrodynamic jet (e‐jet) printing is a high‐resolution printed electronics technique that uses an electric field to generate droplets. It has great application potential with the rapid development of flexible and wearable electronics. Triboelectric nanogenerators (TENG), which can convert mechanical motions into electricity, have found many high‐voltage applications with unique merits of portability, controllability, safety, and cost‐effectiveness. In this work, the application of a TENG is extended to printed electronics by employing it to drive e‐jet printing. A rotary freestanding TENG is applied as the high‐voltage power source for generating stable ink droplet ejection. The TENG‐driven droplet generation and ejection process and printed features with varied operation parameters are investigated. Results reveal that the jetting frequency could be controlled by the TENG's operation frequency, and high‐resolution printing with feature size smaller than nozzle size is achieved using the setup. Notably, TENG as the power source for e‐jet printing supplies a limited amount of current, which leads to better safety for both equipment and personnel compared to conventional high‐voltage power supplies. With the superiority of TENG in the sense of safety and cost, the work presents a promising solution for the next‐generation of high‐resolution printed electronics and broadens the scope of TENG application.
Metal‐Free Oxidative Annulation/Cyclization of 1,6‐Enynes for the Synthesis of 4‐Carbonylquinolines
Authors: Xia Xiao‐Feng , He Wei , Wang Dawei
Published: April 2019

Herein we report on the development of a metal‐free oxidative annulation reaction of 1,6‐enynes, leading to 4‐carbonylquinolines by using dioxygen as a green sustainable oxidant. Key advances include the use of readily available tert‐butyl nitrite (TBN) to promote radical annulation of 1,6‐enynes and easy‐to‐handle reaction conditions. Preliminary mechanistic studies including radical capture reactions and isotope labelling experiments are also conducted.

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Chemical Dopants on Edge of Holey Graphene Accelerate Electrochemical Hydrogen Evolution Reaction
Authors: Kumatani Akichika , Miura Chiho , Kuramochi Hirotaka , Ohto Tatsuhiko , Wakisaka Mitsuru , Nagata Yuki , Ida Hiroki , Takahashi Yasufumi , Hu Kailong , Jeong Samuel , Fujita Jun‐ichi , Matsue Tomokazu , Ito Yoshikazu
Published: April 2019

Carbon‐based metal‐free catalysts for the hydrogen evolution reaction (HER) are essential for the development of a sustainable hydrogen society. Identification of the active sites in heterogeneous catalysis is key for the rational design of low‐cost and efficient catalysts. Here, by fabricating holey graphene with chemically dopants, the atomic‐level mechanism for accelerating HER by chemical dopants is unveiled, through elemental mapping with atomistic characterizations, scanning electrochemical cell microscopy (SECCM), and density functional theory (DFT) calculations. It is found that the synergetic effects of two important factors—edge structure of graphene and nitrogen/phosphorous codoping—enhance HER activity. SECCM evidences that graphene edges with chemical dopants are electrochemically very active. Indeed, DFT calculation suggests that the pyridinic nitrogen atom could be the catalytically active sites. The HER activity is enhanced due to phosphorus dopants, because phosphorus dopants promote the charge accumulations on the catalytically active nitrogen atoms. These findings pave a path for engineering the edge structure of graphene in graphene‐based catalysts.
Second Skin Enabled by Advanced Electronics
Authors: Oh Jin Young , Bao Zhenan
Published: April 2019

Electronic second skin is touted as the next interface to expand applications of electronics for natural and seamless interactions with humans to enable smart health care, the Internet of Things, and even to amplify human sensory abilities. Thus, electronic materials are now being actively investigated to construct “second skin.” Accordingly, electronic devices are desirable to have skin‐like properties such as stretchability, self‐healing ability, biocompatibility, and biodegradability. This work reviews recent major progress in the development of both electronic materials and devices toward the second skin. It is concluded with comments on future research directions of the field.
Difluoromethylation of Tosylhydrazone Compounds with Chlorodifluoromethane under Mild Conditions
Authors: Yu Changjiang , Su Jianke , Ma Xingxing , Zhou Yao , Song Qiuling
Published: April 2019

An effective protocol for the difluoromethylation of tosylhydrazone compounds under mild conditions is disclosed via a transition‐metal‐free pathway; ClCF2H is almost quantitatively converted under the set conditions. In this transformation, the process in which tosylhydrazones are decomposed to lead to diazo species has been completely suppressed. This transformation enables tosylhydrazones as efficient difluorocarbene scavengers and the corresponding difluoromethylated products were obtained in good yields with high functional‐group tolerance.
The importance of scale in comparative microbiome research: New insights from the gut and glands of captive and wild lemurs
Authors: Greene Lydia K. , Bornbusch Sally L. , McKenney Erin A. , Harris Rachel L. , Gorvetzian Sarah R. , Yoder Anne D. , Drea Christine M.
Published: April 2019

Research on animal microbiomes is increasingly aimed at determining the evolutionary and ecological factors that govern host–microbiome dynamics, which are invariably intertwined and potentially synergistic. We present three empirical studies related to this topic, each of which relies on the diversity of Malagasy lemurs (representing a total of 19 species) and the comparative approach applied across scales of analysis. In Study 1, we compare gut microbial membership across 14 species in the wild to test the relative importance of host phylogeny and feeding strategy in mediating microbiome structure. Whereas host phylogeny strongly predicted community composition, the same feeding strategies shared by distant relatives did not produce convergent microbial consortia, but rather shaped microbiomes in host lineage‐specific ways, particularly in folivores. In Study 2, we compare 14 species of wild and captive folivores, frugivores, and omnivores, to highlight the importance of captive populations for advancing gut microbiome research. We show that the perturbational effect of captivity is mediated by host feeding strategy and can be mitigated, in part, by modified animal management. In Study 3, we examine various scent‐gland microbiomes across three species in the wild or captivity and show them to vary by host species, sex, body site, and a proxy of social status. These rare data provide support for the bacterial fermentation hypothesis in olfactory signal production and implicate steroid hormones as mediators of microbial community structure. We conclude by discussing the role of scale in comparative microbial studies, the links between feeding strategy and host–microbiome coadaptation, the underappreciated benefits of captive populations for advancing conservation research, and the need to consider the entirety of an animal's microbiota. Ultimately, these studies will help move the field from exploratory to hypothesis‐driven research.
Three‐dimensional analysis of sexual dimorphism in ribcage kinematics of modern humans
Authors: García‐Martínez Daniel , Bastir Markus , Torres‐Tamayo Nicole , O'Higgins Paul , Torres‐Sánchez Isabel , García‐Río Francisco , Heuzé Yann
Published: April 2019

Objectives

Sexual dimorphism is an important biological factor underlying morphological variation in the human skeleton. Previous research found sex‐related differences in the static ribcage, with males having more horizontally oriented ribs and a wider lower ribcage than females. Furthermore, a recent study found sex‐related differences in the kinematics of the human lungs, with cranio‐caudal movements of the caudal part of the lungs accounting for most of the differences between sexes. However, these movements cannot be quantified in the skeletal ribcage, so we do not know if the differences observed in the lungs are also reflected in sex differences in the motion of the skeletal thorax.

Materials and methods

To address this issue, we quantified the morphological variation of 42 contemporary human ribcages (sex‐balanced) in both maximal inspiration and expiration using 526 landmarks and semilandmarks. Thoracic centroid size differences between sexes were assessed using a t test, and shape differences were assessed using Procrustes shape coordinates, through mean comparisons and dummy regressions of shape on kinematic status. A principal components analysis was used to explore the full range of morphological variation.

Results

Our results show significant size differences between males and females both in inspiration and expiration (p < .01) as well as significant shape differences, with males deforming more than females during inspiration, especially in the mediolateral dimension of the lower ribcage. Finally, dummy regressions of shape on kinematic status showed a small but statistically significant difference in vectors of breathing kinematics between males and females (14.78°; p < .01).

Discussion

We support that sex‐related differences in skeletal ribcage kinematics are discernible, even when soft tissues are not analyzed. We hypothesize that this differential breathing pattern is primarily a result of more pronounced diaphragmatic breathing in males, which might relate to differences in body composition, metabolism, and ultimately greater oxygen demand in males compared to females. Future research should further explore the links between ribcage morphological variation and basal metabolic rate.