Cosmic evolution of bars in simulations of galaxy formation

We investigate the evolution of two bars formed in fully self-consistent hydrodynamic simulations of the formation of Milky Way-mass galaxies. One galaxy shows higher central mass concentration and has a longer and stronger bar than the other at $z = 0$. The stronger bar evolves by transferring its angular momentum mainly to the dark halo. Consequently the rotation speed of the bar decreases with time, while the amplitude of the bar increases with time. These features qualitatively agree with the results obtained by idealized simulations. The pattern speed of the stronger bar largely goes up and down within a half revolution in its early evolutionary stage. These oscillations occur when the bar is misaligned with the $m = 4$ mode Fourier component. These oscillations correlate with the oscillations in the triaxilality of the dark matter halo, but differently from the way identified by idealized simulations. The amplitude of the weaker bar does not increase despite the fact that its rotation slows down with time.This result contradicts what is expected from idealized simulations and is caused by the decline of the central density associated with the mass loss and feedback from the stellar populations. The amplitude of the weaker bar is further weakens by the angular momentum injection by the interactions with stellar clumps in the disk. In the both galaxies, the bars are terminated around the 4:1 resonance.Comment: 17 pages, 18 figures, accepted for publication in PAS

Influence of organization structure on diversification strategy and performance of an organization Critical literature review

The contentious debate by management scholars and researchers on whether strategy influences structure or if it is structure that influences strategy has been going on for some time now. We endeavored to conduct an extensive desk review aimed at establishing if indeed there is any interrelationship between organizational structure and diversification strategy or if organization structure does influence diversification strategy and performance of an organization. Different subsections of this paper present theoretical and in some instances empirical findings by other scholars and researchers on theories relating to organization structure, diversification strategy and organizational performance. From the discussed theories and research findings, the paper concludes that there exists an interdependent relationship between organization structure and diversification strategy which ultimately impacts on the performance of an organization

Artificial Intelligence (AI) tools and Human Intelligence (HI): A Double-edged Dilemma in Business Decision Making

Decision making is the most important role in organizational management. While many factors are likely to influence the quality of decisions made by a manager, intelligence stands out as the most consequential determinant.  In the recent past, there has been a plurality of models and frameworks developed to enable managers make quality decisions amid heightened complexity in today’s business environment. Throughout history, people have heavily relied on their human intelligence (HI) in making critical decisions. However, the advancement of Artificial intelligence (AI) has caused a complete paradigm shift on how decisions are made in contemporary organizational management. The multifaceted nature of HI and its role in any decision-making process cannot be underscored. With the proliferation of AI and its robustness in solving complex business problems and guiding decision making, one might be left wondering if HI is still relevant.  This paper affirms the management dilemma in the application of AI tools considering its tremendous strengths and potential risks. It further explores the potential benefits of balancing AI and HI in business decision making to create a sustainable optimal business model. The paper is mainly qualitative in its approach and it is informed by the desk review of existing literature in the thematic areas. From the review and arguments presented, the paper concludes that the synergy between AI's data-processing capabilities and the irreplaceable human creativity and judgment presents a unique opportunity for superior business decision making resulting to optimization of business models and better performance. The paper recommends for the development and adoption of strategic policy frameworks by organizations and regulatory bodies that promote effective integration of HI with AI.  Finaly, the paper also recommends for deeper empirical research to show some of the best case models on integrating AI and HI for utmost performance. Key Words; Artificial Intelligence (AI), Human intelligence (HI), Double-edged Dilemma DOI: 10.7176/EJBM/16-9-02 Publication date: November 30th 202

Pond dyes are Culex mosquito oviposition attractants

Background British mosquito population distribution, abundance, species composition and potential for mosquito disease transmission are intimately linked to the physical environment. The presence of ponds and water storage can significantly increase the density of particular mosquito species in the garden. Culex pipiens is the mosquito most commonly found in UK gardens and a potential vector of West Nile Virus WNV, although the current risk of transmission is low. However any factors that significantly change the distribution and population of C. pipiens are likely to impact subsequent risk of disease transmission. Pond dyes are used to control algal growth and improve aesthetics of still water reflecting surrounding planting. However, it is well documented that females of some species of mosquito prefer to lay eggs in dark water and/or containers of different colours and we predict that dyed ponds will be attractive to Culex mosquitoes. Methods Black pond dye was used in oviposition choice tests using wild-caught gravid C. pipiens. Larvae from wild-caught C. pipiens were also reared in the pond dye to determine whether it had any impact on survival. An emergence trap caught any adults that emerged from the water. Water butts (80 L) were positioned around university glasshouses and woodland and treated with black pond dye or left undyed. Weekly sampling over a six month period through summer and autumn was performed to quantified numbers of larvae and pupae in each treatment and habitat. Results Gravid female Culex mosquitoes preferred to lay eggs in dyed water. This was highly significant in tests conducted under laboratory conditions and in a semi-field choice test. Despite this, survivorship in black dyed water was significantly reduced compared to undyed water. Seasonal analysis of wild larval and pupal numbers in two habitats with and without dye showed no impact of dye but a significant impact of season and habitat. Mosquitoes were more successful, with significantly higher numbers of pupae, in the habitat where they had vegetation cover and shade. Discussion Our study has raised some interesting possibilities; one is that where used, pond dyes may be encouraging mosquitoes to breed in gardens in close proximity to people. Considering the concerns over potential future spread of disease in urban environments, this as well as shading of ponds and water butts, should inform future advice over reducing mosquito breeding and spread

Allelic Variation Investigation of the Estrogen Receptor Within an Australian Multiple Sclerosis Population

Multiple Sclerosis (MS) is a central nervous system (CNS) chronic inflammatory demyelinating disease leading to various neurological disabilities. The disorder is more prevalent for women with a ratio of 3:2 female to male. Objectives: To investigate variation within the estrogen receptor 1 (ESR1) polymorphism gene in an Australian MS case-control population using two intragenic restriction fragment length polymorphisms; the G594A located in exon 8 detected with the BtgI restriction enzyme and T938C located in intron 1, detected with PvuII. One hundred and ten Australian MS patients were studied, with patients classified clinically as Relapsing Remitting MS (RR-MS), Secondary Progressive MS (SP-MS) or Primary Progressive MS (PP-MS). Also, 110 age, sex and ethnicity matched controls were investigated as a comparative group. No significant difference in the allelic distribution frequency was found between the case and control groups for the ESR1 PvuII (P = 0.50) and Btg1 (P = 0.45) marker. Our results do not support a role for these two ESR1 markers in multiple sclerosis susceptibility, however other markers within ESR1 should not be excluded for potential involvement in the disorder

Chromosomal Instability and Molecular Defects in Induced Pluripotent Stem Cells from Nijmegen Breakage Syndrome Patients

SummaryNijmegen breakage syndrome (NBS) results from the absence of the NBS1 protein, responsible for detection of DNA double-strand breaks (DSBs). NBS is characterized by microcephaly, growth retardation, immunodeficiency, and cancer predisposition. Here, we show successful reprogramming of NBS fibroblasts into induced pluripotent stem cells (NBS-iPSCs). Our data suggest a strong selection for karyotypically normal fibroblasts to go through the reprogramming process. NBS-iPSCs then acquire numerous chromosomal aberrations and show a delayed response to DSB induction. Furthermore, NBS-iPSCs display slower growth, mitotic inhibition, a reduced apoptotic response to stress, and abnormal cell-cycle-related gene expression. Importantly, NBS neural progenitor cells (NBS-NPCs) show downregulation of neural developmental genes, which seems to be mediated by P53. Our results demonstrate the importance of NBS1 in early human development, shed light on the molecular mechanisms underlying this severe syndrome, and further expand our knowledge of the genomic stress cells experience during the reprogramming process

Farmer Perceptions on the Effects of Termites in Kwa Vonza Location, Kitui County, Kenya

Aims: This study aimed to assess (i) the perception of Kwa Vonza farmers regarding the presence of termites in their land, (ii) the perceived importance of termites, and (iii) how they control termites in their properties. Study Design:  This study is based on responses to a questionnaire sent to farmers. Place and Duration of Study: The study took place in Kwa Vonza Location, Yatta Sub County, Kitui County, Kenya, between April and November 2017. Methodology: 60 questionnaires, each comprising 20 multiple-choice questions, were sent out to farmers. Out of these, 54 responses were received. Where the response did not require a Yes or No answer, it elicited a response from a standardized five-point scale to demonstrate agreement with the provided proposition. Data analysis was done using descriptive statistics, in which percentages were tabulated, and frequency tables were generated using Microsoft Excel. Results: 73% of farmers perceived their land as infertile, with the causes ranging from soil erosion, drought, and mono-cropping. 87% of farmers acknowledged termite infestation in their farms but perceived them as destructive. Termite infestation was attributed to deforestation, drought, and flooding. Chemical control was the method of choice to manage termites. Conclusion: Kwa Vonza farmers do not perceive termites as of any agronomic significance but view them as destructive agents. Further research to address the complex issue of soil management at the farm-scale level that involves farmers is necessary to fill gaps in scientific knowledge and produce advice for practical use

Open-label clinical trial of bezafibrate treatment in patients with fatty acid oxidation disorders in Japan

IntroductionFatty acid oxidation disorders (FAODs) are rare diseases caused by defects in mitochondrial fatty acid oxidation (FAO) enzymes. While the efficacy of bezafibrate, a peroxisome proliferator-activated receptor agonist, on the in vitro FAO capacity has been reported, the in vivo efficacy remains controversial. Therefore, we conducted a clinical trial of bezafibrate in Japanese patients with FAODs.Materials and methodsThis trial was an open-label, non-randomized, and multicenter study of bezafibrate treatment in 6 patients with very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency and 2 patients with carnitine palmitoyltransferase-II (CPT-2) deficiency (median age, 8.2 years; ranging from 5.8 to 26.4 years). Bezafibrate was administered for 6 months following a 6-month observation period. The primary endpoint was the frequency of myopathic attacks, and the secondary endpoints were serum acylcarnitines (ACs, C14:1 or C16 + C18:1), creatine kinase (CK) levels, degree of muscle pain (VAS; visual analog scale) during myopathic attacks, and quality of life (QOL; evaluated using validated questionnaires).ResultsThe frequency of myopathic attacks after bezafibrate administration decreased in 3 patients, increased in 3, and did not change in 2. The CK, AC, and VAS values during attacks could be estimated in only three or four patients, but a half of the patients did not experience attacks before or after treatment. Changes in CK, AC, and VAS values varied across individuals. In contrast, three components of QOL, namely, physical functioning, role limitation due to physical problems (role physical), and social functioning, were significantly elevated. No adverse drug reactions were observed.ConclusionIn this study, the frequency of myopathic attacks and CK, AC, and VAS values during the attacks could not be evaluated due to several limitations, such as a small trial population. Our findings indicate that bezafibrate improves the QOL of patients with FAODs, but its efficacy must be examined in future investigations

Caracterización de la gestión de calidad y competitividad de las Mypes en el rubro de panaderías del distrito de Lambayeque, 2019

La información a continuación que tiene por nombre denominada: características de la gestión de calidad y competitividad de la mypes del rubro panaderías del distrito de Lambayeque año 2019, tuvo como objetivo general: caracterización de la gestión de calidad y competitividad de las mypes del rubro panaderías del distrito de Lambayeque año 2019, como objetivos específicos determinar las características de gestión de calidad y determinar las características de competitividad de las micro pequeñas empresas en este rubro de panaderías en el distrito de Lambayeque, año 2019. La metodología para la investigación fue de tipo descriptiva, y de diseño no experimental de corte transversal, porque se realiza sin manipular las variables (Hernández 2006). En la recopilación de los datos se tomó como cantidad considerando a los 14 gerentes de la Mypes, dedicadas a las ventas de servicios elaborados que están situadas en el distrito de Lambayeque. Manipulando como desenvoltura la información y como elemento el interrogatorio, de las cuales concluimos: que el 85.7% si saben que sus productos cumplen con las especificaciones correctas por los controles permanentes que tienen, el 85.7% hacen cambio o mantenimiento de su maquinaria de producción cuando es necesario, 78.6% de gerentes capacitan a su personal cuando es necesario, 78.6% de Mypes tiene más demanda en panes, el 71.4% de representantes o dueños son de sexo masculino, el 64.3% determinan que sus productos son de calidad, 57.1% tienen grado de estudio de nivel primaria, 57.1% de los clientes tienen en cuenta en cuenta el tamaño antes de adquirir un producto, el 57.1% tienen más de 10 años dedicado a este rubro, 50.0% cuentan con 4 a 5 personal en sus Mype. En cuanto a competitividad visualizamos que el 92.9% si utiliza herramientas de innovación, el 85.7% no usa ningún tipo de publicidad para hacer conocido su producto, el 57.1% si crean productos nuevos en su establecimiento, el 41.7%, se diferencian del resto por el precio de sus productos.Trabajo de investigació

Advanced high speed data and clock transmission over optical fibre for square kilometre telescope array

There is an ever present need from Internet users for more bandwidth. This is manifested by continuous increase in bandwidth demanding applications such as 5G wireless, new end user consumer links like thunderbolt, video conferencing, high definition video-on-demand transmitted over the Internet and massive data transfers required with and within data centres for backup, storage and data processing in cloud computing. Fibre optic communications technologies are playing a pivotal role in communication, being a major enabling technology in our increasingly Internet-centric society. As network services continue to become more dynamic and diverse, Internet service providers are faced with a challenge of cost reduction in the transmission network, power and spectral efficiency as well as scalability of the optical network infrastructure to support incremental expansions and virtual machines. Intelligent design of terrestrial optical networks to allow for simultaneous signal transmission through shared network infrastructure, and the use of low cost, power efficient, high bandwidth transmitters such as vertical surface emitting lasers (VCSELs) as well as exploitation of spectral efficient in-complex advanced modulation formats is a viable approach to this situation. In this study, techniques for spectral efficiency upgrade and simultaneous transmission of data signal, reference frequency (RF) clock signal and pulse-per-second (PPS) over shared infrastructure have experimentally been optimized in a laboratory environment for adoption in next-generation telescope array networks such as the Square Kilometre Array (SKA), time keeping systems such as banking systems, Coordinated Universal Time(UTC) timing and Global Positioning Systems (GPS), as well as high capacity spectral efficient short reach optical fibre networks such as data centres. This work starts by experimentally optimizing VCSEL technology for simultaneous transmission of 10 Gbps data and 1.712 GHz RF clock signal over a single G. 655 optical fibre of length 24.75 Km at different channel spacing and different propagation direction for implementation in a cost effective next-generation telescope array network. The wavelength tuneability property of VCSEL transmitters allows for wavelength adjustment, a key requirement for simultaneous data and RF clock signal transmission over a single optical fibre. A receiver sensitivity of -19.19 dBm was experimentally achieved at back-to-back analysis. A 24.75 Km of simultaneous data and RF clock signal transmission performed at 0.4 nm channel spacing introduced a transmission penalty of 1.07 dB and 1.63 dB for counter and co-propagation scheme respectively. This work mainly utilized direct modulation and direct detection using a positive intrinsic negative (PIN) due to its simplicity and cost effectiveness. A novel modulation technique for simultaneous data and polarization-based pulse-per-second timing clock signal transmission using a single VCSEL carrier is experimentally demonstrated. Two signal types, a directly modulated 10 Gbps data signal and a polarization-based pulse per second (PPS) clock signal are modulated onto a single mode 10 GHz bandwidth VCSEL carrier at 1310 nm. Spectral efficiency is maximized by exploiting the inherent orthogonal polarization switching of the xiv VCSEL with changing bias in transmission of the PPS signal. A 10 Gbps VCSEL transmission with PPS over 11 Km of G.652 fibre introduced a transmission penalty of 0.52 dB. The contribution of PPS clock signal to this penalty was found to be 0.08 dB. A technique for simultaneous directly modulated data and phase modulated reference clock signal transmission over a signal channel in wavelength division multiplexing (WDM) solutions is experimentally demonstrated. This is to prepare solutions to the ever-increasing demand over gigabit/s, terabit/s and gigahertz capacities in WDM-based terrestrial optical fibre transmission systems such as telescope array networks. a total capacity of 30 Gbps (310 Gbps) data and 12 GHz ( 4 3 GHz) reference clock signal are multiplexed at a channel spacing of 100 GHz and simultaneously transmitted over a single mode G.655 fibre of length 24.73 Km. The recovery of the phase modulated RF clock signal using a differential delay line interferometry technique is experimentally demonstrated. A 625 Gbps (2525 Gbps) DWDM data transmission system is further implemented in simulation by multiplexing 25 channels at 25 Gbps per channel using 50 GHz channel spacing. A four level pulse amplitude modulation (4-PAM) data modulation format employing VCSELs is experimentally demonstrated for adoption in high bitrate networks such as big data science projects and data centre networks. 4-PAM offers a good trade-off between complexity, efficiency, reach, and sensitivity. A software defined digital signal processing (DSP) receiver is designed and implemented in MATLAB to recover the transmitted 4-PAM data signal cost effectively without the necessity of costly receiver hardware. A novel technique for maximizing carrier spectral efficiency through simultaneous 20 Gbps 4-PAM data and phase modulated 2 GHz RF clock signal transmission on a single mode 10 GHz bandwidth VCSEL carrier at 1310 nm is experimentally demonstrated for the first time to the best of our knowledge. Data transmission and clock stability performance of the designed high spectral efficient VCSEL-based link network is evaluated through BER curve plots, phase noise measurements and Allan variance analysis respectively. VCSEL-based Raman amplification is experimentally demonstrated as a viable approach for RF clock signal distribution in extended reach astronomical telescope array networks and other extended reach terrestrial optical fibre network application. This is achieved by adopting two pumping techniques namely forward pumping and backward pumping. A maximum on off gain of 5.7 dB and 1.5 dB was experimentally attained for forward pumping and backward pumping at 24 dBm pump power respectively, while a maximum 100.8 Km fibre transmission achieved experimentally. In summary, this study has successfully demonstrated in-complex, spectral efficient, low cost and power efficient simultaneous data signal, reference frequency (RF) clock signal and pulse-per-second (PPS) transmission techniques over shared network infrastructure. Simultaneous transmission of data, RF clock and PPS timing signal is relevant in nextgeneration telescope array networks such as the Square Kilometre Array (SKA), time keeping systems such as banking systems, Coordinated Universal Time (UTC) timing and Global Positioning Systems (GPS), as well as high capacity spectral efficient short reach optical fibre networks such as data centres