1,721,529 research outputs found
Decoding Informal Settlements in Core Urban Areas of Karachi: Leveraging Machine Learning Algorithms for Classification and Analysis
No full textThe proliferation of informal settlements in developing countries marks a significant byproduct of unchecked urbanization and economic expansion, posing substantial sustainability challenges within urban systems. This complexity stresses the urgency of dissecting the nature and forces associated with such settlements to forge effective intervention strategies. Focused on Karachi’s primary urban sectors, this research enlightens the dynamics of informal settlements and their contributing factors. By utilizing published public datasets, the study evaluates the efficacy of five machine learning algorithms—K Nearest Neighbors (KNN), Neural Networks (NN), Random Forest (RF), Random Trees (RT), and XGBoost Tree—in predictive modelling of the spatial patterns and associated elements of these settlements. Random Forest distinguished itself among the assessed algorithms by delivering unparalleled precision across critical performance metrics, reaching an F1-Score of 0.80. This investigation further illuminates the critical role of several determinants, such as proximity to the central business district (CBD), railway lines, waterways, commercial zones, health facilities, educational institutions, and poverty markers, in accumulating informal settlements. The insights from this study are instrumental in predictive modeling for informed urban planning and policymaking, aiming to develop a systematic resolution of the challenges posed by informal settlements in Karachi
Putative IgD binding proteins of Neisseria species
No full textNeisseria lactamica is a commensal bacterium of the upper respiratory tract. It is closely related to Neisseria meningitidis; an opportunistic pathogen that asymptomatically colonises the upper respiratory tract, but under certain circumstances, causes invasive disease. In this thesis, it is demonstrated that outer membrane vesicles extracted from Neisseria lactamica, N. cinerea, N. flavescens and N. polysaccharea induce proliferation of peripheral blood-derived B cells. Furthermore, this proliferative response is specific to B cells expressing IgDλ cell surface receptors. Pre-treatment of B cells with F(ab’)2 polyclonal goat anti-human IgD and λ light chain antibodies reduced the proliferation in response to N. lactamica, N. cinerea, N. flavescens and N. polysaccharea. It is also shown here that this phenotype is not shared among all Neisseria since the outer membrane vesicles extracted from N. elongata, N. subflava, N. mucosa, N. macacae, N. gonorrhoea and N. meningitidis are unable to induce a proliferative response in B cells. Two genes of N. lactamica with homology to Moraxella catarrhalis IgD binding protein were identified. Both genes were experimentally knocked out, generating two single knockout strains (ΔNLY_37260 and ΔNLY_36660) and one double knockout strain (ΔNLY_36660 ΔNLY_37260). The double knockout strain does not induce proliferation of B cells expressing IgDλ, while single knockout strains are still mitogenic for IgDλ+ B cells, albeit at reduced levels, suggesting N. lactamica contains two IgD binding proteins, with redundancy between them. Additionally, homologues of Moraxella catarrhalis IgD binding protein MID have been identified in N. cinerea, N. flavescens and N. polysaccharea and experimentally knocked out. Unlike wild-type strains, all knockout strains lacking the gene for putative IgDbp lack the ability to induce proliferation in IgDλ+ B cells. These knockout strains may be used as tools to further explore the putative IgDλ binding protein present in commensal Neisseriaspp.In summary, this work shows that N. lactamica induces an IgDλ+ B cell proliferative response likely due to the presence of an IgDλ binding protein, a characteristic shared by N. cinerea, N. flavescens and N. polysaccharea. This response may play an important role in evasion of the adaptive immune system of the upper respiratory tract, analogous to the activation of intestinal B cells and subsequent production of sIgA
Low-dimensional exact coherent states in plane Couette flow
No full textA new approach to understanding the dynamics of moderate-Reynolds number wall bounded flows has emerged recently, based on the computation of steady (equilibrium) or exactly recurring (periodic) solutions of the Navier-Stokes equations. Such solutions are thought to represent coherent structures, and the connections in state space between these solutions can explain the dynamics and self-sustaining nature of wall-bounded turbulent flows.Herein new equilibrium solution branches for plane Couette flow are reported which add to the inventory of known solution branches. The exact solutions are found by projecting known equilibria onto the resolvent modes of McKeon and Sharma (2010 to generate approximate solutions that are subsequently used as seeds in a Newto Krylov-hookstep search. Searches initialised with these projections have a convergence rate of 96%. The low-dimensional nature of the resulting equilibria is attributed to the projection generated by the resolvent model; resolvent modes for a given equilibrium solution span a low-dimensional space which the solution approximately inhabits. This property is exploited to generate new branches of equilibria in plane Couette flow, and to jump to known branches. The new branches include bifurcations from previously known bifurcation curves and a disconnected bifurcation curve which displays interesting behaviour when continued in Reynolds number. The unstable manifolds of the new equilibria are computed to expand the known state space structure of plane Couette flow.Additionally, ten new periodic orbits in plane Couette flow are found by projecting known periodic orbits and quasi-recurrent segments of turbulent flows onto the resolvent modes of McKeon and Sharma (2010) to generate low-order representations of periodic flow, points along which are then used as initial conditions in a Newton-Krylov-hookstep search. Moreover, projections of periodic orbits find one new equilibrium solution. The new periodic solutions are in the neighbourhoods of previously known orbits and reveal the geometry of state space in the region separating the laminar and turbulent attractors. We show that the periodic orbits are appropriate representations of the self-sustaining process proposed by Waleffe (1997) and we examine their effect on turbulent trajectories in state space
The records of Nipaecoccus viridis (Newstead) (Hemiptera: Pseudococcidae) deposited in the Florida State Collection of Arthropods
No full textDeeter, Lily A., Ahmed, Muhammad Z. (2023): The records of Nipaecoccus viridis (Newstead) (Hemiptera: Pseudococcidae) deposited in the Florida State Collection of Arthropods. Insecta Mundi 2023 (995): 1-8, DOI: http://doi.org/10.5281/zenodo.822230
Advances on the Use of Geopolymer Recycled Aggregate Concrete in Construction
No full textGeopolymer cement is made up of waste materials, an efficient alternative
to ordinary cement in order to reduce the emission of carbon dioxide. The
use of geopolymer recycled aggregate concrete (GRAC) in structural elements has
been an object of recent several experimental research in which the behaviour of
either the material or structural element was investigated. A review paper will be
done critically to compile the present research on the use of GRAC in construction.
It will cover the effect of different materials composition in GRAC and the
factors affecting its strength focusing on recycled aggregate’s replacement ratio.
The problems related to the strength of GRAC structural members, their tensile
and flexural behaviour will also be addressed. It will also help in finding the future
prospects of the use of GRAC in construction
Business Applications of Cargo Drones in the EU
No full textDrones have become ubiquitous in various industries due to their versatility and efficiency in performing various tasks, from agricultural operations to search and rescue missions. This paper explores the use of drones, particularly cargo drones, in revolutionizing logistics and transportation systems. Medium-range cargo drones offer the potential to transform freight transportation by offering independence from traditional infrastructure and potentially reducing environmental impact. However, the integration of UAVs into existing logistical operations faces several challenges, including regulatory hurdles, technological limitations, and public perception issues. Drones can become a viable form of cargo transportation given that the regulatory challenges are addressed and can be efficiently integrated into the existing logistic operations. It would ultimately result in an efficient last-mile delivery option and will revolutionize the logistics industry
Experimental Behaviour of the Friction Dissipative Device for Hybrid Steel Trussed Concrete Beam to Column Joint
No full textConnessioni trave-colonna dissipative per attrito sono sempre pi ̆ frequentemente impiegate per la realizzazione di strutture antisismiche resilienti grazie alla loro facilit‡ di progettazione, affidabilit‡ di comportamento, ridotta perdita di prestazioni nel tempo e
influenza del comportamento dalle condizioni ambientali, nonchÈ elevate prestazioni garantite da grande rigidezza, facilit‡ di regolazione della resistenza della connessione, elevata e stabile capacit‡ dissipativa e ridotta complessit‡ costruttiva. Qui vengono riportati i risultati dei test condotti su dispositivi di attrito lineare, che Ë il componente principale della connessione dissipativa, e su un
prototipo in scala reale di una connessione fra trave reticolare in acciaio ibrida in calcestruzzo (HSTCB)-colonna recentemente proposta. Per analizzare in modo approfondito la funzionalit‡ del dispositivo di attrito proposto in termini di dissipazione di energia, Ë
stato testato sotto cinque carichi ciclici con diverse ampiezze. I risultati hanno dimostrato l'efficacia delle soluzioni tecniche adottate
per la progettazione del dispositivoFriction dissipative beam-to-column connections are rising popularity to design resilient earthquake-resistant structure due to their ease of design, reliability of behavior, reduced loss of performance over time and influence of environmental conditions on the behavior. High performance is guaranteed by high initial stiffness, ease of tunning connection strength, high and stable dissipative capacity, and reduced construction complexity are further appreciated features. The research is focused on test results conducted on linear friction devices, which is the main component of the dissipative connection, and on a full-scale prototype of a recently proposed friction-based hybrid steel trussed concrete beams (HSTCBs)-to-column connection for moment resisting frame. In order to deeply analyze the functionality of proposed friction device in term of energy dissipation, it has been tested under five cyclic loadings with different amplitudes. The results proved the efficiency of the technical solutions adopted for the device design
Figure 2 in The records of Nipaecoccus viridis (Newstead) (Hemiptera: Pseudococcidae) deposited in the Florida State Collection of Arthropods
No full textFigure 2. Infestation of Nipaecoccus viridis on hemp, Cannabis sativa L., in Florida (FDACS-DPI # E2021-1852-1). a) Settled 3rd instar and young adult females. b) 1st and 2nd instar (10 ×).Published as part of Deeter, Lily A. & Ahmed, Muhammad Z., 2023, The records of Nipaecoccus viridis (Newstead) (Hemiptera: Pseudococcidae) deposited in the Florida State Collection of Arthropods, pp. 1-8 in Insecta Mundi 2023 (995) on page 6, DOI: 10.5281/zenodo.822230
Figure 1 in The records of Nipaecoccus viridis (Newstead) (Hemiptera: Pseudococcidae) deposited in the Florida State Collection of Arthropods
No full textFigure 1. Infestation of Nipaecoccus viridis on blueberries, Vaccinium sp. L., in Florida (FDACS-DPI # E2021-1340-1). a) Adult female. b) Adult female with ovisac. c) Adult females with ovisacs stacked on top of one another. d) Close-up (10×) view of an adult female.Published as part of Deeter, Lily A. & Ahmed, Muhammad Z., 2023, The records of Nipaecoccus viridis (Newstead) (Hemiptera: Pseudococcidae) deposited in the Florida State Collection of Arthropods, pp. 1-8 in Insecta Mundi 2023 (995) on page 5, DOI: 10.5281/zenodo.822230
- …
