Control of magnetotactic bacterium in a micro-fabricated maze

We demonstrate the closed-loop control of a magnetotactic bacterium (MTB), i.e., Magnetospirillum magnetotacticum, within a micro-fabricated maze using a magneticbased manipulation system. The effect of the channel wall on the motion of the MTB is experimentally analyzed. This analysis is done by comparing the characteristics of the transient- and steady-states of the controlled MTB inside and outside a microfabricated maze. In this analysis, the magnetic dipole moment of our MTB is characterized using a motile technique (the u-turn technique), then used in the realization of a closed-loop control system. This control system allows the MTB to reach reference positions within a micro-fabricated maze with a channel width of 10 μm, at a velocity of 8 μm/s. Further, the control system positions the MTB within a region-of-convergence of 10 μm in diameter. Due to the effect of the channel wall, we observe that the velocity and the positioning accuracy of the MTB are decreased and increased by 71% and 44%, respectively

Magnetization reversal times in the 2D Ising model

We present a theoretical framework which is generally applicable to the study of time scales of activated processes in systems with Brownian type dynamics. This framework is applied to a prototype system: magnetization reversal times in the 2D Ising model. Direct simulation results for the magnetization reversal times, spanning more than five orders of magnitude, are compared with theoretical predictions; the two agree in most cases within 20%.Comment: 9 pages, 8 figure

Closed-loop control of magnetotactic bacteria

Realization of point-to-point positioning of a magnetotactic bacterium (MTB) necessitates the application of a relatively large magnetic field gradients to decrease its velocity in the vicinity of a reference position. We investigate an alternative closed-loop control approach to position the MTB. This approach is based on the characterization of the magnetic dipole moment of the MTB and its response to a field with alternating direction. We do not only find agreement between our characterized magnetic dipole moment and previously published results, but also observe that the velocity of the MTB decreases by 37% when a field with alternating direction is applied at 85 Hz. The characterization results allow us to devise a null-space control approach which capitalizes on the redundancy of magnetic-based manipulation systems. This approach is based on two inputs. The first controls the orientation of the MTB, whereas the second generates a field with alternating direction to decrease its velocity. This control is accomplished by the redundancy of our magnetic-based manipulation system which allows for the projection of the second input onto the null-space of the magnetic force-current map of our system. A proportional–derivative control system positions the MTB at an average velocity and region of convergence of 29 μm s−1 and 20 μm, respectively, while our null-space control system achieves an average velocity and region of convergence of 15 μm s−1 and 13 μm, respectively

Palaeoproterozoic magnesite: lithological and isotopic evidence for playa/sabkha environments

Magnesite forms a series of 1- to 15-m-thick beds within the approximate to2.0 Ga (Palaeoproterozoic) Tulomozerskaya Formation, NW Fennoscandian Shield, Russia. Drillcore material together with natural exposures reveal that the 680-m-thick formation is composed of a stromatolite-dolomite-'red bed' sequence formed in a complex combination of shallow-marine and non-marine, evaporitic environments. Dolomite-collapse breccia, stromatolitic and micritic dolostones and sparry allochemical dolostones are the principal rocks hosting the magnesite beds. All dolomite lithologies are marked by delta C-13 values from +7.1 parts per thousand to +11.6 parts per thousand (V-PDB) and delta O-18 ranging from 17.4 parts per thousand to 26.3 parts per thousand (V-SMOW). Magnesite occurs in different forms: finely laminated micritic; stromatolitic magnesite; and structureless micritic, crystalline and coarsely crystalline magnesite. All varieties exhibit anomalously high delta C-13 values ranging from +9.0 parts per thousand to +11.6 parts per thousand and delta O-18 values of 20.0-25.7 parts per thousand. Laminated and structureless micritic magnesite forms as a secondary phase replacing dolomite during early diagenesis, and replaced dolomite before the major phase of burial. Crystalline and coarsely crystalline magnesite replacing micritic magnesite formed late in the diagenetic/metamorphic history. Magnesite apparently precipitated from sea water-derived brine, diluted by meteoric fluids. Magnesitization was accomplished under evaporitic conditions (sabkha to playa lake environment) proposed to be similar to the Coorong or Lake Walyungup coastal playa magnesite. Magnesite and host dolostones formed in evaporative and partly restricted environments; consequently, extremely high delta C-13 values reflect a combined contribution from both global and local carbon reservoirs. A C- 13-rich global carbon reservoir (delta C-13 at around +5 parts per thousand) is related to the perturbation of the carbon cycle at 2.0 Ga, whereas the local enhancement in C-13 (up to +12 parts per thousand) is associated with evaporative and restricted environments with high bioproductivity

Program bina desa di Pulau Panjang, Bangka Selatan: edukasi kelestarian alam dan pemanfaatan potensi

Pulau Panjang, sebagai salah satu pulau di Kepulauan Bangka Belitung, memiliki potensi wisata alam dan edukasi dengan laut alami, pantai dan mangrove. Namun masyarakatnya yang mayoritas berprofesi sebagai nelayan memberikan potensi kerusakan akibat penggunaan trawl dalam penangkapan ikan dan udang. Program bina desa himpunan mahasiswa kultur akuatik berupaya membentuk karakter peduli lingkungan bagi generasi usia dini, mendiskusikan potensi wisata alam pada generasi muda dan membahas potensi produk lokal dan dampak trawl kepada ibu-ibu rumah tangga. Pembentukan karakter peduli lingkungan pada usia dini dilakukan melalui permainan bersih sampah plastik dan menanam pohon. Potensi alam lokal didiskusikan dengan generasi pemuda. Pengembangan potensi produk lokal dan bahaya alat tangkap trawl disampaikan kepada ibu-ibu rumah tangga. Besar harapan terbentuknya karakter peduli lingkungan yang melandasi tindakan masyarakat Pulau Panjang dalam memanfaatkan lingkungan untuk kesejahteraanny

A Literature Review on Cloud Computing Adoption Issues in Enterprises

Part 3: Creating Value through ApplicationsInternational audienceCloud computing has received increasing interest from enterprises since its inception. With its innovative information technology (IT) services delivery model, cloud computing could add technical and strategic business value to enterprises. However, cloud computing poses highly concerning internal (e.g., Top management and experience) and external issues (e.g., regulations and standards). This paper presents a systematic literature review to explore the current key issues related to cloud computing adoption. This is achieved by reviewing 51 articles published about cloud computing adoption. Using the grounded theory approach, articles are classified into eight main categories: internal, external, evaluation, proof of concept, adoption decision, implementation and integration, IT governance, and confirmation. Then, the eight categories are divided into two abstract categories: cloud computing adoption factors and processes, where the former affects the latter. The results of this review indicate that enterprises face serious issues before they decide to adopt cloud computing. Based on the findings, the paper provides a future information systems (IS) research agenda to explore the previously under-investigated areas regarding cloud computing adoption factors and processes. This paper calls for further theoretical, methodological, and empirical contributions to the research area of cloud computing adoption by enterprises

Inhaled microparticles containing clofazimine are efficacious in treatment of experimental tuberculosis in mice

Inhalable clofazimine-containing dry powder microparticles (CFM-DPI) and native clofazimine (CFM) were evaluated for activity against Mycobacterium tuberculosis in human monocyte-derived macrophage cultures and in mice infected with a low-dose aerosol. Both formulations resulted in 99% killing at 2.5 g/ml in vitro. In mice, 480 g and 720 g CFM-DPI inhaled twice per week over 4 weeks reduced numbers of CFU in the lung by as much as log10 2.6; 500 g oral CFM achieved a log10 0.7 reduction.The Indian work was funded by a grant from CSIR, India (NWP0035). R.K.V., A.K.S., and A.K.A. received research fellowships from CSIR, India, and M.M. received one from ICMR, India. The South African work was supported by The South African Medical Research Council (M.P.M., M.C., R.A.) and a K-RITH collaborative grant (Howard Hughes Medical Institute and the University of KwaZulu-Natal, to P.B.F. and W.A.G.).http://aac.asm.org/am2014ay201

Moduli Stabilisation versus Chirality for MSSM like Type IIB Orientifolds

We investigate the general question of implementing a chiral MSSM like D-brane sector in Type IIB orientifold models with complete moduli stabilisation via F-terms induced by fluxes and space-time instantons, respectively gaugino condensates. The prototype examples are the KKLT and the so-called large volume compactifications. We show that the ansatz of first stabilising all moduli via F-terms and then introducing the Standard Model module is misleading, as a chiral sector notoriously influences the structure of non-perturbative effects and induces a D-term potential. Focusing for concreteness on the large volume scenario, we work out the geometry of the swiss-cheese type Calabi-Yau manifold P_[1,3,3,3,5][15]_(3,75) and analyse whether controllable and phenomenologically acceptable Kaehler moduli stabilisation can occur by the combination of F- and D-terms.Comment: 43 pages, 4 figures, v2: refs. adde

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

Background: Disorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021. Methods: We estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined. Findings: Globally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer. Interpretation: As the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed. Funding: Bill & Melinda Gates Foundation