Impact of women driving cars on the sustainable development and traffic safety in the Kingdom of Saudi Arabia - Phase 2 Survey Results -

The aim of this report is to provide the analysis of the descriptive statistics of the second phase of the She Drives KSA survey that took place one year after women started driving. The report first analyses transport-related aspects for the households of the participants. Next, it focuses on the privately employed drivers of the participants’ households. Driving license possession or not of women is analysed next, while information is also provided about the driving schools they attended. Women’s travel behaviour is analysed as well by particularly emphasizing and comparing the travel behaviour of women who drive to those who do not drive. The car preferences of the participant women who have or are about to have a driving license is analysed next. Women and men attitudes and perceptions towards the social, economic, environmental and traffic safety impact that women starting driving may have follows in the analysis. Finally, potential policies to support the transition to women driving in the Kingdom of Saudi Arabia are presented to conclude the report

Do routinely measured risk factors for obesity explain the sex gap in its prevalence? Observations from Saudi Arabia.

BACKGROUND: The prevalence of adult obesity is higher in women than men in most countries. However, the pathways that link female sex with excess obesity are still not fully understood. We examine whether socioeconomic and behavioural factors may mediate the association between sex and obesity in the Saudi Arabian setting where there is female excess in obesity. METHODS: We performed a mediation analysis using a cross-sectional, national household survey from Saudi Arabia with 4758 participants (51% female). A series of multivariable regression models were fitted to test if socioeconomic position, physical activity, sedentary behaviour, diet, and smoking mediate the association between sex and obesity (BMI >=30). The findings were confirmed using causal mediation analysis. RESULTS: Women in this sample were roughly twice as likely as men to be obese (crude OR 1.9; 95% CI 1.6-2.3). The odds ratio remained significantly higher for women compared to men in models testing for mediation (OR range 1.95-2.06). Our data suggest that indicators of socio-economic position, physical activity, sedentary behaviour, diet, and smoking do not mediate the sex differences in obesity. CONCLUSIONS: Our analysis shows that most commonly measured risk factors for obesity do not explain the sex differences in its prevalence in the Saudi context. Further research is needed to understand what might explain the female excess in obesity prevalence. We discuss how data related to the lived experience of Saudi men and women may tap into underlying mechanisms by which the sex difference in obesity prevalence are produced

Zinc Metal Ion Affected the Structural Stability of Amyloid-Like Nanofibrils

Synthetic peptides that self-assemble into well-defined structures with a cross-β arrangement are called amyloid-like fibrils. Amyloids are associated with a list of disorders and neuro-degenerative diseases, such as Alzheimer's and Parkinson`s disease. We previously showed that amyloid-like nanofibrils with a repeating motif “IHIH” were functional fibrils. They were able to bind a metal ion through imidazole moieties and mimic the native carbonic anhydrase enzyme by hydrolysing the CO2 molecule. Thus, these synthetic amyloid fibrils were suggest-ed to be good candidates to moderate and update the modern enzymatic molecules. This study aims to shed a light on the stability of these amyloid nanofibrils over a study period of 25 days, in the presence/absence of a metal ion. The work continued for approximately 7 months in the Biochemistry department, School of Life Sciences at the University of Sussex in the United Kingdom. A set of designed peptides with a repeating motif “IHIH” were ex-plored, based on some structural studies. Short and long peptides with free ends as well as closed ends were investigated. Peptides allowed to self-assemble with and without a metal ion (zinc) were then examined using circular dichroism, fluorimetry and electron microscopy for structural biophysical analysis. Regardless of the metal ion contribution, peptides showed stable secondary structures with a -sheet conformation for the incubation time of 25 days. Their morphologies did not appear to change over time. However, the presence of a zinc ion has an effect on the secondary structure of the mature fibrils. Results indicated that fibrils grown with the zinc ion have a significantly higher propensity to form -sheets secondary structures during incubation time. The presence of a zinc ion also affected the dimensions of the amyloid-like fibrils by the end of the study course, at which point they significantly re-duced. This effect of zinc ion on synthetic amyloid fibrils has not been previously reported. The stabilities of the zinc-nanofibrils point to their potential for use in modifying or updating the enzyme-mimic analytical reactions. The effect of adding zinc on the fibrillation seems to be crucial. Although it apparently improved the -sheet assembly, it affected the width/length of the synthetic amyloids. This effect could be promising toward reducing the generation of amyloid fibrils and ultimately understanding the pathogenesis of Alzheimer disease

Specificity of amino acid sequence and its role in secondary and supersecondary structure generation

Schematic presentation of loops (7 aa) linking two β-strands (fragments of β-sheets). The left one – helical form represents fuzzy oil drop distribution of hydrophobicity. The right one not able to generate the helical form represents the status recognized as amyloid seed in amyloids discussed in this work

The diversity and utility of amyloid fibrils formed by short amyloidogenic peptides

Amyloidogenic peptides are well known for their involvement in diseases such as type 2 diabetes and Alzheimer's disease. However, more recently, amyloid fibrils have been shown to provide scaffolding and protection as functional materials in a range of organisms from bacteria to humans. These roles highlight the incredible tensile strength of the cross-β amyloid architecture. Many amino acid sequences are able to self-assemble to form amyloid with a cross-β core. Here we describe our recent advances in understanding how sequence contributes to amyloidogenicity and structure. For example, we describe penta- and hexapeptides that assemble to form different morphologies; a 12mer peptide that forms fibrous crystals; and an eight-residue peptide originating from α-synuclein that has the ability to form nanotubes. This work provides a wide range of peptides that may be exploited as fibrous bionanomaterials. These fibrils provide a scaffold upon which functional groups may be added, or templated assembly may be performed

Characteristics of the fission fragments induced by the 129Xe + natSn reactions at E = 8–15A MeV

The study of nuclear multifragmentation is important for understanding the reaction mechanisms in heavy-ion collisions. In the present work, we study the nuclear reaction 129Xe + natSn in the energy range E = 8 to 15 AMeV. This experiment was performed at GANIL with the multidetector INDRA. We study the charge distributions produced in this reaction, which are broad and cover a large atomic number range. By using the data of this experiment, we identify four channels differing by the number of fragments: 1, 2, 3 and 4 fragments. In this contribution we will show a method to reconstruct the average size and excitation energy of the primary fission fragments, before their decay. The method employed is based on the fragment-light charged particles relative velocity correlation functions. Preliminary results will be presented

Zinc-dysprosium functionalized amyloid fibrils

The heterometallic Zn2Dy2 entity bearing partially saturated metal centres covalently decorates a highly ordered amyloid fibril core and the functionalised assembly exhibits catalytic Lewis acid behaviour

Identifying the coiled-coil triple helix structure of β-peptide nanofibers at atomic resolution

Peptide self-assembly represents a powerful bottom-up approach to the fabrication of new nanomaterials. β3-peptides are non-natural peptides composed entirely of β-amino acids, which have an extra methylene in the backbone and we reported the first fibers derived from the self-assembly of β3-peptides that adopt unique 14-helical structures. β3-peptide assemblies represent a class of stable nanomaterials that can be used to generate bio- and magneto-responsive materials with proteolytic stability. However, the three-dimensional structure of many of these materials remains unknown. In order to develop structure-based criteria for the design of new β3-peptide-based biomaterials with tailored function, we investigated the structure of a tri-β3-peptide nanoassembly by molecular dynamics simulations and X-ray fiber diffraction analysis. Diffraction data was collected from aligned fibrils formed by Ac-β3[LIA] in water and used to inform and validate the model structure. Models with threefold radial symmetry resulted in stable fibers with a triple-helical coiled-coil motif and measurable helical pitch and periodicity. The fiber models revealed a hydrophobic core and twist along the fiber axis arising from a maximization of contacts between hydrophobic groups of adjacent tripeptides on the solvent-exposed fiber surface. These atomic structures of macro-scale fibers derived from β3-peptide-based materials provide valuable insight into the effects of the geometric placement of the side-chains and the influence of solvent on the core fiber structure which is perpetuated in the superstructure morphology

Chemically and thermally stable silica nanowires with a β-sheet peptide core for bionanotechnology

Background: A series of amyloidogenic peptides based on the sequence KFFEAAAKKFFE template the silica precursor, tetraethyl orthosilicate to form silica-nanowires containing a cross-β peptide core. Results: Investigation of the stability of these fibres reveals that the silica layers protect the silica-nanowires allowing them to maintain their shape and physical and chemical properties after incubation with organic solvents such as 2-propanol, ethanol, and acetonitrile, as well as in a strong acidic solution at pH 1.5. Furthermore, these nanowires were thermally stable in an aqueous solution when heated up to 70 °C, and upon autoclaving. They also preserved their conformation following incubation up to 4 weeks under these harsh conditions, and showed exceptionally high physical stability up to 1000 °C after ageing for 12 months. We show that they maintain their β-sheet peptide core even after harsh treatment by confirming the β-sheet content using Fourier transform infrared spectra. The silica nanowires show significantly higher chemical and thermal stability compared to the unsiliconised fibrils. Conclusions: The notable chemical and thermal stability of these silica nanowires points to their potential for use in microelectromechanics processes or fabrication for nanotechnological devices

Transition of nano-architectures through self-assembly of lipidated β3-tripeptide foldamers

β3-peptides consisting exclusively of β3-amino acids adopt a variety of non-natural helical structures and can self-assemble into well-defined hierarchical structures by axial head-to-tail self-assembly resulting in fibrous materials of varying sizes and shapes. To allow control of fiber morphology, a lipid moiety was introduced within a tri-β3-peptide sequence at each of the three amino acid positions and the N-terminus to gain finer control over the lateral assembly of fibers. Depending on the position of the lipid, the self-assembled structures formed either twisted ribbon-like fibers or distinctive multilaminar nanobelts. The nanobelt structures were comprised of multiple layers of peptide fibrils as revealed by puncturing the surface of the nanobelts with an AFM probe. This stacking phenomenon was completely inhibited through changes in pH, indicating that the layer stacking was mediated by electrostatic interactions. Thus, the present study is the first to show controlled self-assembly of these fibrous structures, which is governed by the location of the acyl chain in combination with the 3-point H-bonding motif. Overall, the results demonstrate that the nanostructures formed by the β3-tripeptide foldamers can be tuned via sequential lipidation of N-acetyl β3-tripeptides which control the lateral interactions between peptide fibrils and provide defined structures with a greater homogeneous population