Airbnb Strategic Audit Overview

This study provides an overview of Airbnb, an online marketplace for short-term rentals and experiences. It highlights the company\u27s history, business strategies, value chain, acquisitions, code of ethical conduct, and organizational structure. With a Blue Ocean strategy combining differentiation and cost leadership, Airbnb has achieved remarkable success, boasting a valuation of over $67B and generating annual revenue exceeding$1.5B. The company\u27s unique business model involves participating in all parts of the value chain, and it has expanded geographically through acquisitions and product market expansion. Airbnb\u27s code of ethics reflects its core values, and its organizational structure fosters flexibility and remote work options. Overall, the company incentivizes performance through cash bonuses and equity- based compensation plans

Longitudinal patterns of leukoaraiosis and brain atrophy in symptomatic small vessel disease.

Cerebral small vessel disease is a common condition associated with lacunar stroke, cognitive impairment and significant functional morbidity. White matter hyperintensities and brain atrophy, seen on magnetic resonance imaging, are correlated with increasing disease severity. However, how the two are related remains an open question. To better define the relationship between white matter hyperintensity growth and brain atrophy, we applied a semi-automated magnetic resonance imaging segmentation analysis pipeline to a 3-year longitudinal cohort of 99 subjects with symptomatic small vessel disease, who were followed-up for ≥1 years. Using a novel two-stage warping pipeline with tissue repair step, voxel-by-voxel rate of change maps were calculated for each tissue class (grey matter, white matter, white matter hyperintensities and lacunes) for each individual. These maps capture both the distribution of disease and spatial information showing local rates of growth and atrophy. These were analysed to answer three primary questions: first, is there a relationship between whole brain atrophy and magnetic resonance imaging markers of small vessel disease (white matter hyperintensities or lacune volume)? Second, is there regional variation within the cerebral white matter in the rate of white matter hyperintensity progression? Finally, are there regionally specific relationships between the rates of white matter hyperintensity progression and cortical grey matter atrophy? We demonstrate that the rates of white matter hyperintensity expansion and grey matter atrophy are strongly correlated (Pearson's R = -0.69, P < 1 × 10(-7)), and significant grey matter loss and whole brain atrophy occurs annually (P < 0.05). Additionally, the rate of white matter hyperintensity growth was heterogeneous, occurring more rapidly within long association fasciculi. Using voxel-based quantification (family-wise error corrected P < 0.05), we show the rate of white matter hyperintensity progression is associated with increases in cortical grey matter atrophy rates, in the medial-frontal, orbito-frontal, parietal and occipital regions. Conversely, increased rates of global grey matter atrophy are significantly associated with faster white matter hyperintensity growth in the frontal and parietal regions. Together, these results link the progression of white matter hyperintensities with increasing rates of regional grey matter atrophy, and demonstrate that grey matter atrophy is the major contributor to whole brain atrophy in symptomatic cerebral small vessel disease. These measures provide novel insights into the longitudinal pathogenesis of small vessel disease, and imply that therapies aimed at reducing progression of white matter hyperintensities via end-arteriole damage may protect against secondary brain atrophy and consequent functional morbidity

Mouse Dipeptidyl Peptidase 4 Is Not a Functional Receptor for Middle East Respiratory Syndrome Coronavirus Infection

Human dipeptidyl peptidase 4 (hDPP4) was recently identified as the receptor for Middle East respiratory syndrome coronavirus (MERS-CoV) infection, suggesting that other mammalian DPP4 orthologs may also support infection. We demonstrate that mouse DPP4 cannot support MERS-CoV infection. However, employing mouse DPP4 as a scaffold, we identified two critical amino acids (A288L and T330R) that regulate species specificity in the mouse. This knowledge can support the rational design of a mouse-adapted MERS-CoV for rapid assessment of therapeutics

Interobserver reliability and diagnostic performance of Chiari II malformation measures in MR imaging—part 2

PURPOSE: Brain MR imaging is essential in the assessment of Chiari II malformation in clinical and research settings concerning spina bifida. However, the interpretation of MR images of the malformation is not always straightforward. Morphometric analyses of the extent of Chiari II malformation may improve the assessment. In an attempt to select appropriate morphometric measures for this purpose, we investigated the interobserver reliability and diagnostic performance of several morphometric measures of Chiari II malformation on MR images. METHODS: Brain MR images of 79 children [26 with open spinal dysraphism, 17 with closed spinal dysraphism, and 36 without spinal dysraphism; mean age 10.6 (SD 3.2; range, 6-16) years] were evaluated. All children had been assessed for Chiari II malformation (defined as cerebellar herniation in combination with open spinal dysraphism; n = 23). Three observers blindly and independently reviewed the MR images for 21 measures of the cerebellum, brainstem, and posterior fossa in three planes. The interobserver reliability was assessed by an agreement index (AI = 1 - RRE) and the diagnostic performance by receiver operating characteristic analyses. RESULTS: Reliability was good for most measures, except for the degree of herniation of the vermis and tonsil. Most values differed statistically significantly between children with and without Chiari II malformation. The measures mamillopontine distance and cerebellar width showed excellent diagnostic performance. CONCLUSIONS: Morphometric measures may reliably quantify the morphological distortions of Chiari II malformation on MR images and provide additional tools to assess the severity of Chiari II malformation in clinical and research settings

Seasonal Variations in Radon-222 Soil Fluxes and Canopy Inventories in Brazilian Amazonian

The role of Amazonian tropical rainforests in the global carbon cycle as a net sink for carbon dioxide remains a source of controversy due to difficulties in calculating differences between immense photosynthetic and respiration fluxes. A new method for tracking net carbon dioxide fluxes utilizes a combination of canopy inventory and soil flux measurements of the noble gas Radon-222 to determine canopy-atmosphere gas exchange rates (Martens et al., 2004). I utilized canopy and soil flux Radon-222 data collected during 2000-2004 to search for a positive correlation between temporal variations in these two parameters between the wet and dry seasons. No statistically significant correlation was found between the two parameters, however, a visual trend was seen in which radon soil fluxes and canopy concentrations both increased during the dry season and decreased during the wet season. It is possible that other factors, such as storm events, influence radon canopy concentrations thus obscuring a quantitative relationship with soil fluxes. A future goal of this project is to continue Radon-222 work in Brazil in collaboration with Brazilian colleagues at the Federal University of West Pará (UFOPa).Bachelor of Scienc