The proximity-concentration tradeoff under uncertainty

In this article, we analyse the firm's choice between serving a foreign market through exports or through foreign affiliate sales in an environment characterized by country-specific shocks to the cost of production. Our model predicts that country pairs with less-correlated output fluctuations trade more, relative to affiliate sales, whereas countries with more-volatile fluctuations are served relatively more by exporters than by foreign affiliates selling abroad. Using detailed data on trade and affiliate sales, we find empirical support for our model's predictions

Intrafirm trade and vertical fragmentation in U.S.multinational corporations

Using firm-level data, we document two new facts regarding intrafirm trade and the activities of the foreign affiliates of U.S. multinational corporations. First, intrafirm trade is concentrated among a small number of large affiliates within large multinational corporations; the median affiliate ships nothing to the rest of the corporation. Second, we find that the input-output coefficient linking the parent’s and affiliate’s industries of operation—a characteristic commonly associated with production fragmentation— is not related to a corresponding intrafirm low of goods

Haemostatic profile of the San (Bushmen} relocated to Schmidtsdrif

Objective. To document the routine haemostatic variables of a group of San relocated from Namibia to South Africa.Design. Cross-sectional study done in two stages.Setting. Schmidtsdrif military camp in late 1990 and early 1991.Subjects. Healthy adult San volunteers: 31 males and 54 females from the Vasakela and Barakwena groups in 1990; 135 males from the Vasakela group in 1991. The subjects were all soldiers or their dependants.Main outcome measures. The following tests were performed: activated partial thromboplastin time, prothrombin time, thrombin time, fibrinogen and coagulation factors V, VII, VIII, IX, X, XI and XII. The results were compared with a Western population reference group (N =50).Main results. Almost all the haemostatic variables were statistically significantly lower than those of the reference group. The mean derived fibrinogen concentration in the plasma in the first stage of the study (1990) was significantly higher, but this reverted to normal during the second stage (1991), perhaps reflecting a general improvement in health.Conclusions. Even though the San are one of the best studied groups of indigenous people, this is the first published report on their haemostatic condition. The generally lower levels of haemostatic variables may reflect the lower prevalence of cardiovascular disease in the San. The population needs to be followed up as they westernise

Medication Management Program Among Elderly at a Residential Facility

Abstract This quality improvement project aimed to address medication management-related issues at a residential facility. The project\u27s population was elderly residents who self- administered their medications. A root cause analysis and SWOT analysis identified multiple factors contributing to medication management errors, including lack of resident education, resident competency, and technology limitations. An intervention plan was developed and implemented in two phases. Phase 1 involved conducting medication reconciliation, assessing resident competency, and 1:1 educational sessions with the residents. Educational retention was assessed by using a pre-test and a post-test. Phase 2, to be implemented in the future, will address technology limitations, incorporate an electronic medical records (EMR) system, and provide ongoing staff education. Results from Phase 1 include 80% recalled new information while 20% showed no change after completion of the educational session and the pre/post-test; from those residents assessed with the Medi-Cog, 55% scored above 8 out of 10 while 45% scored below the cutoff score of 8, and last 100% of the Medication Administration Records (MAR) were reviewed. Although time constraints prevented Phase 2 interventions from being implemented, implementing an EMR system and a professional development plan for staff education are expected to contribute to further improvements in medication management at the residential facility. Continued monitoring and collaboration with the residents and staff are vital for sustained success

What Challenges Can Arise from Coordinating Housing Development with Transportation?

More systematic coordination between transportation and housing development is increasingly recognized as a promising strategy for creating more sustainable communities. In California, the importance of transportation-housing coordination is reflected in recent legislative efforts to address the state’s long-standing housing affordability crisis. One approach is to encourage higher density affordable housing developments near transit or in similarly transportation-efficient areas, such as locations with low vehicle miles traveled (VMT). However, little is known about how transportation access should be considered in guiding housing development, what challenges can arise from coordinating housing development with transportation, and what the state can do to better deal with these challenges and achieve more equitable residential densification

A cancer rainbow mouse for visualizing the functional genomics of oncogenic clonal expansion.

Field cancerization is a premalignant process marked by clones of oncogenic mutations spreading through the epithelium. The timescales of intestinal field cancerization can be variable and the mechanisms driving the rapid spread of oncogenic clones are unknown. Here we use a Cancer rainbow (Crainbow) modelling system for fluorescently barcoding somatic mutations and directly visualizing the clonal expansion and spread of oncogenes. Crainbow shows that mutations of ß-catenin (Ctnnb1) within the intestinal stem cell results in widespread expansion of oncogenes during perinatal development but not in adults. In contrast, mutations that extrinsically disrupt the stem cell microenvironment can spread in adult intestine without delay. We observe the rapid spread of premalignant clones in Crainbow mice expressing oncogenic Rspondin-3 (RSPO3), which occurs by increasing crypt fission and inhibiting crypt fixation. Crainbow modelling provides insight into how somatic mutations rapidly spread and a plausible mechanism for predetermining the intratumor heterogeneity found in colon cancers

Evaluation of long chain 1,14-alkyl diols in marine sediments as indicators for upwelling and temperature

Long chain alkyl diols form a group of lipids occurring widely in marine environments. Recent studies have suggested several palaeoclimatological applications for proxies based on their distributions, but have also revealed uncertainty about their applicability. Here we evaluate the use of long chain 1,14-alkyl diol indices for reconstruction of temperature and upwelling conditions by comparing index values, obtained from a comprehensive set of marine surface sediments, with environmental factors such as sea surface temperature (SST), salinity and nutrient concentration. Previous studies of cultures indicated a strong effect of temperature on the degree of saturation and the chain length distribution of long chain 1,14-alkyl diols in Proboscia spp., quantified as the diol saturation index (DSI) and diol chain length index (DCI), respectively. However, values of these indices for surface sediments showed no relationship with annual mean SST of the overlying water. It remains unknown as to what determines the DSI, although our data suggest that it may be affected by diagenesis, while the relationship between temperature and DCI may be different for different Proboscia species. In addition, contributions from algae other than Proboscia diatoms may affect both indices, although our data provide no direct evidence for additional long chain 1,14-alkyl diol sources. Two other indices using the abundance of 1,14-diols vs. 1,13-diols and C30 1,15-diols have been applied previously as indicators for upwelling intensity at different locations. The geographical distribution of their values supports the use of 1,14 diols vs. 1,13 diols [C28 + C30 1,14-diols]/[(C28 + C30 1,13-diols) + (C28 + C30 1,14-diols)] as a general indicator for high nutrient or upwelling conditions

\u3cem\u3eCandida Albicans\u3c/em\u3e Stimulates \u3cem\u3eStreptococcus Mutans\u3c/em\u3e Microcolony Development via Cross-Kingdom Biofilm-Derived Metabolites

Candida albicans is frequently detected with heavy infection of Streptococcus mutans in plaque-biofilms from children affected with early-childhood caries, a prevalent and costly oral disease. The presence of C. albicans enhances S. mutans growth within biofilms, yet the chemical interactions associated with bacterial accumulation remain unclear. Thus, this study was conducted to investigate how microbial products from this cross-kingdom association modulate S. mutans build-up in biofilms. Our data revealed that bacterial-fungal derived conditioned medium (BF-CM) significantly increased the growth of S. mutans and altered biofilm 3D-architecture in a dose-dependent manner, resulting in enlarged and densely packed bacterial cell-clusters (microcolonies). Intriguingly, BF-CM induced S. mutans gtfBC expression (responsible for Gtf exoenzymes production), enhancing Gtf activity essential for microcolony development. Using a recently developed nanoculture system, the data demonstrated simultaneous microcolony growth and gtfB activation in situ by BF-CM. Further metabolites/chromatographic analyses of BF-CM revealed elevated amounts of formate and the presence of Candida-derived farnesol, which is commonly known to exhibit antibacterial activity. Unexpectedly, at the levels detected (25–50 μM), farnesol enhanced S. mutans-biofilm cell growth, microcolony development, and Gtf activity akin to BF-CM bioactivity. Altogether, the data provide new insights on how extracellular microbial products from cross-kingdom interactions stimulate the accumulation of a bacterial pathogen within biofilms

Stability of sub-surface oxygen at Rh(111)

Using density-functional theory (DFT) we investigate the incorporation of oxygen directly below the Rh(111) surface. We show that oxygen incorporation will only commence after nearly completion of a dense O adlayer (\theta_tot = 1.0 monolayer) with O in the fcc on-surface sites. The experimentally suggested octahedral sub-surface site occupancy, inducing a site-switch of the on-surface species from fcc to hcp sites, is indeed found to be a rather low energy structure. Our results indicate that at even higher coverages oxygen incorporation is followed by oxygen agglomeration in two-dimensional sub-surface islands directly below the first metal layer. Inside these islands, the metastable hcp/octahedral (on-surface/sub-surface) site combination will undergo a barrierless displacement, introducing a stacking fault of the first metal layer with respect to the underlying substrate and leading to a stable fcc/tetrahedral site occupation. We suggest that these elementary steps, namely, oxygen incorporation, aggregation into sub-surface islands and destabilization of the metal surface may be more general and precede the formation of a surface oxide at close-packed late transition metal surfaces.Comment: 9 pages including 9 figure files. Submitted to Phys. Rev. B. Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm