Photoinactivation of Eight Health-Relevant Bacterial Species: Determining the Importance of the Exogenous Indirect Mechanism

It is presently unknown to what extent the endogenous direct, endogenous indirect, and exogenous indirect mechanisms contribute to bacterial photoinactivation in natural surface waters. In this study, we investigated the importance of the exogenous indirect mechanism by conducting photoinactivation experiments with eight health-relevant bacterial species (<i>Bacteroides thetaiotaomicron, Campylobacter jejuni</i>, <i>Enterococcus faecalis</i>, <i>Escherichia coli</i> K12, <i>E. coli</i> O157:H7, <i>Salmonella enterica</i> serovar Typhimurium LT2, <i>Staphylococcus aureus</i>, and <i>Streptococcus bovis</i>). We used three synthetic photosensitizers (methylene blue, rose bengal, and nitrite) and two model natural photosensitizers (Suwannee River natural organic matter and dissolved organic matter isolated from a wastewater treatment wetland) that generated singlet oxygen and hydroxyl radical. <i>B. thetaiotaomicron</i> had larger first order rate constants than all other organisms under all conditions tested. The presence of the synthetic photosensitizers generally enhanced photoinactivation of Gram-positive facultative anaerobes (<i>Ent. faecalis</i>, <i>Staph. aureus</i>, and <i>Strep. bovis</i>). Among Gram-negative bacteria, only methylene blue with <i>E. coli</i> K12 and rose bengal with <i>C. jejuni</i> showed an enhancing effect. The presence of model natural photosensitizers either reduced or did not affect photoinactivation rate constants. Our findings highlight the importance of the cellular membrane and photosensitizer properties in modulating the contribution of the exogenous indirect mechanism to the overall bacterial photoinactivation

Exogenous indirect photoinactivation of bacterial pathogens and indicators in water with natural and synthetic photosensitizers in simulated sunlight with reduced UVB

ABSTRACT Aims: To investigate the UVB-independent and exogenous indirect photoinactivation of eight human health-relevant bacterial species in the presence of photosensitizers. Methods and Results: Eight bacterial species were exposed to simulated sunlight with greatly reduced UVB light intensity in the presence of three synthetic photosensitizers and two natural photosensitizers. Inactivation curves were fit with shoulder-log linear or first order kinetic models, from which the presence of a shoulder and magnitude of inactivation rate constants were compared. 84% reduction in the UVB light intensity roughly matched a 72-95% reduction in the overall bacterial photoinactivation rate constants in sensitizer-free water. With the UVB light mostly reduced, the exogenous indirect mechanism contribution was evident for most bacteria and photosensitizers tested, although most prominently with the Gram-positive bacteria. Conclusions: Results confirm the importance of UVB light in bacterial photoinactivation and, with the reduction of the UVB light intensity, that the Gram-positive bacteria are more vulnerable to the exogenous indirect mechanism than Gram-negative bacteria. Significance and Impact of Study: UVB is the most important range of the sunlight spectrum for bacterial photoinactivation. In aquatic environments where photosensitizers are present and there is high UVB light attenuation, UVA and visible wavelengths can contribute to exogenous indirect photoinactivation

Identification of Relevant ICF Categories in Vocational Rehabilitation: A Cross Sectional Study Evaluating the Clinical Perspective

Introduction Vocational rehabilitation (VR) emphasizes a need for medical support, rehabilitation and biopsychosocial approach to enable individuals to successfully participate in the workforce. Optimal rehabilitation management relies on an in-depth knowledge of the typical spectrum of problems encountered of patients in VR. The International Classification of Functioning, Disability and Health (ICF) is based on a universal conceptual model and provides a holistic view of functioning of the lived experience of people such as those undergoing VR. The objectives of this study are to describe the functioning and health of persons undergoing VR and to identify the most common problems around work and in VR using the ICF as the reference framework. Methods An empirical cross-sectional multicenter study was conducted using convenience sampling from March 2009 to March 2010. Data were collected using a Case Record Form rated by health professionals which was based on an extended version of the ICF Checklist containing 292 ICF categories and sociodemographic information. Results 152 patients with various health conditions participated. We identified categories from all four ICF components: 24 for body functions, six for body structures, 45 for activities and participation, and 25 for environmental factors. Conclusions Our study identified a multitude of ICF categories that describe functioning domains and which represent the complexity of VR. Such a comprehensive approach in assessing patients in VR may help to understand and customize the process of VR in the clinical setting and to enhance multidisciplinary communicatio

The diagnostic targeting of a carbohydrate virulence factor from M.Tuberculosis

10.1038/srep10281Scientific Reports

Evolution of olivine lattice preferred orientation during simple shear in the mantle

Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 272 (2008): 501-512, doi:10.1016/j.epsl.2008.03.063.Understanding the variation of olivine lattice preferred orientation (LPO) as a function of shear strain is important for models that relate seismic anisotropy to the kinematics of deformation. We present results on the evolution of olivine orientation as a function of shear strain in samples from a shear zone in the Josephine Peridotite (southwest Oregon). We find that the LPO in harzburgites re-orients from a pre-existing LPO outside the shear zone to a new LPO with the olivine [100] maximum aligned sub-parallel to the shear direction between 168% and 258% shear strain. The strain at which [100] aligns with the shear plane is slightly higher than that observed in experimental samples, which do not have an initial LPO. While our observations broadly agree with the experimental observations, our results suggest that a pre-existing LPO influences the strain necessary for LPO alignment with the shear direction. In addition, olivine re-alignment appears to be dominated by slip on both (010)[100] and (001)[100], due to the orientation of the pre-existing LPO. Fabric strengths, quantified using both the J- and M- indices, do not increase with increasing shear strain. Unlike experimental observations, our natural samples do not have a secondary LPO peak. The lack of a secondary peak suggests that subgrain rotation recrystallization dominates over grain boundary migration during fabric re-alignment. Harzburgites exhibit girdle patterns among [010] and [001] axes, while a dunite has point maxima. Combined with the observation that harzburgites are finer grained than dunites, we speculate that additional phases (i.e., pyroxenes) limit olivine grain growth and promote grain boundary sliding. Grain boundary sliding may relax the requirement for slip on the hardest olivine system, enhancing activation of the two easiest olivine slip systems, resulting in the [010] and [001] girdle patterns. Overall, our results provide an improved framework for calibration of LPO evolution models.This work was partly supported by NSF grants EAR-0230267 and EAR-0409609. Funding for fieldwork was provided by the WHOI Academic Programs Office as part of a 2003 field class run by P.B.K. and G.H

The translocator maintenance protein Tam41 is required for mitochondrial cardiolipin biosynthesis

The mitochondrial inner membrane contains different translocator systems for the import of presequence-carrying proteins and carrier proteins. The translocator assembly and maintenance protein 41 (Tam41/mitochondrial matrix protein 37) was identified as a new member of the mitochondrial protein translocator systems by its role in maintaining the integrity and activity of the presequence translocase of the inner membrane (TIM23 complex). Here we demonstrate that the assembly of proteins imported by the carrier translocase, TIM22 complex, is even more strongly affected by the lack of Tam41. Moreover, respiratory chain supercomplexes and the inner membrane potential are impaired by lack of Tam41. The phenotype of Tam41-deficient mitochondria thus resembles that of mitochondria lacking cardiolipin. Indeed, we found that Tam41 is required for the biosynthesis of the dimeric phospholipid cardiolipin. The pleiotropic effects of the translocator maintenance protein on preprotein import and respiratory chain can be attributed to its role in biosynthesis of mitochondrial cardiolipin

Host Defense against Viral Infection Involves Interferon Mediated Down-Regulation of Sterol Biosynthesis

Upon infection, our immune cells produce a small protein called interferon, which in turn signals a protective response through a series of biochemical reactions that involves lowering the cells' ability to make cholesterol by targeting a gene essential for controlling the pathway for cholesterol metabolism

Integrative multi-omics database (iMOMdb) of Asian pregnant women

Asians are underrepresented across many omics databases, thereby limiting the potential of precision medicine in nearly 60% of the global population. As such, there is a pressing need for multi-omics derived quantitative trait loci (QTLs) to fill the knowledge gap of complex traits in populations of Asian ancestry. Here, we provide the first blood-based multi-omics analysis of Asian pregnant women, constituting high-resolution genotyping (N= 1079), DNA methylation (N=915) and transcriptome profiling (N=238). Integrative omics analysis identified 219 154 CpGs associated with cis-DNA methylation QTLs (meQTLs) and 3703 RNAs associated with cis-RNA expression QTLs (eQTLs). Ethnicity was the largest contributor of inter-individual variation across all omics datasets, with 2561 genes identified as hotspots of this variation; 395 of these hotspot genes also contained both ethnicity-specific eQTLs and meQTLs. Gene set enrichment analysis of these ethnicity QTL hotspots showed pathways involved in lipid metabolism, adaptive immune system and carbohydrate metabolism. Pathway validation by profiling the lipidome (similar to 480 lipids) of antenatal plasma (N = 752) and placenta (N = 1042) in the same cohort showed significant lipid differences among Chinese, Malay and Indian women, validating ethnicity-QTL gene effects across different tissue types. To develop deeper insights into the complex traits and benefit future precision medicine research in Asian pregnant women, we developed iMOMdb, an open-access database.Peer reviewe

Characterizing the Nano and Micro Structure of Concrete toImprove its Durability

New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full-field soft X-ray imaging in the water window is providing new insight on the nano scale of the cement hydration process, which leads to a nano-optimization of cement-based systems. Hard X-ray microtomography images of ice inside cement paste and cracking caused by the alkali?silica reaction (ASR) enables three-dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is studied. Results of experiments using these tools are shown on this paper