The microaerophily and photosensitivity of Propionibacterium acnes

E. MARTIN GRIBBON, J.G. SHOESMITH, W.J. CUNLIFFE AND K.T. HOLLAND. 1994. The effect of oxygen on the in vitro propagation of Propionibacterium acnes was investigated under defined culture conditions. This micro-organism is the predominant bacterial resident within the pilosebaceous follicles of sebum-rich areas of human skin. The organism was grown in continuous culture in defined synthetic medium with glucose as the main carbon-energy source at various air saturation concentrations and in the presence and absence of light. Steady state continuous cultures were achieved at very low oxygen tensions in the presence of light, and at higher levels of oxygen when non-illuminated. Culture biomass yields were higher than those of anaerobic cultures. Bacterial cells were inactivated in the presence of light at high oxygen concentrations because of photosensitization reactions involving excess oxygen and microbial porphyrin species.     

Unraveling the Genetic Etiology of Adult Antisocial Behavior: A Genome-Wide Association Study

Crime poses a major burden for society. The heterogeneous nature of criminal behavior makes it difficult to unravel its causes. Relatively little research has been conducted on the genetic influences of criminal behavior. The few twin and adoption studies that have been undertaken suggest that about half of the variance in antisocial behavior can be explained by genetic factors. In order to identify the specific common genetic variants underlying this behavior, we conduct the first genome-wide association study (GWAS) on adult antisocial behavior. Our sample comprised a community sample of 4816 individuals who had completed a self-report questionnaire. No genetic polymorphisms reached genome-wide significance for association with adult antisocial behavior. In addition, none of the traditional candidate genes can be confirmed in our study. While not genome-wide significant, the gene with the strongest association (p-value = 8.7×10⁻⁵) was DYRK1A, a gene previously related to abnormal brain development and mental retardation. Future studies should use larger, more homogeneous samples to disentangle the etiology of antisocial behavior. Biosocial criminological research allows a more empirically grounded understanding of criminal behavior, which could ultimately inform and improve current treatment strategies.     

Risk Ranking of Antimicrobials in the Aquatic Environment from Human Consumption: An Irish Case Study

A mechanistic model is presented for determination of antimicrobial presence in the environment, using antimicrobial characteristics and Irish-specific usage data. The model simulates release of antimicrobials into the aquatic environment by integrating the effects of antimicrobial use, metabolism, degradation, and dilution. Predicted environmental concentrations (PECs) were ranked in relation to their potential to select for resistant bacteria, toxicity (chronic and acute), and hazard quotient (HQ). The simulated mean PECs of penicillins (PEN), β-lactams (BET), tetracyclines (TET), macrolides (MAC), quinolone/fluoroquinolones (Q/F), and sulphonamides/trimethoprim (S/T) were 1.05, 0.19, 0.06, 0.07, 0.02, and 0.08 mg/m³, respectively. All antimicrobials, excluding Q/F, showed a low HQ (<1) indicating low toxicity. Q/F had a HQ of 1.51 indicating moderate toxicity. All antimicrobial groups expressed varying resistance formation potential with Q/F having the highest. Q/F also exhibited the lowest degradation rate. A sensitivity analysis indicated a possible role for considering metabolism during regulation of new antimicrobials as this can significantly influence PEC values. The observed results suggest that current antimicrobial use can lead to levels in the environment that may increase resistance formation. The results and limitations presented here accentuate the need for further investigation into antimicrobials in the environment and contribution to resistant strains.     

Dispersal patterns in a medium‐density Irish badger population: Implications for understanding the dynamics of tuberculosis transmission

European badgers (Meles meles) are group‐living mustelids implicated in the spread of bovine tuberculosis (TB) to cattle and act as a wildlife reservoir for the disease. In badgers, only a minority of individuals disperse from their natal social group. However, dispersal may be extremely important for the spread of TB, as dispersers could act as hubs for disease transmission. We monitored a population of 139 wild badgers over 7 years in a medium‐density population (1.8 individuals/km²). GPS tracking collars were applied to 80 different individuals. Of these, we identified 25 dispersers, 14 of which were wearing collars as they dispersed. This allowed us to record the process of dispersal in much greater detail than ever before. We show that dispersal is an extremely complex process, and measurements of straight‐line distance between old and new social groups can severely underestimate how far dispersers travel. Assumptions of straight‐line travel can also underestimate direct and indirect interactions and the potential for disease transmission. For example, one female disperser which eventually settled 1.5 km from her natal territory traveled 308 km and passed through 22 different territories during dispersal. Knowledge of badgers' ranging behavior during dispersal is crucial to understanding the dynamics of TB transmission, and for designing appropriate interventions, such as vaccination.     

Applying neural networks to predict HPC-I/O bandwidth over seismic data on lustre file system for ExSeisDat

Cluster Computing - HPC or super-computing clusters are designed for executing computationally intensive operations that typically involve large scale I/O operations. This most commonly involves...     

Factors influencing eating ability of old in-patients in a rehabilitation hospital in Japan

Objectives: This study was designed to determine the factors influencing eating ability of old in‐patients in a rehabilitation hospital. Design: Cross‐sectional investigation. Setting: Forty‐six in‐patients in the rehabilitation ward of Hashimoto Hospital in Kagawa Prefecture in Japan were investigated using a multi‐disciplinary approach. Main outcome measures: Age, gender, state of dentition, muscle activity of lip, cheek and tongue, biting force, salivary flow rate per a minute (SFR), masticatory ability for gummy jelly, swallowing ability, texture of meal, independency of walking (Functional Independence Measure=FIM) and ability to communicate. Results: Bivariate analysis for the relationship between surveyed items and masticatory ability (chi‐square test) identified that better masticatory ability for gummy jelly was associated with age (<85 years), gender (male), state of dentition (dentate), SFR (high), activity of lip (good), biting force (high), swallowing ability (good) and activity of communication (high). Among these items, SFR (p=0.001), gender (p=0.004), ability to communicate (p=0.005) and age (p=0.012) were found having an influence on the masticatory ability (logistic regression analysis). On the other hand, age (<85years), gender (male), SFR (high), activity of lip (good), activity of cheek (good), biting force (high), masticatory ability (good) and swallowing ability (good) had a relationship with normal texture of meal. In regression analysis, only two items, activity of lip (p=0.003) and swallowing ability (p=0.024) emerged as factors on texture of meal. Conclusions: Masticatory ability for gummy jelly was influenced by cognitive function and was excluded from the factors on the state of meal. These results suggested the limitation of evaluation using test food, so dentists should observe eating behaviour of in‐patients. In addition, dentists should pay attention to the activity of the lip and swallowing ability as well as dentition and prostheses in the rehabilitation of eating ability. As SFR was the most significant factor on masticatory ability, this emphasizes the necessity of care for dry mouth caused by side effects of multi‐medication     

Pathogen Sources Estimation and Scenario Analysis Using the Soil and Water Assessment Tool (SWAT)

Concerns over water quality in Ireland have increased in recent years, in part due to the more frequent contamination of drinking water by pathogens such as Escherichia coli and Cryptosporidium. The objective of this study was to assess the use of SWAT for pathogen source estimation and to analyze the effects of various source scenarios on pathogen outputs in Irish catchments. Two agricultural catchments in Ireland susceptible to pathogen contamination of source water were the center of the SWAT model development with the primary focus on levels of E. coli in surface water. Model simulations used site and source specific information which was analyzed considering the total E. coli count for the simulation period (Fergus: January 2005–October 2006; Kilshanvey: January 2006–July 2007). Pathogen source estimation identified point sources as the most significant contributors to E. coli output with direct deposition the primary contributor (95%) in Kilshanvey and wastewater treatment plant outflow (89%) the main contributor in the Fergus catchment. A scenario analysis evaluated possible situations that may occur in study locations. The analysis indicated that restriction of livestock access to water sources and improved wastewater treatment would represent effective methods of improving water quality in both catchments.     

Biomechanics of single chondrocytes under direct shear

Articular chondrocytes experience a variety of mechanical stimuli during daily activity. One such stimulus, direct shear, is known to affect chondrocyte homeostasis and induce catabolic or anabolic pathways. Understanding how single chondrocytes respond biomechanically and morphologically to various levels of applied shear is an important first step toward elucidating tissue level responses and disease etiology. To this end, a novel videocapture method was developed in this study to examine the effect of direct shear on single chondrocytes, applied via the controlled lateral displacement of a shearing probe. Through this approach, precise force and deformation measurements could be obtained during the shear event, as well as clear pictures of the initial cell-to-probe contact configuration. To further study the non-uniform shear characteristics of single chondrocytes, the probe was positioned in three different placement ranges along the cell height. It was observed that the apparent shear modulus of single chondrocytes decreased as the probe transitioned from being close to the cell base (4.1 ± 1.3 kPa), to the middle of the cell (2.6 ± 1.1 kPa), and then near its top (1.7 ± 0.8 kPa). In addition, cells experienced the greatest peak forward displacement (~30% of their initial diameter) when the probe was placed low, near the base. Forward cell movement during shear, regardless of its magnitude, continued until it reached a plateau at ~35% shear strain for all probe positions, suggesting that focal adhesions become activated at this shear level to firmly adhere the cell to its substrate. Based on intracellular staining, the observed height-specific variation in cell shear stiffness and plateau in forward cell movement appeared to be due to a rearrangement of focal adhesions and actin at higher shear strains. Understanding the fundamental mechanisms at play during shear of single cells will help elucidate potential treatments for chondrocyte pathology and loading regimens related to cartilage health and disease.     

Discovery of (-)-6-[2-[4-(3-fluorophenyl)-4-hydroxy-1-piperidinyl]-1-hydroxyethyl]-3,4-dihydro-2(1H)-quinolinone--a potent NR2B-selective N-methyl D-aspartate (NMDA) antagonist for the treatment of pain

(-)-6-[2-[4-(3-Fluorophenyl)-4-hydroxy-1-piperidinyl]-1-hydroxyethyl]-3,4-dihydro-2(1H)-quinolinone was identified as an orally active NR2B-subunit selective N-methyl-d-aspartate (NMDA) receptor antagonist. It has very high selectivity for NR2B subunits containing NMDA receptors versus the HERG-channel inhibition (therapeutic index=4200 vs NR2B binding IC(50)). This compound has improved pharmacokinetic properties compared to the prototype CP-101,606.     

Influence of bite force and tongue pressure on oro-pharyngeal residue in the elderly

Objective: To investigate the influence of maximal bite force, maximal tongue pressure, number of mastications and swallowing on the oro‐pharyngeal residue in the elderly. Background: Oro‐pharyngeal residue in the elderly is an indication of dysphagia. Pharyngeal residue is especially critical as it may cause aspiration pneumonia, which is one of the major causes of death in elderly. Materials and methods: Videofluorographic recordings were performed on 14 elderly volunteers (six males, eight females, age range 65–93 years) without any history or symptoms of dysphagia. The subjects were instructed to consume 9 g of barium containing bread in two manners; free mastication and swallow (FMS: masticate and swallow freely), and limited mastication and swallow (LMS: swallow once after 30 chewing actions). The amount of oral and pharyngeal residue was evaluated using a 4‐point rating scale. Maximal occlusal force was measured by a pressure sensitive sheet, and maximal tongue pressure using a handy probe. Multiple regression analysis was performed to examine the influence of these items on the amount of oral and pharyngeal residue in FMS and LMS. Results: In FMS, age was found to be a factor which increased oral residue (p = 0.053), and the number of swallowing (p = 0.017) and the state of the prosthesis (p = 0.030) reduced the pharyngeal residue. In LMS, tongue pressure was a factor which reduced oral residue (p = 0.015) and increased pharyngeal residue (p = 0.008). Conclusion: It is suggested that in the elderly tongue pressure contributed to propulsion of the food bolus from oral cavity into the pharynx, and multiple swallowing contributed to the reduction in the amount of pharyngeal residue.