Post-restoration evaluation of urban streams in central Texas

This Working paper includes an image of Waller Creek at Shipe Park post-restoration. More relevant data/information will likely surface in the completed report.Waller Creek Working Grou

Neuromorphic Learning towards Nano Second Precision

Temporal coding is one approach to representing information in spiking neural networks. An example of its application is the location of sounds by barn owls that requires especially precise temporal coding. Dependent upon the azimuthal angle, the arrival times of sound signals are shifted between both ears. In order to deter- mine these interaural time differences, the phase difference of the signals is measured. We implemented this biologically inspired network on a neuromorphic hardware system and demonstrate spike-timing dependent plasticity on an analog, highly accelerated hardware substrate. Our neuromorphic implementation enables the resolution of time differences of less than 50 ns. On-chip Hebbian learning mechanisms select inputs from a pool of neurons which code for the same sound frequency. Hence, noise caused by different synaptic delays across these inputs is reduced. Furthermore, learning compensates for variations on neuronal and synaptic parameters caused by device mismatch intrinsic to the neuromorphic substrate.Comment: 7 pages, 7 figures, presented at IJCNN 2013 in Dallas, TX, USA. IJCNN 2013. Corrected version with updated STDP curves IJCNN 201

Bone mineral density of female long distance runners in Nelson Mandela Bay

Long distance running may present positive and negative effects on the bone mineral density (BMD) of such participants. The advantage of high impact loads placed on the body of these runners may be neutralised or reversed, as too high a load may cause a decreased BMD. Furthermore, competitive female runners are generally considered to be leaner than their peers due to the nature of the sport. Therefore, it is expected that the majority of these runners would have a low body fat percentage (BF%) and body mass index (BMI) which may negatively affect the BMD, resulting in impaired bone quality. Due to the general inaccessibility of BMD assessments because of the cost involved, the incidence of risk for lowered BMD among long distance runners and particularly female runners are not readily known. The primary aim of the present study was therefore to determine the BMD rating and its association with body composition (BF% and BMI) and other selected factors among female long distance runners in Nelson Mandela Bay (NMB). The study utilized a quantitative approach and was exploratory, descriptive and non-experimental in nature. Non-probability, convenience sampling was implemented. A total of 40 female long distance runners between the age of 25 and 68 years (with a mean age of 43.6 ± 9.67 years) who have completed at least two marathon events were included in the study. The study utilized a questionnaire to collect demographic and other relevant information from the participants; a stadiometer and an electronic scale to measure height and weight and ultimately calculate BMI; and a bone densitometer with Dual-Energy X-ray Absorptiometry (DXA) (Hologic Discovery W) to determine the various BMD variables required as well as the BF%. Three densitometry scans were performed by a qualified radiographer which presented four analyses namely that of the relevant BMD variables for the hip, lumbar spine and total body, respectively, as well as of the BF% for the total body. The results of the study in respect of the overall BMD profile of the female long distance runners was considered to be normal except for the lumbar spine, found to be osteopenic when considering the mean T-score for this region of those 50 years and older. Overall the participants had an ‘average’ BF% (26.71 ± 6.33%) classification according to the ACSM classification rating system and were classified as ‘normal’ (22.80 ± 2.58 kg/m²) in respect of the BMI category rating. Significant correlations (r ≥ 0.312) were found between BMI and BMD related Z-scores for the hip, lumbar spine and total body, respectively. When considering the effect of selected variables on the various BMD variables, BF% and BMI, respectively, the following significant (p 0.2) results were found: (1) BMD (one or more rating and or Z-score) was positively influenced (had higher ratings) in runners who were overweight, consumed alcoholic beverages of five or less per week and who ran less than 51 km/week, respectively; (2) BMD (one or more rating and or Z-score) was negatively influenced (had lower ratings) in runners who had more full-term pregnancies and among those who were menopausal, respectively; (3) BF% and BMI were both found to be lower in runners who: were not menopausal, competed in six or more ultra-marathon events, completed marathons in less than or equal to three hours and 50 minutes, had an incidence of breaking a bone due to a traumatic event, and engaged in an average weekly running distance of more than 50 km/week, respectively

The effect of cereal grain type on production performance and Clostridium perfringens colonization in cattle

Three experiments were conducted to investigate the effects of various cereal grain types on the production performance of dairy cattle and the colonization of Clostridium perfringens in the intestinal tract of cattle. The first experiment investigated the effect of feeding two different cultivars of barley (cv. Harrington and Valier) and two different cultivars oat (cv. Derby and AC Assiniboia) grain on feed intake, milk yield and milk constituents. It was found that barley or oat may both be successfully incorporated into the concentrate portion of western Canadian dairy rations. NRC Dairy 2001 predictions for both oat and barley diets very closely predicted dry matter intake and milk production. AC Assiniboia oat fed cows produced the lowest percentage of fat (

Hybrid XML Retrieval: Combining Information Retrieval and a Native XML Database

This paper investigates the impact of three approaches to XML retrieval: using Zettair, a full-text information retrieval system; using eXist, a native XML database; and using a hybrid system that takes full article answers from Zettair and uses eXist to extract elements from those articles. For the content-only topics, we undertake a preliminary analysis of the INEX 2003 relevance assessments in order to identify the types of highly relevant document components. Further analysis identifies two complementary sub-cases of relevance assessments ("General" and "Specific") and two categories of topics ("Broad" and "Narrow"). We develop a novel retrieval module that for a content-only topic utilises the information from the resulting answer list of a native XML database and dynamically determines the preferable units of retrieval, which we call "Coherent Retrieval Elements". The results of our experiments show that -- when each of the three systems is evaluated against different retrieval scenarios (such as different cases of relevance assessments, different topic categories and different choices of evaluation metrics) -- the XML retrieval systems exhibit varying behaviour and the best performance can be reached for different values of the retrieval parameters. In the case of INEX 2003 relevance assessments for the content-only topics, our newly developed hybrid XML retrieval system is substantially more effective than either Zettair or eXist, and yields a robust and a very effective XML retrieval.Comment: Postprint version. The editor version can be accessed through the DO

Identification of new molecular targets and antibiotics as novel strategies against filarial infections : Characterization of lipid II biosynthesis in <em>Wolbachia</em> endobacteria

Wolbachia are obligate intracellular bacteria found in many arthropods and some filarial nematodes that are pathogenic in humans. The Wolbachia genomes are highly reduced, but encode proteins required for the synthesis of the peptidoglycan precursor lipid II. Recombinant proteins and purified Wolbachia membranes synthesize lipid I and II and these cell wall precursors are essential for Wolbachia cell division. It is unclear how lipid II is further processed and a peptidoglycan-like structure has not been detected. To provide insight into wolbachial lipid II processing, the putative penicillin-binding proteins (PBPs) PBP2 and PBP6a from Wolbachia endosymbionts of the filarial nematode Brugia malayi (wBm) were analyzed in this study. Also, the activity of AmiD and PBP3 from Wolbachia endosymbionts of Drosophila melanogaster (wMel) were characterized, two lipid II processing enzymes additionally present in genomes of Wolbachia residing in arthropods. Binding studies were performed to measure a potential interaction between the peptidoglycan-associated outer membrane lipoprotein (Pal) from wBm and lipid II as well as PBP2. To detect a putative peptidoglycan-like structure in Wolbachia, lipid II was labeled in Wolbachia from Aedes albopictus using dipeptide analogues. Moreover, an established cell-free Wolbachia culture was further studied regarding potential growth facilitating factors and impact of antibiotics. The results of the present study demonstrate PBP activity in dependence on functional serines of the active site motifs SXXK. PBPs are typically blocked by β-lactam antibiotics that bind to the serine of the highly conserved SXXK motif. Nevertheless, the PBPs were resistant to β-lactams. Contrary to their E. coli orthologs, all examined wolbachial PBPs encode additional SXXK motifs which might contribute to enzyme functionality and might explain β-lactam resistance. In silico analyses predicted that due to protein folding, β-lactams might not have access to all active site motifs. Therefore, in contrast to canonical systems like E. coli, these enzymes are not appropriate targets to deplete Wolbachia. AmiD showed zinc-dependent amidase activity and cleaved intact peptidoglycan, monomeric lipid II and additionally anhydromuropeptides, substrates that are generated by cleaved glycosidic bonds of glycan strands. The conservation of the capability of AmiD to cleave anhydromuropeptides gives a hint that at least insect Wolbachia may contain a peptidoglycan-like structure with connected glycan strands. Lipid II and PBP2 both interacted with the outer membrane protein Pal from wBm suggesting that lipid II and PBP2 are present in the Wolbachia periplasmic space. These results together with the active PBPs from wBm indicate that lipid II might be processed to a peptidoglycan-like structure also in Wolbachia residing in filarial nematodes. The dipeptide labeling provided visual evidence of a lipid II- containing structure in Wolbachia for the first time, which was absent in fosfomycin-treated cells with impaired lipid II synthesis. Moreover, fosfomycin led to an aberrant phenotype of cell-free Wolbachia resulting in enlarged cells. None of the other applied antibiotics including β- lactams showed an effect on morphology providing further evidence that Wolbachia are resistant to this class of antibiotics. In conclusion, the results of this study together with latest research findings regarding peptidoglycan in intracellular bacteria indicate that Wolbachia are not cell wall-less bacteria, but rather have a physical structure composed of lipid II that can interact with outer membrane proteins and that is necessary for coordinated cell division