matrixes, [ 5 ] the use of thick protein fi lms, [ 9 ] and the use of semiconductor electrode materials. [ 10,11 ] The integration of PSI with carbon nano-materials, however, has been limited. The work of Carmeli and co-workers demonstrated how PSI could be covalently attached to carbon nanotubes. [ 12 ] Additionally, our research group demonstrated how PSI could be interfaced as a monolayer on a graphene electrode. [ 13 ] The use of carbon nanostructures such as graphene and carbon nanotubes to develop nano-composite materials has become an area of great research interest due to the unique properties of these materials. [ 14 ] The time-consuming and challenging preparation of graphene, however, has resulted in the increased interest in graphene oxide (GO). [ 15 ] GO, the oxidized form of graphene, is easily generated through the oxidation and subsequent exfoliation of graphite. The oxygen functional groups enable GO to be dispersed in polar solvents (i.e., water) and further functionalized. However, because the conjugation of the system is disrupted, the conductivity of GO is fi ve orders of magnitude lower than graphite. [ 16 ] To regain conductivity, GO is commonly reduced to generate reduced graphene oxide (RGO). [ 17 ] Both GO and RGO have been incorporated with various materials to develop new functional composites. [ 18,19 ] The addition of GO and RGO is particularly attractive for PSIbased devises for a number of reasons. GO and RGO are both water-soluble, making the integration of these materials with PSI straightforward. Furthermore, the low cost and facile synthesis of GO and RGO make these materials ideal candidates for making inexpensive composite materials. The functional groups present on GO make possible the interaction with both the polar groups of PSI as well as the electrochemical mediator. However, the improved conductivity of RGO can facilitate electron transfer between the PSI complexes and the underlying electrode. Here we describe how incorporating either GO or RGO with PSI can improve the photoelectrochemical properties of p-doped silicon. Experimental SectionExtraction and Isolation of Photosystem I : Photosystem I complexes were isolated from commercially available baby spinach leaves as described previously. [ 11 ] Briefl y, the baby spinach was Photosystem I is a photoactive membrane protein used in nature to photoexcite electrons with nearly unit internal quantum effi ciency, sparking interest in using this biomaterial for solar energy conversion. Films of PSI deposited on p-doped silicon have previously demonstrated signifi cant photocurrents with an electrochemical mediator; however, improvement in electron transfer is needed. Here, it is investigated how PSI can be combined with graphene oxide (GO) or reduced graphene oxide (RGO) to generate composite fi lms capable of improved photoelectrochemical performance. It is found that both composite fi lms outperformed the PSI fi lm alone, and the PSI-GO composite fi lm is found to perform the best. The enhancement is attributed to the d...

Background Bovine respiratory disease (BRD) is caused by interactions among host, environment, and pathogens. One standard method for antemortem pathogen identification in cattle with BRD is deep-guarded nasopharyngeal swabbing, which is challenging, costly, and waste generating. The objective was to compare the ability to recover Mannheimia haemolytica and compare microbial community structure using 29.5 inch (74.9 cm) deep-guarded nasopharyngeal swabs, 16 inch (40.6 cm) unguarded proctology swabs, or 6 inch (15.2 cm) unguarded nasal swabs when characterized using culture, real time-qPCR, and 16S rRNA gene sequencing. Samples for aerobic culture, qPCR, and 16S rRNA gene sequencing were collected from the upper respiratory tract of cattle 2 weeks after feedlot arrival. Results There was high concordance of culture and qPCR results for all swab types (results for 77% and 81% of sampled animals completely across all 3 swab types for culture and qPCR respectively). Microbial communities were highly similar among samples collected with different swab types, and differences identified relative to treatment for BRD were also similar. Positive qPCR results for M. haemolytica were highly concordant (81% agreed completely), but samples collected by deep-guarded swabbing had lower amounts of Mh DNA identified (Kruskal–Wallis analysis of variance on ranks, P < 0.05; Dunn-test for pairwise comparison with Benjamini–Hochberg correction, P < 0.05) and lower frequency of positive compared to nasal and proctology swabs (McNemar’s Chi-square test, P < 0.05). Conclusions Though differences existed among different types of swabs collected from individual cattle, nasal swabs and proctology swabs offer comparable results to deep-guarded nasopharyngeal swabs when identifying and characterizing M. haemolytica by culture, 16S rRNA gene sequencing, and qPCR.

1.1 Background:Bovine respiratory disease (BRD) is caused by interactions among host, environment, and pathogens. The current standard for antemortem pathogen identification in cattle with BRD is deep-guarded nasopharyngeal swabbing, which is challenging, costly, and waste generating. The objective was to compare the ability to recover Mannheimia haemolytica and compare microbial community structure using 29.5 inch (74.9 cm) deep-guarded nasopharyngeal swabs, 16 inch (40.6 cm) unguarded proctology swabs, or 6 inch (15.2 cm) unguarded nasal swabs when characterized using culture, real time-qPCR, and 16S rRNA gene sequencing. Samples for aerobic culture, qPCR, and 16S rRNA gene sequencing were collected from the upper respiratory tract of high-risk cattle 2 weeks after feedlot arrival. 1.2 ResultsThere was high concordance of culture and qPCR results for all swab types (results for 77% and 81% of samples animals completely across all 3 swab types for culture and qPCR respectively). Microbial communities were highly similar among samples collected with different swabs types, and differences identified relative to treatment for BRD were also similar. Positive qPCR results for M. haemolytica were highly concordant (81% agreed completely), but samples collected by deep-guarded swabbing had higher Ct values (Kruskal-Wallis analysis of variance on ranks, P < 0.05; Dunn-test for pairwise comparison with Benjamini-Hochberg correction, P < 0.05) and lower frequency of positive compared to nasal and proctology swabs (McNemar’s Chi-square test, P <0.05). 1.3 ConclusionsThough slight differences existed among different types of swabs collected from individual cattle, nasal swabs and proctology swabs offer comparable results to deep-guarded nasopharyngeal swabs when identifying and characterizing M. haemolytica by culture, 16S rRNA microbiome, and qPCR.

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Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in beef cattle. Common management practices in addition to BRD have been shown previously to cause inflammation. The objectives of this study were: (1) characterize the inflammatory profiles as indicated by haptoglobin concentrations, over a receiving period in high-risk cattle; (2) evaluate the impact of on-arrival metaphylactic antimicrobial therapy on inflammatory profiles in high risk cattle; and (3) examine the relationship between inflammatory profile and BRD morbidity and mortality in high risk cattle. This 70 d trial was repeated over two years. A total of 160 black/black white face crossbred heifers were acquired from local auction markets and randomly assigned at arrival to treatment groups. Heifers were purchased by an order buyer from auction barns. At arrival, heifers were randomly assigned to either receive tulathromycin (Draxxin, META, n = 40) or not (NO META, n = 40) upon arrival. Each group was housed on a 10-acre pasture planted in annual ryegrass where they were offered complete commercial supplemental feed (14% CP) and free choice (both Purina Animal Nutrition, Nashville, TN) mineral and were observed daily for clinical signs of BRD. Cattle were weighed and blood was collected every seven days from d0 to d20, and again on d70. Haptoglobin concentrations were determined using ELISA. Effects of treatment and morbidity on haptoglobin concentration were tested using the MIXED procedure of SAS. Overall morbidity was 28.5%. Initial body weight (227 kg META, 229 kg NO META, P &gt; 0.10) did not differ between the two treatment groups. However, final body weight differed between treatment groups (294 kg META, 289kg NO META). Haptoglobin concentrations remained elevated over time for all groups (P = 0.03). Metaphylaxis did not affect haptoglobin concentration (P &gt; 0.10). There was a significant increase in BRD cases from day 0 to 20 (P = 0.00). Morbidity (BRD vs no BRD) did not impact haptoglobin concentrations. Overall, metaphylaxis did not affect haptoglobin levels or BRD incidence.