Microbial contamination survey of environmental fresh and saltwater resources of upolu island, Samoa
Analysis of microbe diversity in freshwater resources and nearshore seawater samples of Upolu Island was performed to investigate the distribution of harmful bacteria. For this, 124 samples were collected from 23 river systems, two volcanic lakes, and 45 locations inside and outside the barrier reef of Upolu Island, Samoa. Physicochemical parameters for general water quality, detection of coliform bacteria and 16S rRNA amplicon sequencing were performed on all samples. Fecal indicator bacteria (FIB) testing indicated a wide distribution of coliform bacteria in all sampled freshwater sites with evidence of fecal coliform in most locations. Importantly, evidence of coliform bacteria was found in most seawater samples inside and along the reef, apart from those samples taken ~20 km offshore. Illumina 16S rRNA amplicon sequencing of the V4 hypervariable region confirmed the presence of various types of harmful bacterial species, namely from the Enterobacteriaceae, Enterococcae, Streptococcaceae, and Vibrionacea families. By combining the sensitivity of FIB testing and next-generation sequencing, we were able to show the extent of potential contaminations in fresh and seawater samples and simultaneously identify the potential pathogenic bacterial genera present. The wide distribution of potential harmful bacteria from river runoff or direct sewage dumping has an impact on human health, leading to many skin and intestinal diseases, and is potentially detrimental to coral reef community health.
The oronasopharyngeal space and renewed formalization of the functional matrix hypothesis [Editorial]
The Cutting Edge: Surface Texture Analysis following Resection of Nerve Stumps Using Various Instruments
Background/UNASSIGNED:Preparation of nerve ends is an essential part of nerve repair surgery. Multiple instruments have been described for this purpose; however, no consensus exists regarding which is the least traumatic for tissue handling. We believe that various instruments used for nerve-end excision will lead to different surface roughness. Methods/UNASSIGNED:Median and ulnar nerves from fresh frozen cadavers were dissected, and 1-2â€‰cm lengths were excised using a No. 11 blade, a razor blade, or a pair of scissors. Using electron microscopy, 3-dimensional surface analysis of roughness (Sa) for each specimen was performed using ZeeScan optical hardware and GetPhase software (PhaseView, Buisson, France). An ANOVA or Kruskal-Wallis test compared roughness measures among cutting techniques. Results/UNASSIGNED:= 0.003), with the lowest by No. 11 blade (3 ÂµM, IQR: 1.87-4.38), followed by scissors (3.29 ÂµM, IQR: 1.56-4.96), and razor (5.41 ÂµM, IQR: 4.95-6.21). Conclusion/UNASSIGNED:This novel technique of 3-dimensional surface analysis found razor blade use demonstrated poor roughness, whereas a No. 11 blade or nerve-specific scissors led to equivocally smooth nerve ends.
In vitro shear bond strength of 2 resin cements to zirconia and lithium disilicate: An in vitro study
STATEMENT OF PROBLEM/BACKGROUND:) or glazed material will affect the shear bond strength (SBS) of different resin cements. PURPOSE/OBJECTIVE:Â ceramic, both glazed and nonglazed, and a lithium disilicate (LDS) ceramic. MATERIAL AND METHODS/METHODS:plates at the appropriate layer, and 2 cylinders were luted to each LDS plate. The specimens were stored in a moist environment for 24 hours at 37 Â°C. The SBS test was performed with a universal testing machine. Visual inspections of the debonded surfaces were compared under magnification. The data were analyzed with a 2-way ANOVAÂ and a subsequent Student t test (Î±=0.05). RESULTS:. CONCLUSIONS:Â cubic and tetragonal layers, the DPRC had higher bond strengths to the nonglazed surfaces.
Weaning, parturitions and illnesses are recorded in rhesus macaque (Macaca mulatta) dental cementum microstructure
Many open questions in evolutionary studies relate to species' physiological adaptations, including the evolution of their life history and reproductive strategies. There are few empirical methods capable of detecting and timing physiologically impactful events such as weaning, parturition and illnesses from hard tissue remains of either extant or extinct species. Cementum is an incremental tissue with post eruption annual periodicity, which covers the tooth root and functions as a recording structure of an animal's physiology. Here we test the hypothesis that it is possible to detect and time physiologically impactful events through the analysis of dental cementum microstructure. Our sample comprises 41 permanent and deciduous teeth from male and female rhesus macaques (Macaca mulatta) with known medical, lifestyle and life history information. We develop a semi-automated method of cementum histological analysis for the purpose of event detection and timing, aimed at significantly reducing the amount of intra- and interobserver errors typically associated with histological analyses. The results of our work show that we were able to detect known events including weaning, parturition, illness and physical trauma with high accuracy (false negative rateâ€‰=â€‰3.2%; nâ€‰=â€‰1), and to time them within an average absolute difference of 0.43 years (R2 â€‰=â€‰.98; pâ€‰<â€‰.05). Nonetheless, we could not distinguish between the several types of stressful events underlying the changes in cementum microstructure. While this study is the first to identify a variety of life history events in macaque dental cementum, laying foundations for future work in conservation and evolutionary studies of both primates and toothed mammals at large, there are some limitations. Other types of analyses (possibly chemical ones) are necessary to tease apart the causes of the stressors.
Adjuvant Therapy with 1% Alendronate Gel for Experimental Periodontitis Treatment in Rats
Purpose: The aim of this study was to evaluate the effects of locally delivered 1% alendronate (ALN) gel used as an adjunct to non-invasive periodontal therapy. Methods: Ligature-induced periodontitis was performed in 96 rats. The ligature was tied in the cervical area of the mandibular left first molar. The animals were randomly divided into 4 groups: 1) NT, no treatment; 2) SRP, scaling and root planning; 3) SRP/PLA, SRP followed by filling the periodontal pocket with placebo gel (PLA); and 4) SRP/ALN, SRP followed by filling the periodontal pockets with 1% ALN gel. Histomorphometric (percentage of bone in the furcation region [PBF]) and immunohistochemical (receptor activator of nuclear factor-ÎºB ligand, osteoprotegerin, and tartrate-resistant acid phosphatase) analyses were performed. Data were statistically analyzed, with the threshold of statistical significance set at Pâ‰¤0.05. Results: The SRP, SRP/PLA, and SRP/ALN groups presented a higher PBF than the NT group (Pâ‰¤0.01) at 7, 15, and 30 days. The SRP/ALN group presented a higher PBF than the SRP/PLA group in all experimental periods, as well as a higher PBF than the SRP group at 15 and 30 days. No differences were observed in the immunohistochemical analyses (P>0.05 for all). Conclusions: Locally delivered 1% ALN gel used as an adjunct to SRP enhanced bone regeneration in the furcation region in a rat model of experimental periodontitis.
Bone Remodeling in the Face of Young Chimpanzees and Humans [Meeting Abstract]
Adjuvant therapy with alendronate gel 1% for treatment of experimental periodontitis in rats
Biominerals fossilisation: Fish bone diagenesis in plio"“pleistocene african hominid sites of Malawi
Fish fossilisation is relatively poorly known, and skeletal element modifications resulting from predation, burial and diagenesis need to be better investigated. In this article, we aim to provide new results about surface, structural and chemical changes in modern and fossil fish bone. Fossil samples come from two distinct localities of roughly the same age in the Pliocene"“Pleistocene Chiwondo Beds adjacent to Lake Malawi. Optical and scanning electron microscope (SEM) observations, energy dispersive spectroscopy (EDS) analyses and Fourier transform infrared (FTIR) spectrometry were carried out on three categories of fish bones: (i) fresh modern samples collected in the lake, (ii) extracted from modern fish eagle regurgitation pellets, and (iii) fossils from Malema and Mwenirondo localities. A comparison of these data allowed us to detect various modifications of bone surfaces and structure as well as composition changes. Some differences are observed between fresh bones and modern pellets, and between pellets and fossils. Moreover, fossil fish bone surface modifications, crystallinity, and chemical composition from Malema and Mwenirondo differ despite their chronological and spatial proximities (2.5"“2.4 Ma, 500 m). In both sites, the post-predation modifications are strong and may hide alterations due to the predation by bird of prey such as the fish eagle. The combination of the used methods is relevant to analyses of diagenetic alterations in fish bones.
MH-ICP-MS Analysis of the Freshwater and Saltwater Environmental Resources of Upolu Island, Samoa
The elemental composition of freshwater and saltwater samples around the South Pacific island of Upolu, Samoa has been investigated together with other indicators of water quality. Up to 69 elements from Li (3) to U (92) are measured in each sample, analyzed by Mattauch-Herzog-inductively coupled plasma-mass spectrometry (MH-ICP-MS). One hundred and seventy-six samples were collected from surface freshwater sources (24 rivers, two volcanic lakes, one dam) and from seawater sources from the surface to 30 m depth (45 inner reef, reef, and outer reef locations) around Upolu Island, including river mouths and estuaries. Principal component and hierarchical clustering correlation analyses were performed on quantile normalized log transformed elemental composition data to identify groups of samples with similar characteristics and to improve the visualization of the full spectrum of elements. Human activities, such as the use of herbicides and pesticides, may relate to observed elevated concentrations of some elements contained in chemicals known to have deleterious obesogenic effects on humans that may also cause coral reef decline. Furthermore, the salinity of some saltwater samples tested were very high, possibly due to climate variability, which may additionally harm the health and biodiversity of coral reefs.