2,863 research outputs found
Neonatal growth of Steller sea lion (Eumetopias jubatus) pups in Alaska
The growth rate of Steller sea lion (Eumetopias jubatus) pups was studied in southeast Alaska, the Gulf of Alaska, and the Aleutian Islands during the first six weeks after birth. The Steller sea lion population is currently stable in southeast Alaska but is declining in the Aleutian Islands and parts of the Gulf of Alaska. Male pups (22.6 kg [±2.21 SD]) were significantly heavier than female pups (19.6 kg [±1.80 SD]) at 1−5 days of age, but there were no significant differences among rookeries. Male and female pups grew (in mass, standard length, and axillary girth) at the same rate. Body mass and standard length increased at a faster rate for pups in the Aleutian Islands and the western Gulf of Alaska (0.45−0.48 kg/day and 0.47−0.53 cm/day, respectively) than in southeast Alaska (0.23 kg/day and 0.20 cm/day). Additionally, axillary girth increased at a faster rate for pups in the Aleutian Islands (0.59 cm/ day) than for pups in southeast Alaska v(0.25 cm/day). Our results indicate a greater maternal investment in male pups during gestation, but not during early lactation. Although differences in pup growth rate occurred among rookeries, there was no evidence that female sea lions and their pups were nutritionally stressed in the area of population declin
Age-Related Gene Expression Differences in Monocytes from Human Neonates, Young Adults, and Older Adults.
A variety of age-related differences in the innate and adaptive immune systems have been proposed to contribute to the increased susceptibility to infection of human neonates and older adults. The emergence of RNA sequencing (RNA-seq) provides an opportunity to obtain an unbiased, comprehensive, and quantitative view of gene expression differences in defined cell types from different age groups. An examination of ex vivo human monocyte responses to lipopolysaccharide stimulation or Listeria monocytogenes infection by RNA-seq revealed extensive similarities between neonates, young adults, and older adults, with an unexpectedly small number of genes exhibiting statistically significant age-dependent differences. By examining the differentially induced genes in the context of transcription factor binding motifs and RNA-seq data sets from mutant mouse strains, a previously described deficiency in interferon response factor-3 activity could be implicated in most of the differences between newborns and young adults. Contrary to these observations, older adults exhibited elevated expression of inflammatory genes at baseline, yet the responses following stimulation correlated more closely with those observed in younger adults. Notably, major differences in the expression of constitutively expressed genes were not observed, suggesting that the age-related differences are driven by environmental influences rather than cell-autonomous differences in monocyte development
Pyla-Vigla: A Case Study Assessing the Imperial Strategies of the Hellenistic Diadochoi in Cyprus
The aim of the present study is to examine the mechanisms the Diadochoi implemented to gain and maintain control over Cyprus using Pyla-Vigla, a recently discovered fortified garrison, as a case study. Alexander the Great’s successors faced a seemingly insurmountable problem: How does one govern, control, and maintain the largest territorial empire the world had ever seen? Alexander’s imperial strategy was predicated upon maintaining native governing institutions of newly subjugated lands and appointing new leaders. This system could not work for the Diadochoi because without a clear path to succession, a twenty-nine-year period of incessant conflict ensued throughout the Eastern Mediterranean. The surviving successors adopted various strategies to exercise imperial authority over their rivals, which ultimately led to the creation of three ruling Hellenistic dynasties: Ptolemies, Seleucids, and Antigonids. Pyla-Vigla represents one of many such strategies
Tuning the Nigerian Slit Gong
An experimental and theoretical investigation of the Nigerian slit gong is reported. It is shown that in tuning the gong the artisan ensures that the frequencies of the two lowest mechanical resonances are nearly coincident with the frequencies of two of the acoustic resonances of the internal cavity. Four possible tuning parameters are identified and the effects of changing these parameters is discussed
Optimal Feeding Time and Duration of Hybrid Crappie Kept Indoors
Crappie (Pomoxis spp.) is a popular sport fish with food fish potential. Feeding behavioral patterns should be considered prior to nutrtitional studies. The objective of this study was to determine the best feeding time and duration for hybrid crappie raised in indoor recirculating aquaculture systems. Three feeding treatments with three replciates consisted of two 12 hour feeding periods initiated at 0800 (12h-amLD) and 1700 (12h-pmLD) and a 24 feeding period started at 0800 (24h-amLD). Treatments in experimental tanks were arranged in a random block design and stocked with 14 hybrid fingerlings fed for 12 weeks. Fingerling fish were spwaned in pongs using previously feed trained black crappe females (P. nigromaculatus) and white crappie males (P. annularis). Weight gain, feed conversion ratio (FCR), survival rate, consumption rate and proximate analysis of fish flesh and visceral were measured. Mean mass weight gains for 12h-amLD, 12h-pmLD, and 24-amLD were 153, 196, and 139g. There were no significant differences (p ≥ 0.05) among weight gains. Mean FCR were 1.69, 1.82, and 2.57 for 12h-amLD, 12h-pmLD, and 24-amLD, respectively. A significant diffference in FCR occured between 24h and the two 12 hour treaments. There were no significant differences in survival rate, feed consumption, or composition of fish flesh among treatments. The only significant difference in visceral was between 12h treatments for ash. This study indicated that feeding times or durations did not affect hybrid crappies body weight gain. However, there could be a FCR advantage with the 12 hour feeding schedules.https://bluetigercommons.lincolnu.edu/lucer-pubs/1008/thumbnail.jp
A glimpse into the biogeography, seasonality, and ecological functions of arctic marine Oomycota
Source at https://doi.org/10.1186/s43008-019-0006-6. © The Author(s). 2019High-latitude environments are warming, leading to changes in biological diversity patterns of taxa. Oomycota are a group of fungal-like organisms that comprise a major clade of eukaryotic life and are parasites of fish, agricultural crops, and algae. The diversity, functionality, and distribution of these organisms are essentially unknown in the Arctic marine environment. Thus, it was our aim to conduct a first screening, using a functional gene assay and high-throughput sequencing of two gene regions within the 18S rRNA locus to examine the diversity, richness, and phylogeny of marine Oomycota within Arctic sediment, seawater, and sea ice. We detected Oomycota at every site sampled and identified regionally localized taxa, as well as taxa that existed in both Alaska and Svalbard. While the recently described diatom parasite Miracula helgolandica made up about 50% of the oomycete reads found, many lineages were observed that could not be assigned to known species, including several that clustered with another recently described diatom parasite, Olpidiopsis drebesii. Across the Arctic, Oomycota comprised a maximum of 6% of the entire eukaryotic microbial community in Barrow, Alaska May sediment and 10% in sea ice near the Svalbard archipelago. We found Arctic marine Oomycota encode numerous genes involved in parasitism and carbon cycling processes. Ultimately, these data suggest that Arctic marine Oomycota are a reservoir of uncharacterized biodiversity, the majority of which are probably parasites of diatoms, while others might cryptically cycle carbon or interface other unknown ecological processes. As the Arctic continues to warm, lower-latitude Oomycota might migrate into the Arctic Ocean and parasitize non-coevolved hosts, leading to incalculable shifts in the primary producer community
Biweekly Growth Characteristics of Juvenile Bluegill Fed Different Protein Diets
This study evaluated growth rates of juvenile bluegill (Lepomis macrochius) fed different protein levels, raised indoors. Six experimental diets containing protein levels of 32, 35, 38, 41, 44, and 47% with 346 kcal/g energy were fed to four replicates of 12 fish with initial mean weight of 24.9±0.51g. Fish were fed by hand to satiation three times daily for 16 weeks. Percent weight gain, for fish fed 32, 35, 38, 41, 44, and 47% protein diets were 180.5±43.8, 203.6±32.33, 256.4±19.4, 235.8±20.63, 249.1±19.59, and 275.2±47.3, and specific growth rates 0.91±0.15, 0.98±0.10, 1.13±0.05, 1.08±0.05, 1.11±0.05, and 1.17±0.11, respectively for the study. Biweekly mean weight differences (p ≤ 0.05) occured after week eight, with fish fed 47% diet consistently havingh higher mean wight than those fed 32%. Biweekly weight gain was connsistently different after week two between fish fed 47% and 32% protein. However, fish fed 38 and 44% diets sometimes had significantly more gain than those fed 32 and 35%. Biweekly feed consumption differed after week ten with fish fed 47 and 38% consistently consumed more food than fish fed 32% protein. Feed conversion ratio differences occurred at every period with the most common differences seen between the 32 and 47% groups. This study indicated that growth characteristics could be improved with higher protein diets in juvenile bluegill.https://bluetigercommons.lincolnu.edu/lucer-pubs/1006/thumbnail.jp
Conformational Entropy as a Means to Control the Behavior of Poly(diketoenamine) Vitrimers In and Out of Equilibrium.
Control of equilibrium and non-equilibrium thermomechanical behavior of poly(diketoenamine) vitrimers is shown by incorporating linear polymer segments varying in molecular weight (MW) and conformational degrees of freedom into the dynamic covalent network. While increasing MW of linear segments yields a lower storage modulus at the rubbery plateau after softening above the glass transition (Tg ), both Tg and the characteristic time of stress relaxation are independently governed by the conformational entropy of the embodied linear segments. Activation energies for bond exchange in the solid state are lower for networks incorporating flexible chains; the network topology freezing temperature decreases with increasing MW of flexible linear segments but increases with increasing MW of stiff segments. Vitrimer reconfigurability is therefore influenced not only by the energetics of bond exchange for a given network density, but also the entropy of polymer chains within the network
Classical Swine Fever Surveillance in Feral Swine
Diseases such as classical swine fever (CSF) and foot-and-mouth disease have been eradicated in the United States, but possible reintroductions merit the development of an enhanced surveillance system. Important foreign animal or transboundary diseases like these pose a significant risk to the health of wildlife and livestock in the United States. Wildlife Services (WS) performs surveillance in targeted feral swine (Sus scrofa) populations as part of a comprehensive United States Department of Agriculture, Animal and Plant Health Inspection Service effort to demonstrate disease-free status in our nation\u27s livestock and wildlife. Surveillance is based on risk assessments which identify high risk states and the vicinity of feral swine to transitional or commercial swine production facilities. During 2007 and 2008, WS sampled and tested (n = 3661) feral swine. CSF was not detected in feral swine in the United States through this surveillance effort
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