Age and Growth Determination of the Black Bullhead From Soft Fin Rays

Introduction: Knowledge of the age of individuals comprising populations of fish is essential to the fishery biologist. From such information he is able to calculate the rate of growth, determine the age at which sexual maturity is attained and the longevity of the species. These calculations and determinations can be applied in the management of populations and in setting fishery regulations. There are numerous methods being used to determine the age of an individual fish. Of these, the scale method is the most important means of age determination being utilized with species of fish possessing scales (Cooper, 1951). This method assumes that the ratio of body length to scale length is constant for all sizes of fish. As the fish grows, the scale increases in size proportionally and lays down concentric ridges called circuli. If growth of the fish is uninterrupted, no change will occur in the growth pattern of the scale. However, in areas that experience seasonal changes in temperature, the rate of metabolism will decrease in this rate of growth during periods of cold weather. The decrease in the rate of growth results in a corresponding period of interrupted growth of the scale and is recognized by the spacing of the circuli. The circuli tend to be more widely spaced during the summer’s growth and more closely spaced during the winter’s growth. Another growth characteristic of the scale is that with a decrease in the growth rate the circuli will be interrupted and will end at different places along the lateral margin. Then, with the resumption of growth, the new ridges parallel the entire scale margin and hence out across the unfinished circuli previously formed. This phenomenon is called “cutting over” and is very useful in determining the yearmark or “annulus”. In the analysis of a scale for age determination of cutting over and the spacing of the circuli are utilized to locate the annulus. The age of the fish is then determined by counting the number of annuli. The first annulus is measured from the center (focus) of the scale to the outer margin of the first closely spaced circuli encountered and/or to where the cutting-over effects are observed. The other annuli present are measured form the outer margin of the previous year’s growth to the next outer margin where the annular characteristics are located. Then, by measuring the distance between annuli, the rate of growth can be calculated for each year group with this assumption that the distance between the annuli is in direct proportion to the growth in length of the fish for that period (Lagler, 1956). (See more in Text

Alien Registration- Sprague, James H. (Houlton, Aroostook County)

https://digitalmaine.com/alien_docs/34878/thumbnail.jp

Impact of sustainable feeds on omega-3 long-chain fatty acid levels in farmed Atlantic salmon, 2006–2015

As the global population and its demand for seafood increases more of our fish will come from aquaculture. Farmed Atlantic salmon are a global commodity and, as an oily fish, contain a rich source of the health promoting long-chain omega-3 fatty acids, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Replacing the traditional finite marine ingredients, fishmeal and fish oil, in farmed salmon diets with sustainable alternatives of terrestrial origin, devoid of EPA and DHA, presents a significant challenge for the aquaculture industry. By comparing the fatty acid composition of over 3,000 Scottish Atlantic salmon farmed between 2006 and 2015, we find that terrestrial fatty acids have significantly increased alongside a decrease in EPA and DHA levels. Consequently, the nutritional value of the final product is compromised requiring double portion sizes, as compared to 2006, in order to satisfy recommended EPA + DHA intake levels endorsed by health advisory organisations. Nevertheless, farmed Scottish salmon still delivers more EPA + DHA than most other fish species and all terrestrial livestock. Our findings highlight the global shortfall of EPA and DHA and the implications this has for the human consumer and examines the potential of microalgae and genetically modified crops as future sources of these important fatty acids

Blacks in Massachusetts: Comparative Demographic, Social and Economic Experiences with Whites, Latinos, and Asians

This report describes the social and economic, and education status of Blacks in Massachusetts, within a comparative framework with Whites, Asians, and Latino/as. A range of population, household, and economic variables are highlighted under the following categories: Population Characteristics; Families and Households; Education and Schooling; Housing; Health Characteristics; Labor Force, Occupations and Employment; and Income and Poverty. The information presented in this report is based on data from the 2010 Decennial Census; the American Community Survey 2009 – 2013 5 Year Estimates; the American Community Survey 2009-2013 5-Year Estimates Public Use Microdata Sample (PUMS) as well as PUMS for the single year 2013; and the Current Population Survey’s Annual Social and Economic Supplement (2015), and other CPS reports

Molecular analysis of endocrine disruption in hornyhead turbot at wastewater outfalls in southern california using a second generation multi-species microarray.

Sentinel fish hornyhead turbot (Pleuronichthysverticalis) captured near wastewater outfalls are used for monitoring exposure to industrial and agricultural chemicals of ~ 20 million people living in coastal Southern California. Although analyses of hormones in blood and organ morphology and histology are useful for assessing contaminant exposure, there is a need for quantitative and sensitive molecular measurements, since contaminants of emerging concern are known to produce subtle effects. We developed a second generation multi-species microarray with expanded content and sensitivity to investigate endocrine disruption in turbot captured near wastewater outfalls in San Diego, Orange County and Los Angeles California. Analysis of expression of genes involved in hormone [e.g., estrogen, androgen, thyroid] responses and xenobiotic metabolism in turbot livers was correlated with a series of phenotypic end points. Molecular analyses of turbot livers uncovered altered expression of vitellogenin and zona pellucida protein, indicating exposure to one or more estrogenic chemicals, as well as, alterations in cytochrome P450 (CYP) 1A, CYP3A and glutathione S-transferase-α indicating induction of the detoxification response. Molecular responses indicative of exposure to endocrine disruptors were observed in field-caught hornyhead turbot captured in Southern California demonstrating the utility of molecular methods for monitoring environmental chemicals in wastewater outfalls. Moreover, this approach can be adapted to monitor other sites for contaminants of emerging concern in other fish species for which there are few available gene sequences

On the Link between Martian Total Ozone and Potential Vorticity

AbstractWe demonstrate for the first time that total ozone in the martian atmosphere is highly correlated with the dynamical tracer, potential vorticity, under certain conditions. The degree of correlation is investigated using a Mars global circulation model including a photochemical model. Potential vorticity is the quantity of choice to explore the dynamical nature of polar vortices because it contains information on winds and temperature in a single scalar variable. The correlation is found to display a distinct seasonal variation, with a strong positive correlation in both northern and southern winter at poleward latitudes in the northern and southern hemisphere respectively.The identified strong correlation implies variations in polar total ozone during winter are predominantly controlled by dynamical processes in these spatio-temporal regions. The weak correlation in northern and southern summer is due to the dominance of photochemical reactions resulting from extended exposure to sunlight. The total ozone/potential vorticity correlation is slightly weaker in southern winter due to topographical variations and the preference for ozone to accumulate in Hellas basin. In northern winter, total ozone can be used to track the polar vortex edge.The ozone/potential vorticity ratio is calculated for both northern and southern winter on Mars for the first time. Using the strong correlation in total ozone and potential vorticity in northern winter inside the polar vortex, it is shown that potential vorticity can be used as a proxy to deduce the distribution of total ozone where satellites cannot observe for the majority of northern winter. Where total ozone observations are available on the fringes of northern winter at poleward latitudes, the strong relationship of total ozone and potential vorticity implies that total ozone anomalies in the surf zone of the northern polar vortex can potentially be used to determine the origin of potential vorticity filaments

Dissecting the polar dichotomy of the noncondensable gas enhancement on Mars using the NASA Ames Mars General Circulation Model

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95628/1/jgre2298.pd

A degenerative retinal process in HIV-associated non-infectious retinopathy

HIV retinopathy is the most common non-infectious complication in the eyes of HIV-positive individuals. Oncotic lesions in the retinal nerve fiber layer, referred to as cotton wool spots (CWS), and intraretinal (IR) hemorrhages are frequently observed but are not unique to this pathology. HIV-positive patients have impaired color vision and contrast sensitivity, which worsens with age. Evidence of inner-retinal lesions and damage have been documented ophthalmoscopically, however their long term structural effect has not been investigated. It has been hypothesized that they may be partially responsible for loss of visual function and visual field. In this study we utilized clinical data, retinal imaging and transcriptomics approaches to comprehensively interrogate non-infectious HIV retinopathy. The methods employed encompassed clinical examinations, fundus photography, indirect ophthalmoscopy, Farmsworth-Munsell 100 hue discrimination testing and Illumina BeadChip analyses. Here we show that changes in the outer retina, specifically in the retinal pigment epithelium (RPE) and photoreceptor outer segments (POS) contribute to vision changes in non-infectious HIV retinopathy. We find that in HIV-positive retinae there is an induction of rhodopsin and other transcripts (including PDE6A, PDE6B, PDE6G, CNGA1, CNGB1, CRX, NRL) involved in visual transduction, as well as structural components of the rod photoreceptors (ABCA4 and ROM1). This is consistent with an increased rate of renewal of rod outer segments induced via increased phagocytosis by HIV-infected RPE previously reported in culture. Cone-specific transcripts (OPN1SW, OPN1LW, PDE6C, PDE6H and GRK7) are uniformly downregulated in HIV positive retina, likely due to a partial loss of cone photoreceptors. Active cotton wool spots and intraretinal hemorrhages (IRH) may not affect photoreceptors directly and the interaction of photoreceptors with the aging RPE may be the key to the progressive vision changes in HIV-positive patients