264 research outputs found

    Gill Ventilation Rates of Mayfly Nymphs (Ephemeroptera: Heptageniidae) as a Biomonitoring Technique

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    Gill ventilation frequency (GVF) of the mayfly nymph Stenacron interpunctatum (Ephemeroptera: Heptageniidae) was studied to assess the applicability of a relatively simple, real time video methodology and to assess the potential of GVF rates for use in a chronic assay of sediment pore water. Stenacron interpunctatum nymphs were exposed to pore water samples taken along a transect from the mouth of the Fox River to Sturgeon Bay in the Green Bay area of Lake Michigan. This transect has previously been shown to exhibit several distinct gradients in sediment and water column conditions with distance from the Fox River. The highest GVF value of 6.68 ± 0.27 Hz was observed in pore water from the more polluted area near the Fox River. A lower GVF value of 5.44 ± 0.32 Hz was observed in pore water from the station near Sturgeon Bay and of 4.25 ± 0.27 Hz from the cleaner Lake Michigan station. GVF values exhibited a decreasing trend with relative distance from the mouth of the Fox River (r2 = 0.76)

    A Preservative-Free Emergent Trap for the Isotopic and Elemental Analysis of Emergent Insects From a Wetland System

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    This study reports a cost-effective, live emergent trap designed for the preservative-free use in both biogeochemical and ecological analyses of emerging insects. The trap proved to be advantageous in several ways. First, the simple design made the trap time-efficient since it was easy to set-up, change, and maintain. Second, live sampling not only provided uncontaminated organisms for elemental and stable isotopic analyses, it minimized disfigurement. This resulted in rapid and easy handling, as well as identification, of adult insects. Finally, trap avoidance by ephemeropterans and odonates, a common problem encountered in the literature, was minimal and organisms from both insect orders were successfully collected

    Aquatic Oligochaeta of Mud Lake, and its inlet and outlet stream

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    Aquatic invertebrates of Wisconsin have been studied extensively, but until recently, little work has been done with aquatic oligochaetes (segmented worms). Much of the previous work was primarily concerned with the tubificid fauna of the Great Lakes (Hiltunen 1961; Howmiller 1972; Howmiller and Beeton 1910; Spencer 1980). Also, Howmiller (1914) described the aquatic Oligochaeta found in the inland waters of Wisconsin, and Howmiller and Loden (1916) provided additional information which contains the most current list of species found in Wisconsin. A study was carried out during May and June 1980 at the University of Wisconsin - Milwaukee Field Station to determine composition and density of aquatic oligochaetes present in a bog lake (Mud Lake) and its inlet and outlet streams

    O estágio na Embrapa Clima Temperado.

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    Influence of harvest processes on pork loin and ham quality

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    The purpose of this study was to determine the specific effects of extending the interval between dwell time and the duration of scalding on pork quality attributes. Sixty-four Duroc × Yorkshire pigs were randomly assigned to a 2 × 2 factorial treatment arrangement. Treatments included extending the dwell duration from 5 to 10 min and extending the scald duration from 5 to 8 min. All carcasses entered the cooler 50 min after exsanguination. At exsanguination, blood was collected for three 1-min intervals and then for a final 2-min period. Temperature and pH of the LM and semimembranosus muscle (SM) were measured at 45 min, and at 2, 4, 6, and 24 h postmortem (PM). Hunter L*, a*, and b* values were determined on the LM, SM, and biceps femoris (BF). Purge loss was measured on the SM, BF, and the sirloin end of the loin. Drip loss was measured in duplicate from LM chops after 1 and 5 d of storage. Warner-Bratzler shear force (WBS) measurements were determined on LM chops aged 1, 3, 5, and 7 d PM. Over 99% of the collected blood was obtained during the first 3 min after sticking. Carcasses scalded for 8 min had greater (P \u3c 0.05) semi-membranosus 2 h temperature (28.8°C) than carcasses scalded 5 min (27.3°C). An 8-min scald process resulted in longissimus dorsi chops with lower hue angle and greater WBS values than the 5-min scald process. Increasing dwell time from 5 to 10 min resulted in biceps femoris chops with greater hue angle and loin chops with greater WBS values at 3 d PM. Harvest processes did not significantly affect subjective quality scores, Hunter L* values, purge or drip loss. Lengthening the duration of dwell and scalding may result in a more rapid PM pH decline. Reducing the duration of scalding may lead to increased time for manual removal of hair. Because of differences in facilities, it is recommended that individual facilities monitor dwell and scald durations to determine how to best minimize time of entry into the cooler

    BRS 185 soybean.

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    BRS 185 is a soybean cultivar developed by Embrapa Soybean for sowing in Parana State. It flowers and reaches maturity 53 and 121 days after germination and yields 3,090 kg/ha. BRS 185 is resistant to stem canker, frog-eye leaf spot, bacterial pustule and moderately resistant to powdery mildew.Autoria: DOMITTI [i.e. DOMIT], L. A

    BRS 184 soybean.

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    BRS 184 is a soybean cultivar developed by Embrapa Soybean for sowing in Parana State. It flowers and reaches maturity 53 and 121 days after germination and yields 3,210 kg/ha. BRS 184 is resistant to stem canker, frog-eye leaf spot, bacterial pustule and moderately resistant to powdery mildew
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