21 research outputs found
Aquatic Macroinvertebrates Collected from Thirty-two Missouri Ozark Streams
A previously reported study of the distribution and status of an endemic dragonfly in Missouri emphasized data collected by aerial netting and examination of specimens housed in the Wilbur Enns Museum of Entomology. Dip net samples were also taken, however, to find naiads of the target species at sites where adults might not have been found and to determine whether there were associated species. Forty-one collections were made in 32 Ozark streams between mid-May and early June 1999-2000. Of the 372 taxa identified, Psephenus herricki was the most frequently associated species. Six of the 32 streams either had not been sampled previously or the results have not been published. Three species (Paragordius varius, Haliplus confluentus and Haliplus deceptus) are first reports for Missouri
Biomass Dynamics of Tipula (Insecta: Diptera) in Forested Streams of the Interior Highlands, Arkansas
Abundance patterns of aquatic macroinvertebrates that utilize coarse particulate organic matter as a food source are important indicators of non--point source pollution associated with silviculture activities. This group, referred to as shredders, typically decreases in abundance as its food source—primarily leaves—is removed from the ecosystem. We tested whether larval biomass of the crane fly Tipula, a common member of the group, was an effective estimator of shredder abundance. Additionally, we used regression analysis to test whether the length to dry mass relationship of Tipula differed among geographic regions, between seasons, and between years. Results did not indicate significant differences in the relationship among these variables. Thus, we concluded that a general length to dry mass relationship was appropriate for Tipula in streams of the Interior Highlands. Our results were similar to those reported from North Carolina and Virginia. Tipula biomass was positively correlated with the total richness of the macroinvertebrate assemblage, a common measurement of stream quality, but was not correlated with the numerical abundance of the shredder functional feeding group. Thus, we concluded that Tipula biomass would not be an effective surrogate for whole assemblage metrics in biological assessments
Winter and Spring Water Quality of the Big Creek Watershed, Craighead County, Arkansas: Nutrients, Habitat, and Macroinvertebrates
The objective of this study was to assess the water quality of the Big Creek watershed during the winter and spring of 2002 by analyzing water physical, chemical variables, aquatic macro-invertebrates, and habitat. The Big Creek watershed, arising on Crowley\u27s Ridge in northeast Arkansas, is a small deltaic watershed and is an area of intense cultivation. Four stations, Big Creek Upper (BCU), Mud Creek (MC),Lost Creek (LC), and Big Creek Lower (BCL) were established for this study from Big Creek, Mud Creek and Lost Creek. Water samples were collected on a weekly basis for 10 weeks from January 2002 through March 2002. We analyzed these streams for temperature, pH, D.O., conductivity, TSS, chlorophyll- a, DOC, total N and P, total dissolved N and P, nitrate, ammonium, and soluble reactive phosphorus. During this time period, we also sampled aquatic macroinvertebrates and assessed stream habitat according to USEPA rapid bioassessment protocols. Overall, nutrients and TSS were high, pH fluctuated from 5.8 to 7.8, and D.O. was moderate to high, ranging from 6.75 to 13.24 mg/L. Generally, physical and chemical water variables were correlated with changes in stream discharge. For a 20-jab dip-net sample, macroinvertebrate species richness ranged from 9 to 23 taxa, while abundance ranged from 38 to 209 individuals per station. Physical habitat index scores ranged from 75 to 104 (maximum of 200) indicating marginal physical habitat. We report that this watershed has high concentrations of nutrients and suspended solids during the winter and spring wet season and that the macroinvertebrate communities are influenced by stream conditions, including marginal physical habitat
Tryptophan depletion in context of the inflammatory and general nutritional status of a low-income South African HIV-infected population
MV was the project leader. PB developed and validated the GC-MS method for
the analysis of tryptophan and performed the biochemical and immunological
analyses. MV and PB were responsible for the project design, analyses of the
results and writing of the manuscript. PL was involved in the sourcing of
patients and the clinical examination of all patients.The authors wish to thank the participants and staff of the Immunology
Clinic at Kalafong Hospital and the South African National Blood Service at
the Pretoria West satellite site.BACKGROUND : The essential amino acid tryptophan cannot be synthesised in the body and must be acquired
through dietary intake. Oxidation of tryptophan, due to immune induction of the enzyme indoleamine 2,3-
dioxygenase (IDO), is considered to be the main cause of tryptophan depletion in HIV infection and AIDS.
We examined plasma tryptophan levels in a low-income sub-Saharan HIV-infected population and compared it to
that of developed countries. Tryptophan levels were further examined in context of the general nutritional and
inflammatory status.
METHODS : This cross-sectional study included 105 HIV-positive patients recruited from the Kalafong Hospital in
Pretoria, South Africa, and 60 HIV-negative controls.
RESULTS : Patient tryptophan levels were in general markedly lower than those reported for developed countries. In
contrast to reports from developed countries that showed tryptophan levels on average to be 18.8 % lower than
their control values, tryptophan levels in our study were 44.1 % lower than our controls (24.4 ± 4.1 vs. 43.6 ±
11.9 μmol/l; p < 0.001). Tryptophan levels correlated with both CD4 counts (r = 0.341; p = 0.004) and with proinflammatory
activity as indicated by neopterin levels (r = −0.399; p = 0.0001). Nutritional indicators such as albumin
and haemoglobin correlated positively with tryptophan and negatively with the pro-inflammatory indicators
neopterin, interleukin 6 and C-reactive protein. The most probable causes of the lower tryptophan levels seen in
our population are food insecurity and higher levels of inflammatory activity.
CONCLUSIONS : We contend that inflammation-induced tryptophan depletion forms part of a much wider effect of
pro-inflammatory activity on the nutritional profile of HIV-infected patients.This research was supported by grant funding
received from the Medical Research Council of South Africa and the South
African Sugar Association (SASA Project 213).http://www.jhpn.net/index.php/jhpnam2016Internal MedicinePhysiologyPsychiatr