Deformities in the menta of chironomid larvae from the Experimental Lakes Area, Ontario

1995 ◽  
Vol 52 (10) ◽  
pp. 2290-2295 ◽  
Author(s):  
G. A. Bird ◽  
M. J. Rosentreter ◽  
W. J. Schwartz
Keyword(s):  
Environmental Degradation ◽  
Genetic Effect ◽  
Dry Weight ◽  
Common Occurrence ◽  
Experimental Lakes Area ◽  
Chironomid Larvae ◽  
Background Levels ◽  
Mouthpart Deformities ◽  
The Common ◽  
Reference Lakes

Chironomus spp. larvae in Experimental Lakes Area Lake 382, which received experimental additions of cadmium, were exposed to cadmium concentrations up to approximately 200 ng∙L−1 in water and to about 4 μg∙g−1 in dry sediment, resulting in body burdens of about 3.5 μg∙(g dry weight)−1. Mentum deformities in Chironomus spp. larvae in Lake 382 and five reference lakes ranged from 0 to 16%, which was within the range reported for other contaminated lakes (2 to 83%). The frequency of deformities in Lake 382 was not detectably different either in larvae collected between 1989 and 1992, or in those from reference lakes. Incidence of deformities was higher in four of the five reference lakes than in Lake 382. The constancy of the deformities (confined mainly to the median tooth, commonly with cleft or forked median teeth) is consistent with an inherited genetic effect; therefore, we consider the deformities to be natural abnormalities. We conclude that the low cadmium levels added to Lake 382 did not induce mentum deformities and that background levels of deformities are high (up to 16%) in Experimental Lakes Area lakes. The common occurrence of natural abnormalities must be considered when using chironomid mouthpart deformities as an index of environmental degradation.

Calcium and Trace Metal Composition of Crayfish (Orconectes virilis) in Relation to Experimental Lake Acidification

1987 ◽  
Vol 44 (S1) ◽  
pp. s107-s113 ◽  
Author(s):  
Robert L. France
Keyword(s):  
Trace Metal ◽  
Dry Weight ◽  
Lake Acidification ◽  
Orconectes Virilis ◽  
Tissue Concentrations ◽  
Experimental Lakes Area ◽  
Background Levels ◽  
Metal Composition ◽  
Mn Content ◽  
Subjective Estimates

Subjective estimates indicate that the carapaces of crayfish from experimentally acidified Lake 223 (pH 5.4–5.6) in the Experimental Lakes Area are becoming less rigid. Decreased carapace rigidity was inversely correlated with carapace dry weight and Ca++ content. Orconectes virilis from L223 have 25–35% less Ca++ in their exoskeletons (mean % dry wt ± SE = 13.90 ± 0.54) than do those from reference lakes (19.82 ± 0.33, 20.34 ± 0.63, and 22.18 ± 0.51). Lake 223 crayfish have accumulated higher tissue concentrations of both Mn (L223 value of 240 μg∙g−1 dry wt compared to a mean ± SE for reference populations of 48 ± 11 μg∙g−1 dry wt) and Hg(L223 value of 0.52 μg∙g−1 dry wt compared to reference mean of 0.26 ± 0.05 μg∙g−1 dry wt). Mn content of carapaces in crayfish from acidified L223 were also elevated threefold over background levels for the ELA region.

scholarly journals Subtype Characterization and Zoonotic Potential of Cryptosporidium felis in Cats in Guangdong and Shanghai, China

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 89
Author(s):  
Jiayu Li ◽  
Fuxian Yang ◽  
Ruobing Liang ◽  
Sheng Guo ◽  
Yaqiong Guo ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Phylogenetic Analysis ◽  
Genetic Characterization ◽  
Zoonotic Potential ◽  
Common Occurrence ◽  
High Genetic Diversity ◽  
Gp60 Gene ◽  
The Common ◽  
Subtyping Tool

Cryptosporidiumfelis is an important cause of feline and human cryptosporidiosis. However, the transmission of this pathogen between humans and cats remains controversial, partially due to a lack of genetic characterization of isolates from cats. The present study was conducted to examine the genetic diversity of C. felis in cats in China and to assess their potential zoonotic transmission. A newly developed subtyping tool based on a sequence analysis of the 60-kDa glycoprotein (gp60) gene was employed to identify the subtypes of 30 cat-derived C. felis isolates from Guangdong and Shanghai. Altogether, 20 C. felis isolates were successfully subtyped. The results of the sequence alignment showed a high genetic diversity, with 13 novel subtypes and 2 known subtypes of the XIXa subtype family being identified. The known subtypes were previously detected in humans, while some of the subtypes formed well-supported subclusters with human-derived subtypes from other countries in a phylogenetic analysis of the gp60 sequences. The results of this study confirmed the high genetic diversity of the XIXa subtype family of C. felis. The common occurrence of this subtype family in both humans and cats suggests that there could be cross-species transmission of C. felis.

The risk of aspiration in Dettol poisoning: a retrospective cohort study

1995 ◽  
Vol 14 (2) ◽  
pp. 190-191 ◽  
Author(s):  
Thomas Y.K. Chan ◽  
Julian A.J.H. Critchley ◽  
Joseph T.F. Lau
Keyword(s):  
Retrospective Cohort ◽  
Matched Control ◽  
Gastric Lavage ◽  
Common Occurrence ◽  
Pine Oil ◽  
Control Subjects ◽  
Increased Risk ◽  
The Common ◽  
Risk Of Aspiration ◽  
Increase In Risk

1 To determine if the risk of aspiration is increased in 'Dettol' (4.8% chloroxylenol, pine oil and isopropyl alco hol) poisoning and the factors that may be responsible, a study was made of 89 patients and 89 matched control subjects with other forms of poisoning admitted to the Prince of Wales Hospital, Hong Kong. 2 Aspiration was more common in patients with Dettol poisoning (8% vs 3%, P = 0.16). There were more control subjects with drowsiness at presentation (54% vs 24%, P < 0.0001), but the use of gastric lavage (88% vs 64%, P < 0.001) and the occurrence of vomiting (62% vs 17%, P < 0.0001) were more common in patients with Dettol poisoning. 3 Our findings suggest that Dettol poisoning may be asso ciated with an increased risk of aspiration. This increase in risk may be related to the use of gastric lavage and the common occurrence of vomiting in patients with Dettol poisoning.

DYNAMICS OF A2 FINGER PULLEY RUPTURE

2007 ◽  
Vol 07 (01) ◽  
pp. 75-87 ◽  
Author(s):  
MING A. TAN ◽  
FRANZ K. FUSS ◽  
GÜNTHER NIEGL
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Initial Rate ◽  
Constant Force ◽  
Common Occurrence ◽  
Pulley System ◽  
Convergence Test ◽  
A2 Pulley ◽  
The Common ◽  
Rupture Mechanism

A mathematical model of the A2 pulley system will enable us to have a better understanding of the mechanics of the pulley-tendon system and provide us with insights of the pulley rupture mechanism. The A2 pulley was modeled based on parallel pulley fibers attached to a phalanx with a tendon passing them. Mechanical properties of the pulleys such as stiffness, strength and friction were included in the model. A convergence test was done to ensure the accuracy of the test. The model managed to show high loads on flexed finger may lead to pulley ruptures. Further studies on the rupture mechanism showed that pulley ruptures are self-propagating when a constant force is applied and the rate of rupture increases, as fewer intact fibers are present to support the load. The initial rate of propagation is much slower and this accelerates as more fibers are ruptured. This explains the common occurrence of partial pulley ruptures.

Burns first aid

2019 ◽  
pp. 59-66
Author(s):  
Jorge Leon-Villapolas
Keyword(s):  
Operative Management ◽  
First Aid ◽  
Burn Injuries ◽  
Tissue Preservation ◽  
Common Occurrence ◽  
Conflicting Information ◽  
History Of ◽  
The Common ◽  
The Uk ◽  
The Way

In the UK alone there are approximately 175,000 acute burn injuries /year. There is a great variation in the way these injuries are managed. Advances in our understanding of the pathophysiology and natural history of burn injuries have highlighted the importance of early intervention in minimizing later functional and cosmetic morbidity. Differences in beliefs and ethnic background have a large impact on the way that burns are initially dealt with, as we know that only a minority of patients presenting with burns are optimally managed pre-hospital. Lack of education and conflicting information about burns first aid is believed to be a major factor in the common occurrence of burnt patients presenting with a variety of domestic remedies being applied to their burns as first aid. Judicious application of simple burns first aid is the first step for soft tissue preservation, improvement of outcomes and a decrease in the need for operative management.

Examples of twinning and parallel growth in zircons from some Precambrian granites and gneisses

1974 ◽  
Vol 39 (305) ◽  
pp. 587-594 ◽  
Author(s):  
J. Jocelyn ◽  
R. T. Pidgeon
Keyword(s):  
Late Stage ◽  
Common Occurrence ◽  
Chemical Corrosion ◽  
Growth History ◽  
History Of ◽  
Growth Zones ◽  
The Common ◽  
Transverse Fractures ◽  
Parallel Growth

SummaryGrowth twins, parallel growths, and necked crystals are described from zircon populations from granitic gneisses from the Precambrian of SW. Greenland. From observations of the distribution of internal growth zones it is concluded that whereas twinning takes place early in the growth history of elbow twins it can occur at any time during crystallization of the zircon. Parallel growth is attributed to a process of synneusis or attachment of zircons that have initially undergone separate growth histories. This implies that viscosity conditions of the rocks were low enough to permit the movement and collision of growing zircon crystals. The common occurrence of zircons with central constrictions, sometimes superimposed on transverse fractures, in zircon suites from the granitic gneisses is explained in terms of late-stage chemical corrosion accompanied by brittle fracturing.

Simultaneous Determinations of MSMA and Arsenic Acid in Plants

Weed Science ◽  
1973 ◽  
Vol 21 (3) ◽  
pp. 166-169 ◽  
Author(s):  
J. U. Lakso ◽  
S. A. Peoples ◽  
D. E. Bayer
Keyword(s):  
Gossypium Hirsutum ◽  
Dry Weight ◽  
Weight Basis ◽  
Sorghum Halepense ◽  
Arsenic Acid ◽  
Background Levels ◽  
Cotton Plants

Monosodium methanearsonate (MSMA) and arsenic acid (AA) were measured simultaneously in johnsongrass (Sorghum halepense(L.) Pers.) and cottonseed (Gossypium hirsutumL. ‘SJ-1’) by a bicolorimetric method. Tissues from plants sprayed with MSMA while growing and tissues with MSMA and AA added just prior to extraction were analyzed. Johnsongrass sprayed with MSMA solution at 11.2 kg/ha contained, on a dry weight basis, 423.0 ppmw of MSMA and 0.00 ppmw of AA at 7 days and 10.83 and 0.21 ppmw, respectively, after 54 days of regrowth. The cotton plants were sprayed twice to runoff with MSMA, first with 0.3 g/L and second with 1.2 g/L. Cottonseed from the sprayed cotton plants contained, on a dry weight basis, 2.45 ppmw of MSMA and 0.08 ppmw of AA after the first picking and 3.02 and 0.10 ppmw, respectively, after the second. Background levels of MSMA and AA were, respectively, on a dry weight basis, 0.63 and 0.02 ppmw in johnsongrass and 0.58 and 0.00 ppmw in cottonseed.

Population ecology of the freshwater mussel Anodonta grandis grandis in a Precambrian Shield lake

1990 ◽  
Vol 68 (9) ◽  
pp. 1931-1941 ◽  
Author(s):  
J. D. Huebner ◽  
D. F. Malley ◽  
K. Donkersloot
Keyword(s):  
Yellow Perch ◽  
Live Weight ◽  
Freshwater Mussel ◽  
Dry Weight ◽  
Fine Sand ◽  
Turnover Time ◽  
Experimental Lakes Area ◽  
Precambrian Shield ◽  
Sublittoral Zone ◽  
Anodonta Grandis

Anodonta grandis grandis is found in about half of 50 Experimental Lakes Area lakes surveyed but is abundant in only some of these lakes, including lake 377. Lake 377 is a typical small Precambrian Shield lake, 27.7 ha in area and 17.9 m in maximum depth, with [Ca2+] of [Formula: see text], conductivity of 25 μmho∙cm−1 (1 mho = 1 S), and alkalinity of [Formula: see text]. The water renewal time of approximately 187 days is shorter than that of most Precambrian Shield lakes. Bottom sediments in the sublittoral zone ranged from fine sand through granules to cobbles and boulders. Several species of possible glochidial host fish including yellow perch were collected from lake 377. The size of the mussel population, estimated by depth-stratified random sampling, was 36 800 ± 12 000 (± 95% confidence interval). Mean density was 0.133 mussels/m2 lake surface, and maximum density was 4.3 mussels/m2. Mussels were most abundant in the 1.5- to 3.1-m depth stratum. Mean lengths and weights in collections ranged from 77 to 87 mm and from 43 to 56 g, respectively. Maximum length and weight were 117.9 mm and 109.6 g, respectively. Based on external annuli, mussels live to 15+ years in lake 377. Flesh and shell averaged 25.1 and 23.2% of live weight, respectively. Calcium constituted 44.7% of the ash weight of shell. We estimated a standing dry weight biomass of mussels of 330–390 mg∙m−2 and dry weight production of 60 mg∙m−2∙year−1. This is [Formula: see text] of the estimated annual dry weight algal production. The shells of live mussels contain [Formula: see text] of the total calcium in lake 377. Despite oligotrophic conditions and low [Ca2+], lake 377 supports a substantial population of A. g. grandis growing at a moderate rate. Lake 377 may be a favourable habitat for this species because of its short water-turnover time.

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