Evidence of a remnant self-sustaining strain of lake trout in the Lake Michigan basin

Managers have long embraced the need to maintain diversity as a requisite condition for population and community sustainability. In the case of Great Lakes lake trout, diversity has been severely compromised. The identification of new gamete sources may be beneficial to lake trout reintroduction efforts, particularly in situations where native stocks have been completely extirpated such as in Lake Michigan. Lake trout from Elk Lake, Michigan, are genetically distinct from domestic hatchery strains and historical forms of lake trout from Lake Michigan. Importantly, Elk Lake fish were genetically distinct from Marquette strain lake trout which were previously stocked into Elk Lake. Elk Lake fish were most similar to Lake Michigan basin-derived Lewis Lake (LLW) and Green Lake (GLW) hatchery strains and to historical Lake Michigan populations from the Charlevoix, Michigan area. While all individuals exhibited characteristics of lean form lake trout, the body shape of lake trout from Elk Lake, stocked lean fish from Lake Michigan and Lake Superior wild lean strains from near Isle Royale differed. Elk Lake fish were more fusiform, elongate, and streamlined with a narrower caudal peduncle compared to hatchery lean strains and wild lean forms from the Isle Royale region of Lake Superior. The lake trout population in Elk Lake is a remnant of a now extirpated native Lake Michigan population that was established either by natural colonization or stocking from historical Lake Michigan populations. Elk Lake lake trout is as genetically diverse as other strains used in Great Lakes reintroduction efforts and likely represent a viable gamete source representing genetic diversity lost from Lake Michigan.     

Iron balance in hemodialysis patients

Iron deficiency is a frequent complication in chronically hemodialyzed patients because of the significant blood losses associated with this technique. Quantitating iron stores (by marrow examination or serum iron and total iron-binding capacity) on a repetitive basis had been difficult or unreliable, often resulting in failure to recognize iron deficiency superimposed on the existing anemia of chronic renal failure, or overtreating, which can lead to iron excess. Use of the serum ferritin allows easier quantitation of iron stores and, when measured serially in dialysis patients, can predict the emergence of iron deficiency. There was no correlation between serum ferritin levels and serum iron, total iron-binding capacity, or percent transferrin saturation. Iron absorption studies show that food iron absorption is physiologic, increasing when the serum ferritin is below 30 ng/ml, decreasing when more than 300 ng/ml. Treatment of iron deficiency with oral iron compounds increases serum ferritin levels and usually can maintain iron balance.     

Melting curve and related thermodynamic properties of He3 below 1°K

Measurements of the melting curve of He³ have been made between 16.6° mK and 0.7°K. The liquid and solid molar volumes at melting have been extended from 0.33°K to below 0.03°K, and the molar volume change on melting V _m obtained. An increase in V _m from 1.20 cm³/mole at 0.33°K to 1.28 cm³/mole at 0.06°K is found, with an extrapolation to 1.27 cm³/mole atT=0. Examination of the thermodynamic consistency of the data indicates that our melting curve slopes are accurate, within experimental error, down to a temperature of 0.04°K. The demagnetization apparatus is described, with considerable attention devoted to thermometry, thermal equilibrium, and experimental techniques. Construction details of the high-sensitivity capacitive strain gauge are given.Research supported by the National Science Foundation.     

CL-20 performance exceeds that of HMX and its sensitivity is moderate

The explosive performance of ϵ-CL-20 was found to be approximately 14% greater than HMX as determined by cylinder expansion and tantalum plate acceleration experiments. This makes it the most powerful explosive ever tested at small volume expansions of the detonation products. In general CL-20 is more sensitive than HMX. However, the sensitivity of CL-20 to one-dimensional shock loading was found to be similar to HMX.