Geographic Variation in Specific Gravity Among Japanese Larch From Different Provenances

Genetic variation in wood specific gravity is reported for Japanese larch from twenty seed sources at age 17 years from planting in central New Brunswick, Canada. Information on native tamarack and European larch is also presented. Differences in mean specific gravity among provenances of Japanese larch (range 0.385 to 0.417) are highly significant. Specific gravity is not correlated with 12-year height, specific gravity of trees of the same provenances growing in Michigan, or with latitude, or elevation of the provenances. There is a weak but significant negative correlation between specific gravity and tree diameter at 1.3 m. Provenance x environment interaction in respect to specific gravity is high, making it difficult to identify provenances that will be superior over a wide area

Value of an Educational Program on Osteoporosis

Cooperative Extension helped initiate a community-based educational program on osteoporosis prevention and treatment. The program utilized a network of partners and coalitions. A team approach was taken in presenting the educational session, offered twice, and answering/discussing participant questions. Statistically significant differences were observed in the program participants\u27 reported knowledge of osteoporosis, taking of calcium supplements, eating of a calcium-rich diet, and performing weight-bearing exercises 1 month after the sessions as compared to prior. The results demonstrate that Cooperative Extension can play a leadership role in building partnerships that implement effective programs that improve the health behaviors of individuals and strengthen the community

Prevalence and Correlates of Sex Selling and Sex Purchasing among Adults Seeking Treatment for Cocaine Use Disorder

Exchange sex places individuals with cocaine use disorder (CUD) at particularly high risk for deleterious safety and health outcomes. A substance use treatment provider who is aware of a patient\u27s exchange sex behavior is better able to provide appropriate screening, care, and/or referral to risk reduction services. However, little is known about exchange sex, especially purchasing, among treatment-seeking adults with CUD. The current study examined the prevalence and correlates of sex selling and sex purchasing among treatment-seeking men and women with CUD

A perpetual switching system in pulmonary capillaries

Of the 300 billion capillaries in the human lung, a small fraction meet normal oxygen requirements at rest, with the remainder forming a large reserve. The maximum oxygen demands of the acute stress response require that the reserve capillaries are rapidly recruited. To remain primed for emergencies, the normal cardiac output must be parceled throughout the capillary bed to maintain low opening pressures. The flow-distributing system requires complex switching. Because the pulmonary microcirculation contains contractile machinery, one hypothesis posits an active switching system. The opposing hypothesis is based on passive switching that requires no regulation. Both hypotheses were tested ex vivo in canine lung lobes. The lobes were perfused first with autologous blood, and capillary switching patterns were recorded by videomicroscopy. Next, the vasculature of the lobes was saline flushed, fixed by glutaraldehyde perfusion, flushed again, and then reperfused with the original, unfixed blood. Flow patterns through the same capillaries were recorded again. The 16-min-long videos were divided into 4-s increments. Each capillary segment was recorded as being perfused if at least one red blood cell crossed the entire segment. Otherwise it was recorded as unperfused. These binary measurements were made manually for each segment during every 4 s throughout the 16-min recordings of the fresh and fixed capillaries (>60,000 measurements). Unexpectedly, the switching patterns did not change after fixation. We conclude that the pulmonary capillaries can remain primed for emergencies without requiring regulation: no detectors, no feedback loops, and no effectors-a rare system in biology. NEW & NOTEWORTHY The fluctuating flow patterns of red blood cells within the pulmonary capillary networks have been assumed to be actively controlled within the pulmonary microcirculation. Here we show that the capillary flow switching patterns in the same network are the same whether the lungs are fresh or fixed. This unexpected observation can be successfully explained by a new model of pulmonary capillary flow based on chaos theory and fractal mathematics

Desulfovibrio desulfuricans G20 Tetraheme Cytochrome Structure at 1.5 A˚ and Cytochrome Interaction with Metal Complexes

The structure of the type I tetraheme cytochrome c3 from Desulfovibrio desulfuricans G20 was determined to 1.5 A˚ by X-ray crystallography. In addition to the oxidized form, the structure of the molybdate-bound form of the protein was determined from oxidized crystals soaked in sodium molybdate. Only small structural shifts were obtained with metal binding, consistent with the remarkable structural stability of this protein. In vitro experiments with pure cytochrome showed that molybdate could oxidize the reduced cytochrome, although not as rapidly as U(VI) present as uranyl acetate. Alterations in the overall conformation and thermostability of the metal-oxidized protein were investigated by circular dichroism studies. Again, only small changes in protein structure were documented. The location of the molybdate ion near heme IV in the crystal structure suggested heme IV as the site of electron exit from the reduced cytochrome and implicated Lys14 and Lys56 in binding. Analysis of structurally conserved water molecules in type I cytochrome c3 crystal structures identified interactions predicted to be important for protein stability and possibly for intramolecular electron transfer among heme molecule