Hot topic: using a stearoyl-CoA desaturase transgene to alter milk fatty acid composition

Stearoyl-CoA desaturase enzyme converts specific medium- and long-chain saturated fatty acids to their monounsaturated form. Transgenic goats expressing a bovine beta-lactoglobulin promoter-rat stearoyl-CoA desaturase cDNA construct in mammary gland epithelial cells were produced by pronuclear microinjection. The fatty acid composition of milk from 4 female transgenic founders was analyzed on d 7, 14, and 30 of their first lactation. In 2 animals, the expression of the transgene changed the overall fatty acid composition of the resulting milk fat to a less saturated and more monounsaturated fatty acid profile at d 7 of lactation; however, this effect diminished by d 30. In addition, one animal had an increased proportion of the rumen-derived monounsaturated fatty acid C18:1 trans11 converted by stearoyl-CoA desaturase to the conjugated linoleic acid isomer C18:2 cis9 trans11. Milk that has higher proportions of monounsaturated fatty acids and conjugated linoleic acid may have benefits for human cardiovascular health.     

Proximal electromagnetic shear forces

We perform a simple model calculation to estimate the electromagnetically induced shear force caused by a current dissipation when a charged tip is moved parallel to a conducting material. For parameters typical in shear force imaging, the force is many orders of magnitude below reported values. Thus, proximal electromagnetic tip–sample forces can be neglected in discussions of shear force imaging.     

Analytical modeling of bone-cement interface and failure prediction

Artificial joint replacement is becoming increasingly important in orthopedics. Several hundreds of thousands of operations, especially of the hip joint, have already been performed. The design of such joints depends largely on how accurately they can be modeled analytically such that their load transmission characteristics can be determined. One of the most critical areas of investigation is the interface existing between bone and implant in the orthopedic prostheses applications. This investigation examines the effect of varying modulus between bone and cement (PMMA) on the failure of the joint. An energy criterion is used rather than the stress criteria normally applied in the open literature.

The results of the present study show that the modulus variation within the interface can have a significant influence on the stress and energy fields in the region near a material interface. It is found that if the interface modulus has a gradual variation, the predicted stress fields resemble those with a single material interface model which has a higher (stiffer) average modulus. The interface modulus variation and average modulus are shown to have a significant effect on the predicted location and onset of failure which is of primary interest. The present modeling scheme is intended to demonstrate some of the effects which might locally be found near the bone and cement interface in a prosthetic joint.     

Dodecyl acetate,a second pheromone component of the cabbage looper moth,Trichoplusia ni

Dodecyl acetate was identified as a second component of the sex pheromone ofTrichoplusia ni (Hübner). Dodecyl acetate comprised 9.6% by weight of the total pheromone [(Z)-7-dodecenyl acetate plus dodecyl acetate] extracted from glands and 7.3% by weight of the total pheromone evaporated from the surfaces of glands. Dodecyl acetate appears to function as a short-range pheromone component. Evaporation at female release rates of a 1090 mixture of dodecyl acetate and (Z)-7-dodecenyl acetate in the field caused a significantly greater percentage of males to land on the pheromone source, increased significantly the time they spent on the source, but decreased significantly the time they spent searching for the source when within 50 cm, as compared to (Z)-7-dodecenyl acetate alone.Lepidoptera: Noctuidae.     

Hepatitis C: Part II. Prevention counseling and medical evaluation

An estimated 3.9 million Americans are infected with hepatitis C virus (HCV), and most do not know that they are infected. This group includes persons who are at risk for HCV-associated chronic liver disease and who also serve as reservoirs for transmission of HCV to others. Because there is no vaccine to prevent HCV infection and immune globulin is not effective for postexposure prophylaxis, prevention of HCV infection is paramount. Patients who are at risk of exposure to HCV should be advised on steps they might take to minimize their risk of infection. Patients who are infected with HCV should be counseled on ways to prevent transmission of HCV to others and to avoid hepatotoxins. They should also be examined for liver disease and referred for treatment, if indicated.     

Neutron powder diffraction and solid-state deuterium NMR studies of Ca2RuD6 and the stability of transition metal hexahydride salts

The crystal structure of Ca₂RuD₆ has been determined by neutron powder diffraction: space group Fm3m, K₂PtCl₆ structure, as found for other hexahydride salts of group 8 metals with alkaline earth or lanthanide counter ions. No structural phase transition was observed between 340 K and 50 K. The deuterium nuclear quadrupole coupling constant, 54.7 kHz, leads to an ionic character of the Ru–D bond of 76%. The known trends in the behaviour of A₂MH₆ salts are interpreted in terms of the ionization energies of the cation and the central metal atom.     

Emotional distress following genetic testing for hereditary breast and ovarian cancer: A meta-analytic review.

Objective: Meta-analysis was used to synthesize results of studies on emotional consequences of predictive genetic testing for BRCA1/2 mutations conferring increased risk of breast and ovarian cancer. Design: Studies assessing anxiety or cancer-specific distress before and after provision of test results (k = 20) were analyzed using a random-effects model. Moderator variables included country of data collection and personal cancer history of study participants. Main Outcome Measures: Standardized mean gain effect sizes were calculated for mutation carriers, noncarriers, and those with inconclusive results over short (0–4 weeks), moderate (5–24 weeks), or long (25–52 weeks) periods of time after testing. Results: Distress among carriers increased shortly after receiving results and returned to pretesting levels over time. Distress among noncarriers and those with inconclusive results decreased over time. Some distress patterns differed in studies conducted outside the United States and for individuals with varying cancer histories. Conclusion: Results underscore the importance of time; changes in distress observed shortly after test-result disclosure frequently differed from the pattern of distress seen subsequently. Although emotional consequences of this testing appear minimal, it remains possible that testing may affect cognitive and behavioral outcomes, which have rarely been examined through meta-analysis. Testing may also affect understudied subgroups differently. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Liquid infrared atmospheric pressure matrix-assisted laser desorption/ionization ion trap mass spectrometry of sialylated carbohydrates

A 2.94-microm Er:YAG laser for IR atmospheric pressure matrix-assisted laser desorption/ionization on an ion trap mass spectrometer is used for the analysis of sialylated oligosaccharides. This approach provided the opportunity to utilize liquid matrixes and is effective in determining structural features--sequence, branching, and linkage--of intact, fully sialylated molecular species.