The cost of incline locomotion in ghost crabs (<Emphasis Type="Italic">Ocypode quadrata</Emphasis>) of different sizes

It is well established that the metabolic cost of horizontal locomotion decreases as a regular function of animal body mass, regardless of body form and phylogeny. How body size affects the cost of incline exercise remains much less clear. Studies on vertebrates have led to the hypotheses that the cost of vertical work is independent of body mass and that the added cost of locomoting on inclines is lower for small animals. Studies on vertebrates and a few invertebrates provide evidence both for and against these hypotheses. To gain further insight into the cost of incline exercise, we measured oxygen consumption of small (2.33 ± 0.07 g) and large (46.66 ± 5.33 g) ghost crabs (Ocypode quadrata) locomoting horizontally and up a 20° incline. The slope of the oxygen consumption versus speed relationship (= minimum cost of transport) was not significantly different for small crabs exercising horizontally and on an incline. However, the intercept for incline exercise was significantly higher, indicating that small crabs used more energy during incline exercise than during horizontal exercise. Incline had no effect on the slope or intercept of the oxygen consumption versus speed relationship for large crabs. Our results suggest that the cost of incline locomotion may be large for small animals and that the cost is not independent of body size. Our results add to the growing body of research indicating that body mass is but one factor that determines the cost of incline locomotion and efficiency of vertical work.     

Dietary specialization and Eucalyptus species preferences in Queensland koalas (Phascolarctos cinereus)

Koalas specialize on Eucalyptus leaves, but also feed selectively. Food choice is not random, but depends on various factors that are not well understood, although most research has focused on the role of secondary plant compounds. We studied the feeding choices of four adult male koalas housed at the San Diego Zoo. All subjects had a choice of nine types of Eucalyptus leaves over the eight‐week study. The most preferred species was E. camuldulensis, but individual males exhibited different feeding preferences. We conclude that food selectivity among koalas is probably due to multiple factors, rather than only a consequence of secondary plant chemicals. A combination of intrinsic factors, such as developmental trajectory and reproductive state, as well as extrinsic factors, such as leaf chemical fingerprint and moisture, probably interact to shape koala foraging preferences. Koalas forage almost exclusively on Eucalyptus species, but have evolved an adaptive flexibility, enabling them to exploit various Eucalyptus species. Zoo Biol 30:52–58, 2011. © 2010 Wiley‐Liss, Inc.     

A chemoenzymatic synthesis of deoxy sugar esters involving stereoselective acetylation of hemiacetals catalyzed by CALB

An extension of the scope of the chemoenzymatic strategy for the synthesis of stereochemically pure pyranose deoxy sugar esters of different carboxylic acids has been achieved. The objective of the work was to extend the strategy to the synthesis of furanose deoxy sugar derivatives and additionally, to N-Boc-protected amino acid esters. With all used carboxylic acids (deoxycholic acid, α-methoxyphenylacetic acid, N-Boc-l-phenylalanine and N-Boc-l-tyrosine) the lipase-catalyzed stereoselective acetylation of furanose or pyranose hemiacetal moiety as a key step afforded one desired stereochemically pure acetylated hemiacetal deoxy sugar ester in high de.     

Metabolic remodeling in human colorectal cancer and surrounding tissues: alterations in regulation of mitochondrial respiration and metabolic fluxes

The aim of the work was to evaluate whether or not there is glycolytic reprogramming in the neighboring cells of colorectal cancer (CRC). Using postoperative material we have compared the functional capacity of oxidative phosphorylation (OXPHOS) in CRC cells, their glycolytic activity and their inclination to aerobic glycolysis, with those of the surrounding and healthy colon tissue cells. Experiments showed that human CRC cannot be considered a hypoxic tumor, since the malignancy itself and cells surrounding it exhibited even higher rates of OXPHOS than healthy large intestine. The absence of acute hypoxia in colorectal carcinomas was also confirmed by their practically equal glucose-phosphorylating capacity as compared with surrounding non-tumorous tissue and by upregulation of VEGF family and their ligands. Studies indicated that human CRC cells in vivo exert a strong distant effect on the energy metabolism of neighboring cells, so that they acquire the bioenergetic parameters specific to the tumor itself. The growth of colorectal carcinomas was associated with potent downregulation of the creatine kinase system. As compared with healthy colon tissue, the tumor surrounding cells display upregulation of OXPHOS and have high values of basal and ADP activated respiration rates. Strong differences between the normal and CRC cells in the affinity of their mitochondria for ADP were revealed; the corresponding K_m values were measured as 93.6±7.7 µM for CRC cells and 84.9±9.9 µM for nearby tissue; both these apparent K_m (ADP) values were considerably (by almost 3 times) lower in comparison with healthy colon tissue cells (256±34 µM).     

A new synthesis of 4′-resveratrol esters and evaluation of the potential for anti-depressant activity

The 4′-ester analog of the disease preventative resveratrol 1 (RV), 4′-acetyl-RV 2 along with 4′-pivaloate 13 and benzoate 14 RV were synthesized. The previously developed palladium catalyzed decarbonylative Heck coupling was used to assemble the stilbene core together with 3,5-dibenzyl protected phenol intermediates that allowed for efficient coupling and deprotection using boron trifluoride etherate. Studies with Long-Evans rats were performed to establish safety, toxicity, and behavioral parameters. In addition, the Porsalt forced-swim test was used to demonstrate anti-depressant activity.     

THE INHERITANCE AND PHYSIOLOGY OF BORON RESPONSE IN THE TOMATO

Wall , J. R., and C. F. Andrus . (U.S.D.A., U. S. Vegetable Breeding Laboratory, Charleston, S. C.) The inheritance and physiology of boron response in the tomato. Amer. Jour. Bot. 49(7): 758–762. Illus. 1962.—Brittle stem (btl), an abnormal sublethal phenotype in the tomato caused by boron deficiency, was found to be controlled by a single recessive gene. The threshold of boron concentration for brittle-stem expression is not constant but fluctuates and is intimately associated with a number of interrelated environmental factors. Light duration and intensity are especially significant, while temperature and nitrogen, phosphorus, and calcium availability probably contribute to btl expression. It is suggested that when boron supply is limiting, brittle-stem (boron deficiency) symptoms are intensified by any environmental factor or factors which enhance plant growth. Plants of btl/btl genotype contain much less boron in their leaves than do those of the control variety ‘Rutgers’; conversely, these plants contain more boron in their roots when grown in nutrient cultures of high boron content. This finding is discussed in relation to possible modes of gene action.     

Induction of human immunodeficiency virus type 1 (HIV-1)-specific T-cell responses in HIV vaccine trial participants who subsequently acquire HIV-1 infection

Candidate human immunodeficiency virus type 1 (HIV-1) vaccines designed to elicit T-cell immunity in HIV-1-uninfected persons are under investigation in phase I to III clinical trials. Little is known about how these vaccines impact the immunologic response postinfection in persons who break through despite vaccination. Here, we describe the first comprehensive characterization of HIV-specific T-cell immunity in vaccine study participants following breakthrough HIV-1 infection in comparison to 16 nonvaccinated subjects with primary HIV-1 infection. Whereas none of the 16 breakthrough infections possessed vaccine-induced HIV-1-specific T-cell responses preinfection, 85% of vaccinees and 86% of nonvaccinees with primary HIV-1 infection developed HIV-specific T-cell responses postinfection. Breakthrough subjects' T cells recognized 43 unique HIV-1 T-cell epitopes, of which 8 are newly described, and 25% were present in the vaccine. The frequencies of gamma interferon (IFN-gamma)-secreting cells recognizing epitopes within gene products that were and were not encoded by the vaccine were not different (P = 0.64), which suggests that responses were not anamnestic. Epitopes within Nef and Gag proteins were the most commonly recognized in both vaccinated and nonvaccinated infected subjects. One individual controlled viral replication without antiretroviral therapy and, notably, mounted a novel HIV-specific HLA-C14-restricted Gag LYNTVATL-specific T-cell response. Longitudinally, HIV-specific T cells in this individual were able to secrete IFN-gamma and tumor necrosis factor alpha, as well as proliferate and degranulate in response to their cognate antigenic peptides up to 5 years postinfection. In conclusion, a vaccinee's ability to mount an HIV-specific T-cell response postinfection is not compromised by previous immunization, since the CD8+ T-cell responses postinfection are similar to those seen in vaccine-na?ve individuals. Finding an individual who is controlling infection highlights the importance of comprehensive studies of breakthrough infections in vaccine trials to determine whether host genetics/immune responses and/or viral characteristics are responsible for controlling viral replication.