Marine Conservation versus International Free Trade: Reconciling Dolphins with Tuna and Sea Turtles with Shrimp

During the 1990s, the World Trade Organization (WTO) rejected as impermissible unilateral efforts by the United States to promote conservation of endangered marine species through trade sanctions against other governments. These acts of unilateral economic coercion were held to be discriminatory tactics done in unfair restraint of international trade. But in so doing, the WTO findings aroused the ire of environmentalists worldwide. These findings by the WTO became portrayed not as decisions upholding free trade, but as mandates against marine conservation and environmental protection. Even so, this denial of lawful permissibility to use unilateral economic coercion to protect endangered species internationally does not signal the demise of national efforts to conserve living marine resources. Rather, these WTO findings point up the manner in which potential trade and marine conservation disputes should be handled, i.e., through means of peaceful settlement. The key to future international marine conservation relies on a multilateral rather than a unilateral approach. Thus, environmentally conscious governments, such as the United States, should continue to encourage global adoption of marine conservation policies without impinging on international norms and standards of international commercial transactions.     

Metabolic engineering of Aspergillus oryzae NRRL 3488 for increased production of l-malic acid

Malic acid, a petroleum-derived C4-dicarboxylic acid that is used in the food and beverage industries, is also produced by a number of microorganisms that follow a variety of metabolic routes. Several members of the genus Aspergillus utilize a two-step cytosolic pathway from pyruvate to malate known as the reductive tricarboxylic acid (rTCA) pathway. This simple and efficient pathway has a maximum theoretical yield of 2 mol malate/mol glucose when the starting pyruvate originates from glycolysis. Production of malic acid by Aspergillus oryzae NRRL 3488 was first improved by overexpression of a native C4-dicarboxylate transporter, leading to a greater than twofold increase in the rate of malate production. Overexpression of the native cytosolic alleles of pyruvate carboxylase and malate dehydrogenase, comprising the rTCA pathway, in conjunction with the transporter resulted in an additional 27 % increase in malate production rate. A strain overexpressing all three genes achieved a malate titer of 154 g/L in 164 h, corresponding to a production rate of 0.94 g/L/h, with an associated yield on glucose of 1.38 mol/mol (69 % of the theoretical maximum). This rate of malate production is the highest reported for any microbial system.     

Alzheimer disease periventricular white matter lesions exhibit specific proteomic profile alterations

The white matter (WM) represents approximately half the cerebrum volume and is profoundly affected in Alzheimer’s disease (AD). However, both the WM responses to AD as well as potential influences of this compartment to dementia pathogenesis remain comparatively neglected. Neuroimaging studies have revealed WM alterations are commonly associated with AD and renewed interest in examining the pathologic basis and importance of these changes.     

An analysis of the reproductive pattern in the sea star Astropecten irregularis (Pennant) from the Bristol Channel

Summary

The reproductive cycle in Astropecten irregularis is described, making use of a range of statistical techniques detailed previously. Analysis of gonad weights proved more satisfactory than the use of gonad indices, as the latter are not independent of animal size. When examining the course of oogenesis, standardised residuals in an (R × C) contingency table are much easier to interpret than size/frequency polygons.

The species has an annual cycle with spawning in June or July, but the gonads are small even when the animals are gravid, and the annual cycle in gonad weights is more marked in males. Proliferation of oogonia may apparently occur at any time of year, and the ripe ovary contains many small, previtellogenic oocytes. There is an annual cycle of small magnitude in the size of the pyloric caecum, with a peak in December.     

Asymmetric hybridization and gene flow between Joshua trees (Agavaceae: Yucca) reflect differences in pollinator host specificity

The angiosperms are by far the largest group of terrestrial plants. Their spectacular diversity is often attributed to specialized pollination. Obligate pollination mutualisms where both a plant and its pollinator are dependent upon one another for reproduction are thought to be prone to rapid diversification through co‐evolution and pollinator isolation. However, few studies have evaluated the degree to which pollinators actually mediate reproductive isolation in these systems. Here, we examine evidence for hybridization and gene flow between two subspecies of Joshua tree (Yucca brevifolia brevifolia and Yucca brevifolia jaegeriana) pollinated by two sister species of yucca moth. Previous work indicated that the pollinators differ in host specificity, and DNA sequence data suggested asymmetric introgression between the tree subspecies. Through intensive sampling in a zone of sympatry, a large number of morphologically intermediate trees were identified. These included trees with floral characters typical of Y. b. jaegeriana, but vegetative features typical of Y. b. brevifolia. The opposite combination—Y. b. brevifolia flowers with Y. b. jaegeriana vegetative morphology—never occurred. Microsatellite genotyping revealed a high frequency of genetically admixed, hybrid trees. Coalescent‐based estimates of migration indicated significant gene flow between the subspecies and that the direction of gene flow matches differences in pollinator host fidelity. The data suggest that pollinator behaviour determines the magnitude and direction of gene flow between the two subspecies, but that specialized pollination alone is not sufficient to maintain species boundaries. Natural selection may be required to maintain phenotypic differences in the face of ongoing gene flow.     

Enhanced bioactivity of silybin B methylation products

Flavonolignans from milk thistle (Silybum marianum) have been investigated for their cellular modulatory properties, including cancer chemoprevention and hepatoprotection, as an extract (silymarin), as partially purified mixtures (silibinin and isosilibinin), and as pure compounds (a series of seven isomers). One challenge with the use of these compounds in vivo is their relatively short half-life due to conjugation, particularly glucuronidation. In an attempt to generate analogues with improved in vivo properties, particularly reduced metabolic liability, a semi-synthetic series was prepared in which the hydroxy groups of silybin B were alkylated. A total of five methylated analogues of silybin B were synthesized using standard alkylation conditions (dimethyl sulfate and potassium carbonate in acetone), purified using preparative HPLC, and elucidated via spectroscopy and spectrometry. Of the five, one was monomethylated (3), one was dimethylated (4), two were trimethylated (2 and 6), and one was tetramethylated (5). The relative potency of all compounds was determined in a 72 h growth-inhibition assay against a panel of three prostate cancer cell lines (DU-145, PC-3, and LNCaP) and a human hepatoma cell line (Huh7.5.1) and compared to natural silybin B. Compounds also were evaluated for inhibition of both cytochrome P450 2C9 (CYP2C9) activity in human liver microsomes and hepatitis C virus infection in Huh7.5.1 cells. The monomethyl and dimethyl analogues were shown to have enhanced activity in terms of cytotoxicity, CYP2C9 inhibitory potency, and antiviral activity (up to 6-fold increased potency) compared to the parent compound, silybin B. In total, these data suggested that methylation of flavonolignans can increase bioactivity.     

Donkey milk kefir induces apoptosis and suppresses proliferation of Ehrlich ascites carcinoma by decreasing iNOS in mice

Donkey milk and donkey milk kefir exhibit antiproliferative, antimutagenic and antibacterial effects. We investigated the effects of donkey milk and donkey milk kefir on oxidative stress, apoptosis and proliferation in Ehrlich ascites carcinoma (EAC) in mice. Thirty-four adult male Swiss albino mice were divided into four groups as follows: group 1, administered 0.5 ml water; group 2, administered 0.5 ml water + EAC cells; group 3, administered 0.5 ml donkey milk + EAC cells; group 4, administered 0.5 ml donkey milk kefir + EAC cells. We introduced 2.5 x 10⁶ EAC cells into each animal by subcutaneous injection. Tap water, donkey milk and donkey milk kefir were administered by gavage for 10 days. Animals were sacrificed on day 11. After measuring the short and long diameters of the tumors, tissues were processed for histology. To determine oxidative stress, cell death and proliferation iNOS and eNOS, active caspase-3 and proliferating cell nuclear antigen were assessed using immunohistochemistry. A TUNEL assay also was used to detect apoptosis. Tumor volume decreased in the donkey milk kefir group compared to the control and donkey milk groups. Tumor volume increased in the donkey milk group compared to the control group. Proliferating cell nuclear antigen levels were higher in the donkey milk kefir group compared to the control and donkey milk groups. The number of apoptotic cells was less in the donkey milk group, compared to the control, whereas it was highest in the donkey milk kefir group. Donkey milk administration increased eNOS levels and decreased iNOS levels, compared to the control group. In the donkey milk kefir group, iNOS levels were significantly lower than those of the control and donkey milk groups, while eNOS levels were similar to the control group. Donkey milk kefir induced apoptosis, suppressed proliferation and decreased co-expression of iNOS and eNOS. Donkey milk promoted development of the tumors. Therefore, donkey milk kefir appears to be more beneficial for treating breast cancer than donkey milk.     

Comparing surface and indwelling electromyographic signals of the supraspinatus and infraspinatus muscles during submaximal axial humeral rotation

This study quantified the relationship between EMG signals recorded by surface and indwelling electrodes for the infraspinatus and supraspinatus during submaximal axial humeral rotation. Muscular activity was measured on 20 participants during 82 submaximal isometric internal or external axial humeral rotations in a range of postures and intensities. Equations to predict indwelling magnitudes from surface data were generated and the effects of humeral angle and intensity on this relationship were also evaluated.Supraspinatus surface data explained 72–76% of the variance in the indwelling data. Surface data overestimated indwelling data by up to 30% of maximal voluntary contraction (MVC). Infraspinatus surface data explained 62–64% of the variance in the indwelling data, but overestimated by 72% and 400% MVC in external and internal axial humeral rotation trials, respectively. Humeral abduction angle and exertion intensity both altered the relationship between electrode types modestly (p < 0.01) for most muscles and exertions. Better variance explanation was achieved for these submaximal exertions than previously reported values for maximal exertions.These results help inform electrode type selection for the recording of supraspinatus and infraspinatus EMG. Caution is recommended when interpreting surface recordings as indicators of indwelling recordings for exertions where the muscle studied is not a primary mover.