Biodiversity hotspots are not congruent with conservation areas in the Gulf of California

As marine systems are threatened by increasing human impacts, mechanisms to maintain biodiversity and ecosystem functions and services are needed. Protecting areas of conservation importance may serve as a proxy for maintaining these functions, while also facilitating efficient use and management of limited resources. Biodiversity hotspots have been used as surrogates for spatial conservation importance; however, as many protected areas have been established opportunistically and under differing criteria, it is unclear how well they actually protect hotspots. We evaluated how well the current protected area network and priority areas selected through previous systematic conservation planning exercises preserve biodiversity hotspots in the Gulf of California, Mexico. We also determined spatial congruence between biodiversity hotspots based on different criteria, which may determine their ability to be used as surrogates for each other. We focus on the Gulf of California because it is a megadiverse system where limited information regarding species diversity and distribution has constrained development of strategies for conservation and management. We developed a species occurrence database and identified biodiversity hotspots using four different criteria: species richness, rarity, endemism, and threatened species. We interpolated species occurrence, while accounting for heterogeneous sampling efforts. We then assessed overlap of hotspots with existing protected areas and priority areas, and between hotspots derived by distinct criteria. We gathered 286,533 occurrence records belonging to 12,105 unique species, including 6388 species identified as rare, 642 as endemic, and 386 as threatened. We found that biodiversity hotspots showed little spatial overlap with areas currently under protection and previously identified priority areas. Our results highlight the importance of distinct spatial areas of biodiversity and suggest that different ecological mechanisms sustain different aspects of diversity and multiple criteria should be used when defining conservation areas.     

Ecological guidelines for designing networks of marine reserves in the unique biophysical environment of the Gulf of California

No-take marine reserves can be powerful management tools, but only if they are well designed and effectively managed. We review how ecological guidelines for improving marine reserve design can be adapted based on an area’s unique evolutionary, oceanic, and ecological characteristics in the Gulf of California, Mexico. We provide ecological guidelines to maximize benefits for fisheries management, biodiversity conservation and climate change adaptation. These guidelines include: representing 30% of each major habitat (and multiple examples of each) in marine reserves within each of three biogeographic subregions; protecting critical areas in the life cycle of focal species (spawning and nursery areas) and sites with unique biodiversity; and establishing reserves in areas where local threats can be managed effectively. Given that strong, asymmetric oceanic currents reverse direction twice a year, to maximize connectivity on an ecological time scale, reserves should be spaced less than 50–200 km apart depending on the planktonic larval duration of target species; and reserves should be located upstream of fishing sites, taking the reproductive timing of focal species in consideration. Reserves should be established for the long term, preferably permanently, since full recovery of all fisheries species is likely to take?>?25 years. Reserve size should be based on movement patterns of focal species, although marine reserves?>?10 km long are likely to protect?~?80% of fish species. Since climate change will affect species’ geographic range, larval duration, growth, reproduction, abundance, and distribution of key recruitment habitats, these guidelines may require further modifications to maintain ecosystem function in the future.     

A structural analysis of the natural egress of Toxoplasma gondii

Previous studies have analysed the process of Toxoplasma gondii egress with the aid of inducers, such as calcium ionophores. Although calcium transients have been successful in triggering T. gondii egress, the structural panorama of “natural” and artificial events should match. The present study approaches the natural egress of this parasite using super-resolution and electron microscopy and reveals lytic and non-lytic events of individual egress; this corroborates the use of calcium ionophore as a reliable tool to trigger parasite egress. Altogether, our data suggest that different signalling routes can converge to similar structural aspects in natural and induced egress.     

The Value of Forests to World Food Security

We assembled information on the contribution and value of forests to world food security. An assessment was made of the role of forests and non-timber products in the food system of developing countries. We estimated that upwards of 300 million people annually earn part or all of their livelihood and food from forests. A total of about $90 billion in non-timber products are harvested each year. Forests also help to protect land, water, and biological resources, and they play an important role in maintaining the productivity of agricultural and environmental systems.     

Biochemical and histochemical evidence of nonspecific binding of alpha7nAChR antibodies to mouse brain tissue.

Alpha 7 nicotinic acetylcholine receptors are involved in learning and memory, and are implicated in the pathology of Alzheimer's disease and schizophrenia. Detection of alpha7 subunits can be accomplished via immunodetection or alpha-bungarotoxin-binding techniques. Standard protocols for immunohistochemistry and Western blotting were followed using several commercially available antibodies. Various mice were evaluated, including non-transgenics, APP, PS1, APP+PS1, and alpha7 knockouts. Initial results with amyloid-depositing mice revealed alpha7 immunolabeled astrocytes, in addition to expected neuronal staining. Subsequent studies with intrahippocampal injections of lipopolysaccharide (LPS) into alpha7 knockout mice showed that both neuronal and astrocytic labeling by alpha7 antibodies was nonspecific. On Western blots of mouse brain proteins, none of the bands detected with antibodies directed against alpha7 subunits diminished in the alpha7 knockout mice. Although LPS-related changes in the expression of some bands were found, these also were unaffected by the alpha7 genotype of the mice. In general, the Western staining patterns for these antibodies revealed few overlapping bands. These immunodetection data are in contrast to genotyping results and mRNA analyses that confirmed the disruption of the alpha7 allele and lack of alpha7 message in the knockouts. These findings suggest caution in interpreting results when using several commercially available alpha7 nicotinic receptor antibodies.     

Stoichiometric tracking of soil nutrients by a desert insect herbivore

Abstract Biogeochemistry and population biology have developed independently, with few attempts at linkage, almost none of which were mechanistically based. We hypothesize that biogeochemical cycling is linked to herbivore population dynamics through the influence of soil nutrient availability on foliar nutrient content, which constrains herbivore investment in phosphorus (P)‐rich molecules necessary for growth. We show that variation in desert soil P availability is linked to abundance of an insect herbivore (Sabinia setosa) through the influence of soil P on the C:P ratio of the host plant (Prosopis velutina). Low P availability increases C:P ratio of Prosopis leaves, leading to a decline in body %P, %RNA and abundance of Sabinia. Tight association between soil, plant and herbivore P provides the first evidence of a mechanistic pathway linking P biogeochemistry to terrestrial food webs by altering the supply of dietary P to herbivores, thus limiting their capacity for growth by constraining the production of P‐rich cellular ribosomal RNA (rRNA).     

Purification and biochemical characterization of an endoxylanase from Aspergillus versicolor

An endoxylanase (β-1,4-xylan xylanohydrolase, EC 3.2.1.8) was purified from the culture filtrate of a strain of Aspergillus versicolor grown on oat wheat. The enzyme was purified to homogeneity by chromatography on DEAE-cellulose and Sephadex G-75. The purified enzyme was a monomer of molecular mass estimated to be 19 kDa by SDS-PAGE and gel filtration. The enzyme was glycoprotein with 71% carbohydrate content and exhibited a pI of 5.4. The purified xylanase was specific for xylan hydrolysis. The enzyme had a K _m of 6.5 mg ml⁻¹ and a V _max of 1440 U (mg protein)⁻¹.     

The action of cyclic-AMP on GA3 controlled responses III. Characteristics of barley endosperm acid phosphatase induction by gibberellic acid and cyclic 3', 5'-adenosine monophosphate

Studies on the induction of barley endosperm acid phosphataseby GA₃ and cyclic-AMP revealed (1) acid phosphatase inductionby GA₃ and cyclic-AMP is inhibited in a similar manner by ABA,cycloheximide and 6-methyl purine, (2) combinations of GA₃ andphosphodiesterase inhibitors such as caffeine and theophyllinepromoted the level of acid phosphatase induction obtainablewith the hormone alone, and (3) cyclic-AMP and GA₃ may be actingas triggers in the induction of this enzyme. Some of the implicationsof these results are discussed. (Received May 25, 1972; )     

Engineered biosynthesis of bacteriochlorophyll gF in Rhodobacter sphaeroides

Engineering photosynthetic bacteria to utilize a heterologous reaction center that contains a different (bacterio) chlorophyll could improve solar energy conversion efficiency by allowing cells to absorb a broader range of the solar spectrum. One promising candidate is the homodimeric type I reaction center from Heliobacterium modesticaldum. It is the simplest known reaction center and uses bacteriochlorophyll (BChl) g, which absorbs in the near-infrared region of the spectrum. Like the more common BChls a and b, BChl g is a true bacteriochlorin. It carries characteristic C3-vinyl and C8-ethylidene groups, the latter shared with BChl b. The purple phototrophic bacterium Rhodobacter (Rba.) sphaeroides was chosen as the platform into which the engineered production of BChl g_F, where F is farnesyl, was attempted. Using a strain of Rba. sphaeroides that produces BChl b_P, where P is phytyl, rather than the native BChl a_P, we deleted bchF, a gene that encodes an enzyme responsible for the hydration of the C3-vinyl group of a precursor of BChls. This led to the production of BChl g_P. Next, the crtE gene was deleted, thereby producing BChl g carrying a THF (tetrahydrofarnesol) moiety. Additionally, the bchG^Rs gene from Rba. sphaeroides was replaced with bchG^Hm from Hba. modesticaldum. To prevent reduction of the tail, bchP was deleted, which yielded BChl g_F. The construction of a strain producing BChl g_F validates the biosynthetic pathway established for its synthesis and satisfies a precondition for assembling the simplest reaction center in a heterologous organism, namely the biosynthesis of its native pigment, BChl g_F.