Letter from Charles H. Robinson to John Muir, 1913 Jan 11.

1East Auburn Calif.January 11 1913.Mr. John MuirMartinez Calif.Dear Sir:This to solicit your aid and great influence in furtherance of a project which has a living appeal to every lover of nature. It is the construction of a scenic bridle trail to connect Lake Tahoe and the Yosemite. This will of necessity be laid along the High Sierras, a region which you have made peculiarly your own. A bill will be introduced to the Legislature now in Session by Senator Birdsall making an appropriation for the construction of such a trail under the direction of the State engineer. The proposition antagonizes no person nor interest so far as I can see, and should, and I think will, meet with enthusiastic support.As president of the Sierra Club you can bring their influence to bear. A request from the Sierra Club would probably be all that is necessary to bring their support to the measure.Can you help?Yours Very RespectfullyCapt. Charles H. Robinson0535

"Re-educating" tumor-associated macrophages by targeting NF-kappaB

The nuclear factor kappaB (NF-kappaB) signaling pathway is important in cancer-related inflammation and malignant progression. Here, we describe a new role for NF-kappaB in cancer in maintaining the immunosuppressive phenotype of tumor-associated macrophages (TAMs). We show that macrophages are polarized via interleukin (IL)-1R and MyD88 to an immunosuppressive "alternative" phenotype that requires IkappaB kinase beta-mediated NF-kappaB activation. When NF-kappaB signaling is inhibited specifically in TAMs, they become cytotoxic to tumor cells and switch to a "classically" activated phenotype; IL-12(high), major histocompatibility complex II(high), but IL-10(low) and arginase-1(low). Targeting NF-kappaB signaling in TAMs also promotes regression of advanced tumors in vivo by induction of macrophage tumoricidal activity and activation of antitumor activity through IL-12-dependent NK cell recruitment. We provide a rationale for manipulating the phenotype of the abundant macrophage population already located within the tumor microenvironment; the potential to "re-educate" the tumor-promoting macrophage population may prove an effective and novel therapeutic approach for cancer that complements existing therapies

Downward shortwave surface irradiance from 17 sites for the FIRE/SRB Wisconsin experiment

A field experiment was conducted in Wisconsin during Oct. to Nov. 1986 for purposes of both intensive cirrus cloud measurments and SRB algorithm validation activities. The cirrus cloud measurements were part of the FIRE. Tables are presented which show data from 17 sites in the First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment/Surface Radiation Budget (FIRE/SRB) Wisconsin experiment region. A discussion of intercomparison results and calibration inconsistencies is also included

Allocating group-level payments for ecosystem services: experiences from a REDD+ pilot in Tanzania

Payments for ecosystem services (PES) typically reward landowners for managing their land to provide ecosystem services that would not otherwise be provided. REDD+—Reduced Emissions from Deforestation and Forest Degradation—is a form of PES aimed at decreasing carbon emissions from forest conversion and extraction in lower-income countries. A key challenge for REDD+ occurs when it is implemented at a group, rather than an individual landowner, level. Whilst achieving a group-level reduction relies on individuals changing their interaction with the forest, incentives are not aligned explicitly at the individual level. Rather, payments are made to a defined group as a single entity in exchange for verified reduced forest loss, as per a PES scheme. In this paper, we explore how REDD+ has been implemented in one multiple-village pilot in Tanzania with the village defining the group. Our findings suggest that considerable attention has been paid towards monitoring, reporting, verification (MRV), and equity. No explicit mechanism ensures individual compliance with the village-level PES, and few villages allocate funds for explicit enforcement efforts to protect the forest from illegal activities undertaken by individual group members or by outsiders. However, the development of village-level institutions, “social fencing,” and a shared future through equal REDD+ payments, factor into decisions that influence the level of compliance at the village level that the program will eventually achieve

Cyclic photophosphorylation reactions catalyzed by ferredoxin, methyl viologen and anthraquinone sulfonate. Use of photochemical reactions to optimize redox poising

The flavin analogue 5-deazariboflavin is a convenient catalyst for the photoreduction of low-potential redox compounds. In an anaerobic medium with Tricine buffer as the electron donor, 5-deazariboflavin is capable of photoreducing both ferredoxin and methyl viologen. We have used this method to conduct a comparative study of the Photosystem I photophosphorylation activities supported by the reduced forms of ferredoxin, methyl viologen and anthraquinone sulfonate. All of these catalysts are capable of generating high rates (200-500 [mu]mol ATP/h per mg chlorophyll) of cyclic photophosphorylation, but only the activity dependent on ferredoxin exhibits sensitivity to antimycin A. This finding suggests that the size of the catalyst and its ability to approach the thylakoid membrane, rather than low-redox potential, governs antimycin A sensitivity. Ferredoxin-catalyzed activity is, however, less sensitive to inhibition by dibromothymoquinone than are the activities supported by methyl viologen and anthraquinone sulfonate. This discrepancy is due to binding of the inhibitor by ferredoxin.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23293/1/0000230.pd

On the origin of light-induced changes in the proton magnetic relaxation rate of chloroplast thylakoid membrane suspensions

The spin-lattice relaxation rate of solvent protons in suspensions of chloroplast thylakoid membranes undergoes a large transient depression following illumination in white light. This change appears to require the presence of chelatable paramagnetic ions; it is absent in chloroplasts exposed to 1 m EDTA during the homogenization step of the isolation procedure, but reappears when 50 [mu] MnCl2 is added to these suspensions. Conditions that inhibit light-induced R1 changes are (i) anaerobiosis, (ii) inhibition of plastocyanin function byHg+2/CN, and (iii) the presence of superoxide dismutase. These observations suggest that chemical oxidation of nonfunctional Mn (II) by superoxide ion, which is generated under aerobic conditions by autooxidizable acceptors of Photosystem I, is responsible for the phenomenon. This interpretation was confirmed by experiments involving superoxide generation in the dark, using the NADPH-driven diaphorase activity of ferredoxin-NADP-reductase with benzylviologen as an autooxidizable acceptor.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24430/1/0000701.pd

Topology of NH2OH-induced Mn(II) release from chloroplast thylakoid membranes

Permeant and impermeant metal ion chelators have been used in conjunction with NMR relaxation time measurements (T1) of solvent protons to probe the membrane topology of the Mn(II) released from the water-oxidizing center of chloroplast thylakoid membranes by NH2OH. Chelex, a tightly binding divalent metal ion exchanger, quantitatively removes Mn2+ (added as MnCl2) from the external thylakoid membrane without significantly affecting oxygen evolution activity or photophosphorylation efficiency. Because of its obvious impermeance (the resin is supplied as 0.2 mm beads), chelex selectively removes only manganese that is in equilibrium with the external aqueous phase. Both internal and external manganese pools are removed by chelex in the presence of A23187, a divalent cation-specific ionophore. Topological experiments using these reagents have shown that NH2OH releases Mn(II) predominantly to the loculus in freshly prepared, dark-adapted thylakoid membranes at 0-3[deg]C. This topology changes radically as a result of three pretreatments: (1) incubation of thylakoid membranes in the dark at 25[deg]C, which redirects Mn(II) release toward the external medium with a half-time of 10-15 min; (2) illumination with saturating white light, which decreases the half-time of reorientation to about 1 min; (3) freeze-thawing in 0.4 M sucrose, which results in the appearance of 40-60% of the NH2OH-liberated Mn(II) in the external medium. None of these treatments substantially degrades O2 evolution activity or osmotic integrity as judged from measurements of photophosphorylation efficiency. It is concluded that the topology of the manganese site associated with photosystem II is not static but changes dramatically in response to external stimuli, possibly reflecting a regulatory mechanism of photophosphorylation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24312/1/0000578.pd

Effect of manganese on the nuclear magnetic relaxivity of water protons in chloroplast suspensions

Field dispersion profiles of the proton spin-lattice relaxation rate, T1-1, in chloroplast suspensions show a local maximum near 20 MHz, probably due to bound Mn(II); EDTA extraction eliminates, and MnCl2 addition restores, the paramagnetic relaxivity. Since neither treatment affects water oxidation, the Mn(II) site monitored appears to lie outside the water-splitting enzyme. Intense illumination almost totally suppresses the paramagnetic relaxivity through an electron-transport-dependent mechanism. Previous reports that chloroplast nuclear magnetic relaxivity varies cyclically in flash experiments require reevaluation in terms of the probable role of Mn(II) that is nonfunctional in water oxidation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23264/1/0000198.pd

NMR relaxivity changes in chloroplast suspensions. Effects of NH2OH and of treatments altering the redox state of the photosynthetic electron transport chain

Treatments (illumination, chemical oxidation or reduction) which are potentially capable of producing paramagnetic centers in chloroplast thylakoid membranes do not produce enhancements of the proton magnetic relaxivities of these preparations. However, exposure of thylakoid membranes to varying concentrations of hydroxylamine induces a time-dependent increase in relaxivity for which the steady-state magnitude is dependent on hydroxylamine concentration. The appearance of relaxivity is correlated kinetically with inactivation of oxygen-evolving centers; in addition both processes show a threshold effect with respect to hydroxylamine concentration. Kinetic analyses of these hydroxylamine-induced effects suggest that at low ([les]100 [mu]M) and at intermediate (200-500 [mu]M) concentrations, hydroxylamine extraction is partially counteracted by a reverse process that reactivates oxygen-evolving centers in the dark.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23091/1/0000008.pd