Bioeconomic Model of Community Incentives for Wildlife Management Before and After CAMPFIRE

This paper formulates a bioeconomic model to analyze community incentives for wildlife management under benefit-sharing programs like the Communal Areas Management Programme for Indigenous Resources (CAMPFIRE) in Zimbabwe. Two agents influence the wildlife stock: a parks agency determines hunting quotas, and a local community chooses to either aid or discourage outside poachers. Wildlife generates revenues from hunting licenses and tourism; it also intrudes on local agriculture. We consider two benefit-sharing regimes: shares of wildlife tourism rents and shares of hunting licenses. Resource sharing does not necessarily improve community welfare or incentives for wildlife conservation. Results depend on the exact design of the benefit shares, the size of the benefits compared with agricultural losses, and the way in which the parks agency sets hunting licenses.bioeconomic, CAMPFIRE, community, poaching, wildlife, benefit sharing

5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetramethoxycalix[4]arene tetrahydrofuran solvate

The asymmetric unit of the title compound, C44H64O4·C4H8O, comprises two crystallographically independent calixarene mol-ecules, which display a partial cone conformation, and two tetrahydrofuran molecules. The crystal packing is stabilized by C - H⋯π contacts involving the meth-oxy groups, while the solvent mol-ecules are located in voids between the calixarene molecules. Two of the tert-butyl residues of each calixarene mol-ecule are disordered over two positions [0.74/0.26 (ring B), 0.71/0.29 (ring C), 0.77/0.23 (ring C′), 0.67/0.33 (ring D′)], resulting in bond distances that deviate from ideal values

Hurricane Intensity, Sea Surface Temperature, and Stochastic Variation

Abstract not provide

5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetra­methoxy­calix[4]arene dichloro­methane hemisolvate

In the title compound, C48H64O4·0.5CH2Cl2, both crystallographically independent calixarene mol­ecules display a partial cone conformation. Their crystal packing is stabilized by C—H⋯π contacts involving the meth­oxy groups. The solvent mol­ecule is located inter­stitially between two calixarene units with C—H⋯Cl contacts to meth­oxy and tert-butyl groups. One tert-butyl residue of each calixarene mol­ecule is disordered over two positions (occupancies 0.60/0.40 and 0.63/0.37), resulting in bond distances that deviate from ideal values. The tetra­mer calixarene mol­ecules present models with approximate non-crystallographic Cs symmetry

Extreme enrichment in atmospheric 15N15N.

Molecular nitrogen (N2) comprises three-quarters of Earth's atmosphere and significant portions of other planetary atmospheres. We report a 19 per mil (‰) excess of 15N15N in air relative to a random distribution of nitrogen isotopes, an enrichment that is 10 times larger than what isotopic equilibration in the atmosphere allows. Biological experiments show that the main sources and sinks of N2 yield much smaller proportions of 15N15N in N2. Electrical discharge experiments, however, establish 15N15N excesses of up to +23‰. We argue that 15N15N accumulates in the atmosphere because of gas-phase chemistry in the thermosphere (>100 km altitude) on time scales comparable to those of biological cycling. The atmospheric 15N15N excess therefore reflects a planetary-scale balance of biogeochemical and atmospheric nitrogen chemistry, one that may also exist on other planets

Fine tuning of crystal architecture by intermolecular interactions: synthon engineering

There has been a long time effort to influence or favourably fine tune structural properties by introduction of substituents or guest molecules of different sizes, shapes and chemical composition to consequently alter physico-chemical properties of the respective crystals. These attempts require the recognition, understanding and application of intermolecular interactions, crystallographic and, in case of occurrence, non-crystallographic symmetries. It brings us to the field of crystal engineering, which aims to produce new substances with required properties based on the knowledge of the structural properties of already characterised solids. A series of calixarene crystal structures are presented where the crystal packing is determined by spatial or by electrostatic effects. A series of laterally substituted calixarenes where both steric requirements and electrostatic forces play a role in the crystal architecture shows how the supramolecular synthon can be engineered

Anbaueignung neuer Futterpflanzenmischungen: Prüfung der Anbaueignung und des Futterwertes von Chicorée und Esparsette als Mischungspartner von Grünlandmischungen als Anpassungsstrategie an den Klimawandel

Futterchicorée und Esparsette als Mischungspartner von Grünlandmischungen zeichnen sich durch eine höhere Trockenstressverträglichkeit als bisher angebaute Futterpflanzen aus. Sie können in begrenztem Umfang zu einer Verbesserung der Futterbausituation in extremen Trockenphasen beitragen. Vor allem auf wärmeren, leichten Standorten mit großer Durchwurzelungstiefe lassen sie sich deutlich besser anbauen als auf flachgründigen, schweren Böden in kühlerer Lage. Dabei ist eine Nutzung mit geringer Schnittfrequenz bzw. Beweidung einer intensiven Bestandesführung vorzuziehen. Redaktionsschluss: 31.03.202

Taxon‐specific dark survival of diatoms and flagellates affects Arctic phytoplankton composition during the polar night and early spring

Effects of prolonged darkness on Arctic phytoplankton composition were investigated with lab experiments and a pigment time series in Kongsfjorden, Spitsbergen (78°55′N). Chlorophyll a (Chl a), pigment composition, particulate organic carbon, cell numbers, and photosynthetic characteristics were studied in Arctic diatoms (Thalassiosira antarctica, Thalassiosira nordenskioeldii) and flagellates (Rhodomonas sp., Micromonas sp.) during 8 weeks of darkness and subsequent recovery in irradiance. Loss of photosynthetic functionality after 2 weeks of darkness was reversible in all species when returned to irradiance. Diatoms were more resistant to prolonged darkness (> 2 weeks) compared to the flagellates, with lower decline rates of Chl a and maximum quantum yield of PSII. T. nordenskioeldii showed rapid growth during recovery throughout 8 weeks of dark incubation, whereas recovery of flagellates diminished within 4 weeks. Ratios of taxonomic marker pigments relative to Chl a of all species showed limited variation during 8 weeks of dark incubation. The experimentally observed enhanced dark survival of diatoms was in agreement with pigment observations during four polar nights (2013–2017) in Kongsfjorden, which showed increased relative diatom abundance during declining biomass (down to 0.02 mg Chl a m−3). Therefore, a period of prolonged darkness gives Arctic diatoms a head start during the early stages of the spring bloom. The taxon‐specific survival traits can influence the geographical distribution of diatoms and flagellates within the polar oceans and their phenology. Furthermore, the persistence of Chl a of nonviable phytoplankton during darkness might influence biomass estimates during the polar night