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Aim: The International Tree‐Ring Data Bank (ITRDB) is the most comprehensive database of tree growth. To evaluate its usefulness and improve its accessibility to the broad scientific community, we aimed to: (a) quantify its biases, (b) assess how well it represents global forests, (c) develop tools to identify priority areas to improve its representativity, and d) make available the corrected database. Location: Worldwide. Time period: Contributed datasets between 1974 and 2017. Major taxa studied: Trees. Methods: We identified and corrected formatting issues in all individual datasets of the ITRDB. We then calculated the representativity of the ITRDB with respect to species, spatial coverage, climatic regions, elevations, need for data update, climatic limitations on growth, vascular plant diversity, and associated animal diversity. We combined these metrics into a global Priority Sampling Index (PSI) to highlight ways to improve ITRDB representativity. Results: Our refined dataset provides access to a network of >52 million growth data points worldwide. We found, however, that the database is dominated by trees from forests with low diversity, in semi‐arid climates, coniferous species, and in western North America. Conifers represented 81% of the ITRDB and even in well‐sampled areas, broadleaves were poorly represented. Our PSI stressed the need to increase the database diversity in terms of broadleaf species and identified poorly represented regions that require scientific attention. Great gains will be made by increasing research and data sharing in African, Asian, and South American forests. Main conclusions: The extensive data and coverage of the ITRDB show great promise to address macroecological questions. To achieve this, however, we have to overcome the significant gaps in the representativity of the ITRDB. A strategic and organized group effort is required, and we hope the tools and data provided here can guide the efforts to improve this invaluable database.

A major component of California’s yearly precipitation comes from wintertime atmospheric river (AR) events which bring large amounts of moisture from the tropics up to the midlatitudes. Understanding these systems, specifically the effects of aerosol particles on precipitation associated with these storms, was a major focus of the 2015 Atmospheric Radiation Measurement (ARM) Cloud Aerosol Precipitation Experiment (ACAPEX), which was part of the wintertime CalWater 2015 campaign. The measurement campaign provided sampling platforms on four aircraft, including the ARM Aerial Facility G-1, as well as the NOAA Ronald H.Brown research vessel and at a ground station in Bodega Bay, CA. Measurements of ice nucleating particles (INPs) were made with the Colorado State University (CSU) Continuous Flow Diffusion Chamber (CFDC) aboard the G-1, and Aerosol filters were collected on the G-1, at the Bodega Bay site and on the Ronald H.Brown for post-processing via immersion freezing in the CSU Ice Spectrometer. Aerosol composition was measured aboard the G-1with the Aerosol Time-of-Flight Mass Spectrometer (ATOFMS). Here we present INP concentrati ons and aerosol chemical compositions during the course of the aircraft campaign. During the AR event, we found that marine aerosol was the main aerosol type and that marine INPs were dominant at cloud activation temperatures, which is in stark contrast to the dominance of dust INPs during the AR events in the CalWater 2011 campaign.

Hair plucking has been observed in many captive primate species, including the great apes; however, the etiology of this behavioral pattern is poorly understood. While this behavior has not been reported in wild apes, an ethologically identical behavior in humans, known as trichotillomania, is linked to chronic psychosocial stress and is a predominantly female disorder. This study examines hair plucking (defined here as a rapid jerking away of the hair shaft and follicle by the hand or mouth, often accompanied by inspection and consumption of the hair shaft and follicle) in a captive group of bonobos (N = 13) at the Columbus Zoo and Aquarium in Columbus, Ohio. Plucking data were collected using behavior and all-occurrence sampling; 1,450 social and self-directed grooming bouts were recorded during 128 hr of observation. Twenty-one percent of all grooming bouts involved at least one instance of plucking. Urine samples (N = 55) were collected and analyzed for the stress hormone cortisol. Analyses of urinary cortisol levels showed a significant positive correlation between mean cortisol and self-directed plucking for females (r = 0.88, P

All the great ape species are known tool users in both the wild and captivity, although there is great variation in ability and behavioral repertoire. Differences in tool use acquisition between chimpanzees and gorillas have been attributed to differing levels of social tolerance as a result of differences in social structure. Chimpanzees also show sex differences in acquisition and both chimpanzees and bonobos demonstrate a female bias in tool use behaviors. Studies of acquisition are limited in the wild and between species comparisons are complicated in captivity by contexts that often do not reflect natural conditions. Here we investigated tool use acquisition in a captive group of naive bonobos by simulating naturalistic conditions. We constructed an artificial termite mound fashioned after those that occur in the wild and tested individuals within a social group context. We found sex differences in latencies to attempt and to succeed where females attempted to fish, were successful more quickly, and fished more frequently than males. We compared our results to those reported for chimpanzees and gorillas. Males across all three species did not differ in latency to attempt or to succeed. In contrast, bonobo and chimpanzee females succeeded more quickly than did female gorillas. Female bonobos and female chimpanzees did not differ in either latency to attempt or to succeed. We tested the social tolerance hypothesis by investigating the relationship between tool behaviors and number of neighbors present. We also compared these results to those reported for chimpanzees and gorillas and found that bonobos had the fewest numbers of neighbors present. The results of this study do not support the association between number of neighbors and tool behavior reported for chimpanzees. However, bonobos demonstrated a similar sex difference in tool use acquisition, supporting the hypothesis of a female bias in tool use in Pan.

Accurate maps of the locations of trees are useful for many ecological studies but are often difficult to obtain with traditional surveying methods because the trees hinder line of sight measurements. An alternative method, inspired by earlier work of E Rohlf and J. Archie, is presented. This "Interpoint method" is based solely on tree diameter and tree-to-tree distance measurements. A computer performs the necessary triangulation and detects gross errors. The Interpoint method was used to map trees in seven long-term study plots at the Harvard Forest, ranging from 0.25 ha (200 trees) to 0.80 ha (889 trees). The question of accumulation of error was addressed though a computer simulation designed to model field conditions as closely as possible. The simulation showed that the technique is highly accurate and that errors accumulate quite slowly if measurements are made with reasonable care (e.g., average predicted location errors after 1000 trees and after 10000 trees were 9 cm and 15 cm, respectively, for measurement errors comparable to field conditions; similar values were obtained in an independent survey of one of the field plots). The technique requires only measuring tapes, a computer, and two or three field personnel. Previous field experience is not required. The Interpoint method is a good choice for mapping trees where a high level of accuracy is desired, especially where expensive sur- veying equipment and trained personnel are not available.

Puerto Rico is subject to frequent and severe impacts from hurricanes, whose long-term ecological role must be assessed on a scale of centuries. In this study we applied a method for reconstructing hurricane disturbance regimes developed in an earlier study of hurricanes in New England. Patterns of actual wind damage from historical records were analyzed for 85 hurricanes since European settlement in 1508. A simple meteorological model (HURRECON) was used to reconstruct the impacts of 43 hurricanes since 1851. Long-term effects of topography on a landscape scale in the Luquillo Experimental Forest (LEF) were simulated with a simple topographic exposure model (EXPOS). Average return intervals across Puerto Rico for F0 damage (loss of leaves and branches) and F1 damage (scattered blowdowns, small gaps) on the Fujita scale were 4 and 6 years, respectively. At higher damage levels, a gradient was created by the direction of the storm tracks and the weakening of hurricanes over the interior mountains. Average ...

Reintroduction of populations of endangered species is a challenging task, involving a number of environmental, demographic and genetic factors. Genetic parameters of interest include historical patterns of genetic structure and gene flow. Care must be taken during reintroduction to balance the contrasting risks of inbreeding and outbreeding depression. The Mauna Loa silversword, Argyroxiphium kauense, has experienced a severe decline in population size and distribution in the recent past. Currently, three populations with a total of fewer than 1000 individuals remain. We measured genetic variation within and among the remnant populations using seven microsatellite loci. We found significant genetic variation remaining within all populations, probably related to the recent nature of the population impact, the longevity of the plants, and their apparent self-incompatibility. We also found significant genetic differentiation among the populations, reinforcing previous observations of ecological and morphological differentiation. With respect to reintroduction, the results suggest that, in the absence of additional data to the contrary, inbreeding depression may not be a substantial risk as long as propagules for the founding of new populations are adequately sampled from within each source population before additional inbreeding takes place. The results further suggest that if mixing of propagules from different source populations is not required to increase within-population genetic variation in the reintroduced populations, it may best be avoided.

Hurricanes are a major factor controlling ecosystem structure, function, and dynamics in many coastal forests, but their ecological role can be understood only by assessing impacts in space and time over a period of centuries. We present a new method for reconstructing hurricane disturbance regimes using a combination of historical research and computer modeling. Historical evidence of wind damage for each hurricane in the selected region is quantified using the Fujita scale to produce regional maps of actual damage. A simple meteorological model (HURRECON), parameterized and tested for selected recent hurricanes, provides regional estimates of wind speed, direction, and damage for each storm. Individual reconstructions are compiled to analyze spatial and temporal patterns of hurricane impacts. Long-term effects of topography on a landscape scale are then simulated with a simple topographic exposure model (EXPOS). We applied this method to the region of New England, USA, examining hurricanes since European settlement in 1620. Results showed strong regional gradients in hurricane frequency and intensity from southeast to northwest: mean return intervals for F0 damage on the Fujita scale (loss of leaves and branches) ranged from 5 to 85 yr, mean return intervals for F1 damage (scattered blowdowns, small gaps) ranged from 10 to >200 yr, and mean return intervals for F2 damage (extensive blowdowns, large gaps) ranged from 85 to >380 yr. On a landscape scale, mean return intervals for F2 damage in the town of Petersham, Massachusetts, ranged from 125 yr across most sites to >380 yr on scattered lee slopes. Actual forest damage was strongly dependent on land use and natural disturbance history. Annual and decadal timing of hurricanes varied widely. There was no clear century-scale trend in the number of major hurricanes. The historical-modeling approach is applicable to any region with good historical records and will enable ecologists and land managers to incorporate insights on hurricane disturbance regimes into the interpretation and conservation of forests at landscape to regional scales.

Arundo donax L. (giant reed) is an invasive perennial plant that has spread widely in riparian areas in California, where it has altered wildlife habitats, created a fire hazard, compromised water conservation efforts, and affected flood control. Currently, physical removal is the primary means of controlling this weed, which is ineffective because of prolific asexual reproduction from an extensive rhizome system. We conducted controlled experiments on the sprouting potential of vegetative propagules, effects of storage duration and conditions on sprouting, and survival and growth of propagules in various soil types and moisture regimens. Sprouting and regrowth varied greatly with propagule type and size and with treatment and duration of storage after removal from the plant. Over 90% of stem and rhizome pieces with at least one node sprouted. Stem sprouting was affected by prior storage duration, temperature and moisture, whereas only storage duration and moisture affected rhizome sprouting. Sprouting was reduced by drying propagules at 30 °C for 1 week and by storage in a soil slurry. After 16 weeks, even propagules maintained optimally in moist soil showed reduced sprouting. Rhizome pieces sprouted readily from a soil depth of 25 cm, whereas stem pieces sprouted from less than 10 cm. Responsiveness of asexual reproduction in A. donax to environmental cues suggests that mechanical control can be improved by careful timing and treatment of cut biomass pieces to minimize or inhibit sprouting.

In yeast iso-1-cytochrome c, the side chain of histidine 26 (His26) attaches omega loop A to the main body of the protein by forming a hydrogen bond to the backbone atom carbonyl of glutamic acid 44. The His26 side chain also forms a stabilizing intra-loop interaction through a hydrogen bond to the backbone amide of asparagine 31. To investigate the importance of loop-protein attachment and intra-loop interactions to the structure and function of this protein, a series of site-directed and random-directed mutations were produced at His26. Yeast strains expressing these variant proteins were analyzed for their ability to grow on non-fermentable carbon sources and for their intracellular production of cytochrome c. While the data show that mutations at His26 lead to slightly decreased intracellular amounts of cytochrome c, the level of cytochrome c function is decreased more. The data suggest that cytochrome c reductase binding is affected more than cytochrome c oxidase or lactate dehydrogenase binding. We propose that mutations at this residue increase loop mobility, which, in turn, decreases the protein's ability to bind redox partners.

We previously developed a method of tremor quantification using long-term electromyography registration of antagonistic forearm muscles that is reliable, sensitive, and specific for pathologic tremors. The present study demonstrates that tremor occurrence as measured by this method correlates well with clinical parameters of tremor in idiopathic Parkinson's disease (PD) and essential tremor (ET) (subscores of the Unified Parkinson's Disease Rating Scale for PD, tremor rating according to Bain et al. for ET). We conclude that the method is a valid and objective means of tremor quantification in PD and ET.

Omega (omega)-loop A, residues 18-32 in wild-type yeast iso-1-cytochrome c, has been deleted and replaced with loop sequences from three other cytochromes c and one from esterase. Yeast expressing a partial loop deletion do not contain perceptible amounts of holoprotein as measured by low-temperature spectroscopy and cannot grow on nonfermentable media. Strains expressing loop replacement mutations accumulate holoprotein in vivo, but the protein function varies depending on the sequence and length of the replacement loop; in vivo expression levels do not correlate with their thermal denaturation temperatures. In vitro spectroscopic studies of the loop replacement proteins indicate that all fold into a native-like cytochrome c conformation, but are less stable than the wild-type protein. Decreases in thermal stability are caused by perturbation of loop C backbone in one case and a slight reorganization of the protein hydrophobic core in another case, rather than rearrangement of the loop A backbone. A single-site mutation in one of the replacement mutants designed to relieve inefficient hydrophobic core packing caused by the new loop recovers some, but not all, of the lost stability.

We discuss the errors in common approximations of the volume flow rate for laminar flow through conduits with noncircular transverse sections. Before calculating flow rates, ideal geometric shapes are chosen to represent the noncircular transverse sections. The Hagen-Poiseuille equation used with hydraulic diameter underestimates the volume flow rate for laminar flow through conduits even with such ideal shapes. Correction factors that have been proposed for the Hagen-Poiseuille equation also lead to underestimates of the volume flow rate for those shapes. The exact solutions are sometimes difficult to attain, but rates calculated using the exact solutions for the ideal shapes may be as much as five times higher than the approximated rates for common transversely elongated shapes. Either the exact solutions or the approximations may be used to calculate volume flow rates through the xylem of plants. Both of these methods actually approximate flow through the original conduits because the shapes used are approximations of the conduits' transverse sections. We recommend using the exact solutions whenever possible; they should be closer to the real solution than other approximations. We give tables of correction factors for use in the cases where calculating volume flow rate from the approximate solution, the Hagen-Poiseuille equation, is more feasible. Obtaining theoretical volume flow rates that are larger than previously thought highlights the need to clarify the causes of differences between the theoretical rates and the smaller measured volume flow rates in plant xylem. As part of an ongoing project to understand the dynamics of water flow through the xylem we discuss exact equations to calculate water flow through noncircular ideal capillaries and investigate the errors in frequently used approximations. In determining theoretical volume flow rates through the xylem of plants, the Hagen-Poiseuille equation for laminar flow through conduits is often used. The Hagen-Poiseuille equation provides the exact solution for laminar flow in individual ideal capillaries with circular transverse sections, but the application of this equation to conduits with noncircular transverse sections using the hydraulic diameter results in errors in the calculated volume flow rates. Exact solutions for the determination of volume flow rate through capillaries with some common noncircular transverse sections have recently been published in English (White, 1991). In general, errors in calculated flow rates may result from anatomical deviations of the xylem conduits from ideal capillaries, or from methods used to calculate the volume flow rate. This paper investigates the latter more completely than previous botanical literature (e.g., Leyton, 1975; Nonweiler, 1975; Petty, 1978; Pickard, 1981; Zimmermann, 1983; Calkin, Gibson, and Nobel, 1986; Lewis, 1992), discusses some exact solutions for volume flow rates through some common noncircular conduits, .and recommends methods for the calculation of theoretical volume flow rates based on desired accuracy, speed, and ease of calculation.

Hurricanes represent an important natural disturbance process to tropical and temperate forests in many coastal areas of the world. The complex patterns of damage created in forests by hurricane winds result from the interaction of meteorological, physiographic, and biotic factors on a range of spatial scales. To improve our understanding of these factors and of the role of catastrophic hurricane wind as a disturbance process, we take an integrative approach. A simple meteorological model (HURRECON) utilizes meteorological data to reconstruct wind conditions at specific sites and regional gradients in wind speed and direction during a hurricane. A simple topographic exposure model (EXPOS) utilizes wind direction predicted by HURRECON and a digital elevation map to estimate landscape—level exposure to the strongest winds. Actual damage to forest stands is assessed through analysis of remotely sensed, historical, and field data. These techniques were used to evaluate the characteristics and impacts of two important hurricanes: Hurricane Hugo (1989) in Puerto Rico and the 1938 New England Hurricane, storms of comparable magnitude in regions that differ greatly in climate, vegetation, physiography, and disturbance regimes. In both cases patterns of damage on a regional scale were found to agree with the predicted distribution of peak wind gust velocities. On a landscape there was also good agreement between patterns of forest damage and predicted exposure in the Luquillo Experimental Forest in Puerto Rico and the town of Petersham, Massachusetts. At the Harvard and Pisgah Forests in central New England the average orientation of wind—thrown trees was very close to the predicted peak wind direction, while at Luquillo there was also good agreement, with some apparent modification of wind direction by the mountainous terrain. At Harvard Forest there was evidence that trees more susceptible to windthrow were felled earlier in the storm. This approach may be used to study the effects of topography on wind direction and the relation of forest damage to wind speed and duration; to establish broad—scale gradients of hurricane frequency, intensity, and wind direction for particular regions; and to determine landscape—level exposure to long—term hurricane disturbance at particular sites.

In order to identify the biological roles of protein-linked oligosaccharides, we have isolated mutants by a selection for amoebae with temperature-sensitive defects in glycan assembly and processing. Of these, 75% were also temperature sensitive for development [Boose and Henderson, 1986]. Two such mutants with distinct developmental phenotypes and glycosylation patterns are described. Mutant HT7 cannot complete aggregation at the restrictive temperature and is defective in expression of EDTA-resistant cohesion. The biochemical defect appears to be early in glycan processing. A revertant of HT7 has recovered aggregation capability, EDTA-resistant cohesion, and reverted almost totally to wild-type glycosylation. Mutant HT15 aggregates at the restrictive temperature but then disperses into a cell lawn. It is less deficient in EDTA-resistant cohesion than HT7 and has a different glycosylation profile. These results provide strong support for a role of protein N-linked oligosaccharides in aggregation-stage intercellular cohesion.

The heavy chain of tissue plasminogen activator (t-PA) consists of four domains [finger, epidermal-growth-factor (EGF)-like, kringle 1 and kringle 2] that are homologous to similar domains present in other proteins. To assess the contribution of each of the domains to the biological properties of the enzyme, site-directed mutagenesis was used to generate a set of mutants lacking sequences corresponding to the axons encoding the individual structural domains. The mutant proteins were assayed for their ability to hydrolyze artificial and natural substrates in the presence and absence of fibrin, to bind to lysine-Sepharose and to be inhibited by plasminogen activator inhibitor-1. All the deletion mutants exhibit levels of basal enzymatic activity very similar to that of wild-type t-PA assayed in the absence of fibrin. A mutant protein lacking the finger domain has a 2-fold higher affinity for plasminogen than wild-type t-PA, while the mutant that lacks both finger and EGF-like domains is less active at low concentrations of plasminogen. Mutants lacking both kringles neither bind to lysine-Sepharose nor are stimulated by fibrin. However, mutants containing only one kringle (either kringle 1 or kringle 2) behave indistinguishably from one another and from the wild-type protein. We conclude that kringle 1 and kringle 2 are equivalent in their ability to mediate stimulation of catalytic activity by fibrin.

The development and regional distribution of deoxyuridine 5'-triphosphatase (dUTPase) in rabbit brain was studied. After partial purification of the dUTPase activity, newborn brain and liver activities fell from Vmax values of 1.0 and 6.9 nmol/mg protein/min, respectively, to adult levels of 0.1 (brain) and less than 0.01 (liver). The dUTPase activity was evenly distributed throughout the entire adult rabbit brain, and there was no difference in the Km of dUTPase in newborn and adult brain (0.1 microM). The low level of dUTPase in adult brain and the lack of activity in adult liver were not due to inhibitors or phenylmethylsulfonyl fluoride-sensitive proteases. dUTPase in brain, as in other tissues, probably inhibits the misincorporation of uracil into DNA.

A family is described in which six members were of a week subgroup of B. Presence of the subgroup in each individual was first indicated by lack of anti-B in that person's serum. Additional tests showed that the B subgroup red blood cells would adsorb anti-B and yield that antibody on elution, and that the saliva of two B subgroup persons tested contained B and H substances. The blood of one of the family members with the weak B antigen was inadvertently transfused to a group O recipient but caused no ill effects.