Miracle-dz/UniFAR-FTUs huggingface dataset:
Manejo da estrutura diamétrica remanescente de florestas tropicais

O incremento de uma floresta sob uma exploracao madeireira depende nao apenas do ritmo de crescimento das especies como tambem da distribuicao diametrica remanescente que devera permanecer pos corte. O trabalho avaliou, mediante simulacao, a estrutura diametrica remanescente de um talhao de floresta ombrofila no estado do Amazonas, visando a garantia de ter incremento que recupere a extracao. A simulacao do crescimento da floresta pos-exploracao, respeitando a taxa calculada e a estrutura, permitiram um incremento que pode recuperar o volume comercial inicial durante o ciclo considerado (25 anos). Observouse nas simulacoes que a remocao de todo volume comercial disponivel das especies estudadas impede a recuperacao da floresta no ciclo considerado. Observou-se tambem que as classes diametricas comerciais remanescentes (acima do centro de classe de 45 cm) sao responsaveis por 81 % do incremento necessario para recuperacao do volume comercial removido. Identificou-se um ponto otimo de classe diâmetro a ser mantida na floresta, acima do qual o retorno do volume comercial e nulo. O ponto crucial da recuperacao do volume extraido e o potencial de incremento da estrutura que deve permanecer no compartimento.
Porcine Microsomal Vitamin D3 25-Hydroxylase (CYP2D25)

The metabolic activation of the prohormone vitamin D3 requires a 25-hydroxylation that has been reported to be catalyzed by both mitochondrial CYP27A and a microsomal vitamin D3 25-hydroxylase in the liver. CYP27A has been extensively studied, but its role as a physiologically important vitamin D3 25-hydroxylase has been questioned. The present paper reports that the microsomal vitamin D325-hydroxylase, purified from pig liver, converted vitamin D3 into 25-hydroxyvitamin D3 in substrate concentrations which are within the physiological range (apparentK m = 0.1 μm). The enzyme 25-hydroxylated vitamin D3, 1α-hydroxyvitamin D3 and vitamin D2 and also converted tolterodine, a substrate for human CYP2D6, into its 5-hydroxymethyl metabolite. Tolterodine inhibited the microsomal 25-hydroxylation, whereas quinidine, an inhibitor of CYP2D6, did not markedly inhibit the reaction. The primary structure of the microsomal vitamin D3 25-hydroxylase, designated CYP2D25, shows 77% identity with that of human CYP2D6. Northern blot and reverse transcription-polymerase chain reaction experiments revealed that CYP2D25 mRNA is expressed in higher levels in liver than in kidney and in small amounts in adrenals, brain, heart, intestine, lung, muscle, spleen, and thymus. Experiments with human liver microsomes and recombinantly expressed CYP2D6 strongly indicate that the microsomal 25-hydroxylation of vitamin D3 in human liver is catalyzed by an enzyme different from CYP2D6.
Microbiotic Crusts and Ecosystem Processes

Microbiotic crusts are biological soil crusts composed of lichens, cyanobacteria, algae, mosses, and fungi. The biodiversity of these crusts is poorly understood; several cosmopolitan species dominate in most areas, but many species are confined to one or a few sites. Nitrogen fixation by organisms within the crust can be the dominant source of nitrogen input into many ecosystems, although rates of nitrogen input are limited by water availability, temperature, and nitrogen loss from the crust. Photosynthetic rates of the microbiotic crust can be 50% of those observed for higher plants, but the contribution of crusts to carbon cycling is not known. The microbiotic crust binds soil particles together, and this significantly increases soil surface stability and resistance to erosion. Greenhouse studies have found that crusts can enhance seed germination, seedling survivorship, and plant nutrient status, but further experiments are needed under field conditions. Crusts are extremely susceptible to surface dis.
Effects of Urban Development on Fish Population Dynamics in Kelsey Creek, Washington

Abstract A 30-month study of the comparative dynamics of the fish populations inhabiting Kelsey Creek, located in the City of Bellevue, Washington, and a nearby pristine control stream suggest that urban development has resulted in a restructuring of the fish community. Environmental perturbations, including habitat alteration, increased nutrient loading, and degradation of the intragravel environment appeared to have a greater impact on coho salmon Oncorhynchus kisutch and nonsalmonid fish species than on cutthroat trout Salmo clarki. Although the total biomass (g/m2) of fish in each stream was similar, its composition differed markedly. Ages 0 and I cutthroat trout were the majority of the fish community inhabiting Kelsey Creek, whereas the control stream supported a diverse assemblage of salmonids of various ages and numerous nonsalmonids. The rapid growth and greater biomass of salmonids in Kelsey Creek (a 2-year mean of 3.51 g/m2 versus 2.03 g/m2 in the control stream) resulted in a total annual net .
PHYSIOLOGICAL ONTOGENY

1. Observations on tissue cultures of heart muscle from chicken embryos indicate that in general the growth rate of the individual cells decreases with age. The negative acceleration of growth is greatest at the beginning of life as in the intact embryo. 2. The latent period before growth commences increases with the age of the implanted tissue, but in a different fashion. The acceleration of the latent period is greatest near the end of the incubation period, thus demonstrating that the factors determining the initiation of growth and those determining the extent of growth are not similar.
The Quantum Condition and the Non‐Euclidean Nature of Space‐Time

The origin of the Bohr-de Broglie quantum condition for the stability of atomic and nuclear systems can be interpreted in terms of a locally high Gaussian curvature of space-time equivalent to a large value of the gravitational constant along the lines suggested by Motz’ for the stability of the electron. Assuming the mass is purely electromagnetic in origin and that hadrons are composed of highly relativistic electron-positron pairs in “charmonium” or heavy, integrally charged, quarklike arrangements, and also by adopting a symmetrical definition of the electromagnetic force between two moving particles as proposed by Einstein in 1905, one arrives a t the existence of a minimum approach distance as well as a changing source size or rest mass for the electron and positron in highly relativistic orbits of pion mass that form the basis of all hadrons (FIGURE I). ’ The existence of a minimum approach distance between the fundamental entities is equivalent to a non-Euclidean geometry with a high local G similar to that of Motz, except that this local G is found to increase inversely as the square root of the pair mass during the course of the evolution of the universe by internal pair-production. This process begins with the Newtonian value of G and increases up to a maximum value of e2/m2, starting with a single massive “Lemaitre-atom”-like electron-pair of mass equal to that of the universe, MU, a t the Planck density, c * / ~ G ’ . ~ As a result, the charges in equilibrium orbits move along geodesics of the local space so that they do not radiate, which is contrary to classical electromagnetic theory. In these orbits, the tangential Lorentz contraction of the field source is exactly equaled by the radial contraction produced by the local space-curvature, thus reducing the source to the spherical shape associated with a state of rest. This provides a simple physical or geometrical explanation of the Bohr-de Broglie quantum condition, which can be applied to the stability of electron orbits and, thus, to all matter. Because hadrons appear to be describable as molecular arrangements of highly relativistic electrons and positrons whose masses, sizes, and lifetimes can be accounted for in terms of the basic electromagnetic constants, e, m,, c, and h , without any other arbitrary constants or adjustable parameters: and because the electron and positron may in turn be regarded as self-stabilized, spinning sources of a single field’ analogous to “twisted geons,” “vortex rings,” or “strings” in a fluidlike space-time continuum or ether, the wave-particle nature of matter finds a simple physical explanation. In this model, there is no “hard” or “ponderable” matter. Instead, all matter “particles” consist of stable, spinning sources of electromagnetic fields of finite inner size, with the size of the source determining the rest mass. This explains the relation of heavy quarks to leptons, including their small, pointlike size and spin ‘/2. In this model, the strong force is explained as a relativistic form of the electromag-
Tumor Necrosis Factor α-induced Phosphorylation of Insulin Receptor Substrate-1 (IRS-1)

Tumor necrosis factor-α (TNF) has been suggested to be the mediator of insulin resistance in infection, tumor cachexia, and obesity. We have previously shown that TNF diminishes insulin-induced tyrosine phosphorylation of insulin receptor substrate 1 (IRS-1). The current work examines potential mechanisms that mediate this event. TNF effect on IRS-1 in Fao hepatoma cells was not associated with a significant reduction in insulin receptor tyrosine kinase activity as measured in vitro but impaired the association of IRS-1 with phosphatidylinositol 3-kinase, localizing TNF impact to IRS-1. TNF did not increase protein-tyrosine phosphatase activity and protein-tyrosine phosphatase inhibition by vanadate did not change TNF effect on IRS-1 tyrosine phosphorylation, suggesting that protein-tyrosine phosphatases are not involved in this TNF effect. In contrast, TNF increased IRS-1 phosphorylation on serine residues, leading to a decrease in its electrophoretic mobility. TNF effect on IRS-1 tyrosine phosphorylation was not abolished by inhibiting protein kinase C using staurosporine, while inactivation of Ser/Thr phosphatases by calyculin A and okadaic acid mimicked it. Our data suggest that TNF induces serine phosphorylation of IRS-1 through inhibition of serine phosphatases or activation of serine kinases other than protein kinase C. This increased serine phosphorylation interferes with insulin-induced tyrosine phosphorylation of IRS-1 and impairs insulin action.
Observations on the nesting habits of Oreochromis mossambicus (Peters) (Pisces: Cichlidae) in Sri Lankan reservoirs

The nest-building characteristics of Oreochromis mossambicus (Peters) were studied in five manmade lakes (reservoirs) Sri Lanka. The nests were always found in clusters (arenas) and were generally located in or near coves and/or bays in shallow water. The density of nests in an arena varied between arenas in a reservoir and between reservoirs. The overall mean density of nests ranged between 0.47 and 6.31 m 2 in the five reservoirs. The nests ranged from 11 to 110 cm in diameter, two size groups of nests being recognizable: small, with diameter 10–50 cm, and large with diameter >50 cm. At any nesting site only one size group of nests was found. Nest diameter (ND) was curvilinearly related to mean nest density (D) and linearly to mean distance between nests (Dis), the respective statistical relationships being The diameter of nests was also related to nest depth (Dep) as There was no apparent relationship between nesting characteristics and morphometric characters of the reservoirs.
Cryptic polychaete diversity: a review

This review summarises the current knowledge on cryptic species of polychaetes, one of the most dominant taxa in marine communities, and gives a brief overview of the different methods that has been used for their disclosure. Cryptic species constitute an important part of biodiversity and they are common among all kinds of polychaetes, with different life history traits, and may have sympatric as well as allopatric distributions. It is emphasised that cryptic species must not be neglected for a variety of reasons, and even though the magnitude of cryptic species is largely unknown the available data on polychaetes clearly demonstrate that morphology alone seriously underestimate the number of species. It is suggested that future research should focus on appropriately designed case‐studies using combined approaches, as well as on large‐scale whole sample analyses using next‐generation sequencing in order to be able to answer the many questions that still remains.
Ecological prophets: quantifying metapopulation portfolio effects

A financial portfolio metaphor is often used to describe how population diversity can increase temporal stability of a group of populations. The portfolio effect (PE) refers to the stabilizing effect from a population acting as a group or ‘portfolio’ of diverse subpopulations instead of a single homogeneous population or ‘asset’. A widely used measure of the PE (the average‐CV PE) implicitly assumes that the slope (z) of a log–log plot of mean temporal abundance and variance (Taylor's power law) equals two. Existing theory suggests an additional unexplored empirical PE that accounts for z, the mean–variance PE. We use a theoretical and empirical approach to explore the strength and drivers of the PE for metapopulations when we account for Taylor's power law compared with when we do not. Our empirical comparison uses data from 51 metapopulations and 1070 subpopulations across salmon, moths and reef fishes. Ignoring Taylor's power law may overestimate the stabilizing effect of population diversity for metapopulations. The disparity between the metrics is greatest at low z values where the average‐CV PE indicates a strong PE. Compared with the mean–variance method, the average‐CV PE estimated a stronger PE in 84% of metapopulations by up to sevenfold. The divergence between the methods was strongest for reef fishes (1·0 < z < 1·7) followed by moths (1·5 < z < 1·9). The PEs were comparable for salmon where z ≈ 2. We outline practical recommendations for estimating ecological PEs based on research questions, study systems and available data. Because most PEs were stabilizing and diversity can be slow to restore, our meta‐analysis of metapopulations suggests that the safest management approach is to conserve biological complexity.
Intracerebroventricular nicotine and mecamylamine alter radial‐arm maze performance in rats

In rats, the effects of an intracerebroventricular (ICV) nicotinic agonist nicotine (NIC), the nicotinic antagonist mecamylamine (MEC), and combinations of NIC + MEC were assessed in a radial‐arm maze (RAM). In experiment 1, exploratory behavior was assessed in untrained rats (N = 13). The rats received 4 μg, 8.65 nmol NIC (NIC 4), 200 μg, 0.98 μmol MEC (MEC), and saline (SAL) ICV infusions. NIC 4 caused a significant increase in choice distribution compared to SAL (P < 0.025). In experiment 2, rats (N = 10) were trained to perform a working memory task for food reinforcement in the RAM. ICV doses of SAL, NIC 4, NIC 8, MEC, MECNIC 4, and MECNIC 8 were administered after completion of the training period. MEC caused a significant deficit in choice accuracy when compared to SAL (P < 0.025). This deficit was reversed when NIC 8 was coadministered with MEC (P < 0.05). There were no significant effects on choice latency for either study. The effects of ICV NIC and MEC on RAM performance are generally similar to their systemic effects in that NIC improves and MEC impairs choice accuracy. The reversal of the MEC‐induced choice deficit by ICV NIC administration has not been reported with systemic administration. ICV MEC induces a choice accuracy deficit without increasing choice latency. This has not been seen with systemic MEC administration. The current result implies that the MEC‐induced choice accuracy deficit did not result from MEC‐induced sedation. The data indicate that previously reported changes in choice accuracy from peripherally administered NIC and MEC result from their central effects. © 1994 Wiley‐Liss, Inc.
Infectious and parasitic diseases of wild birds.

Almost every one who has become interested in the field of wildlife diseases has at one time or another kept a checklist of the species of wild birds that have been reported to have varioits diseases or parasites. After a few months, the list almost inavriably winds up in the wastebasket as one begins to realize how numerous these reports are and how widely scattered in the literature. Those who have been forced to undertake the task of organizing and presenting a course in “Wildlife Diseases” as part of a university curriculum have foitnd that the task of sitmmarizing this widely dispersed literature is a staggering chore.
Neuropilin-2 and Neuropilin-1 Are Receptors for the 165-Amino Acid Form of Vascular Endothelial Growth Factor (VEGF) and of Placenta Growth Factor-2, but Only Neuropilin-2 Functions as a Receptor for the 145-Amino Acid Form of VEGF*

Neuropilin-1 (np-1) and neuropilin-2 (np-2) are receptors for axon guidance factors belonging to the class 3 semaphorins. np-1 also binds to the 165-amino acid heparin-binding form of VEGF (VEGF165) but not to the shorter VEGF121 form, which lacks a heparin binding ability. We report that human umbilical vein-derived endothelial cells express the a17 and a22 splice forms of the np-2 receptor. Both np-2 forms bind VEGF165 with high affinity in the presence of heparin (KD 1.3 × 10− 10 m) but not VEGF121. np-2 also binds the heparin-binding form of placenta growth factor. These binding characteristics resemble those of np-1. VEGF145 is a secreted heparin binding VEGF form that contains the peptide encoded by exon 6 of VEGF but not the peptide encoded by exon 7, which is present in VEGF165. VEGF145 binds to np-2 with high affinity (KD 7 × 10− 10 m). Surprisingly, VEGF145 did not bind to np-1. Indeed, VEGF145does not bind to MDA-MB-231 breast cancer cells, which predominantly express np-1. By contrast, VEGF145 binds to human umbilical vein-derived endothelial cells, which express both np-1 and np-2. The binding of VEGF165 to porcine aortic endothelial cells expressing recombinant np-2 did not affect the proliferation or migration of the cells. Nevertheless, it is possible that VEGF-induced np-2-mediated signaling will take place only in the presence of other VEGF receptors such as VEGF receptor-1 or VEGF receptor-2.
Glucagon-Like Peptide I Increases Cytoplasmic Calcium in Insulin-Secreting βTC3-Cells by Enhancement of Intracellular Calcium Mobilization

In the insulin-secreting β-cell line (STC3, stimulation with 11.2 mmol/1 glucose caused a rise in the intracellular free Ca2+ concentration ([Ca2+]i) in only 18% of the tested cells. The number of glucose-responsive cells increased after pretreatment of the cells with glucagon-like peptide I (GLP-I)(7–36)amide and at 10−11 mol/1; 84% of the cells responded to glucose with a rise in [Ca2+]i. GLP-I(7–36)amide induces a rapid increase in [Ca2+]i only in cells exposed to elevated glucose concentrations (≥5.6 mmol/1). The action of GLP-I(7–36)amide and forskolin involved a 10-fold increase in cytoplasmic cAMP concentration and was mediated by activation of protein kinase A. It was not associated with an effect on the membrane potential but required some (small) initial entry of Ca2+ through voltage-dependent L-type Ca2+ channels, which then produced a further increase in [Ca2+]i by mobilization from intracellular stores. The latter effect reflected Ca2+-induced Ca2+ release and was blocked by ryanodine. Similar increases in [Ca2+]i were also observed in voltageclamped cells, although there was neither activation of a background (Ca2+-permeable) inward current nor enhancement of the voltage-dependent L-type Ca2+ current. These observations are consistent with GLP-I(7–36) amide inducing glucose sensitivity by promoting mobilization of Ca2+ from intracellular stores. We propose that this novel action of GLP-I(7–36)amide represents an important factor contributing to its insulinotropic action.
Structure of marine predator and prey communities along environmental gradients in a glaciated fjord

Spatial patterns of marine predator communities are influenced to varying degrees by prey distribution and environmental gradients. We examined physical and biological attributes of an estuarine fjord with strong glacier influence to determine the factors that most influence the structure of predator and prey communities. Our results suggest that some species, such as walleye pollock (Theragra chalcogramma), black-legged kittiwake (Rissa tridactyla), and glaucous-winged gull (Larus glaucescens), were widely distributed across environmental gradients, indicating less specialization, whereas species such as capelin (Mallotus villosus), harbor seal (Phoca vitulina), and Kittlitz's murrelet (Brachyramphus brevirostris) appeared to have more specialized habitat requirements related to glacial influence. We found that upper trophic level communities were well correlated with their mid trophic level prey community, but strong physical gradients in photic depth, temperature, and nutrients played an important role.
The Journal of Investing

W e open our Spring 2003 issue with a commentary by Frankfurter, who discusses the growing legitimacy of behavioral finance, if last year’s recipients of the obel Prize in Economics are any indication. There is hope yet to “shed the straitjacket of modern finance,” he says. In our first article, Enderle, Pope, and Siegel discuss the uses and characteristics of the leading broad-capitalization indexes of equities in the United States. With the abundance of market indexes available, it can be difficult to differentiate among them. The next article by Peters examines taxefficient equity products. Evidence continues to show that the traditional approach to not differentiate between taxable and tax-exempt investors limits opportunities for taxable investors. Arnott and Darnell provide a series of questions and issues to consider in making the decision between active and passive management. Johnson and Siegel conclude that the increased volatility and uncertainty in credit markets mean that investors who have to trade in and out of the bond market may want to consider a government-only portfolio. Bierman investigates a convertible bond investment strategy that can be part of a common stock portfolio strategy. He discusses the risk-return characteristics of different investment hedging strategies available to hedge funds. Antunovich and Laster examine the returns to investing in highly regarded firms, and conclude that more research is needed before we can explain why admired firms outperform unadmired firms over horizons longer than a year. Investors and analysts are increasingly questioning the credibility of company financial data. Fleming proposes improved disclosure requirements for restating earnings per share. Rajan and Tamimi examine the relationship between ISO 9000 registration and stock performance. Randall, Suk, and Tully provide some evidence that mutual fund flows are important as a determinant of monthly stock market movements, raising the point that some may be able to profit from early knowledge of how investors are moving money. We conclude the issue with a discussion by Below of leveraged index investing, which is gaining in popularity with investors and had spectacular performance in the late 1990s. Below’s study suggests that leveraged index funds appear a viable alternative for very long-term investors seeking to outperform the underlying index. We look forward to your feedback. It can be sent to us at: journals@investment research.org.
Native Bunchgrass (Stipa Pulchra) on Hastings Reservation, California

Species composition, cover, and standing crop were sampled in 13 small patches of the native bunchgrass Stipa pulchra on an area protected from grazing for 27 years. The common species present were representatives of lightly grazed annual grassland. Cover of Stipa, as basal area intercept, averaged 11%. Standing crop of all species averaged 98 g/m2, with Stipa comprising 37% of the total. Comparison of the 13 protected stands with four grazed stands showed differences in species composition, but basal area intercept and standing crop of Stipa were not significantly different. An ordination of all 17 stands using species frequency in quadrats showed a pattern consistently related to percentage slope. See full-text article at JSTOR