Miracle-dz/UniFAR-FTUs huggingface dataset:
Inferring long‐distance dispersal and topographic barriers during post‐glacial colonization from the genetic structure of red maple (Acer rubrum L.) in New England

Aim This study aims to assess the role of long‐distance seed dispersal and topographic barriers in the post‐glacial colonization of red maple (Acer rubrum L.) using chloroplast DNA (cpDNA) variation, and to understand whether this explains the relatively higher northern diversity found in eastern North American tree species compared with that in Europe.
Low Frequency Disadvantage in the Exploitation of Pollinators by Corolla Variants in Phlox

The propensity of pollinators to feed upon alternative corolla variants of Phlox drummondii was related to relative morph frequency in experimental populations. The amount of service a variant received was measured in terms of the frequency of random outcrossing, because the variants are self-compatible. The frequency of random outcrossing did not differ significantly in populations in which the variant ratio was 3:1, 1:1, or 1:3. However, when the ratios were 9:1, or 1:9, the frequency of outcrossing was significantly lower than that in the other populations. This indicated that the level of pollinator exploitation of a corolla variant is frequency dependent and that the minority phenotype is at a disadvantage. The pollinator behavior inferred from the outcrossing data is consistent with that observed in communities where the alternative "phenotypes" are species. The consequence of a rare phenotype disadvantage is the elimination of conspicuous variability for the key floral characters.
Biphasic control of nuclear factor‐χB activation by the T cell receptor complex: role of tumor necrosis factor α

The regulation of nuclear factor (NF)‐χB activation by the T cell receptor (TcR)/CD3 complex in primary human T cells has been studied at various times after activation. Only p50 NF‐χB protein bound the χB element of interleukin‐2 receptor (IL‐2R) α chain promoter on resting T cells. However, immediately after TcR/CD3 cross‐linking (after approximately 1 h; immediate) binding of p50.p65 heterodimers was observed. p50.c‐rel heterodimers were also detected bound to this sequence at early time points (7–16 h; early), and both remained active at later time points (40 h; late) after activation. This regulation takes place mainly at the level of nuclear translocation of p65 and c‐rel, at immediate and early time points. Activation also induced c‐rel and p105/p50 mRNA synthesis, but not p65 mRNA whose expression was constitutive. Interestingly, all those early and late events, but not the immediate ones, were inhibited by a neutralizing anti‐tumor necrosis factor α (TNF‐α) monoclonal antibody. Similarly, cycloheximide prevented the p65 and c‐rel translocation and consequent formation of active binding heterodimers, at early and late times. Cyclosporin A impaired not only early and late, but also immediate events; however, addition of TNF‐α prevented all inhibition. These results indicate that the regulation of NF‐χB activation during T cell activation by TcR/CD3 signals is biphasic: TcR/CD3 triggers its immediate translocation, which is transient if no TNF‐α is present. TNF‐α, therefore, emerges as the main factor responsible for a second phase of NF‐χB regulation, controlling both translocation of p65 and c‐rel, and new mRNA synthesis for c‐rel and p105/p50.
Deep slab seismicity limited by rate of deformation in the transition zone

Similar to earthquakes at Earth’s surface, deep earthquakes occur where sinking tectonic plates deform the fastest. Deep earthquakes within subducting tectonic plates (slabs) are enigmatic because they appear similar to shallow earthquakes but must occur by a different mechanism. Previous attempts to explain the depth distribution of deep earthquakes in terms of the temperature at which possible triggering mechanisms are viable, fail to explain the spatial variability in seismicity. In addition to thermal constraints, proposed failure mechanisms for deep earthquakes all require that sufficient strain accumulates in the slab at a relatively high stress. Here, I show that simulations of subduction with nonlinear rheology and compositionally dependent phase transitions exhibit strongly variable strain rates in space and time, which is similar to observed seismicity. Therefore, in addition to temperature, variations in strain rate may explain why there are large gaps in deep seismicity (low strain rate), and variable peaks in seismicity (bending regions), and, possibly, why there is an abrupt cessation of seismicity below 660 km.
"Strains" and the classical biological control of insect pests

The classical biological control technique of introducing two or more populations of the same species of beneficial agent to increase the genetic diversity of that species (and so increase the changes of achieving a successful project) is reviewed. Cases of multiple introductions of conspecific populations against insect targets were listed and the effect of subsequent introductions on the outcome of the project was recorded. Of 178 projects identified, involving 417 separate importations, only 11 (6.2%) were successful through a second or later importation of the same morphologically defined species of beneficial agent. Of these, five involved host-related "strains' that are likely to be cryptic species, so the success rate for the introduction of conspecific populations falls to 3.4%. Introducing two or more populations of the same species is less likely to result in enhanced success than if other species of natural enemies are sought for "normal' classical biological control (historical success rate 12-16%). -from Authors
What does species richness tell us about functional trait diversity? Predictions and evidence for responses of species and functional trait diversity to land-use change

In the conservation literature on land-use change, it is often assumed that land-use intensification drives species loss, driving a loss of functional trait diversity and ecosystem function. Modern research, however, does not support this cascade of loss for all natural systems. In this paper we explore the errors in this assumption and present a conceptual model taking a more mechanistic approach to the species-functional trait association in a context of land-use change. We provide empirical support for our model's predictions demonstrating that the association of species and functional trait diversity follows various trajectories in response to land-use change. The central premise of our model is that land-use change impacts upon processes of community assembly, not species per se. From the model, it is clear that community context (i.e. type of disturbance, species pool size) will affect the response trajectory of the relationship between species and functional trait diversity in communities undergoing land-use change. The maintenance of ecosystem function and of species diversity in the face of increasing land-use change are complementary goals. The use of a more ecologically realistic model of responses of species and functional traits will improve our ability to make wise management decisions to achieve both aims in specific at-risk systems.
Distribuição e estrutura etária de Ocypode quadrata (Fabricius, 1787) (Crustacea, Decapoda, Ocypodidae) em praia arenosa do litoral sul do Brasil

Spatial distribution and population structure of Ocypode quadrata (Fabricius, 1787) were studied at Pinhal beach, Rio Grande do Sul, from November/91 to December/93. Analysis of frequency distributions of the ghost crab population was based on indirect census, with burrow diameter measurement. It was identified the presence of two age-groups, with the possible presence of a third one. The maximal life span was estimated to be about 3 years. Burrow diameter/carapace width, lenght/width and weight/width relationships were estimated from samples obtained by excavating burrows and individual capture by traps. These relationship were ajusted by the following equations, respectively: DT = 0,6648 + 1,0013.L; C = 0,77.L1,02; and P = 0,0004.L3,0876 (DT is burrow diameter; C is the carapace lenght; L is the carapace width; and P is the weight). Spatial distribution analysis was performed based on distance and altitude to water line. These crabs dig burrows preferentialy in the central large range of the beach, although having possibility of migration at adverses conditions. Burrow shape also was analysed.
Changes in needle morphology, anatomy, and mineral content during the recovery of protected balsam fir trees initially defoliated by the spruce budworm

Morphological, anatomical, and chemical changes in foliage of 25- to 30-year-old balsam fir trees (Abiesbalsamea (L.) Mill. ) that had been completely defoliated in 1977 by the spruce budworm (Choristoneurafumiferana (Clem.)) and then protected for 5 years by insecticide, were compared with foliage from adjacent undefoliated trees. The comparison showed that in 1978, the 1st year of refoliation, needle length, weight, and width were greater in the defoliated trees, while in 1979 they were less. In 1980, needle length was again less, but no difference was observed in needle weight and width. Needle length, weight, and width were similar in the defoliated and undefoliated trees in 1981 and 1982. Needle density in the defoliated trees was lower in 1978, but greater in 1979, while no difference occurred in 1980–1982. Foliar nitrogen content was higher in the defoliated trees in 1978–1980. Foliar phosphorus and potassium content were higher in the defoliated trees only in 1978. Needle and mesophyll cross-sectio.
The development of the bristles in normal and some mutant types of Drosophila melanogaster

This paper describes the development of the normal macro- and micro-chaetae of Drosophila, together with that of twelve mutant types. The phenotypes of twenty combinations of these genes have been studied. Each normal bristle is secreted by a single cell, the trichogen, which lies beneath a tormogen cell which secretes a socket. These bristle cells are first distinguishable in the epidermis at about 15 hr. after puparium formation, when they have already divided to form a pair, and are slightly larger than the normal epidermal cells. The secretion of the bristle proceeds most rapidly between 30 and 55 hr. , during which time the bristle cells are very large and obviously highly polyploid. The socket, apparently, does not completely enclose the base of the bristle in the earliest stages. The development of the microchaetae is essentially similar to that of the macrochaetae. The actions of the twelve genes can be summarized as follows: Scute causes a primary absence of certain bristle cells, and extra-bristle-complex-41e and hairy the presence of supernumerary groups. Split frequently causes an extra division, so that a group of four cells is formed; these may be arranged as two trichogens and two tormogens, or one trichogen and three tormogens; or the whole group may fail to reach the surface of the epithelium, when no bristle or socket is formed. Dichaete may produce an effect similar to the last-described of split, and it may also cause an extra division of the trichogen, producing a double bristle in a single socket. Hairless causes the trichogens of some bristle groups to lie level with the tormogens, and to develop like them into sockets. In Stubble the tormogens are shifted rather to one side of the trichogens, so that the bristle is less closely invested by the socket, and becomes thicker and shorter. In shaven-naked the trichogen is irregularly displaced, becoming more or less converted into a tormogen; the small bristle which may be secreted is often peculiarly fanned out at the tip, suggesting an effect of the gene on the nature of the material secreted. Spineless and morula slow down the growth of the bristle cells. Singed, forked and Bristle all affect the nature of the bristle secretion, there being some reason to suggest that the effects of Bristle and singed may be similar and different to that of forked.
Decomposition and nutrient dynamics of Quercus pubescens leaf litter in a naturally enriched CO2 Mediterranean ecosystem

1. The chemical composition (i.e. N, P, C, lignin and polyphenol concentrations) of Quercus pubescens leaf litter derived from a natural CO2 spring in Tuscany (Italy) was analysed and compared to litter from a nearby reference site. Litter was incubated for 25 months at both the natural CO2 spring and the reference site, and monitored for decomposition rates, nutrient and lignin concentrations. 2. Long-term exposure to elevated CO2 concentrations from the natural spring was associated with a change in the chemical composition of the Oak leaf litter, with decreases in P and polyphenol concentrations and increases in lignin. No differences in N concentrations were observed between the enriched CO2 litter from the natural spring and the reference litter. 3. Decomposition was reduced in the CO2 spring, with the lower P concentration of the native litter, combined with the lack of soil fauna observed at that site, being the factors most probably responsible for the measured decreases in mass loss. However, litter from the CO2 spring and reference litter decomposed at the reference site showed similar rates of decomposition. 4. All litter showed similar N concentrations during decomposition, with N being mineralized throughout the incubation period from both litter regardless of the site of incubation. In contrast, P dynamics differed between litter, with P being immobilized in the litter derived from the spring, and mineralized from the reference litter. When the litter from the spring was incubated at the reference site, there was a trend for net P uptake from the surrounding environment. The chemical composition of decomposing litter from the spring appeared to match that of the reference litter after 3 months of incubation at the reference site. 5. The results from the CO2 spring suggest that litter decomposition may be retarded under elevated levels of atmospheric CO2. However, results from field surveys around CO2 vents should be viewed with caution because differences may relate to factors other than the known differences in CO2 concentrations.
Mesodermal Differentiation: Signal Integration During Development

This Teaching Resource provides a summary and slides derived from a lecture on the signaling cascades that mediate early embryogenesis and is part of the course "Cell Signaling Systems: A Course for Graduate Students. " The lecture focuses on the mechanisms underlying germ layer formation, patterning, and suppression in the vertebrate embryo, with particular emphasis on the regulation of mesodermal development in the model organism Xenopus laevis.
Predicting IDDM

RESULTS— Of 36 untreated subjects with positive islet cell antibodies, 10 became insulin dependent during a 6-yr period of observation. In 8 untreated subjects, insulin dependence developed a mean of 4.6 mo after their first-phase insulin response fell to <30 u,U/ml. The time of development of IDDM after the first-phase insulin response fell to <46 |xU/ml (the 1st percentile of normal) was 14 mo. The mean time for the development of IDDM after the first-phase insulin response fell to <67 |xU/ml (the 5th percentile of normal) was 19 mo. HbAlc remained in the normal range for all subjects in the prediabetic stage. Similarly, fasting blood glucose concentrations at the time of testing for the firstphase insulin response was in the normal range.
The genetic basis of growth, reproduction, and maternal environment in Romney ewes

This paper is the first in a series of studies on the genetic variation and covariation in growth and reproductive characters of the New Zealand Romney sheep. The data used were obtained over a period of 11 years (1955-1965 inclusive) from a random-bred experimental flock maintained at Massey University, Palmerston North, New Zealand. Among the environmental factors studied, type of birth and rearing has a marked effect on liveweights measured at different times from weaning to the yearling stage. On average, the singles were about 9 lb heavier than the twins at weaning, or c. 17 % heavier in terms of the mean weaning weight. Presumably because of their pre-weaning growth handicap, the twins compared with the singles exhibited post-weaning compensatory growth. The age of the dam and of the individual moderately affected the weaning weight of the lamb. However, their effects on post-weaning liveweight characters over the hogget stage (from weaning to about 14 months) showed that the influence of age of dam remained undiminished whereas that of the individual tended to decrease with time from weaning. The number of times a ewe hogget comes into oestrus during the first autumn of her life (number of hogget oestruses) was unaffected by type of birth and rearing, moderately affected by age of the individual, but relatively strongly influenced by the age of dam effect. Some doubt existed as to whether the average difference in fertility (number of lambs born per ewe) between ewes themselves born as singles and twins (type of birth effect) could be regarded as environmental or as genetic in nature. The present results indicated that in the fertility data, type of birth effect contained a genetic component, and adjustment should not be made for difference in type of birth if the aim is to study genetic variation and covariation in fertility of the ewe. The estimates of heritability for the various characters were made. by using paternal half-sib correlation (method 1) and regression of daughter on dam (method 2). In general, good agreement existed between corresponding values of heritability obtained by different methods of analysis. The estimates of heritabilities by methods 1 and 2 were: weaning weight (December) 0.30 and 0.23; March liveweight, 0.45 and 0 35; June liveweight, 0.39 and 0.42; hogget liveweight (yearling in October), 0.51 and 0.46; number of hogget oestruses, 0.32 and 0.27; number of lambs born per ewe at the first lambing (2-year-old), 0.053 and 0.045; over the first two lambings, 0.121 and 0.111; over the first three lambings, 0.032 and 0.205. The results are discussed in relation to genetic improvement in the ewe's fertility by direct selection.
Identification of quantitative trait loci for drought tolerance at seedling stage by screening a large number of introgression lines in maize

The maize genome hosts tremendous phenotypic and molecular diversity. Introgression lines (ILs), developed by continuous backcrossing to recurrent parents, could provide a unique genetic stock for quantitative trait locus (QTL) mapping. Using maize lines from six heterotic groups of different ecological zones, we developed > 500 BC 2 F 2 IL sets by crossing 11 inbred lines (as recurrent parents) with > 200 local maize inbred lines (as donor parents). Of them, 34 IL sets were selected as a subset for drought tolerance screening and a total of 417 ILs survived under severe water stress at seedling stage. One set of 32 surviving ILs, derived from Chang7-2/DHuang212, was used for QTL mapping with simple sequence repeat markers covering the whole genome, with seven QTL detected. Furthermore, investigating all surviving ILs, we identified two common regions in bin 3.04, corresponding to marker intervals bnLg1904-umc1772 and umc1223-bnlgl957, respectively, which shared high genetic variation in three IL sets. Our results indicated that selective genotyping can be used to identify genetic loci for complex traits. The ILs, highly selected for drought tolerance in this study, provide a unique set of materials for both genomic studies and development of enhanced germplasm resources.
Alterations of circadian rhythms of thyroid-stimulating hormone, thyroid, adrenal and insulin hormones, and blood glucose profiles following lithium treatment in alternate Light–Dark, constant Light and constant Dark regimens in rats

Lithium, widely used for the treatment of mania, has adverse side effects on circadian rhythms of pineal and testicular hormones. Objective was to examine the role of lithium on circadian rhythms of other hormones and glucose profiles in light–dark (12L:12D), constant light (12L:12L) and constant dark (12D:12D) regimens in rats. Intraperitoneal injection of lithium (2 mEq/kg body wt daily for 15 days) sustained circadian rhythms of T3, T4, thyroid-stimulating hormone (TSH), corticosterone, norepinephrine and epinephrine in light–dark and constant dark but not in constant light. But it abolished circadian rhythms of insulin and blood glucose in all the photoperiodic regimens, except insulin, without changing their pattern in constant dark. Patterns of circadian rhythms of thyroid and TSH, and adrenal hormones remained unchanged after lithium treatment in L–D or D–D, except TSH in L–D. The probable role of photoperiodic cue and lithium on circadian and/or nycthemeral (daily) rhythms of hormones and blood glucose profiles is discussed.
Plant species diversity and environmental heterogeneity: spatial scale and competing hypotheses

Questions: What is the observed relationship between plant species diversity and spatial environmental heterogeneity? Does the relationship scale predictably with sample plot size? What are the relative contributions to diversity patterns of variables linked to productivity or available energy compared to those corresponding to spatial heterogeneity? Methods: Observational and experimental studies that quantified relationships between plant species richness and within-sample spatial environmental heterogeneity were reviewed. Effect size in experimental studies was quantified as the standardized mean difference between control (homogeneous) and heterogeneous treatments. For observational studies, effect sizes in individual studies were examined graphically across a gradient of plot size (focal scale). Relative contributions of variables representing spatial heterogeneity were compared to those representing available energy using a response ratio. Results: Forty-one observational and 11 experimental studies quantified plant species diversity and spatial environmental heterogeneity. Observational studies reported positive species diversity-spatial heterogeneity correlations at all points across a plot size gradient from ∼1.0 × 10−1 to ∼1.0 × 1011 m2, although many studies reported spatial heterogeneity variables with no significant relationships to species diversity. The cross-study effect size in experimental studies was not significantly different from zero. Available energy variables explained consistently more of the variance in species richness than spatial heterogeneity variables, especially at the smallest and largest plot sizes. Main conclusions: Species diversity was not related to spatial heterogeneity in a way predictable by plot size. Positive heterogeneity-diversity relationships were common, confirming the importance of niche differentiation in species diversity patterns, but future studies examining a range of spatial scales in the same system are required to determine the role of dispersal and available energy in these patterns.