Miracle-dz/UniFAR-FTUs huggingface dataset:
Analyses of mutants of three genes that influence root hair development in Zea mays (Gramineae) suggest that root hairs are dispensable

Root hairs are specialized epidermal cells that are thought to play an important role in plant nutrition by facilitating the absorption of water and nutrients. Three maize mutants with abnormal root hair morphologies (rthl, rth2, and rth3) have been isolated from Mutator transposon stocks. All three root hair mutant phenotypes are controlled by single recessive alleles. The rthl mutant initiates normal-looking root hair primordia that fail to elongate. The normal-looking root hair primordia of the rth2 mutant elongate to only approximately one-fifth to one-fourth the length of wild type root hairs. Like rthl primordia, rth3 primordia undergo little elongation. However, unlike the relatively normal-looking rthl primordia, rth3 primordia are distinctly abnormal when viewed through a scanning electron microscope. The rthl mutant exhibits pleiotropic nutrient deficiencies, while the rth2 and rth3 mutants grow vigorously. This finding suggests that under some environmental conditions, root hairs are less important to plant growth than has been previously thought. The rthl, rth2, and rth3 genes have been mapped to chromosomes IL, 5L, and IS, respectively, via crosses with BA translocation stocks. The rth2 allele exhibits reduced transmission through the male gametophyte, but a normal rate of transmission through female gametophytes; rthl and rth3 are transmitted at normal rates. Root hairs are specialized root epidermal cells that are thought to play an important role in the absorption of water and nutrients from the rhizosphere by increasing the absorptive surface area of roots (Clarkson, 1985). The formation of root hairs occurs in two distinct stages: during "initiation," localized "bulges" (root hair primordia) form at the predetermined trichoblasts (hair-bearing epidermal cells); during "elongation," the "bulges" extend in a unipolar direction to form the tubular root hairs. This extension occurs via tip growth, a process common to root hairs and pollen tubes, and involves the addition of new membrane components at a cell's growing tip (Cormack, 1962; Newcomb and Bonnett, 1965; Sievers and
Competition, predation and interspecific synchrony in cyclic small mammal communities

Although competition and predation are considered to be among the most important biotic processes influencing the distribution and abundance of species in space and time, the relative and interactive roles of these processes in communities comprised of cyclically fluctuating populations of small mammals are not well known. We examined these processes in and among populations of field voles, sibling voles, bank voles and common shrews in western Finland, using spatially replicated trapping data collected four times a year during two vole cycles (1987–1990 and 1997–1999). Populations of the four species exhibited relatively strong interspecific temporal synchrony in their multiannual fluctuations. During peak phases, we observed slight deviations from close temporal synchrony: field vole densities peaked at least two months earlier than those of either sibling voles or bank voles, while densities of common shrews peaked even earlier. The growth rates of all four coexisting small mammal species were best explained by their own current densities. The growth rate of bank vole populations was negatively related to increasing densities of field voles in the increase phase of the vole cycle. Apart from this, no negative effects of interspecific density, direct or delayed, were observed among the vole species. The growth rates of common shrew populations were negatively related to increasing total rodent (including water voles and harvest mice) densities in the peak phase of the vole cycle. Sibling voles appeared not to be competitively superior to field voles on a population level, as neither of these Microtus voles increased disproportionately in abundance as total rodent density increased. We suggest that interspecific competition among the vole species may occur, but only briefly, during the autumn of peak years, when the total available amount of rodent habitat becomes markedly reduced following agricultural practices. Our results nonetheless indicate that interspecific competition is not a strong determinant of the structure of communities comprised of species exhibiting cyclic dynamics. We suggest that external factors, namely predation and shortage of food, limit densities of vole populations below levels where interspecific competition occurs. Common shrews, however, appear to suffer from asymmetric space competition with rodents at peak densities of voles; this may be viewed as a synchronizing effect.
RICHNESS AND COMPOSITION OF OASIS BIRD COMMUNITIES: SPATIAL ISSUES AND SPECIES–AREA RELATIONSHIPS

Abstract We used data on breeding bird communities of the oases of southern Tunisia to investigate variation in species richness and composition among local communities in relation to spatial configuration of the oasis system and to assess significance of the relationship between oasis size and local richness. Oases could be grouped into three regional systems, namely littoral, saharan, and mountainous oases. We found that at the scale of the entire oasis system, species richness and species composition exhibited significant spatial autocorrelation. That result was consistent with our prediction that the particular spatial organization of oases may have led to regional differences in availability of potential colonizers and that higher species exchange within oasis zones than among oasis zones may have played an important role in shaping local communities. With regard to the species–area relationship, we thus found that a model accounting for spatial covariance was more parsimonious than a standard regression model not incorporating information on the spatial location of oases. Overall, oasis size was a good predictor of species richness, but results were sensitive to spatial scale at which the relationship was examined. Aside from oceanic islands and forest patches, oases may constitute interesting systems to study how regional processes affect local diversity.
EFFECT OF DISTANCE BETWEEN HOST TREES AND LEAF LITTER REMOVAL ON POPULATION DENSITY OF CAMERARIA OHRIDELLA DESCHKA & DIMIC, 1986 (LEPIDOPTERA, GRACILLARIIDAE) - PEST OF CHESTNUT (AESCULUS SP.) TREES

The influence of distance between host trees and leaf litter removal on population density of Cameraria ohridella have been for the first time examined in an isolated population of horse chestnut (Aesculus hippocastanum L.) trees. The observation was performed in the small town (area 13,58 km2) in Wielkopolska region (West Poland) on the total number of 49 trees: 31 (11 clumps) of them with autumnal leaves removal (controlled sites), and 18 (5 clumps) without this procedure (uncontrolled sites). The main factors determining the extent of the leaf destruction by larvae were the leaf litter removal and the number of subsequent generations on a given tree. The effect of mean distance between trees on the infestation level was statistically significant only for the third generation larvae, when analyzing all sites. There was no significant correlation when checking the impact of mean and short distance on the leaves infestation between controlled and uncontrolled sites. The abundance of the first generation of the larvae of raked sites is possibly a result of low number of in situ overwintering individuals and the number of immigrants from uncontrolled areas. Assuming the random choice of direction of the migration, the effect of the immigrants on the trees which leaves have been disposed of is not as high as it should be expected. Additionally, the moths can be blown away by the wind in a random direction. Consequently, the noted increase in the leaves infestation by the third generation larvae can be result of the rate of population increase innate for the species and only partly a result of immigration from refuge areas.
Hepatocyte Nuclear Factor-1α Gene Mutations and Diabetes in Norway

Mutations in the hepatocyte nuclear factor (HNF)-1 alpha gene cause maturity-onset diabetes of the young (MODY), type 3. To estimate the prevalence of MODY3 in Norwegian diabetic pedigrees, we screened a total of 130 families for HNF-1 alpha mutations; 42 families with clinical MODY, 75 with suspected MODY, and 13 pedigrees with multiplex type 1 diabetes. Twenty-two families with clinical MODY, 15 families with suspected MODY, and one family with type 1 diabetes multiplex harbored HNF-1 alpha mutations. Thus, in about half of Norwegian families with clinical MODY, mutations in the HNF-1 alpha gene could be detected. Eight of the 18 different mutations identified were novel (G47E, T196fsdelCCAA, IVS3-1G>A, S256T, A276D, S445fsdelAG, M522V, and S531T). Haplotypes were determined for recurrent mutations, indicating a founder effect in Norway for the hot-spot mutation P291fsinsC and possibly also for P112L and R131W. To examine the molecular mechanisms underlying MODY3, we investigated the functional properties of 13 HNF-1 alpha mutations. Two mutant HNF-1 alpha proteins (R171X, R263C) were unable to bind DNA and at least five mutants (R131W, R171X, P379fsdelCT, S445fsdelAG, and Q466X) showed defective nuclear translocation. Transcriptional activation was reduced for most of the MODY3-associated mutants. Accordingly, the functional studies of HNF-1 alpha mutants indicate that beta-cell dysfunction in MODY3 is caused by loss-of-function mechanisms like reduced DNA binding, impaired transcriptional activation, and defects in subcellular localization.
Conjugal Transfer of Large Plasmids Conferring Oxytetracycline (OTC) Resistance: Transfer between Environmental Aeromonads, Fish-Pathogenic Bacteria, and Escherichia coli

Abstract The ability of environmental, motile Aeromonas species and fish-pathogenic bacteria to transfer oxytetracycline resistance to various bacterial species was assessed in vitro and in situ. Oxytetracycline-resistant motile aeromonads and A. salmonicida with large plasmids were used as donors; the recipients were a rifampicin-resistant Escherichia coli, the fish pathogens Yersinia ruckeri and Flavobacterium psychrophilum, a Pseudomonas putida strain, and motile aeromonads originating from aquatic environments. Transfers of oxytetracycline resistance were seen in both laboratory and environmental settings. In vitro transfers from motile Aeromonas spp. to E. coli using filter mating yielded transfer frequencies ranging from 1.4 × 10−9 to 6.8 × 10−5 transconjugants per recipient. Tetracycline resistance determinants A and D and unidentified tetracycline resistance determinants were transferred, usually on plasmids of approximately 150 kilo-base-pairs in size. In vitro transfer from motile Aeromonas spp.
Growth, body composition, intestinal enzyme activities and microflora of juvenile Jian carp (Cyprinus carpio var. Jian) fed graded levels of dietary phosphorus

This study investigated the effects of valine on growth, intestinal enzyme activities and microflora in juvenile Jian carp (Cyprinus carpio var. Jian). A total of 1200 fish with an average initial weight of 9.67 ± 0.03 g were fed diets containing 5.3 (unsupplemented control), 8.7, 11.8, 14.9, 18.7 and 20.1 g valine kg−1 diet for 60 days. Results indicated that the specific growth rate, feed efficiency, body protein and lipid content of fish were significantly improved by the dietary valine (P < 0.05). The hepatopancreas weight and activities of trypsin, amylase, lipase, chymotrypsin, glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) took the similar trends. Similarly, the optimum levels of dietary valine induced increases in the intestinal length, weight, folds height and activities of alkaline phosphatase, gamma-glutamyl transpeptidase and creatine kinase. In contrast, the trends of muscle GOT activity and plasma ammonia content were opposite. Intestinal Aeromonas, Escherichia coli, Lactobacillus and Bacillus were changed by dietary valine supplementations. The dietary valine requirement for Jian carp (9.67–76.4 g) based on SGR was 13.7 g valine kg−1 diet (4.0 g valine 100 g−1 CP). Together, these results indicated that valine improved fish growth, digestive and absorptive ability.
Season of Attachment and Growth of Sedentary Marine Organisms at Lamoine, Maine

In recent years a number of studies have been made of the ecology of sedentary marine organisms in various regions. Interest in this subject has been stimulated by the problem of fouling of ships, buoys and other immersed objects. Aside from practical applications these animal and plant communities are of general ecological interest. Examples of papers dealing with this subject are those of Visscher ('27), Coe ('32), Pomerat and Reiner ('42), and Engle & Loosanoff ('44). None have dealt with the faunal region represented by Frenchman's Bay on the Coast of Maine, although a general biological survey of the Mt. Desert region has been made (Procter, '33), and its result~s have been useful in the present study. The objectives of the study at Lamoine were: (1) To identify the species of "foulers"; (2) To determine the seasonal range of attachment and the time of maximal attachment; (3) To study the growth of individual species after attachment; and (4) To correlate the amount and type of fouling with ecological conditions. Preliminary observations were made during the summer of 1942, and more extensive surveys carried out in 1943 and 1944. Dr. Benjamin Speicher has assisted in identification, and has given valuable suggestions based on several summers' observations at Lamoine.
On Plant-Remains from the Silurian of Victoria, Australia, that Extend and Connect Floras Hitherto Described

Two accounts of plant-remains from the Early Palaeozoic rocks of Victoria have been given recently. The more critical as to the age of the plants (Lang and Cookson, 1935) dealt with a small flora found in beds of mudstone containing graptolites. The latter, from two of the localities (Alexandra and Yarra Track), were determined by Dr. G. L. Elles and established the age of the beds as Lower Ludlow. The flora is thus certainly of this age in these two cases, but, since some of the beds in which it occurs are regarded as Middle Silurian by Australian geologists, the age was stated generally as “not younger than Lower Ludlow. ” There is no doubt as to these vascular or land-plants being Silurian.
www.cognizantcommunication.com Gene Expression Profiling of the Hypoxia Signaling Pathway in Hypoxia-Inducible Factor 1 α Null Mouse Embryonic

92093 Hypoxia is defined as a deficiency of oxygen reaching the tissues of the body, and it plays a critical role in development and pathological conditions, such as cancer. Once tumors outgrow their blood supply, their central portion becomes hypoxic and the tumor stimulates angiogenesis through the activation of the hypoxia-inducible factors (HIFs). HIFs are transcription factors that are regulated in an oxygen-dependent manner by a group of prolyl hydroxylases (known as PHDs or HPHs). Our understanding of hypoxia signaling is limited by our incomplete knowledge of HIF target genes. cDNA microarrays and a cell line lacking a principal HIF protein, HIF1 α , were used to identify a more complete set of hypoxia-regulated genes. The microarrays identified a group of 286 clones that were significantly influenced by hypoxia and 54 of these were coordinately regulated by cobalt chloride. The expression profile of HIF1 α − / − cells also identified a group of downregulated genes encoding enzymes involved in protecting cells from oxidative stress, offering an explanation for the increased sensitivity of HIF1 α − / − cells to agents that promote this type of response. The microarray studies confirmed the hypoxia-induced expression of the HIF regulating prolyl hydroxylase, PHD2. An analysis of the members of the PHD family revealed that they are differentially regulated by cobalt chloride and hypoxia. These results suggest that HIF1 α is the predominant isoform in fibroblasts and that it regulates a wide battery of genes critical for normal cellular function and survival under various tumor HIF1 α protein. These included genes that encode for proteins involved in protection against oxidative suppressor protein, which directs HIF degradation by recruiting the ubiquitination machinery. By contrast, stress. These results suggest that the HIF1 α protein regulates a wide variety of genes and may be partially under hypoxic conditions, the PHDs are unable to hy-droxylate the cytoplasmic HIFs. The unmodified HIFs regulated by feedback inhibition. cells under enced by hypoxia and cobalt in a HIF1 α -independent hypoxia. These results suggest that the changes in ex-manner and may involve HIF2 α or HIF3 α because pression patterns for the transcripts represented within both are expressed in these cells at a much lower Figure 4 are predominantly HIF1 α dependent.
Macrozoobenthos in Yangtze floodplain lakes: patterns of density, biomass, and production in relation to river connectivity

Abstract A systematic investigation of macrozoobenthos was conducted in Yangtze floodplain waters to reveal patterns of density, biomass, and production in relation to river connectivity. In the Yangtze-connected lakes, 78 taxa belonging to 33 families and 62 genera were identified. Macrozoobenthos density was 327 individuals/m2, biomass was 1.40 g dry mass/m2, and production was 3.23 g dry mass m−2 y−1. The assemblages were characterized by high diversity, high production, and high bivalve-filterer abundance. The key factor determining the macrozoobenthic assemblages was river connectivity. As river connectivity increased, 3 types of response patterns were observed: 1) density, biomass, and production of collector-filterers (mainly Bivalvia), shredders (e.g., Stictochironomus), and predators (e.g., Dytiscidae) showed unimodal changes, i.e., first increased and then decreased; 2) density, biomass, and production of collector-gatherers (mainly Tubificidae and Chironomidae) decreased continuously; and 3) density of scrapers (mainly Gastropoda) decreased, whereas their biomass and production changed unimodally. At an intermediate level of river connectivity, biomass and production of total macrozoobenthos reached maxima, whereas density decreased with increasing river connectivity. Previous research showed that α diversity of zoobenthos also peaks at moderate connectivity with rivers. Therefore, to maintain high productivity as well as high biodiversity in the Yangtze floodplain, protecting the remnants of river-connected lakes and linking disconnected lakes freely with the mainstream are crucial.
New Psocoptera in the Early Cretaceous amber of SW France and Lebanon (Insecta: Psocoptera: Trogiomorpha)

Proprionoglaris guyoti gen. nov., sp. nov., Parapsyllipsocus vergereaui gen. nov., sp. nov., and Prospeleketor albianensis gen. nov., sp. nov. are described from the Early Cretaceous amber of Archingeay (SW France). Libanoglaris mouawadi gen. nov., sp. nov. is described from the Early Cretaceous amber of Lebanon. They are all placed into the suborder Trogiomorpha, incertae familiae. The discovery of these new taxa together with a first phylogenetic analysis of the trogiomorphan families demonstrate the necessity of a cladistic redefinition of the currently admitted major subdivisions of this suborder.
Stable Carbon and Nitrogen Isotope Tracers of Trophic Dynamics in Natural Populations and Fisheries of the Lahontan Lake System, Nevada

The influence of combined inorganic N on the growth of N2-fixing blue-green algae (Aphanizomenon flos-aquae) in Lahontan Reservoir was detected with N isotopic compositions (δ15N = + 1.2 to + 7.0) that were enriched in 15N. In Pyramid Lake, however, the δ15N of the entire food web was influenced by a contribution of isotopically light N released from N2-fixing blue-green algae (Nodularia spumigena). Carbon isotope ratios (δ13C) of these unpalatable, blue-green algae from both lakes were different enough from the zooplankton and higher animals to preclude a direct trophic link. An enrichment in 13C with trophic level in the food chain was measured in both lakes. Carbon isotope ratio measurements clearly illustrated the isotopic similarity between hatchery-raised Lahontan cutthroat trout (Salmo clarki henshawi) and cui-ui (Chasmistes cujus) and the artificial diet, but differed from the δ13C of their wild counterparts consuming natural foods. There is a consistent isotope fractionation between the δ13C of s.
Overview of the KwaZulu-Natal sardine run

This paper provides an introduction to, and overview of, the natural phenomenon known as the KwaZulu-Natal sardine run. Previous literature on this topic and hypotheses about the reasons why, and the mechanisms how, the run occurs are briefly synthesised and described. Papers contributing to this suite that detail more recent work on a variety of aspects of the sardine run, ranging from physical oceanography through sardine biology and ecology to socio-economic and ecological consequences, are outlined. Such studies will lead to improved understanding of the factors that regulate the timing and intensity of the run, which may permit predictions of whether it will occur, when fish will arrive on the KZN beaches, and how long it will persist. Such predictions would have substantial benefits for this ecologically and economically important event.
Effects of jackbean lectin (ConA) on the feeding behaviour and kinetics of intoxication of the pea aphid, Acyrthosiphon pisum

Mannose‐binding lectins were shown to be useful in creating transgenic plants resistant to insects, including many phloem‐feeding Hemiptera. Before these plants can be used extensively, it is important to understand how these lectins exert their toxic effects on the target organisms. We investigated the feeding alterations induced by presenting the pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), with a diet containing the lectin from Canavalia ensiformis (ConA). A series of behavioural experiments were carried out to detect potential sensory mediation of lectin activity. Choice tests performed with a 400 µg ml−1 ConA diet (3.7 µm of native tetramer) showed that A. pisum quickly rejected the ConA diet, but that this reaction was not typical of a sensory‐mediated phagodeterrent effect. In addition, the aphids did not develop a conditioned taste aversion to the lectin. Diet uptake was evaluated using a radioactive tracer (14C‐methylated inulin), and showed depression of ingestion only after 16 h at 200 µg ml−1 or after 8 h at 400 µg ml−1 ConA. This effect was reversible under our test conditions. No evidence was obtained for early detection of the lectin, even by intoxicated aphids. An electrical penetration graph technique was adapted to artificial diets and provided short‐term continuous analysis on feeding/probing events. At the 400 µg ml−1 level, adults were affected and had reduced ingestion durations as early as in the first 4 h of contact, but experienced an adaptation to the behavioural alterations induced by lectin feeding. Overall, feeding deterrency following exposure to mannose lectins appeared to be a consequence of intoxication, and not due to a sensory mediated process.