Miracle-dz/UniFAR-FTUs huggingface dataset:
Métabolisme et toxinogénèse de Bacillus cereus : rôles de l’enzyme fermentaire LdhA et du régulateur rédox Rex

Bacillus cereus est une bacterie tres largement disseminee dans l'environnement. Certaines souches sont a l'origine de toxi-infections alimentaires de type emetique ou diarrheique. Afin de coloniser l'intestin et induire un syndrome diarrheique, B. cereus doit s'adapter aux variations d'oxygenation et de potentiel d'oxydoreduction rencontrees, se multiplier et secreter des toxines. En comparant les capacites metaboliques et les capacites de secretion de l'enterotoxine Nhe de quatre souches de B. cereus, nous avons mis en evidence que la L-lactate deshydrogenase A (LdhA) etait quelles que soient les conditions de croissance impliquee a la fois dans le metabolisme fermentaire et dans la toxinogenese de B. cereus. LdhA contribue au maintien du ratio NAD+/NADH intracellulaire et son absence affecte les capacites d'expression de plusieurs genes d'enterotoxines en anaerobiose et en aerobiose chez la souche F4430/73. Afin de determiner si l'effet observe sur les toxines etait indirect et dependant du regulateur redox Rex, un mutant ne synthetisant plus Rex a ete construit. La caracterisation de ce mutant a mis en evidence le role de Rex dans le metabolisme de B. cereus, dans la reponse au stress oxydant et dans la toxinogenese. De part sa structure et sa capacite a lie l'ADN, Rex pourrait etre un facteur de transcription controlant l'expression des genes codant les enterotoxines. Sa capacite de fixation sur l'ADN est dependante du ratio NAD+/NADH. Afin de determiner si LdhA pouvait reguler directement l'expression des genes des toxines, ldhA a ete exprime chez E. coli et purifiee sous la forme d'une proteine fusion. Les premieres experiences de retard sur gel n'ont pas permis de mettre en evidence de fixation sur les regions promotrices de toxines
Nonlethal assessment of freshwater mussel physiological response to changes in environmental factors

The development of effective nonlethal biomonitoring techniques is imperative for the preservation of imperiled freshwater mussel populations. Changes in hemolymph chemistry profiles and tissue glycogen are potential biomarkers for nonlethally monitoring stress in mussels. We sampled three species in the Flint River Basin over 2 years to evaluate how these hemolymph and tissue biomarkers responded to environmental changes. We used hierarchical linear models to evaluate the relationships between variation in the biomarkers and environmental factors and found that the responses of the hemolymph and tissue parameters were strongly related to stream discharge. Shifts in alanine aminotransferase and glycogen showed the largest relations with discharge at the time of sampling, while magnesium levels were most explained by the discharge for 5 days prior to sampling. Aspartate aminotransferase, bicarbonate, and calcium showed the strongest relations with mean discharge for 15 days prior to sampling. The modeling .
Inverted Apical CD24 and Weak EZH2 Expressions Are Phenotypic Characteristics of Pure Invasive Micropapillary Carcinoma of the Breast

Invasive micropapillary carcinomas (IMPC) of the breast account for less than 2% of all breast cancers and have been recently described as luminal B carcinomas. CD24, CD44, ALDH1 and EZH2 are commonly used as stem-cell markers that display differential expression as a function of stage and molecular type, but their pattern of expression according to this rare histological type remains poorly defined and unknown for EZH2. We assessed expression of these markers in a series of 28 micropapillary breast carcinomas and compared the results with those obtained in a series of luminal A (27 cases) and B (34 cases) invasive carcinomas not otherwise specified (IC-NST). CD24 and CD44 were expressed in most cases. However, CD24 was expressed at the inverted apical membrane in 85% of invasive micropapillary carcinoma and at the apical pole of gland-forming cells in 45% of luminal A (p-val = 6.8 × 10－4) and 13% of luminal B cases (p-val = 1.1 × 10－7). ALDH1 was expressed in the stroma in most tumors, but in only 25%, 11% and 15% in epithelial cells of IMPC, luminal A and B IC-NST, respectively. Nuclear expression of EZH2 was not observed in luminal A tumors, and was detected in 35% (12/34) of luminal B carcinomas (p-val = 6.1 × 10－3) and only 4% (1/28) of invasive micropapillary carcinomas. This series shows that invasive micropapillary carcinomas harbor a CD24-positive inverted apical pole associated with weak EZH2 expression, phenotypical characteristics that distinguish this entity from other luminal carcinomas.
SPERMATOPHORES OF SIX EASTERN NORTH AMERICAN PYRAMIDELLID GASTROPODS AND THEIR SYSTEMATIC SIGNIFICANCE (WITH THE NEW GENUS BOONEA)

1. Six east North American odostomioid species (Gastropoda: Pyramidellidae) are shown to have spermatophores that are species-specific in structure and position. The spermatophores of Boonea seminuda, B. bisuturalis and B. impressa are stuck in the mantle cavity; those of Fargoa dianthophila, F. bushiana and F. bartschi are attached to the shell in a constant position.2. A supraspecific classification based on spermatophores does not accord with the traditional ones based on shell sculpture. By comparing all available lines of evidence, the spermatophore classification is shown to accord more closely with phyletic relationships. Shell sculpture has converged and diverged evolutionarily and is therefore unreliable in supraspecific pyramidellid systematics. With due allowances for variation it is, however, useful at the species level.3. The new genus Boonea is named, based on spermatophore and other data, with "Odostomia" seminuda as type-species.4. Reasons are given for using the name F. bartschi for "O. m.
La dyskératose congénitale : qui est coupable ?

d’anticorps reconnaissant des motifs multiples ne manquent pas, il s’agissait jusqu’a maintenant d’une reconnaissance croisee entre des molecules qui etaient apparentees d’un point de vue structural. Ce que nous demontrent de maniere inattendue D.S. Tawfik et al. c’est la capacite d’une molecule unique d’anticorps a interagir avec des antigenes totalement differents via des sites distincts. Une telle demonstration pose la question de l’avantage d’un tel potentiel, et de sa signification biologique ! Les deux sites de liaison aux antigenes que presente une molecule d’immunoglobuline sont-ils equivalents? Peuventils reconnaitre des antigenes differents et/ou deux epitopes distincts proches dans l’espace a la surface d’une molecule antigenique ? Fonctionnent-ils de maniere cooperative ? S’agit-il la d’un moyen pour le systeme immunitaire d’assurer plus efficacement la neutralisation et l’elimination des molecules reconnues ? Comme bien souvent, ces resultats experimentaux posent plus de questions qu’ils n’apportent de reponses. Mais ce qui est certain, c’est que nous sommes en face d’une decouverte importante, dont nous ne faisons que commencer a entrevoir les consequences ! ◊ Antibody diversity is endless!
Human body odor, mosquito bites and the risk of disease transmission

Mosquitoes and other blood feeding insects are temporal ectoparasites, which move away from the host after a blood meal. It is known that blood components are mainly utilized by mosquitoes for egg production and, in a few examples, as an energy supply. Odors emanating from the host have different substrates from which they originate (e.g. urine, faces, skin, breath). These odors are important as long-range and short-range cues for host recognition. However, the exact relationship between human body odors and the attractiveness to blood-sucking insects remains unknown. Furthermore, the basis as to why certain individuals are preferentially bitten by hungry mosquitoes more than others is unclear. The present review briefly summarizes the sources of human odor that might play a role in mosquito attraction. Evidence suggests that body odors are actually a by- product of the decomposition of odorless skin chemicals, and that the final attraction is due to the balance between attractive and non-attractive fractions. Finally, the implications of variable human attractiveness in areas of parasite transmission are discussed in relation with the vectorial capacity model. It is suggested that differences in attractiveness should be considered when assessing risk factors in those endemic transmission foci.
Development and Characterization of Additional Microsatellite DNA Markers for Grape

Twenty-two new grape microsatellite markers were developed from CT-repeat regions cloned from Vitis vinifera Pinot noir and Cabernet Sauvignon. These loci were amplified in from 51 to 347 cultivars of V. vinifera. Twelve of the markers are polymorphic and informative in V. vinifera. Five are monomorphic in V. vinifera and the remaining five are polymorphic but less useful because they have only two alleles or more than two bands are amplified per individual. The number of alleles detected in the twelve informative markers ranged from 4 to 19, with heterozygosity values ranging from 0.42 to 0.90. Primer sequences and allele frequencies in the cultivars tested are reported for these markers. Revised allele frequencies are also presented for three previously reported microsatellite markers. Genotypes for the 12 informative new markers are presented for seven suggested reference cultivars.
Intraspecific specialization: foraging behaviors of the threespine stickleback, Gasterosteus aculeatus

The present longitudinal study examines a natural population of threespine sticklebacks, Gasterosteus aculeatus form Little Mud Lake in British Colombia, Canada to determine if individual fish within a given population exhibited a preference for finding prey on the bottom of the lake, prey floating in the water column of the lake, or prey in other microhabitats of the lake. Individuals were labeled using colored beads in order to view under water. Foraging behaviors were recorded to determine the presence of individual specialization within the focal sympatric population. Comparing the proportion of strikes on various microhabitats for multiple individuals shows that individual specialization is present within the focal population of sticklebacks. Data shows that some fish prefer the
NÍVEIS CRÍTICOS DE POTÁSSIO PARA O CRESCIMENTO INICIAL DE NIM (Azadirachta indica A. juss.) EM SOLOS A ZONA DA MATA DE PERNAMBUCO

O objetivo deste trabalho foi avaliar os niveis criticos de potassio no solo e na planta e avaliar seu efeito no crescimento inicial das mudas de nim (Azadirachta indica), em dois diferentes solos da zona da mata de Pernambuco. O experimento foi conduzido em estufa de vidro coberto com sombrite. Foram coletadas amostras de dois tipos de solos na profundidade de 0,0 - 0,20 m de. As sementes foram semeadas em recipientes com capacidade de 1,0 dm3 de solo. A adubacao foi feita aplicando-se as doses de 0, 50, 100, 150 e 300 mg.dm-3 de K. Foi empregado o (DIC), com arranjo fatorial 2 x 5, com quatro repeticoes. Transcorrido o periodo experimental, foram efetuadas as medicoes de altura, e do diâmetro e determinado o peso da materia seca da parte aerea, Apos a retirada das mudas foram feitas analises do solo, para as determinacoes de K recuperado e determinacao dos niveis criticos do solo e coletado a parte aerea das plantas para determinacao dos niveis criticos na planta. Os niveis criticos de potassio nos solos e plantas estudados variaram de 49,62 a 109,62 mg.dm-3 e 0,95 a 1,06 mg.dm-3 respectivamente. Conclui-se que as plantas tiveram um melhor desenvolvimento quando cultivadas no Argissolo em todas as variaveis estudadas e com menor nivel critico.
To Guard Mates or Go Forage: Conflicting Demands Affect the Paternity of Male Red-Winged Blackbirds

Behaviors involved in finding mates and producing offspring have clear fitness benefits (i.e., more descendants) and would seem to be favored by selection. Yet activities other than mating can simultaneously affect fitness, such as providing parental care (see, e.g., Trivers 1972; Emlen and Oring 1977; Maynard Smith 1977), seeking alternative matings (see, e.g., Parker 1970; Grafen 1980), and avoiding predators and finding food (see, e.g., Williams 1966; Gadgil and Bossert 1970). Selection favoring increased allocation to mating might hus be opposed by selection favoring allocation to one or more of these other actions. Although this idea has played an important part in theoretical studies of mating behavior and life histories and is a common explanation for observed patterns of behavior (see, e.g., Williams 1966, 1975; Trivers 1972; Emlen and Oring 1977; Maynard Smith 1977; Thornhill and Alcock 1983; Clutton-Brock 1991; Lessels 1991), there are surprisingly few experimental studies that directly test theory by manipulating aspects of the hypothesized conflicting demand. One interesting type of mating behavior is the guarding of mates. Males of many taxa sequester fertilizable females by remaining attached to them for long periods of time (see, e.g., Parker 1970; Siva-Jothy 1987; Carroll 1993), following them around (see, e.g., Beecher and Beecher 1979; Thornhill and Alcock 1983; Birkhead and M0ller 1992), or chasing all other males away (see, e.g., M0ller 1987a; Sherman 1989). Tremendous variation exists in the extent, timing, and form of guarding, not just among species but even within populations (see, e.g., M0ller 1987a). If mate guarding is indeed subject to conflicting demands, then this variation could be due to variation in factors influencing either the benefits or costs of guarding. Variation in the benefits of guarding might arise from variation in the ability of males to prevent matings between their mates and other males. If males varied in attractiveness tofemales, then females might vary in their propensity to elude their mates and pursue copulations with other males. For example, in eastern bluebirds (Sialia sialis), males that guard more intensely have lower paternity than males that guard less intensely (Gowaty and Bridges 1991), which might occur if the mates of preferred males avoid other males whereas mates of less preferred males do not. Alternatively, males might differ in their competitive abilities; some males might be intrinsically poor at guarding whereas others might be good at guarding. The idea that guarding varies in effectiveness has not often been examined; in fact, the widely held assumption that guarding behavior increases paternity has rarely been tested directly. Some studies of insects and mammals have shown that the male present during fertilization
Role of Base and nucleotide excision repair pathways in processing of clustered DNA lesions induced by ionising radiation

﻿Ionising radiation (IR) induces a wide spectrum of lesions in DNA, including double- and single-strand breaks, abasic (AP) sites and a variety of base lesions. IR-induced damage to DNA can range from simple, isolated lesions to clustered DNA damage in which multiple lesions are formed, usually within a single helical turn of the DNA. Individual lesions within a cluster are recognised by repair enzymes of the base excision repair (BER) pathway, however, clustered DNA damage may be recognised as a bulky lesion and be processed by nucleotide excision repair (NER). Additionally, the presence of other closely spaced lesions may affect the rate and fidelity of DNA repair and, in doing so, may contribute to the harmful effects of ionising radiation. The aim of this study is to gain further understanding of the repairability of clustered DNA damage and the effects of multiple lesions on cellular repair systems. 7, 8-dihydro-8-oxoguanine (8-oxoG), thymine glycol (Tg), AP sites and single-strand breaks (SSB), some of the most frequently formed IR-induced DNA lesions, were employed in synthetic oligonucleotides to model various types of clustered lesions and their repairability was studied using purified base excision repair enzymes and cell extracts. It was revealed that BER is the major repair system involved in the processing of clustered DNA lesions, and that some clustered lesions are repaired with decreased efficiency. Both the composition of lesions in a cluster and the positioning of the various lesions determine their repairability by base excision repair enzymes.
Digital Endocasts of the Cranial Cavity and Osseous Labyrinth of the Burrowing Snake Uropeltis woodmasoni (Alethinophidia: Uropeltidae)

Abstract The endocranial space, nerve pattern, and inner ear of a specimen of Uropeltis woodmasoni are described from digital endocasts rendered from high-resolution X-ray computed tomography scans. The cast of the endocranial space reveals short, stout olfactory bulbs as well as general shortening of the brain along the longitudinal axis. The pattern of innervation agrees with descriptions reported for other uropeltid snakes, although this individual exhibits skull asymmetry in the pathway of the glossopharyngeal nerve and the bifurcation of the jugular canal. There are no internal connections between the perilymphatic canal leading to the foramen pseudorotundum, the recessus scala tympani, and the jugular canal, a situation that differs from those of other alethinophidian snakes. The inner ear is compactly packaged with smoothly curved semicircular canals located in close proximity to the vestibule. Semicircular canal size is comparable to those of larger snakes, and the small size of the skull (9.4 mm) coupled with relative enlargement of the sensory regions of the brain and otic capsule is consistent with the morphological pattern of miniaturized vertebrates, although compounding factors, including phylogeny, ontogeny, and variation, are currently not well understood.
Genetic aspects of domestication

The available data on the domestication and history of cattle are summarized in this chapter, including the appearance of phenotypes that today are the subject of genetic research. Focus is given on taurine cattle spread over the old world, zebus around the equator, large taurines during classical antiquity, small cattle in medieval Europe, modernization of cattle husbandry and industrial cattle, crossbreds and local breeds.
The Niacin and Biotin Requirement of Trout

Abstract Brook, brown, and rainbow trout were fed diets containing various levels of niacin and biotin. After a period, trout were killed and their livers analyzed for the vitamin content. The diet level of the vitamin causing maximum storage in the liver was considered as the tentative requirement of the trout. The requirement for niacin was found to be between 3.0 and 4.1 milligrams per kilogram of trout daily. Maximum storage was between 34 and 38 micrograms per gram of liver. There was no difference in requirement between species or the two temperatures of the experiment. There was a difference between species in their requirement for biotin. Brook and rainbow trout needed between 6,700 and 26,880 milli-micrograms per kilogram of weight and brown trout between 43,360 and 76,980 milli-micrograms. Temperature of the experiment had no effect upon the requirement. Maximum storage was approximately 1,100 milli-micrograms per gram of liver in brown trout and about 1,200 milli-micrograms for brook and rainbo.
Histochemical classification of myofiber types in the triceps surae and flexor digitorum superficialis muscle of Japanese macaques.

Leg muscles of Japanese macaques (Macaca fuscata) were examined to characterize histochemical properties of myofiber types. Myofiber types were classified by differences in reactivity for myosin ATPase, NADH tetrazolium reductase (NADH-TR), and menadione-linked glycerol-3-phosphate dehydrogenase (3-GPD). The myofibers that reacted strongly for acid-stable myosin ATPase and were weakly reactive or unreactive for alkali-stable myosin ATPase were classified as slow-twitch/oxidative (SO) myofibers, which reacted strongly for NADH-TR and weakly to moderately for 3-GPD. The myofibers that were unreactive to moderately reactive for acid-stable myosin ATPase and strongly reactive for alkali-stable myosin ATPase were classified into fast-twitch/oxidative/glycolytic (FOG) myofibers with a moderate to strong activity for NADH-TR and 3-GPD and into fast-twitch/glycolytic (FG) myofibers with a weak NADH-TR activity and a strong 3-GPD activity. Slow-twitch myofibers with a strong activity for NADH-TR and 3-GPD were characterized as slow-twitch/oxidative/glycolytic (SOG) myofibers. The presence or absence of the SOG myofibers depended on the individuals. The soleus muscle had larger percentages of SO myofibers than of FOG and FG myofibers. The gastrocnemius and flexor digitorum superficialis muscles generally had larger percentages of FG myofibers than of FOG and SO myofibers including SOG myofibers.
LIGHT AND ELECTRON MICROSCOPE OBSERVATIONS ON ALGAL LYSIS BY BACTERIUM CP-I

Summary Bacterium CP-I isolated from Scottish waters is an aerobic prokaryote with a high guanine: cyto-sine ratio (68%), which causes lysis of a variety of blue-green algae. When suspensions of algae and bacteria are mixed the bacteria can be seen to glide towards the algae where they become attached end-on round the algal cells. There is evidence that the bacteria produce substances at the point of contact with the algae which are necessary for algal lysis to occur. Lysis of vegetative cells may occur within 30 minutes of the bacteria becoming attached. Heterocysts do not lyse in this way although their intracellular contents may eventually degenerate. When vegetative cells rupture, the protoplasmic contents, including gas vacuoles when present, are released and empty-looking ‘ghosts’ which retain the original cell shape may remain for a time although these too eventually break down. There is some evidence that the mode of filament lysis may be random, intercalary or terminal. At the ultrastructural level the initial effect of CP-I is to cause lysis of the L2 layer of the algal cell wall and this effect is similar to that obtained using lysozyme. This is followed by rupture or disintegration of the other cell wall layers, and ‘scroll’-like structures, either of coiled up cell wall material (Microcystis) or of the plasmalemma (Nostoc) may be found scattered throughout the preparations of lysed cells. In fully lysed cells there is a loss of polyphosphate bodies, structured granules, gas vacuoles, and most other cellular inclusions. Released gas vesicles can be collected from the surface of the solution of lysed cells, and there is evidence that these vesicles may fracture easily near the conical ends. In fully lysed cells, the thylakoid membranes remain, often with wide lumens between. This thylakoidal system is contorted and branched, ramifies through the cell and shows constrictions of the membrane system at intervals. Continuity between the plasmalemma and the thylakoidal system can be seen clearly, Lipid droplets which are resistant to CP-I treatment are found in the lumen of the thylakoidal system. Heterocysts are not as markedly affected by CP-I as are vegetative cells, but eventually heterocyst disorganization also occurs. The use of CP-I provides a technique for preparing material for the study of algal membranes and gas vesicles.
Lipid peroxidation in plant cells, its physiological role and changes under heavy metal stress

Lipid peroxidation, which is a natural and essential process, can occur in a non-enzymatic and/or enzymatic way in plant cells. Some of its products have cytotoxic effects on cells, but others function as plant effectors. The lipid peroxidation in plants exposed to heavy metal stress depends on the metal, plant organ, plant species and its genotype.