Jaws from the deep: biological and ecological insights on the kitefin shark Dalatias licha from the Mediterranean Sea

Due to their late maturation, extreme longevity, low fecundity and slow growth rates, deep-sea Chondrichthyes are extremely vulnerable to human impacts. Moreover, assessing the impact of deep-sea fisheries is difficult, as many species (including sharks) are part of the bycatch and are often discarded at sea, and/or landed under generic commercial-species codes. The lack of this information on fishery data sets and the limited availability of species-specific life history data make challenging the management of deep-sea Chondrichthyes. The kitefin shark Dalatias licha is a cosmopolitan elasmobranch, mainly found on continental and insular shelf-breaks and slopes in warm-temperate and tropical waters. This species is a common by-catch of the deep-sea trawling, considered as “Endangered” by the IUCN Red List for all European waters, Mediterranean Sea included. Here we present the results of a study based on a total of 78 specimens of kitefin shark collected over 3 years in the Ligurian Sea (NW Mediterranean) as by-catch from deep-water fisheries. Total length ranged from 380 to 1164 mm, and individual weight ranged from 198 to 8000 g. Immature and mature individuals showed a sex ratio dominated by males. Adult males were observed throughout the year, while mature females were observed only in spring-summer. These data lead to hypothesise a spatial segregation between genders. The kitefin shark diet was dominated by bony fish (mainly Macrouridae) and other small sharks (e.g., Galeus melastomus and Etmopterus spinax), but their gut included plastic items and parasites. Data reported here underline the rarity, complex ecology and the threat for this shark species and support the urgency of promoting initiatives for their monitoring and conservation

Experimental realization of sub-shot-noise quantum imaging

Properties of quantum states have disclosed new technologies, ranging from quantum information to quantum metrology. Among them a recent research field is quantum imaging, addressed to overcome limits of classical imaging by exploiting spatial properties of quantum states of light . In particular quantum correlations between twin beams represent a fundamental resource for these studies. One of the most interesting proposed scheme exploits spatial quantum correlations between parametric down conversion light beams for realizing sub-shot-noise imaging of the weak absorbing objects, leading ideally to a noise-free imaging. Here we present the first experimental realisation of this scheme, showing its capability to reach a larger signal to noise ratio (SNR) with respect to classical imaging methods. This work represents the starting point of this quantum technology that can have relevant applications, especially whenever there is a need of a low photon flux illumination (e.g. as with certain biological samples)

The SUN Protein Mps3 Is Required for Spindle Pole Body Insertion into the Nuclear Membrane and Nuclear Envelope Homeostasis

The budding yeast spindle pole body (SPB) is anchored in the nuclear envelope so that it can simultaneously nucleate both nuclear and cytoplasmic microtubules. During SPB duplication, the newly formed SPB is inserted into the nuclear membrane. The mechanism of SPB insertion is poorly understood but likely involves the action of integral membrane proteins to mediate changes in the nuclear envelope itself, such as fusion of the inner and outer nuclear membranes. Analysis of the functional domains of the budding yeast SUN protein and SPB component Mps3 revealed that most regions are not essential for growth or SPB duplication under wild-type conditions. However, a novel dominant allele in the P-loop region, MPS3-G186K, displays defects in multiple steps in SPB duplication, including SPB insertion, indicating a previously unknown role for Mps3 in this step of SPB assembly. Characterization of the MPS3-G186K mutant by electron microscopy revealed severe over-proliferation of the inner nuclear membrane, which could be rescued by altering the characteristics of the nuclear envelope using both chemical and genetic methods. Lipid profiling revealed that cells lacking MPS3 contain abnormal amounts of certain types of polar and neutral lipids, and deletion or mutation of MPS3 can suppress growth defects associated with inhibition of sterol biosynthesis, suggesting that Mps3 directly affects lipid homeostasis. Therefore, we propose that Mps3 facilitates insertion of SPBs in the nuclear membrane by modulating nuclear envelope composition

Inner/Outer Nuclear Membrane Fusion in Nuclear Pore Assembly: Biochemical Demonstration and Molecular Analysis

The nuclear pore complex (NPC) is characterized by a long-lived membrane-lined channel connecting the inner and outer nuclear membranes. This stabilized membrane channel, within which the nuclear pore is built, has little evolutionary precedent. In this report we demonstrate and map the inner/outer nuclear membrane fusion in NPC assembly

Endogenous sex hormones affect the mutagen-induced chromosome damage by altering a caffeine-sensitive checkpoint

In the present study we analysed the effect of endogenous sex hormones on the SCE frequencies induced in vitro by mitomycin C (MMC), a bifunctional alkylating agent producing high chromosome damage and mitotic arrest. The analysis has been performed on lymphocytes obtained at three different phases of menstrual cycle, from women with regular cycle and hormones dosage. At all phases we further analysed the effect of a post-treatment with caffeine, an agent that it is known to overrride the DNA damage checkpoints. After MMC, the cultures obtained at ovulation and luteal phases have SCE frequencies statistically higher than the cultures obtained at the progestogenic phase, showing increases of 15 and 25%, respectively. After caffeine, the MMC treated cultures which were set up at the progestogenic phase show a high potentiation of SCE frequencies (28%) whereas the treated cultures set up at ovulatory and luteal phases show little or no potentiation. These findings demonstrate that the endogenous hormones greatly modulate the SCE frequencies induced by the mutagen; they also indicate that hormones action competes with the caffeine effect. Caffeine acts by abrogating the mitotic arrest produced by DNA damage and induced cells with a higher chromosome damage into a premature mitosis. Our findings suggest that endogenous hormones could overcome the checkpoint controls activated in cells after mutagenic exposure. This action may be an epigenetic mechanism relevant in hormone carcinogenesis. \ua9 2004 Elsevier B.V. All rights reserved

Endogenous sex hormones affect the mutagen-induced chromosome damage by altering a caffeine-sensitive checkpoint

In the present study we analysed the effect of endogenous sex hormones on the SCE frequencies induced in vitro by mitomycin C (MMC), a bifunctional alkylating agent producing high chromosome damage and mitotic arrest. The analysis has been performed on lymphocytes obtained at three different phases of menstrual cycle, from women with regular cycle and hormones dosage. At all phases we further analysed the effect of a post-treatment with caffeine, an agent that it is known to overrride the DNA damage checkpoints. After MMC, the cultures obtained at ovulation and luteal phases have SCE frequencies statistically higher than the cultures obtained at the progestogenic phase, showing increases of 15 and 25%, respectively. After caffeine, the MMC treated cultures which were set up at the progestogenic phase show a high potentiation of SCE frequencies (28%) whereas the treated cultures set up at ovulatory and luteal phases show little or no potentiation. These findings demonstrate that the endogenous hormones greatly modulate the SCE frequencies induced by the mutagen; they also indicate that hormones action competes with the caffeine effect. Caffeine acts by abrogating the mitotic arrest produced by DNA damage and induced cells with a higher chromosome damage into a premature mitosis. Our findings suggest that endogenous hormones could overcome the checkpoint controls activated in cells after mutagenic exposure. This action may be an epigenetic mechanism relevant in hormone carcinogenesis

Psicologia, política pública para a população quilombola e racismo

Resumo Este artigo sintetiza parte da pesquisa de doutorado realizada em uma das primeiras comunidades negras rurais do estado de São Paulo a conquistar título de terras quilombolas, o quilombo Maria Rosa. Objetiva-se compreender se, para aquela comunidade, a política pública de titulação de terras opera como dispositivo contra o racismo. Para atingir os objetivos propostos, foram realizadas observações e entrevistas fundamentadas pelas formulações de Enrique Pichon-Rivière e de outros autores da psicologia social e da psicologia de processos grupais, como René Kaës. Como resultado, constatou-se que a política convoca os moradores do quilombo em questão a entrarem em contato com os efeitos do escravismo e do racismo. Todavia, ainda falta uma política articulada, entre os diferentes níveis governamentais e voltada para a temática racial, que lhes dê o devido apoio