622 research outputs found
Biological Monitoring in Caves
Leta 1999 sva opisala 20 jam in kraških vodnjakov, v katerih živi po 20 ali več na podzemlje vezanih vrst živali. Pet izmed teh jam je ali pa je bilo urejenih za turistično izrabo: Postojnsko-planinski jamski sistem (Slovenija), Sistem Baget - Sainte Catherine (Francija), Shelta Cave (Alabama, ZDA), Mammoth Cave (Kentucky, ZDA) in Vjetrenica (Bosna in Hercegovina). Prav dejstvo, da imajo lahko močno preurejene jame z visokim številom obiskovalcev tudi pestro favno, kaže, da se oboje ne izključuje. Številne standardne tehnike za vzorčevanje, so uporabne le v maloštevilnih jamah. Te metode so le omejeno uporabne. Onesnaženje je lahko za jamske živali neposredno pogubno ali pa omogoča površinskim živalim, da tudi v podzemlju izpodrivajo. Zato moramo zasledovati tako gostoto favne, kot tudi spremembe v njeni taksonomski sestavi. Ob načrtovanju novih posegov je treba pred kakršnim koli urejanjem raziskati krajevno favno, tako površinsko kot podzemeljsko. Za biološko zasledovanje stanja priporočava naslednje: 1. vzorčenje skozi daljše obdobje; 2. nastavljanje vab v kopenskih in v vodnih habitatih; 3. nastavljanje lončastih pasti v kopenskih habitatih.In 1999, we described the twenty caves and karst wells that have 20 or more species of obligate cave organisms living in them. Among these caves five are developed as tourist caves — Postojna-Planina Cave System (Slovenia), Baget - Sainte Catherine System (France), Shelta Cave (Alabama, USA), Mammoth Cave (Kentucky, USA), and Vjetrenica Cave (Bosnia & Herzegovina). For these and other tourist caves, there is a special responsibility to protect this fauna. The very fact that caves with large numbers of visitors and with modifications to the cave can have high species diversity shows that the two are not incompatible. Many of the standard sampling techniques, may work in some caves only; they are of restricted use. Pollution may be either directly detrimental to the cave fauna or may enable surface species to outcompete the endemic cave fauna. Therefore, changes in the quantity of fauna have to be monitored as well as changes in its taxonomic composition. In the case of new tourist installations, the local cave and surface fauna has to be investigated prior to any modifications. For biological monitoring, we recommend one of the following: 1. minimum-time census, rather than minimum-area census; 2. baiting in both terrestrial and aquatic habitats; 3. pitfall traps (baited or unbaited) in terrestrial habitats
Cave shrimps Troglocaris s. str. (Dormitzer, 1853), taxonomic revision and description of new taxa after phylogenetic and morphometric studies
FIGURE 1. Distribution map of eight taxa of the subgenus Troglocaris s. str., with phylogroup/subgroup designation (in brackets, as in Zakšek et al. 2009). Different symbols denote taxa, their coloration denotes method of the analysis: black – molecular and morphometric analysis; grey – morphometric analysis; white – molecular analysis.Published as part of Jugovic, Jure, Jalžić, Branko, Prevorčnik, Simona & Sket, Boris, 2012, Cave shrimps Troglocaris s. str. (Dormitzer, 1853), taxonomic revision and description of new taxa after phylogenetic and morphometric studies, pp. 1-31 in Zootaxa 3421 on page 6, DOI: 10.5281/zenodo.20881
Neonatal White Matter Maturation Is Associated With Infant Language Development
Background:
While neonates have no sophisticated language skills, the neural basis for acquiring this function is assumed to already be present at birth. Receptive language is measurable by 6 months of age and meaningful speech production by 10-18 months of age. Fiber tracts supporting language processing include the corpus callosum (CC), which plays a key role in the hemispheric lateralization of language; the left arcuate fasciculus (AF), which is associated with syntactic processing; and the right AF, which plays a role in prosody and semantics. We examined if neonatal maturation of these fiber tracts is associated with receptive language development at 12 months of age.
Methods:
Diffusion-weighted imaging (DWI) was performed in 86 infants at 26.6 ± 12.2 days post-birth. Receptive language was assessed via the MacArthur-Bates Communicative Development Inventory at 12 months of age. Tract-based fractional anisotropy (FA) was determined using the NA-MIC atlas-based fiber analysis toolkit. Associations between neonatal regional FA, adjusted for gestational age at birth and age at scan, and language development at 12 months of age were tested using ANOVA models.
Results:
After multiple comparisons correction, higher neonatal FA was positively associated with receptive language at 12 months of age within the genu (p < 0.001), rostrum (p < 0.001), and tapetum (p < 0.001) of the CC and the left fronto-parietal AF (p = 0.008). No significant clusters were found in the right AF.
Conclusion:
Microstructural development of the CC and the AF in the newborn is associated with receptive language at 12 months of age, demonstrating that interindividual variation in white matter microstructure is relevant for later language development, and indicating that the neural foundation for language processing is laid well ahead of the majority of language acquisition. This suggests that some origins of impaired language development may lie in the intrauterine and potentially neonatal period of life. Understanding how interindividual differences in neonatal brain maturity relate to the acquisition of function, particularly during early development when the brain is in an unparalleled window of plasticity, is key to identifying opportunities for harnessing neuroplasticity in health and disease
Strand directionality affects cation binding and movement within tetramolecular G-quadruplexes
Nuclear magnetic resonance study of G-quadruplex
structures formed by d(TG3T) and its modified
analogs containing a 50-50 or 30-30 inversion of
polarity sites, namely d(30TG50-50G2T30), d(30T50-
50G3T30) and d(50TG30-30G2T5’) demonstrates formation
of G-quadruplex structures with tetrameric
topology and distinct cation-binding preferences.
All oligonucleotides are able to form quadruplex
structures with two binding sites, although the
modified oligonucleotides also form, in variable
amounts, quadruplex structures with only one
bound cation. The inter-quartet cavities at the inversion
of polarity sites bind ammonium ions less
tightly than a naturally occurring 50-30 backbone.
Exchange of 15NH+
4 ions between G-quadruplex
and bulk solution is faster at the 30-end in comparison
to the 50-end. In addition to strand directionality,
cation movement is influenced by formation of an
all-syn G-quartet. Formation of such quartet has
been observed also for the parent d(TG3T) that
besides the canonical quadruplex with only all-anti
G-quartets, forms a tetramolecular parallel
quadruplex containing one all-syn G-quartet, never
observed before in unmodified quadruplex
structures
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