Politics of Plasticity: Implications of the New Science of the “Teen Brain” for Education

Culture, Medicine, and Psychiatry - In recent years, claims that developmental brain science should inform pedagogical approaches have begun to influence educational policies. This article...     

Molecular prospecting for cryptic species in Phyllodistomum lacustri (Platyhelminthes,Gorgoderidae)

Rosas‐Valdez, R., Choudhury, A. & Pérez‐Ponce de León, G. (2011). Molecular prospecting for cryptic species in Phyllodistomum lacustri (Platyhelminthes, Gorgoderidae). —Zoologica Scripta, 40, 296–305. Partial sequences of the 28S ribosomal RNA and cytochrome c oxidase I (COI) genes were compared among populations of a widely distributed and morphologically uniform digenean species in North America, Phyllodistomum lacustri, a parasite characteristically associated with ictalurid catfishes. Specimens were collected from the urinary bladder of ictalurid hosts in six localities of North America, spanning most of the latitudinal range of this freshwater fish group. Sequences of other congeneric species, including a potentially close relative, P. staffordi, were also obtained and used for comparison. Analyses of both molecular markers show very low or no intrapopulation variation within each sampling site. However, samples of P. lacustri from different hosts and regions exhibit varying levels of interpopulation genetic differences. Such differences are explained by the wide geographical distribution and host range of the ictalurids they parasitize, particularly in ictalurids distributed in Mexican freshwaters where they experienced a diversification process. Variation in both nuclear and mitochondrial genes and phylogenetic analyses, in conjunction with geographical and host information (drainage isolation and endemicity of the host species), indicate that at least three populations show potential as cryptic species.     

Cyclobuxoviricine,a steroidal alkaloid from Buxus papilosa

A new steroidal alkaloid has been isolated from the leaves of Buxus papilosa. Its structure has been assigned as 1 on the basis of spectroscopic studies.     

Senescence of Detached Fern Leaves

Detached fern leaves show a loss in the content of pigments,protein and a decline in 2,6-dichlorophenol indophenol Hillreaction of isolated chloroplasts during aging. Light treatmentof leaves could considerably retard aging induced loss in 2,6-dichlorophenolindophenol photoreduction but it exhibits less effect on pigmentand protein loss. (Received February 7, 1983; Accepted July 14, 1983)     

In Vitro Assessment of Probiotic Potential of an Autochthonous Bacterial Isolate,Pseudomonas mosselii COFCAU_PMP5

Microbiology - Microbiota of the fish gut contains many beneficial bacteria that can be used as probiotics in aquaculture. In this study, several in vitro assays along with an in vivo safety...     

Multicolour flow cytometry analyses and autofluorescence in chlorophytes: lessons from programmed cell death studies in Chlamydomonas reinhardtii

Flow cytometry is a valuable tool in phycological studies. However, endogenous cellular compounds like nicotinamide adenine dinucleotide and chlorophyll a and b autofluoresce, potentially interfering with fluorescent markers. Furthermore, autofluorescent properties are not uniform across algae, nor are their effects consistent in different cytometers. The choice of instrument and fluorescent marker, therefore, requires careful consideration. We investigated the suitability of fluorescent markers by using standard four-colour and advanced multicolour flow cytometers in relation to the effects of autofluorescence over ranges of parameters including fluorophore excitation and emission spectra, band-pass filter configurations, voltage gains and the effects of growth in the light and dark. The unicellular chlorophyte and model organism, Chlamydomonas reinhardtii, was used and findings were correlated with investigations of programmed cell death. As previously found C. reinhardtii autofluoresces in the red, far-red and infrared spectra. This is independent of laser excitation wavelength, and autofluorescence emits and spills over into detection channels of both four-colour and multicolour instruments. Band-pass filter configurations capturing longer wavelength emissions or fluorophores excited or emitted in these longer wavelengths are generally unsuitable. Furthermore, neither dark nor light incubation impacted the autofluorescent signals. Consideration of these algal autofluorescent properties and their spillover effects is required to avoid erroneous results. Recommendations for the use of a range of fluorophores in programmed cell death and other studies in C. reinhardtii using four-colour and multicolour instruments are made.     

Chemotherapeutic potential of novel non-toxic nucleoside analogues on EAC ascitic tumour cells

Therapeutic efficacy of nucleoside analogues (NAs) like Gemcitabine, 5-fluorouracil in cancer treatment is already well established. Most of the known NAs are highly toxic to normal cells due to its non-specific action; thus searching for non-toxic NAs are still going on. For that purpose we have synthesised nine different NAs by alteration of their structural and functional groups. The aim of present study is to investigate the therapeutic potential of NAs against mice bearing breast adenocarcinoma cells at IC50 dose for 10 days treatment schedule. Results of the present study showed that, among the seven nucleoside analogues, NA-7 and NA-9 showed maximum therapeutic efficacy in controlling cancer cells by inhibiting cell proliferation and inducing apoptosis without any adverse effects to normal host cells. Additionally, NAs significantly decreased the tumour burden and enhanced survivability of host through generation of reactive oxygen species in tumour cells. These ultimately led to DNA damage, depolarisation of mitochondrial membrane potential and apoptosis in tumour cells. To find out the molecular mechanisms, we showed that administration of NA-7 and NA-9, down- regulating the expression of Bcl-2, cyclin D1, C-myc, P-21 and up-regulating the expression of P-53, Cyt-c, Bax, caspase-3 and caspase-9. The results suggest that NA-7 and NA-9 exhibits significant antitumor activity than 5-fluorouracil by modulating the cell cycle checkpoints and inducing apoptosis in Ehrlich ascites carcinoma (EAC)-bearing mice. Additionally, NA-7 and NA-9 did not show any clastogenic effect on bone marrow cells at sub-lethal dose. Thus, the present study clearly suggested therapeutic benefit of NAs by augmenting anticancer efficacy and diminishing toxicity to the host.