Lil ommi

Ġabra ta’ poeżiji u proża li tinkludi: Tifkiriet biss! ta’ Wallace Ph. Gulia – Elan vital ta’ Joe Saliba – B’tifkira ta’ għeluq il-ħamsin sena tal-mewt ta’ l-għażiż missieri Ċensu Busuttil ta’ E. D. Busuttil – Lil ommi ta’ V. Busuttil.peer-reviewe

Bose-Einstein statistics in thermalization and photoluminescence of quantum well excitons

Quasi-equilibrium relaxational thermodynamics is developed to understand LA-phonon-assisted thermalization of Bose-Einstein distributed excitons in quantum wells. We study the quantum-statistical effects in the relaxational dynamics of the effective temperature of excitons $T = T(t)$. When $T$ is less than the degeneracy temperature $T_0$, well-developed Bose-Einstein statistics of quantum well excitons leads to nonexponential and density-dependent thermalization. At low bath temperatures $T_b \to 0$ the thermalization of quantum-statistically degenerate excitons effectively slows down and $T(t) \propto 1 / \ln t$. We also analyze the optical decay of Bose-Einstein distributed excitons in perfect quantum wells and show how nonclassical statistics influences the effective lifetime $\tau_{opt}$. In particular, $\tau_{opt}$ of a strongly degenerate gas of excitons is given by $2 \tau_R$, where $\tau_R$ is the intrinsic radiative lifetime of quasi-two-dimensional excitons. Kinetics of resonant photoluminescence of quantum well excitons during their thermalization is studied within the thermodynamic approach and taking into account Bose-Einstein statistics. We find density-dependent photoluminescence dynamics of statistically degenerate excitons. Numerical modeling of the thermalization and photoluminescence kinetics of quasi-two-dimensional excitons are given for GaAs/AlGaAs quantum wells.Comment: 19 pages, 9 figures. Phys. Rev. B (accepted for publication

Non-coding RNAs and endometrial cancer

Non-coding RNAs (ncRNAs) are involved in the regulation of cell metabolism and neoplastic transformation. Recent studies have tried to clarify the significance of these information carriers in the genesis and progression of various cancers and their use as biomarkers for the disease; possible targets for the inhibition of growth and invasion by the neoplastic cells have been suggested. The significance of ncRNAs in lung cancer, bladder cancer, kidney cancer, and melanoma has been amply investigated with important results. Recently, the role of long non-coding RNAs (lncRNAs) has also been included in cancer studies. Studies on the relation between endometrial cancer (EC) and ncRNAs, such as small ncRNAs or micro RNAs (miRNAs), transfer RNAs (tRNAs), ribosomal RNAs (rRNAs), antisense RNAs (asRNAs), small nuclear RNAs (snRNAs), Piwi-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), competing endogenous RNAs (ceRNAs), lncRNAs, and long intergenic ncRNAs (lincRNAs) have been published. The recent literature produced in the last three years was extracted from PubMed by two independent readers, which was then selected for the possible relation between ncRNAs, oncogenesis in general, and EC in particular

Għanja tar-rużarju

Ġabra ta’ poeżiji u proża li tinkludi: Cancer and heart infarction ta’ Wallace Ph. Gulia – Freesia ta’ Kilin – Superstizzjonijiet ta’ Emmanuel Ph. Attard – Bla qalb! ta’ Dun Frans Camilleri – Sa nsiefer ta’ Mikiel Agius – Tifkiriet tal-imgħoddi ta’ Alfred Massa – Il-għanja tar-rużarju ta’ Val. V. Barbara.peer-reviewe

Spatio-temporal dynamics of quantum-well excitons

We investigate the lateral transport of excitons in ZnSe quantum wells by using time-resolved micro-photoluminescence enhanced by the introduction of a solid immersion lens. The spatial and temporal resolutions are 200 nm and 5 ps, respectively. Strong deviation from classical diffusion is observed up to 400 ps. This feature is attributed to the hot-exciton effects, consistent with previous experiments under cw excitation. The coupled transport-relaxation process of hot excitons is modelled by Monte Carlo simulation. We prove that two basic assumptions typically accepted in photoluminescence investigations on excitonic transport, namely (i) the classical diffusion model as well as (ii) the equivalence between the temporal and spatial evolution of the exciton population and of the measured photoluminescence, are not valid for low-temperature experiments.Comment: 8 pages, 6 figure

Insulin-Like Peptides and the Target of Rapamycin Pathway Coordinately Regulate Blood Digestion and Egg Maturation in the Mosquito Aedes aegypti

Mosquitoes are insects that vector many serious pathogens to humans and other vertebrates. Most mosquitoes must feed on the blood of a vertebrate host to produce eggs. In turn, multiple cycles of blood feeding promote frequent contacts with hosts and make mosquitoes ideal disease vectors. Both hormonal and nutritional factors are involved in regulating egg development in the mosquito, Aedes aegypti. However, the processes that regulate digestion of the blood meal remain unclear.Here we report that insulin peptide 3 (ILP3) directly stimulated late phase trypsin-like gene expression in blood fed females. In vivo knockdown of the mosquito insulin receptor (MIR) by RNA interference (RNAi) delayed but did not fully inhibit trypsin-like gene expression in the midgut, ecdysteroid (ECD) production by ovaries, and vitellogenin (Vg) expression by the fat body. In contrast, in vivo treatment with double-stranded MIR RNA and rapamycin completely blocked egg production. In vitro experiments showed that amino acids did not simulate late phase trypsin-like gene expression in the midgut or ECD production by the ovaries. However, amino acids did enhance ILP3-mediated stimulation of trypsin-like gene expression and ECD production.Overall, our results indicate that ILPs from the brain synchronize blood meal digestion and amino acid availability with ovarian ECD production to maximize Vg expression by the fat body. The activation of digestion by ILPs may also underlie the growth promoting effects of insulin and TOR signaling in other species

Lil Dun Karm

Ġabra ta’ poeżiji u proża li tinkludi: Qalb ta’ Peter A. Caruana – Ċetta l-internazzjonal ta’ Wallace Ph. Gulia – Tfal Maltin ta’ C. Cassar – Meta ntefa d-dawl ta’ Joe Mejlak – Lil tfajjel jibki ta’ V. Barbara – Għanja lil San Pawl il-Baħar ta’ P. F. Sammut – L-imqass ta’ G. Z. A. – Epigrammi ta’ P. P. Saydon – Iż-żewġ arloġġi ta’ Ġ. Cardona – Li kieku... ta’ Joseph C. Sciberras – Il-Milied it-tajjeb! ta’ Ġ. Borg Pantalleresco – Raħal twelidi ta’ M. Agius – Kannizzati... ta’ Pawlu Aquilina – Quddiem id-dar fejn twieled Dun Karm ta’ Ġużè Cardona – Lil Dun Karm ta’ Pawlu Mifsud.peer-reviewe

Lil ommi

Ġabra ta’ poeżiji u proża li tinkludi: Innu tas-Soċjetà tad-Duttrina Nisranija - M.U.S.E.U.M. ta’ Dun Karm – Ħġejjeġ ta’ Wallace Gulia – Maskarata ta’ Ġużè Chetcuti – Misterju ta’ Ġużi Abela – Lill-kewkba żahrija ta’ Val. V. Barbara – Dawk il-ġarar tal-brandy ta’ J. E. Busuttil – Marida ta’ Vincent Caruana – Meta jdur ir-riħ! ta’ Ivo Muscat-Azzopardi – Lill-Madonna tat-taraġ ta’ Dun Frans Camilleri – Fid-dar ta’ John Keats ta’ Anġ. Dougall – A legend traduzzjoni ta’ May Butcher mir-Russu ta’ A. Pleshcheief – Leġġenda – Għeluq is-sena mill-mewt ta’ missieri ta’ Clo. Gauci – Ġirien Marju ta’ Ġeraldu Azzopardi – Innu tat-tfal tad-duttrina ta’ Val. V. Barbara – Lil Anton Buttigieg, poeta Malti ta’ Dun Pawl Cauchi – Misserijietna ta’ M. Agius – Fir-razzett ta’ Katarin ta’ A. Buttigieg – Lil ommi ta’ Vincenzo Ungaro.N/

Blood Feeding and Insulin-like Peptide 3 Stimulate Proliferation of Hemocytes in the Mosquito Aedes aegypti

All vector mosquito species must feed on the blood of a vertebrate host to produce eggs. Multiple cycles of blood feeding also promote frequent contacts with hosts, which enhance the risk of exposure to infectious agents and disease transmission. Blood feeding triggers the release of insulin-like peptides (ILPs) from the brain of the mosquito Aedes aegypti, which regulate blood meal digestion and egg formation. In turn, hemocytes serve as the most important constitutive defense in mosquitoes against pathogens that enter the hemocoel. Prior studies indicated that blood feeding stimulates hemocytes to increase in abundance, but how this increase in abundance is regulated is unknown. Here, we determined that phagocytic granulocytes and oenocytoids express the A. aegypti insulin receptor (AaMIR). We then showed that: 1) decapitation of mosquitoes after blood feeding inhibited hemocyte proliferation, 2) a single dose of insulin-like peptide 3 (ILP3) sufficient to stimulate egg production rescued proliferation, and 3) knockdown of the AaMIR inhibited ILP3 rescue activity. Infection studies indicated that increased hemocyte abundance enhanced clearance of the bacterium Escherichia coli at lower levels of infection. Surprisingly, however, non-blood fed females better survived intermediate and high levels of E. coli infection than blood fed females. Taken together, our results reveal a previously unrecognized role for the insulin signaling pathway in regulating hemocyte proliferation. Our results also indicate that blood feeding enhances resistance to E. coli at lower levels of infection but reduces tolerance at higher levels of infection